Squashed 'third_party/abseil/' changes from ddf8e52a2..384af0e91
384af0e91 Export of internal Abseil changes
e7ca23aca Export of internal Abseil changes
4611a601a Export of internal Abseil changes
8a9ef3c5d Export of internal Abseil changes
9f8b87b71 Add missing word 'library' in the 'status' description (#868)
e2b1bab19 Export of internal Abseil changes
1bae23e32 Export of internal Abseil changes
6df644c56 Include the status library into the main README. (#863)
68f1ad932 Export of internal Abseil changes
52acfe6fc Export of internal Abseil changes
1918ad2ae Export of internal Abseil changes
938fd0f4e Export of internal Abseil changes
fbdff6f3a Export of internal Abseil changes
acf3390ca Export of internal Abseil changes
592924480 Export of internal Abseil changes
e80c0b353 Export of internal Abseil changes
5d8fc9192 Export of internal Abseil changes
e19260fd7 Export of internal Abseil changes
4fd9a1ec5 Export of internal Abseil changes
4ae673067 Export of internal Abseil changes
1b465af3b Export of internal Abseil changes
6b03bf543 fix build dll (#797)
0bbebc85c Export of internal Abseil changes
0453e1653 Export of internal Abseil changes
a4798817e Export of internal Abseil changes
e96d49687 Export of internal Abseil changes
731852f10 Fix stacktrace on aarch64 architecture. Fixes #805 (#827)
2e5f2bcfd moved deleted functions to public for better compiler errors. (#828)
e9e9b9fc7 Export of internal Abseil changes
b8e890f95 Export of internal Abseil changes
c9894d1dc Export of internal Abseil changes
e9b9e38f6 Export of internal Abseil changes
962b06754 Export of internal Abseil changes
5bf048b84 Export of internal Abseil changes
1e3d25b26 Export of internal Abseil changes
eb317a701 Export of internal Abseil changes
4b915e709 Export of internal Abseil changes
8f1c34a77 Export of internal Abseil changes
60d00a582 Export of internal Abseil changes
f3f785ab5 Export of internal Abseil changes
4b2fbb4ad Export of internal Abseil changes
e493d6acb fix compile fails with asan and -Wredundant-decls (#801)
e63a5a610 Export of internal Abseil changes
c678d6c6b Export of internal Abseil changes
4b4f9aae7 Export of internal Abseil changes
887d0eee6 Export of internal Abseil changes
b978fc02f Export of internal Abseil changes
093cc2760 Export of internal Abseil changes
40fdb59d3 btree: fix sign-compare warnings (#800)
1fd58b69c Export of internal Abseil changes
d1de75bf5 Export of internal Abseil changes
cad3f30b4 Export of internal Abseil changes
9927a0989 Export of internal Abseil changes
7680a5f8e Added missing asserts for seq.index() < capacity_ and unified their usage based on has_element(). (#781)
d3614de61 Export of internal Abseil changes
20feb1cdb Export of internal Abseil changes
c1ae0a497 Export of internal Abseil changes
6af91b351 Export of internal Abseil changes
f2c9c663d Export of internal Abseil changes
3c8b5d758 Export of internal Abseil changes
7ba8cdb56 Export of internal Abseil changes
930fbec75 Export of internal Abseil changes
0e9921b75 Export of internal Abseil changes
a4cbb5f69 Export of internal Abseil changes
4d2ff381a Export of internal Abseil changes
c03c18e7f Export of internal Abseil changes
b321ad86c Export of internal Abseil changes
fbf0fdab6 Export of internal Abseil changes
dc969f34a Export of internal Abseil changes
d0c433455 Export of internal Abseil changes
c6b3f2cf5 Export of internal Abseil changes
1beb3191c Export of internal Abseil changes
1b7e751e5 Export of internal Abseil changes
ce4bc9277 Export of internal Abseil changes
f72cc3516 Export of internal Abseil changes
f66bc7492 Export of internal Abseil changes
1995c6a3c Export of internal Abseil changes
184cf2524 Export of internal Abseil changes
82302f1e0 Export of internal Abseil changes
dea76486c Export of internal Abseil changes
d39fe6cd6 Export of internal Abseil changes
2c8a5b0d8 Export of internal Abseil changes
41a6263fd Export of internal Abseil changes
3c2bed2e7 Export of internal Abseil changes
ea8a689cf fix build on P9 (#739)
672d9e0ae Export of internal Abseil changes
f624790b7 Export of internal Abseil changes
55c04eb92 Export of internal Abseil changes
302b250e1 Disable pthread for standalone wasm build support (#721)
61d8bc057 Merge branch 'master' of https://github.com/abseil/abseil-cpp into master
4b5b25a28 cmake: remove unneeded enable_testing() cmd (#736)
63f2c695e cmake: flag conformance_testing as TESTONLY (#737)
d5269a8b6 Export of internal Abseil changes
23f1f9cf6 Typo in comment (#733)
259301a52 Fix CMake path for INSTALL_INCLUDEDIR (#723)
dc464c1dc Allow overriding Abseil IDE folder (#724)
bf655de09 Export of internal Abseil changes
38db52adb Export of internal Abseil changes
81f34df83 Export of internal Abseil changes
b86fff162 Export of internal Abseil changes
10cb35e45 Export of internal Abseil changes
4ccc0fce0 Export of internal Abseil changes
4a851046a Export of internal Abseil changes
ccdbb5941 Export of internal Abseil changes
01f5f81f9 Export of internal Abseil changes
2c92bdc7c Export of internal Abseil changes
e7ebf9803 Export of internal Abseil changes
2eba343b5 Export of internal Abseil changes
a8b03d90e Export of internal Abseil changes
1d31b5c36 Export of internal Abseil changes
da3a87690 Export of internal Abseil changes
8faf20461 Exclude empty directories (#697)
2069dc796 Export of internal Abseil changes
4832bf6bf Added a BUILD file in root to expose license. (#695)
af8f994af Export of internal Abseil changes
33caf1097 Export of internal Abseil changes
cf1a02e2d Export of internal Abseil changes
768eb2ca2 Export of internal Abseil changes
3f347c462 Fix build on riscv32 (#675)
62cf6a704 Export of internal Abseil changes
d118d4bb1 Export of internal Abseil changes
f2bc9d11e Fix public target name of the random library (#684)
0fecf0e63 Export of internal Abseil changes
cbfd0f0fe Export of internal Abseil changes
c45d1c09d Export of internal Abseil changes
a35ef8a62 Export of internal Abseil changes
bd317cae3 Export of internal Abseil changes
b11574465 fix MSVC warning 4245: conversion signed => unsigned during initialization (#678)
d85783fd0 Export of internal Abseil changes
a1d668990 Export of internal Abseil changes
ca9856cab Export of internal Abseil changes
6e18c7115 Export of internal Abseil changes
3f48ce1c4 init (#673)
cde2e2410 Export of internal Abseil changes
68494aae9 Fix CMake Threads dependency issue
902909a43 Export of internal Abseil changes
cb52b05ea Export of internal Abseil changes
1a02b7a20 Use "-lrt" instead of the resolved find_library result when linking librt (#665)
df60c82df Export of internal Abseil changes
b35973e3e Export of internal Abseil changes
db5773a72 Export of internal Abseil changes
71079e42c Export of internal Abseil changes
2946ac0de Use base_internal::AtomicHook instead of std::atomic (#661)
567bee2f7 Fix ABSL_RANDOM_RANDEN_COPTS setting on FreeBSD (#664)
bf6166a63 Export of internal Abseil changes
111260963 Export of internal Abseil changes
73ea9a957 Export of internal Abseil changes
c01b9916e Add option to use an externally provided GoogleTest target (for usage of abseil as add_subdirectory target) (#647)
d43b7997c Export of internal Abseil changes
62f05b1f5 Export of internal Abseil changes
fba8a316c Export of internal Abseil changes
79e0dc115 Export of internal Abseil changes
132d791b4 bazel: Add missing load statements for cc_binary (#645)
518f17501 Export of internal Abseil changes
092ed9793 Export of internal Abseil changes
2d2a8aea2 Export of internal Abseil changes
7853a7586 Export of internal Abseil changes
c6954897f Export of internal Abseil changes
b92f35f65 Fix CompressedTuple move constructor on MSVC (#637)
a877af1f2 Export of internal Abseil changes
d936052d3 Export of internal Abseil changes
238b9a59c Skip the .exe suffix in the helpshort filter on Windows (#629)
417ea99cb UWP doesn't allow reading regkeys (#594)
40a0e58eb Export of internal Abseil changes
cf3a1998e Export of internal Abseil changes
b19ba9676 Export of internal Abseil changes
06f0e767d BuildBreak: UWP apps can't call GetModuleHandle (#596)
bcefbdcdf Export of internal Abseil changes
0033c9ea9 Fix build on FreeBSD/powerpc (#616)
0d5ce2797 Export of internal Abseil changes
b69c7d880 Export of internal Abseil changes
2a5633fc0 Merge "Export of internal Abseil changes"
f9b3d6e49 Add RISCV support to GetProgramCounter() (#621)
914ff4451 Export of internal Abseil changes
0232c87f2 Add missing ABSL_HAVE_VDSO_SUPPORT conditional (#622)
3c8141051 Export of internal Abseil changes
c44657f55 Export of internal Abseil changes
98eb410c9 Export of internal Abseil changes
bf78e9773 Export of internal Abseil changes
d95d15671 Export of internal Abseil changes
24713a703 Export of internal Abseil changes
72382c21f Export of internal Abseil changes
08a7e7bf9 Export of internal Abseil changes
36bcd9599 Fix pointer format specifier in documentation (#614)
0f86336b6 Export of internal Abseil changes
c512f118d Export of internal Abseil changes
37dd2562e Export of internal Abseil changes
444277026 fix: Add support for more ARM processors detection (#608)
159bf2bf6 Export of internal Abseil changes
a2e6adecc Use https links. (#586)
564001ae5 Export of internal Abseil changes
b3aaac8a3 Export of internal Abseil changes
63ee2f887 Export of internal Abseil changes
a048203a8 Export of internal Abseil changes
1de016636 Export of internal Abseil changes
ad904b6cd Export of internal Abseil changes
7bd1935dc cmake: Fix x86_64 check on Windows for random copts (#518)
292351391 Export of internal Abseil changes
bf86cfe16 Export of internal Abseil changes
12bc53e03 Export of internal Abseil changes
1e39f8626 Export of internal Abseil changes
77f87009a Export of internal Abseil changes
d659fe54b Export of internal Abseil changes
a4b757b5d Export of internal Abseil changes
0514227d2 Export of internal Abseil changes
7f4fe64af Export of internal Abseil changes
16d9fd58a Export of internal Abseil changes
bcaae6009 Export of internal Abseil changes
8ba96a824 Export of internal Abseil changes
2103fd9ac Export of internal Abseil changes
3df7b52a6 Export of internal Abseil changes
fa8c75182 Export of internal Abseil changes
85092b4b6 Fix Conan builds (#400)
e96ae2203 Export of internal Abseil changes
20de2db74 Export of internal Abseil changes
846e5dbed Export of internal Abseil changes
83880e3d8 Merge branch 'master' of https://github.com/abseil/abseil-cpp
8207907f4 Export of internal Abseil changes
39d68a422 docs: fix typo (#397)
078b89b3c Export of internal Abseil changes
19b021cb3 Export of internal Abseil changes
ecc0033b5 Always enable proper symbolize implementation on Windows (#257)
2796d500a Export of internal Abseil changes
e4c8d0eb8 Export of internal Abseil changes
a15364ce4 Export of internal Abseil changes
ab3552a18 Export of internal Abseil changes
e9f9000c7 Fix ABSL_WAITER_MODE detection for mingw (#342)
abea769b5 Fix ABSL_HAVE_ALARM check on mingw (#341)
25597bdfc Export of internal Abseil changes
aad33fefa Export of internal Abseil changes
8fe7214fe Export of internal Abseil changes
debac94cf Export of internal Abseil changes
882b3501a Fix spelling errors (#384)
502efe6d7 Export of internal Abseil changes
ccdd1d57b Export of internal Abseil changes
Change-Id: I59864a0053f6e03d88cc9d5e2a92757039a05484
git-subtree-dir: third_party/abseil
git-subtree-split: 384af0e9141283172e2bff3210dae79fb7130d9c
diff --git a/absl/container/internal/btree.h b/absl/container/internal/btree.h
index b255984..6f5f01b 100644
--- a/absl/container/internal/btree.h
+++ b/absl/container/internal/btree.h
@@ -65,11 +65,13 @@
#include "absl/container/internal/layout.h"
#include "absl/memory/memory.h"
#include "absl/meta/type_traits.h"
+#include "absl/strings/cord.h"
#include "absl/strings/string_view.h"
#include "absl/types/compare.h"
#include "absl/utility/utility.h"
namespace absl {
+ABSL_NAMESPACE_BEGIN
namespace container_internal {
// A helper class that indicates if the Compare parameter is a key-compare-to
@@ -92,6 +94,19 @@
absl::string_view rhs) const {
return compare_internal::compare_result_as_ordering(lhs.compare(rhs));
}
+ StringBtreeDefaultLess(std::less<absl::Cord>) {} // NOLINT
+ absl::weak_ordering operator()(const absl::Cord &lhs,
+ const absl::Cord &rhs) const {
+ return compare_internal::compare_result_as_ordering(lhs.Compare(rhs));
+ }
+ absl::weak_ordering operator()(const absl::Cord &lhs,
+ absl::string_view rhs) const {
+ return compare_internal::compare_result_as_ordering(lhs.Compare(rhs));
+ }
+ absl::weak_ordering operator()(absl::string_view lhs,
+ const absl::Cord &rhs) const {
+ return compare_internal::compare_result_as_ordering(-rhs.Compare(lhs));
+ }
};
struct StringBtreeDefaultGreater {
@@ -106,17 +121,30 @@
absl::string_view rhs) const {
return compare_internal::compare_result_as_ordering(rhs.compare(lhs));
}
+ StringBtreeDefaultGreater(std::greater<absl::Cord>) {} // NOLINT
+ absl::weak_ordering operator()(const absl::Cord &lhs,
+ const absl::Cord &rhs) const {
+ return compare_internal::compare_result_as_ordering(rhs.Compare(lhs));
+ }
+ absl::weak_ordering operator()(const absl::Cord &lhs,
+ absl::string_view rhs) const {
+ return compare_internal::compare_result_as_ordering(-lhs.Compare(rhs));
+ }
+ absl::weak_ordering operator()(absl::string_view lhs,
+ const absl::Cord &rhs) const {
+ return compare_internal::compare_result_as_ordering(rhs.Compare(lhs));
+ }
};
// A helper class to convert a boolean comparison into a three-way "compare-to"
-// comparison that returns a negative value to indicate less-than, zero to
-// indicate equality and a positive value to indicate greater-than. This helper
+// comparison that returns an `absl::weak_ordering`. This helper
// class is specialized for less<std::string>, greater<std::string>,
-// less<string_view>, and greater<string_view>.
+// less<string_view>, greater<string_view>, less<absl::Cord>, and
+// greater<absl::Cord>.
//
// key_compare_to_adapter is provided so that btree users
// automatically get the more efficient compare-to code when using common
-// google string types with common comparison functors.
+// Abseil string types with common comparison functors.
// These string-like specializations also turn on heterogeneous lookup by
// default.
template <typename Compare>
@@ -144,10 +172,52 @@
using type = StringBtreeDefaultGreater;
};
+template <>
+struct key_compare_to_adapter<std::less<absl::Cord>> {
+ using type = StringBtreeDefaultLess;
+};
+
+template <>
+struct key_compare_to_adapter<std::greater<absl::Cord>> {
+ using type = StringBtreeDefaultGreater;
+};
+
+// Detects an 'absl_btree_prefer_linear_node_search' member. This is
+// a protocol used as an opt-in or opt-out of linear search.
+//
+// For example, this would be useful for key types that wrap an integer
+// and define their own cheap operator<(). For example:
+//
+// class K {
+// public:
+// using absl_btree_prefer_linear_node_search = std::true_type;
+// ...
+// private:
+// friend bool operator<(K a, K b) { return a.k_ < b.k_; }
+// int k_;
+// };
+//
+// btree_map<K, V> m; // Uses linear search
+//
+// If T has the preference tag, then it has a preference.
+// Btree will use the tag's truth value.
+template <typename T, typename = void>
+struct has_linear_node_search_preference : std::false_type {};
+template <typename T, typename = void>
+struct prefers_linear_node_search : std::false_type {};
+template <typename T>
+struct has_linear_node_search_preference<
+ T, absl::void_t<typename T::absl_btree_prefer_linear_node_search>>
+ : std::true_type {};
+template <typename T>
+struct prefers_linear_node_search<
+ T, absl::void_t<typename T::absl_btree_prefer_linear_node_search>>
+ : T::absl_btree_prefer_linear_node_search {};
+
template <typename Key, typename Compare, typename Alloc, int TargetNodeSize,
bool Multi, typename SlotPolicy>
struct common_params {
- // If Compare is a common comparator for a std::string-like type, then we adapt it
+ // If Compare is a common comparator for a string-like type, then we adapt it
// to use heterogeneous lookup and to be a key-compare-to comparator.
using key_compare = typename key_compare_to_adapter<Compare>::type;
// A type which indicates if we have a key-compare-to functor or a plain old
@@ -159,9 +229,6 @@
using size_type = std::make_signed<size_t>::type;
using difference_type = ptrdiff_t;
- // True if this is a multiset or multimap.
- using is_multi_container = std::integral_constant<bool, Multi>;
-
using slot_policy = SlotPolicy;
using slot_type = typename slot_policy::slot_type;
using value_type = typename slot_policy::value_type;
@@ -171,6 +238,23 @@
using reference = value_type &;
using const_reference = const value_type &;
+ // For the given lookup key type, returns whether we can have multiple
+ // equivalent keys in the btree. If this is a multi-container, then we can.
+ // Otherwise, we can have multiple equivalent keys only if all of the
+ // following conditions are met:
+ // - The comparator is transparent.
+ // - The lookup key type is not the same as key_type.
+ // - The comparator is not a StringBtreeDefault{Less,Greater} comparator
+ // that we know has the same equivalence classes for all lookup types.
+ template <typename LookupKey>
+ constexpr static bool can_have_multiple_equivalent_keys() {
+ return Multi ||
+ (IsTransparent<key_compare>::value &&
+ !std::is_same<LookupKey, Key>::value &&
+ !std::is_same<key_compare, StringBtreeDefaultLess>::value &&
+ !std::is_same<key_compare, StringBtreeDefaultGreater>::value);
+ }
+
enum {
kTargetNodeSize = TargetNodeSize,
@@ -216,10 +300,6 @@
static void move(Alloc *alloc, slot_type *src, slot_type *dest) {
slot_policy::move(alloc, src, dest);
}
- static void move(Alloc *alloc, slot_type *first, slot_type *last,
- slot_type *result) {
- slot_policy::move(alloc, first, last, result);
- }
};
// A parameters structure for holding the type parameters for a btree_map.
@@ -251,9 +331,17 @@
};
using is_map_container = std::true_type;
- static const Key &key(const value_type &x) { return x.first; }
- static const Key &key(const init_type &x) { return x.first; }
- static const Key &key(const slot_type *x) { return slot_policy::key(x); }
+ template <typename V>
+ static auto key(const V &value) -> decltype(value.first) {
+ return value.first;
+ }
+ static const Key &key(const slot_type *s) { return slot_policy::key(s); }
+ static const Key &key(slot_type *s) { return slot_policy::key(s); }
+ // For use in node handle.
+ static auto mutable_key(slot_type *s)
+ -> decltype(slot_policy::mutable_key(s)) {
+ return slot_policy::mutable_key(s);
+ }
static mapped_type &value(value_type *value) { return value->second; }
};
@@ -294,13 +382,6 @@
static void move(Alloc * /*alloc*/, slot_type *src, slot_type *dest) {
*dest = std::move(*src);
}
-
- template <typename Alloc>
- static void move(Alloc *alloc, slot_type *first, slot_type *last,
- slot_type *result) {
- for (slot_type *src = first, *dest = result; src != last; ++src, ++dest)
- move(alloc, src, dest);
- }
};
// A parameters structure for holding the type parameters for a btree_set.
@@ -314,8 +395,10 @@
using value_compare = typename set_params::common_params::key_compare;
using is_map_container = std::false_type;
- static const Key &key(const value_type &x) { return x; }
- static const Key &key(const slot_type *x) { return *x; }
+ template <typename V>
+ static const V &key(const V &value) { return value; }
+ static const Key &key(const slot_type *slot) { return *slot; }
+ static const Key &key(slot_type *slot) { return *slot; }
};
// An adapter class that converts a lower-bound compare into an upper-bound
@@ -325,8 +408,8 @@
template <typename Compare>
struct upper_bound_adapter {
explicit upper_bound_adapter(const Compare &c) : comp(c) {}
- template <typename K, typename LK>
- bool operator()(const K &a, const LK &b) const {
+ template <typename K1, typename K2>
+ bool operator()(const K1 &a, const K2 &b) const {
// Returns true when a is not greater than b.
return !compare_internal::compare_result_as_less_than(comp(b, a));
}
@@ -351,6 +434,10 @@
// useful information.
template <typename V>
struct SearchResult<V, false> {
+ SearchResult() {}
+ explicit SearchResult(V value) : value(value) {}
+ SearchResult(V value, MatchKind /*match*/) : value(value) {}
+
V value;
static constexpr bool HasMatch() { return false; }
@@ -363,7 +450,6 @@
template <typename Params>
class btree_node {
using is_key_compare_to = typename Params::is_key_compare_to;
- using is_multi_container = typename Params::is_multi_container;
using field_type = typename Params::node_count_type;
using allocator_type = typename Params::allocator_type;
using slot_type = typename Params::slot_type;
@@ -381,15 +467,22 @@
using difference_type = typename Params::difference_type;
// Btree decides whether to use linear node search as follows:
+ // - If the comparator expresses a preference, use that.
+ // - If the key expresses a preference, use that.
// - If the key is arithmetic and the comparator is std::less or
// std::greater, choose linear.
// - Otherwise, choose binary.
// TODO(ezb): Might make sense to add condition(s) based on node-size.
using use_linear_search = std::integral_constant<
bool,
- std::is_arithmetic<key_type>::value &&
- (std::is_same<std::less<key_type>, key_compare>::value ||
- std::is_same<std::greater<key_type>, key_compare>::value)>;
+ has_linear_node_search_preference<key_compare>::value
+ ? prefers_linear_node_search<key_compare>::value
+ : has_linear_node_search_preference<key_type>::value
+ ? prefers_linear_node_search<key_type>::value
+ : std::is_arithmetic<key_type>::value &&
+ (std::is_same<std::less<key_type>, key_compare>::value ||
+ std::is_same<std::greater<key_type>,
+ key_compare>::value)>;
// This class is organized by gtl::Layout as if it had the following
// structure:
@@ -402,8 +495,9 @@
// // TODO(ezb): right now, `start` is always 0. Update insertion/merge
// // logic to allow for floating storage within nodes.
// field_type start;
- // // The count of the number of populated values in the node.
- // field_type count;
+ // // The index after the last populated value in `values`. Currently, this
+ // // is the same as the count of values.
+ // field_type finish;
// // The maximum number of values the node can hold. This is an integer in
// // [1, kNodeValues] for root leaf nodes, kNodeValues for non-root leaf
// // nodes, and kInternalNodeMaxCount (as a sentinel value) for internal
@@ -414,7 +508,7 @@
//
// // The array of values. The capacity is `max_count` for leaf nodes and
// // kNodeValues for internal nodes. Only the values in
- // // [start, start + count) have been initialized and are valid.
+ // // [start, finish) have been initialized and are valid.
// slot_type values[max_count];
//
// // The array of child pointers. The keys in children[i] are all less
@@ -445,7 +539,7 @@
slot_type, btree_node *>;
constexpr static size_type SizeWithNValues(size_type n) {
return layout_type(/*parent*/ 1,
- /*position, start, count, max_count*/ 4,
+ /*position, start, finish, max_count*/ 4,
/*values*/ n,
/*children*/ 0)
.AllocSize();
@@ -482,13 +576,13 @@
// Leaves can have less than kNodeValues values.
constexpr static layout_type LeafLayout(const int max_values = kNodeValues) {
return layout_type(/*parent*/ 1,
- /*position, start, count, max_count*/ 4,
+ /*position, start, finish, max_count*/ 4,
/*values*/ max_values,
/*children*/ 0);
}
constexpr static layout_type InternalLayout() {
return layout_type(/*parent*/ 1,
- /*position, start, count, max_count*/ 4,
+ /*position, start, finish, max_count*/ 4,
/*values*/ kNodeValues,
/*children*/ kNodeValues + 1);
}
@@ -514,12 +608,14 @@
reinterpret_cast<const char *>(this));
}
void set_parent(btree_node *p) { *GetField<0>() = p; }
- field_type &mutable_count() { return GetField<1>()[2]; }
+ field_type &mutable_finish() { return GetField<1>()[2]; }
slot_type *slot(int i) { return &GetField<2>()[i]; }
+ slot_type *start_slot() { return slot(start()); }
+ slot_type *finish_slot() { return slot(finish()); }
const slot_type *slot(int i) const { return &GetField<2>()[i]; }
void set_position(field_type v) { GetField<1>()[0] = v; }
void set_start(field_type v) { GetField<1>()[1] = v; }
- void set_count(field_type v) { GetField<1>()[2] = v; }
+ void set_finish(field_type v) { GetField<1>()[2] = v; }
// This method is only called by the node init methods.
void set_max_count(field_type v) { GetField<1>()[3] = v; }
@@ -532,10 +628,20 @@
field_type position() const { return GetField<1>()[0]; }
// Getter for the offset of the first value in the `values` array.
- field_type start() const { return GetField<1>()[1]; }
+ field_type start() const {
+ // TODO(ezb): when floating storage is implemented, return GetField<1>()[1];
+ assert(GetField<1>()[1] == 0);
+ return 0;
+ }
+
+ // Getter for the offset after the last value in the `values` array.
+ field_type finish() const { return GetField<1>()[2]; }
// Getters for the number of values stored in this node.
- field_type count() const { return GetField<1>()[2]; }
+ field_type count() const {
+ assert(finish() >= start());
+ return finish() - start();
+ }
field_type max_count() const {
// Internal nodes have max_count==kInternalNodeMaxCount.
// Leaf nodes have max_count in [1, kNodeValues].
@@ -563,6 +669,7 @@
// Getters/setter for the child at position i in the node.
btree_node *child(int i) const { return GetField<3>()[i]; }
+ btree_node *start_child() const { return child(start()); }
btree_node *&mutable_child(int i) { return GetField<3>()[i]; }
void clear_child(int i) {
absl::container_internal::SanitizerPoisonObject(&mutable_child(i));
@@ -595,14 +702,14 @@
template <typename K, typename Compare>
SearchResult<int, btree_is_key_compare_to<Compare, key_type>::value>
linear_search(const K &k, const Compare &comp) const {
- return linear_search_impl(k, 0, count(), comp,
+ return linear_search_impl(k, start(), finish(), comp,
btree_is_key_compare_to<Compare, key_type>());
}
template <typename K, typename Compare>
SearchResult<int, btree_is_key_compare_to<Compare, key_type>::value>
binary_search(const K &k, const Compare &comp) const {
- return binary_search_impl(k, 0, count(), comp,
+ return binary_search_impl(k, start(), finish(), comp,
btree_is_key_compare_to<Compare, key_type>());
}
@@ -618,7 +725,7 @@
}
++s;
}
- return {s};
+ return SearchResult<int, false>{s};
}
// Returns the position of the first value whose key is not less than k using
@@ -653,7 +760,7 @@
e = mid;
}
}
- return {s};
+ return SearchResult<int, false>{s};
}
// Returns the position of the first value whose key is not less than k using
@@ -662,7 +769,7 @@
SearchResult<int, true> binary_search_impl(
const K &k, int s, int e, const CompareTo &comp,
std::true_type /* IsCompareTo */) const {
- if (is_multi_container::value) {
+ if (params_type::template can_have_multiple_equivalent_keys<K>()) {
MatchKind exact_match = MatchKind::kNe;
while (s != e) {
const int mid = (s + e) >> 1;
@@ -673,14 +780,14 @@
e = mid;
if (c == 0) {
// Need to return the first value whose key is not less than k,
- // which requires continuing the binary search if this is a
- // multi-container.
+ // which requires continuing the binary search if there could be
+ // multiple equivalent keys.
exact_match = MatchKind::kEq;
}
}
}
return {s, exact_match};
- } else { // Not a multi-container.
+ } else { // Can't have multiple equivalent keys.
while (s != e) {
const int mid = (s + e) >> 1;
const absl::weak_ordering c = comp(key(mid), k);
@@ -701,14 +808,10 @@
template <typename... Args>
void emplace_value(size_type i, allocator_type *alloc, Args &&... args);
- // Removes the value at position i, shifting all existing values and children
- // at positions > i to the left by 1.
- void remove_value(int i, allocator_type *alloc);
-
- // Removes the values at positions [i, i + to_erase), shifting all values
- // after that range to the left by to_erase. Does not change children at all.
- void remove_values_ignore_children(int i, int to_erase,
- allocator_type *alloc);
+ // Removes the values at positions [i, i + to_erase), shifting all existing
+ // values and children after that range to the left by to_erase. Clears all
+ // children between [i, i + to_erase).
+ void remove_values(field_type i, field_type to_erase, allocator_type *alloc);
// Rebalances a node with its right sibling.
void rebalance_right_to_left(int to_move, btree_node *right,
@@ -720,74 +823,87 @@
void split(int insert_position, btree_node *dest, allocator_type *alloc);
// Merges a node with its right sibling, moving all of the values and the
- // delimiting key in the parent node onto itself.
- void merge(btree_node *sibling, allocator_type *alloc);
-
- // Swap the contents of "this" and "src".
- void swap(btree_node *src, allocator_type *alloc);
+ // delimiting key in the parent node onto itself, and deleting the src node.
+ void merge(btree_node *src, allocator_type *alloc);
// Node allocation/deletion routines.
- static btree_node *init_leaf(btree_node *n, btree_node *parent,
- int max_count) {
- n->set_parent(parent);
- n->set_position(0);
- n->set_start(0);
- n->set_count(0);
- n->set_max_count(max_count);
+ void init_leaf(btree_node *parent, int max_count) {
+ set_parent(parent);
+ set_position(0);
+ set_start(0);
+ set_finish(0);
+ set_max_count(max_count);
absl::container_internal::SanitizerPoisonMemoryRegion(
- n->slot(0), max_count * sizeof(slot_type));
- return n;
+ start_slot(), max_count * sizeof(slot_type));
}
- static btree_node *init_internal(btree_node *n, btree_node *parent) {
- init_leaf(n, parent, kNodeValues);
+ void init_internal(btree_node *parent) {
+ init_leaf(parent, kNodeValues);
// Set `max_count` to a sentinel value to indicate that this node is
// internal.
- n->set_max_count(kInternalNodeMaxCount);
+ set_max_count(kInternalNodeMaxCount);
absl::container_internal::SanitizerPoisonMemoryRegion(
- &n->mutable_child(0), (kNodeValues + 1) * sizeof(btree_node *));
- return n;
- }
- void destroy(allocator_type *alloc) {
- for (int i = 0; i < count(); ++i) {
- value_destroy(i, alloc);
- }
+ &mutable_child(start()), (kNodeValues + 1) * sizeof(btree_node *));
}
- public:
- // Exposed only for tests.
- static bool testonly_uses_linear_node_search() {
- return use_linear_search::value;
+ static void deallocate(const size_type size, btree_node *node,
+ allocator_type *alloc) {
+ absl::container_internal::Deallocate<Alignment()>(alloc, node, size);
}
+ // Deletes a node and all of its children.
+ static void clear_and_delete(btree_node *node, allocator_type *alloc);
+
private:
template <typename... Args>
- void value_init(const size_type i, allocator_type *alloc, Args &&... args) {
+ void value_init(const field_type i, allocator_type *alloc, Args &&... args) {
absl::container_internal::SanitizerUnpoisonObject(slot(i));
params_type::construct(alloc, slot(i), std::forward<Args>(args)...);
}
- void value_destroy(const size_type i, allocator_type *alloc) {
+ void value_destroy(const field_type i, allocator_type *alloc) {
params_type::destroy(alloc, slot(i));
absl::container_internal::SanitizerPoisonObject(slot(i));
}
-
- // Move n values starting at value i in this node into the values starting at
- // value j in node x.
- void uninitialized_move_n(const size_type n, const size_type i,
- const size_type j, btree_node *x,
- allocator_type *alloc) {
- absl::container_internal::SanitizerUnpoisonMemoryRegion(
- x->slot(j), n * sizeof(slot_type));
- for (slot_type *src = slot(i), *end = src + n, *dest = x->slot(j);
- src != end; ++src, ++dest) {
- params_type::construct(alloc, dest, src);
+ void value_destroy_n(const field_type i, const field_type n,
+ allocator_type *alloc) {
+ for (slot_type *s = slot(i), *end = slot(i + n); s != end; ++s) {
+ params_type::destroy(alloc, s);
+ absl::container_internal::SanitizerPoisonObject(s);
}
}
- // Destroys a range of n values, starting at index i.
- void value_destroy_n(const size_type i, const size_type n,
- allocator_type *alloc) {
- for (int j = 0; j < n; ++j) {
- value_destroy(i + j, alloc);
+ static void transfer(slot_type *dest, slot_type *src, allocator_type *alloc) {
+ absl::container_internal::SanitizerUnpoisonObject(dest);
+ params_type::transfer(alloc, dest, src);
+ absl::container_internal::SanitizerPoisonObject(src);
+ }
+
+ // Transfers value from slot `src_i` in `src_node` to slot `dest_i` in `this`.
+ void transfer(const size_type dest_i, const size_type src_i,
+ btree_node *src_node, allocator_type *alloc) {
+ transfer(slot(dest_i), src_node->slot(src_i), alloc);
+ }
+
+ // Transfers `n` values starting at value `src_i` in `src_node` into the
+ // values starting at value `dest_i` in `this`.
+ void transfer_n(const size_type n, const size_type dest_i,
+ const size_type src_i, btree_node *src_node,
+ allocator_type *alloc) {
+ for (slot_type *src = src_node->slot(src_i), *end = src + n,
+ *dest = slot(dest_i);
+ src != end; ++src, ++dest) {
+ transfer(dest, src, alloc);
+ }
+ }
+
+ // Same as above, except that we start at the end and work our way to the
+ // beginning.
+ void transfer_n_backward(const size_type n, const size_type dest_i,
+ const size_type src_i, btree_node *src_node,
+ allocator_type *alloc) {
+ for (slot_type *src = src_node->slot(src_i + n - 1), *end = src - n,
+ *dest = slot(dest_i + n - 1);
+ src != end; --src, --dest) {
+ transfer(dest, src, alloc);
}
}
@@ -804,6 +920,7 @@
using key_type = typename Node::key_type;
using size_type = typename Node::size_type;
using params_type = typename Node::params_type;
+ using is_map_container = typename params_type::is_map_container;
using node_type = Node;
using normal_node = typename std::remove_const<Node>::type;
@@ -815,7 +932,7 @@
using slot_type = typename params_type::slot_type;
using iterator =
- btree_iterator<normal_node, normal_reference, normal_pointer>;
+ btree_iterator<normal_node, normal_reference, normal_pointer>;
using const_iterator =
btree_iterator<const_node, const_reference, const_pointer>;
@@ -828,23 +945,23 @@
using iterator_category = std::bidirectional_iterator_tag;
btree_iterator() : node(nullptr), position(-1) {}
+ explicit btree_iterator(Node *n) : node(n), position(n->start()) {}
btree_iterator(Node *n, int p) : node(n), position(p) {}
// NOTE: this SFINAE allows for implicit conversions from iterator to
- // const_iterator, but it specifically avoids defining copy constructors so
- // that btree_iterator can be trivially copyable. This is for performance and
- // binary size reasons.
+ // const_iterator, but it specifically avoids hiding the copy constructor so
+ // that the trivial one will be used when possible.
template <typename N, typename R, typename P,
absl::enable_if_t<
std::is_same<btree_iterator<N, R, P>, iterator>::value &&
std::is_same<btree_iterator, const_iterator>::value,
int> = 0>
- btree_iterator(const btree_iterator<N, R, P> &x) // NOLINT
- : node(x.node), position(x.position) {}
+ btree_iterator(const btree_iterator<N, R, P> other) // NOLINT
+ : node(other.node), position(other.position) {}
private:
// This SFINAE allows explicit conversions from const_iterator to
- // iterator, but also avoids defining a copy constructor.
+ // iterator, but also avoids hiding the copy constructor.
// NOTE: the const_cast is safe because this constructor is only called by
// non-const methods and the container owns the nodes.
template <typename N, typename R, typename P,
@@ -852,12 +969,12 @@
std::is_same<btree_iterator<N, R, P>, const_iterator>::value &&
std::is_same<btree_iterator, iterator>::value,
int> = 0>
- explicit btree_iterator(const btree_iterator<N, R, P> &x)
- : node(const_cast<node_type *>(x.node)), position(x.position) {}
+ explicit btree_iterator(const btree_iterator<N, R, P> other)
+ : node(const_cast<node_type *>(other.node)), position(other.position) {}
// Increment/decrement the iterator.
void increment() {
- if (node->leaf() && ++position < node->count()) {
+ if (node->leaf() && ++position < node->finish()) {
return;
}
increment_slow();
@@ -865,7 +982,7 @@
void increment_slow();
void decrement() {
- if (node->leaf() && --position >= 0) {
+ if (node->leaf() && --position >= node->start()) {
return;
}
decrement_slow();
@@ -873,26 +990,33 @@
void decrement_slow();
public:
- bool operator==(const const_iterator &x) const {
- return node == x.node && position == x.position;
+ bool operator==(const iterator &other) const {
+ return node == other.node && position == other.position;
}
- bool operator!=(const const_iterator &x) const {
- return node != x.node || position != x.position;
+ bool operator==(const const_iterator &other) const {
+ return node == other.node && position == other.position;
+ }
+ bool operator!=(const iterator &other) const {
+ return node != other.node || position != other.position;
+ }
+ bool operator!=(const const_iterator &other) const {
+ return node != other.node || position != other.position;
}
// Accessors for the key/value the iterator is pointing at.
reference operator*() const {
+ ABSL_HARDENING_ASSERT(node != nullptr);
+ ABSL_HARDENING_ASSERT(node->start() <= position);
+ ABSL_HARDENING_ASSERT(node->finish() > position);
return node->value(position);
}
- pointer operator->() const {
- return &node->value(position);
- }
+ pointer operator->() const { return &operator*(); }
- btree_iterator& operator++() {
+ btree_iterator &operator++() {
increment();
return *this;
}
- btree_iterator& operator--() {
+ btree_iterator &operator--() {
decrement();
return *this;
}
@@ -908,6 +1032,8 @@
}
private:
+ friend iterator;
+ friend const_iterator;
template <typename Params>
friend class btree;
template <typename Tree>
@@ -918,8 +1044,6 @@
friend class btree_map_container;
template <typename Tree>
friend class btree_multiset_container;
- template <typename N, typename R, typename P>
- friend struct btree_iterator;
template <typename TreeType, typename CheckerType>
friend class base_checker;
@@ -929,7 +1053,8 @@
// The node in the tree the iterator is pointing at.
Node *node;
// The position within the node of the tree the iterator is pointing at.
- // TODO(ezb): make this a field_type
+ // NOTE: this is an int rather than a field_type because iterators can point
+ // to invalid positions (such as -1) in certain circumstances.
int position;
};
@@ -937,6 +1062,8 @@
class btree {
using node_type = btree_node<Params>;
using is_key_compare_to = typename Params::is_key_compare_to;
+ using init_type = typename Params::init_type;
+ using field_type = typename node_type::field_type;
// We use a static empty node for the root/leftmost/rightmost of empty btrees
// in order to avoid branching in begin()/end().
@@ -945,7 +1072,7 @@
node_type *parent;
field_type position = 0;
field_type start = 0;
- field_type count = 0;
+ field_type finish = 0;
// max_count must be != kInternalNodeMaxCount (so that this node is regarded
// as a leaf node). max_count() is never called when the tree is empty.
field_type max_count = node_type::kInternalNodeMaxCount + 1;
@@ -960,7 +1087,7 @@
static node_type *EmptyNode() {
#ifdef _MSC_VER
- static EmptyNodeType* empty_node = new EmptyNodeType;
+ static EmptyNodeType *empty_node = new EmptyNodeType;
// This assert fails on some other construction methods.
assert(empty_node->parent == empty_node);
return empty_node;
@@ -971,7 +1098,7 @@
#endif
}
- enum {
+ enum : uint32_t {
kNodeValues = node_type::kNodeValues,
kMinNodeValues = kNodeValues / 2,
};
@@ -979,14 +1106,11 @@
struct node_stats {
using size_type = typename Params::size_type;
- node_stats(size_type l, size_type i)
- : leaf_nodes(l),
- internal_nodes(i) {
- }
+ node_stats(size_type l, size_type i) : leaf_nodes(l), internal_nodes(i) {}
- node_stats& operator+=(const node_stats &x) {
- leaf_nodes += x.leaf_nodes;
- internal_nodes += x.internal_nodes;
+ node_stats &operator+=(const node_stats &other) {
+ leaf_nodes += other.leaf_nodes;
+ internal_nodes += other.internal_nodes;
return *this;
}
@@ -1006,7 +1130,8 @@
using const_reference = typename Params::const_reference;
using pointer = typename Params::pointer;
using const_pointer = typename Params::const_pointer;
- using iterator = btree_iterator<node_type, reference, pointer>;
+ using iterator =
+ typename btree_iterator<node_type, reference, pointer>::iterator;
using const_iterator = typename iterator::const_iterator;
using reverse_iterator = std::reverse_iterator<iterator>;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
@@ -1018,28 +1143,46 @@
private:
// For use in copy_or_move_values_in_order.
- const value_type &maybe_move_from_iterator(const_iterator x) { return *x; }
- value_type &&maybe_move_from_iterator(iterator x) { return std::move(*x); }
+ const value_type &maybe_move_from_iterator(const_iterator it) { return *it; }
+ value_type &&maybe_move_from_iterator(iterator it) {
+ // This is a destructive operation on the other container so it's safe for
+ // us to const_cast and move from the keys here even if it's a set.
+ return std::move(const_cast<value_type &>(*it));
+ }
// Copies or moves (depending on the template parameter) the values in
- // x into this btree in their order in x. This btree must be empty before this
- // method is called. This method is used in copy construction, copy
- // assignment, and move assignment.
+ // other into this btree in their order in other. This btree must be empty
+ // before this method is called. This method is used in copy construction,
+ // copy assignment, and move assignment.
template <typename Btree>
- void copy_or_move_values_in_order(Btree *x);
+ void copy_or_move_values_in_order(Btree &other);
// Validates that various assumptions/requirements are true at compile time.
constexpr static bool static_assert_validation();
public:
- btree(const key_compare &comp, const allocator_type &alloc);
+ btree(const key_compare &comp, const allocator_type &alloc)
+ : root_(comp, alloc, EmptyNode()), rightmost_(EmptyNode()), size_(0) {}
- btree(const btree &x);
- btree(btree &&x) noexcept
- : root_(std::move(x.root_)),
- rightmost_(absl::exchange(x.rightmost_, EmptyNode())),
- size_(absl::exchange(x.size_, 0)) {
- x.mutable_root() = EmptyNode();
+ btree(const btree &other) : btree(other, other.allocator()) {}
+ btree(const btree &other, const allocator_type &alloc)
+ : btree(other.key_comp(), alloc) {
+ copy_or_move_values_in_order(other);
+ }
+ btree(btree &&other) noexcept
+ : root_(std::move(other.root_)),
+ rightmost_(absl::exchange(other.rightmost_, EmptyNode())),
+ size_(absl::exchange(other.size_, 0)) {
+ other.mutable_root() = EmptyNode();
+ }
+ btree(btree &&other, const allocator_type &alloc)
+ : btree(other.key_comp(), alloc) {
+ if (alloc == other.allocator()) {
+ swap(other);
+ } else {
+ // Move values from `other` one at a time when allocators are different.
+ copy_or_move_values_in_order(other);
+ }
}
~btree() {
@@ -1049,44 +1192,41 @@
clear();
}
- // Assign the contents of x to *this.
- btree &operator=(const btree &x);
- btree &operator=(btree &&x) noexcept;
+ // Assign the contents of other to *this.
+ btree &operator=(const btree &other);
+ btree &operator=(btree &&other) noexcept;
- iterator begin() {
- return iterator(leftmost(), 0);
- }
- const_iterator begin() const {
- return const_iterator(leftmost(), 0);
- }
- iterator end() { return iterator(rightmost_, rightmost_->count()); }
+ iterator begin() { return iterator(leftmost()); }
+ const_iterator begin() const { return const_iterator(leftmost()); }
+ iterator end() { return iterator(rightmost_, rightmost_->finish()); }
const_iterator end() const {
- return const_iterator(rightmost_, rightmost_->count());
+ return const_iterator(rightmost_, rightmost_->finish());
}
- reverse_iterator rbegin() {
- return reverse_iterator(end());
- }
+ reverse_iterator rbegin() { return reverse_iterator(end()); }
const_reverse_iterator rbegin() const {
return const_reverse_iterator(end());
}
- reverse_iterator rend() {
- return reverse_iterator(begin());
- }
+ reverse_iterator rend() { return reverse_iterator(begin()); }
const_reverse_iterator rend() const {
return const_reverse_iterator(begin());
}
- // Finds the first element whose key is not less than key.
+ // Finds the first element whose key is not less than `key`.
template <typename K>
iterator lower_bound(const K &key) {
- return internal_end(internal_lower_bound(key));
+ return internal_end(internal_lower_bound(key).value);
}
template <typename K>
const_iterator lower_bound(const K &key) const {
- return internal_end(internal_lower_bound(key));
+ return internal_end(internal_lower_bound(key).value);
}
- // Finds the first element whose key is greater than key.
+ // Finds the first element whose key is not less than `key` and also returns
+ // whether that element is equal to `key`.
+ template <typename K>
+ std::pair<iterator, bool> lower_bound_equal(const K &key) const;
+
+ // Finds the first element whose key is greater than `key`.
template <typename K>
iterator upper_bound(const K &key) {
return internal_end(internal_upper_bound(key));
@@ -1097,23 +1237,21 @@
}
// Finds the range of values which compare equal to key. The first member of
- // the returned pair is equal to lower_bound(key). The second member pair of
- // the pair is equal to upper_bound(key).
+ // the returned pair is equal to lower_bound(key). The second member of the
+ // pair is equal to upper_bound(key).
template <typename K>
- std::pair<iterator, iterator> equal_range(const K &key) {
- return {lower_bound(key), upper_bound(key)};
- }
+ std::pair<iterator, iterator> equal_range(const K &key);
template <typename K>
std::pair<const_iterator, const_iterator> equal_range(const K &key) const {
- return {lower_bound(key), upper_bound(key)};
+ return const_cast<btree *>(this)->equal_range(key);
}
// Inserts a value into the btree only if it does not already exist. The
// boolean return value indicates whether insertion succeeded or failed.
// Requirement: if `key` already exists in the btree, does not consume `args`.
// Requirement: `key` is never referenced after consuming `args`.
- template <typename... Args>
- std::pair<iterator, bool> insert_unique(const key_type &key, Args &&... args);
+ template <typename K, typename... Args>
+ std::pair<iterator, bool> insert_unique(const K &key, Args &&... args);
// Inserts with hint. Checks to see if the value should be placed immediately
// before `position` in the tree. If so, then the insertion will take
@@ -1121,14 +1259,23 @@
// logarithmic time as if a call to insert_unique() were made.
// Requirement: if `key` already exists in the btree, does not consume `args`.
// Requirement: `key` is never referenced after consuming `args`.
- template <typename... Args>
+ template <typename K, typename... Args>
std::pair<iterator, bool> insert_hint_unique(iterator position,
- const key_type &key,
+ const K &key,
Args &&... args);
// Insert a range of values into the btree.
+ // Note: the first overload avoids constructing a value_type if the key
+ // already exists in the btree.
+ template <typename InputIterator,
+ typename = decltype(std::declval<const key_compare &>()(
+ params_type::key(*std::declval<InputIterator>()),
+ std::declval<const key_type &>()))>
+ void insert_iterator_unique(InputIterator b, InputIterator e, int);
+ // We need the second overload for cases in which we need to construct a
+ // value_type in order to compare it with the keys already in the btree.
template <typename InputIterator>
- void insert_iterator_unique(InputIterator b, InputIterator e);
+ void insert_iterator_unique(InputIterator b, InputIterator e, char);
// Inserts a value into the btree.
template <typename ValueType>
@@ -1159,20 +1306,10 @@
// Erases range. Returns the number of keys erased and an iterator pointing
// to the element after the last erased element.
- std::pair<size_type, iterator> erase(iterator begin, iterator end);
+ std::pair<size_type, iterator> erase_range(iterator begin, iterator end);
- // Erases the specified key from the btree. Returns 1 if an element was
- // erased and 0 otherwise.
- template <typename K>
- size_type erase_unique(const K &key);
-
- // Erases all of the entries matching the specified key from the
- // btree. Returns the number of elements erased.
- template <typename K>
- size_type erase_multi(const K &key);
-
- // Finds the iterator corresponding to a key or returns end() if the key is
- // not present.
+ // Finds an element with key equivalent to `key` or returns `end()` if `key`
+ // is not present.
template <typename K>
iterator find(const K &key) {
return internal_end(internal_find(key));
@@ -1182,35 +1319,18 @@
return internal_end(internal_find(key));
}
- // Returns a count of the number of times the key appears in the btree.
- template <typename K>
- size_type count_unique(const K &key) const {
- const iterator begin = internal_find(key);
- if (begin.node == nullptr) {
- // The key doesn't exist in the tree.
- return 0;
- }
- return 1;
- }
- // Returns a count of the number of times the key appears in the btree.
- template <typename K>
- size_type count_multi(const K &key) const {
- const auto range = equal_range(key);
- return std::distance(range.first, range.second);
- }
-
// Clear the btree, deleting all of the values it contains.
void clear();
- // Swap the contents of *this and x.
- void swap(btree &x);
+ // Swaps the contents of `this` and `other`.
+ void swap(btree &other);
const key_compare &key_comp() const noexcept {
return root_.template get<0>();
}
- template <typename K, typename LK>
- bool compare_keys(const K &x, const LK &y) const {
- return compare_internal::compare_result_as_less_than(key_comp()(x, y));
+ template <typename K1, typename K2>
+ bool compare_keys(const K1 &a, const K2 &b) const {
+ return compare_internal::compare_result_as_less_than(key_comp()(a, b));
}
value_compare value_comp() const { return value_compare(key_comp()); }
@@ -1226,7 +1346,7 @@
// The height of the btree. An empty tree will have height 0.
size_type height() const {
size_type h = 0;
- if (root()) {
+ if (!empty()) {
// Count the length of the chain from the leftmost node up to the
// root. We actually count from the root back around to the level below
// the root, but the calculation is the same because of the circularity
@@ -1241,9 +1361,7 @@
}
// The number of internal, leaf and total nodes used by the btree.
- size_type leaf_nodes() const {
- return internal_stats(root()).leaf_nodes;
- }
+ size_type leaf_nodes() const { return internal_stats(root()).leaf_nodes; }
size_type internal_nodes() const {
return internal_stats(root()).internal_nodes;
}
@@ -1256,11 +1374,9 @@
size_type bytes_used() const {
node_stats stats = internal_stats(root());
if (stats.leaf_nodes == 1 && stats.internal_nodes == 0) {
- return sizeof(*this) +
- node_type::LeafSize(root()->max_count());
+ return sizeof(*this) + node_type::LeafSize(root()->max_count());
} else {
- return sizeof(*this) +
- stats.leaf_nodes * node_type::LeafSize() +
+ return sizeof(*this) + stats.leaf_nodes * node_type::LeafSize() +
stats.internal_nodes * node_type::InternalSize();
}
}
@@ -1277,24 +1393,23 @@
// divided by the maximum number of elements a tree with the current number
// of nodes could hold. A value of 1 indicates perfect space
// utilization. Smaller values indicate space wastage.
+ // Returns 0 for empty trees.
double fullness() const {
+ if (empty()) return 0.0;
return static_cast<double>(size()) / (nodes() * kNodeValues);
}
// The overhead of the btree structure in bytes per node. Computed as the
// total number of bytes used by the btree minus the number of bytes used for
// storing elements divided by the number of elements.
+ // Returns 0 for empty trees.
double overhead() const {
- if (empty()) {
- return 0.0;
- }
+ if (empty()) return 0.0;
return (bytes_used() - size() * sizeof(value_type)) /
static_cast<double>(size());
}
// The allocator used by the btree.
- allocator_type get_allocator() const {
- return allocator();
- }
+ allocator_type get_allocator() const { return allocator(); }
private:
// Internal accessor routines.
@@ -1324,39 +1439,25 @@
}
// Node creation/deletion routines.
- node_type* new_internal_node(node_type *parent) {
- node_type *p = allocate(node_type::InternalSize());
- return node_type::init_internal(p, parent);
+ node_type *new_internal_node(node_type *parent) {
+ node_type *n = allocate(node_type::InternalSize());
+ n->init_internal(parent);
+ return n;
}
- node_type* new_leaf_node(node_type *parent) {
- node_type *p = allocate(node_type::LeafSize());
- return node_type::init_leaf(p, parent, kNodeValues);
+ node_type *new_leaf_node(node_type *parent) {
+ node_type *n = allocate(node_type::LeafSize());
+ n->init_leaf(parent, kNodeValues);
+ return n;
}
node_type *new_leaf_root_node(const int max_count) {
- node_type *p = allocate(node_type::LeafSize(max_count));
- return node_type::init_leaf(p, p, max_count);
+ node_type *n = allocate(node_type::LeafSize(max_count));
+ n->init_leaf(/*parent=*/n, max_count);
+ return n;
}
// Deletion helper routines.
- void erase_same_node(iterator begin, iterator end);
- iterator erase_from_leaf_node(iterator begin, size_type to_erase);
iterator rebalance_after_delete(iterator iter);
- // Deallocates a node of a certain size in bytes using the allocator.
- void deallocate(const size_type size, node_type *node) {
- absl::container_internal::Deallocate<node_type::Alignment()>(
- mutable_allocator(), node, size);
- }
-
- void delete_internal_node(node_type *node) {
- node->destroy(mutable_allocator());
- deallocate(node_type::InternalSize(), node);
- }
- void delete_leaf_node(node_type *node) {
- node->destroy(mutable_allocator());
- deallocate(node_type::LeafSize(node->max_count()), node);
- }
-
// Rebalances or splits the node iter points to.
void rebalance_or_split(iterator *iter);
@@ -1386,36 +1487,27 @@
iterator internal_emplace(iterator iter, Args &&... args);
// Returns an iterator pointing to the first value >= the value "iter" is
- // pointing at. Note that "iter" might be pointing to an invalid location as
- // iter.position == iter.node->count(). This routine simply moves iter up in
- // the tree to a valid location.
+ // pointing at. Note that "iter" might be pointing to an invalid location such
+ // as iter.position == iter.node->finish(). This routine simply moves iter up
+ // in the tree to a valid location.
// Requires: iter.node is non-null.
template <typename IterType>
static IterType internal_last(IterType iter);
// Returns an iterator pointing to the leaf position at which key would
- // reside in the tree. We provide 2 versions of internal_locate. The first
- // version uses a less-than comparator and is incapable of distinguishing when
- // there is an exact match. The second version is for the key-compare-to
- // specialization and distinguishes exact matches. The key-compare-to
- // specialization allows the caller to avoid a subsequent comparison to
- // determine if an exact match was made, which is important for keys with
- // expensive comparison, such as strings.
+ // reside in the tree, unless there is an exact match - in which case, the
+ // result may not be on a leaf. When there's a three-way comparator, we can
+ // return whether there was an exact match. This allows the caller to avoid a
+ // subsequent comparison to determine if an exact match was made, which is
+ // important for keys with expensive comparison, such as strings.
template <typename K>
SearchResult<iterator, is_key_compare_to::value> internal_locate(
const K &key) const;
- template <typename K>
- SearchResult<iterator, false> internal_locate_impl(
- const K &key, std::false_type /* IsCompareTo */) const;
-
- template <typename K>
- SearchResult<iterator, true> internal_locate_impl(
- const K &key, std::true_type /* IsCompareTo */) const;
-
// Internal routine which implements lower_bound().
template <typename K>
- iterator internal_lower_bound(const K &key) const;
+ SearchResult<iterator, is_key_compare_to::value> internal_lower_bound(
+ const K &key) const;
// Internal routine which implements upper_bound().
template <typename K>
@@ -1425,12 +1517,9 @@
template <typename K>
iterator internal_find(const K &key) const;
- // Deletes a node and all of its children.
- void internal_clear(node_type *node);
-
// Verifies the tree structure of node.
- int internal_verify(const node_type *node,
- const key_type *lo, const key_type *hi) const;
+ int internal_verify(const node_type *node, const key_type *lo,
+ const key_type *hi) const;
node_stats internal_stats(const node_type *node) const {
// The root can be a static empty node.
@@ -1441,19 +1530,12 @@
return node_stats(1, 0);
}
node_stats res(0, 1);
- for (int i = 0; i <= node->count(); ++i) {
+ for (int i = node->start(); i <= node->finish(); ++i) {
res += internal_stats(node->child(i));
}
return res;
}
- public:
- // Exposed only for tests.
- static bool testonly_uses_linear_node_search() {
- return node_type::testonly_uses_linear_node_search();
- }
-
- private:
// We use compressed tuple in order to save space because key_compare and
// allocator_type are usually empty.
absl::container_internal::CompressedTuple<key_compare, allocator_type,
@@ -1475,20 +1557,19 @@
inline void btree_node<P>::emplace_value(const size_type i,
allocator_type *alloc,
Args &&... args) {
- assert(i <= count());
+ assert(i >= start());
+ assert(i <= finish());
// Shift old values to create space for new value and then construct it in
// place.
- if (i < count()) {
- value_init(count(), alloc, slot(count() - 1));
- for (size_type j = count() - 1; j > i; --j)
- params_type::move(alloc, slot(j - 1), slot(j));
- value_destroy(i, alloc);
+ if (i < finish()) {
+ transfer_n_backward(finish() - i, /*dest_i=*/i + 1, /*src_i=*/i, this,
+ alloc);
}
value_init(i, alloc, std::forward<Args>(args)...);
- set_count(count() + 1);
+ set_finish(finish() + 1);
- if (!leaf() && count() > i + 1) {
- for (int j = count(); j > i + 1; --j) {
+ if (!leaf() && finish() > i + 1) {
+ for (int j = finish(); j > i + 1; --j) {
set_child(j, child(j - 1));
}
clear_child(i + 1);
@@ -1496,24 +1577,27 @@
}
template <typename P>
-inline void btree_node<P>::remove_value(const int i, allocator_type *alloc) {
- if (!leaf() && count() > i + 1) {
- assert(child(i + 1)->count() == 0);
- for (size_type j = i + 1; j < count(); ++j) {
- set_child(j, child(j + 1));
+inline void btree_node<P>::remove_values(const field_type i,
+ const field_type to_erase,
+ allocator_type *alloc) {
+ // Transfer values after the removed range into their new places.
+ value_destroy_n(i, to_erase, alloc);
+ const field_type orig_finish = finish();
+ const field_type src_i = i + to_erase;
+ transfer_n(orig_finish - src_i, i, src_i, this, alloc);
+
+ if (!leaf()) {
+ // Delete all children between begin and end.
+ for (int j = 0; j < to_erase; ++j) {
+ clear_and_delete(child(i + j + 1), alloc);
}
- clear_child(count());
+ // Rotate children after end into new positions.
+ for (int j = i + to_erase + 1; j <= orig_finish; ++j) {
+ set_child(j - to_erase, child(j));
+ clear_child(j);
+ }
}
-
- remove_values_ignore_children(i, /*to_erase=*/1, alloc);
-}
-
-template <typename P>
-inline void btree_node<P>::remove_values_ignore_children(
- const int i, const int to_erase, allocator_type *alloc) {
- params_type::move(alloc, slot(i + to_erase), slot(count()), slot(i));
- value_destroy_n(count() - to_erase, to_erase, alloc);
- set_count(count() - to_erase);
+ set_finish(orig_finish - to_erase);
}
template <typename P>
@@ -1527,37 +1611,33 @@
assert(to_move <= right->count());
// 1) Move the delimiting value in the parent to the left node.
- value_init(count(), alloc, parent()->slot(position()));
+ transfer(finish(), position(), parent(), alloc);
// 2) Move the (to_move - 1) values from the right node to the left node.
- right->uninitialized_move_n(to_move - 1, 0, count() + 1, this, alloc);
+ transfer_n(to_move - 1, finish() + 1, right->start(), right, alloc);
// 3) Move the new delimiting value to the parent from the right node.
- params_type::move(alloc, right->slot(to_move - 1),
- parent()->slot(position()));
+ parent()->transfer(position(), right->start() + to_move - 1, right, alloc);
- // 4) Shift the values in the right node to their correct position.
- params_type::move(alloc, right->slot(to_move), right->slot(right->count()),
- right->slot(0));
-
- // 5) Destroy the now-empty to_move entries in the right node.
- right->value_destroy_n(right->count() - to_move, to_move, alloc);
+ // 4) Shift the values in the right node to their correct positions.
+ right->transfer_n(right->count() - to_move, right->start(),
+ right->start() + to_move, right, alloc);
if (!leaf()) {
// Move the child pointers from the right to the left node.
for (int i = 0; i < to_move; ++i) {
- init_child(count() + i + 1, right->child(i));
+ init_child(finish() + i + 1, right->child(i));
}
- for (int i = 0; i <= right->count() - to_move; ++i) {
+ for (int i = right->start(); i <= right->finish() - to_move; ++i) {
assert(i + to_move <= right->max_count());
right->init_child(i, right->child(i + to_move));
right->clear_child(i + to_move);
}
}
- // Fixup the counts on the left and right nodes.
- set_count(count() + to_move);
- right->set_count(right->count() - to_move);
+ // Fixup `finish` on the left and right nodes.
+ set_finish(finish() + to_move);
+ right->set_finish(right->finish() - to_move);
}
template <typename P>
@@ -1576,67 +1656,35 @@
// Lastly, a new delimiting value is moved from the left node into the
// parent, and the remaining empty left node entries are destroyed.
- if (right->count() >= to_move) {
- // The original location of the right->count() values are sufficient to hold
- // the new to_move entries from the parent and left node.
+ // 1) Shift existing values in the right node to their correct positions.
+ right->transfer_n_backward(right->count(), right->start() + to_move,
+ right->start(), right, alloc);
- // 1) Shift existing values in the right node to their correct positions.
- right->uninitialized_move_n(to_move, right->count() - to_move,
- right->count(), right, alloc);
- for (slot_type *src = right->slot(right->count() - to_move - 1),
- *dest = right->slot(right->count() - 1),
- *end = right->slot(0);
- src >= end; --src, --dest) {
- params_type::move(alloc, src, dest);
- }
+ // 2) Move the delimiting value in the parent to the right node.
+ right->transfer(right->start() + to_move - 1, position(), parent(), alloc);
- // 2) Move the delimiting value in the parent to the right node.
- params_type::move(alloc, parent()->slot(position()),
- right->slot(to_move - 1));
-
- // 3) Move the (to_move - 1) values from the left node to the right node.
- params_type::move(alloc, slot(count() - (to_move - 1)), slot(count()),
- right->slot(0));
- } else {
- // The right node does not have enough initialized space to hold the new
- // to_move entries, so part of them will move to uninitialized space.
-
- // 1) Shift existing values in the right node to their correct positions.
- right->uninitialized_move_n(right->count(), 0, to_move, right, alloc);
-
- // 2) Move the delimiting value in the parent to the right node.
- right->value_init(to_move - 1, alloc, parent()->slot(position()));
-
- // 3) Move the (to_move - 1) values from the left node to the right node.
- const size_type uninitialized_remaining = to_move - right->count() - 1;
- uninitialized_move_n(uninitialized_remaining,
- count() - uninitialized_remaining, right->count(),
- right, alloc);
- params_type::move(alloc, slot(count() - (to_move - 1)),
- slot(count() - uninitialized_remaining), right->slot(0));
- }
+ // 3) Move the (to_move - 1) values from the left node to the right node.
+ right->transfer_n(to_move - 1, right->start(), finish() - (to_move - 1), this,
+ alloc);
// 4) Move the new delimiting value to the parent from the left node.
- params_type::move(alloc, slot(count() - to_move), parent()->slot(position()));
-
- // 5) Destroy the now-empty to_move entries in the left node.
- value_destroy_n(count() - to_move, to_move, alloc);
+ parent()->transfer(position(), finish() - to_move, this, alloc);
if (!leaf()) {
// Move the child pointers from the left to the right node.
- for (int i = right->count(); i >= 0; --i) {
+ for (int i = right->finish(); i >= right->start(); --i) {
right->init_child(i + to_move, right->child(i));
right->clear_child(i);
}
for (int i = 1; i <= to_move; ++i) {
- right->init_child(i - 1, child(count() - to_move + i));
- clear_child(count() - to_move + i);
+ right->init_child(i - 1, child(finish() - to_move + i));
+ clear_child(finish() - to_move + i);
}
}
// Fixup the counts on the left and right nodes.
- set_count(count() - to_move);
- right->set_count(right->count() + to_move);
+ set_finish(finish() - to_move);
+ right->set_finish(right->finish() + to_move);
}
template <typename P>
@@ -1649,33 +1697,31 @@
// inserting at the beginning of the left node then bias the split to put
// more values on the right node. If we're inserting at the end of the
// right node then bias the split to put more values on the left node.
- if (insert_position == 0) {
- dest->set_count(count() - 1);
+ if (insert_position == start()) {
+ dest->set_finish(dest->start() + finish() - 1);
} else if (insert_position == kNodeValues) {
- dest->set_count(0);
+ dest->set_finish(dest->start());
} else {
- dest->set_count(count() / 2);
+ dest->set_finish(dest->start() + count() / 2);
}
- set_count(count() - dest->count());
+ set_finish(finish() - dest->count());
assert(count() >= 1);
// Move values from the left sibling to the right sibling.
- uninitialized_move_n(dest->count(), count(), 0, dest, alloc);
-
- // Destroy the now-empty entries in the left node.
- value_destroy_n(count(), dest->count(), alloc);
+ dest->transfer_n(dest->count(), dest->start(), finish(), this, alloc);
// The split key is the largest value in the left sibling.
- set_count(count() - 1);
- parent()->emplace_value(position(), alloc, slot(count()));
- value_destroy(count(), alloc);
+ --mutable_finish();
+ parent()->emplace_value(position(), alloc, finish_slot());
+ value_destroy(finish(), alloc);
parent()->init_child(position() + 1, dest);
if (!leaf()) {
- for (int i = 0; i <= dest->count(); ++i) {
- assert(child(count() + i + 1) != nullptr);
- dest->init_child(i, child(count() + i + 1));
- clear_child(count() + i + 1);
+ for (int i = dest->start(), j = finish() + 1; i <= dest->finish();
+ ++i, ++j) {
+ assert(child(j) != nullptr);
+ dest->init_child(i, child(j));
+ clear_child(j);
}
}
}
@@ -1686,74 +1732,76 @@
assert(position() + 1 == src->position());
// Move the delimiting value to the left node.
- value_init(count(), alloc, parent()->slot(position()));
+ value_init(finish(), alloc, parent()->slot(position()));
// Move the values from the right to the left node.
- src->uninitialized_move_n(src->count(), 0, count() + 1, this, alloc);
-
- // Destroy the now-empty entries in the right node.
- src->value_destroy_n(0, src->count(), alloc);
+ transfer_n(src->count(), finish() + 1, src->start(), src, alloc);
if (!leaf()) {
// Move the child pointers from the right to the left node.
- for (int i = 0; i <= src->count(); ++i) {
- init_child(count() + i + 1, src->child(i));
+ for (int i = src->start(), j = finish() + 1; i <= src->finish(); ++i, ++j) {
+ init_child(j, src->child(i));
src->clear_child(i);
}
}
- // Fixup the counts on the src and dest nodes.
- set_count(1 + count() + src->count());
- src->set_count(0);
+ // Fixup `finish` on the src and dest nodes.
+ set_finish(start() + 1 + count() + src->count());
+ src->set_finish(src->start());
- // Remove the value on the parent node.
- parent()->remove_value(position(), alloc);
+ // Remove the value on the parent node and delete the src node.
+ parent()->remove_values(position(), /*to_erase=*/1, alloc);
}
template <typename P>
-void btree_node<P>::swap(btree_node *x, allocator_type *alloc) {
- using std::swap;
- assert(leaf() == x->leaf());
-
- // Determine which is the smaller/larger node.
- btree_node *smaller = this, *larger = x;
- if (smaller->count() > larger->count()) {
- swap(smaller, larger);
+void btree_node<P>::clear_and_delete(btree_node *node, allocator_type *alloc) {
+ if (node->leaf()) {
+ node->value_destroy_n(node->start(), node->count(), alloc);
+ deallocate(LeafSize(node->max_count()), node, alloc);
+ return;
+ }
+ if (node->count() == 0) {
+ deallocate(InternalSize(), node, alloc);
+ return;
}
- // Swap the values.
- for (slot_type *a = smaller->slot(0), *b = larger->slot(0),
- *end = a + smaller->count();
- a != end; ++a, ++b) {
- params_type::swap(alloc, a, b);
+ // The parent of the root of the subtree we are deleting.
+ btree_node *delete_root_parent = node->parent();
+
+ // Navigate to the leftmost leaf under node, and then delete upwards.
+ while (!node->leaf()) node = node->start_child();
+ // Use `int` because `pos` needs to be able to hold `kNodeValues+1`, which
+ // isn't guaranteed to be a valid `field_type`.
+ int pos = node->position();
+ btree_node *parent = node->parent();
+ for (;;) {
+ // In each iteration of the next loop, we delete one leaf node and go right.
+ assert(pos <= parent->finish());
+ do {
+ node = parent->child(pos);
+ if (!node->leaf()) {
+ // Navigate to the leftmost leaf under node.
+ while (!node->leaf()) node = node->start_child();
+ pos = node->position();
+ parent = node->parent();
+ }
+ node->value_destroy_n(node->start(), node->count(), alloc);
+ deallocate(LeafSize(node->max_count()), node, alloc);
+ ++pos;
+ } while (pos <= parent->finish());
+
+ // Once we've deleted all children of parent, delete parent and go up/right.
+ assert(pos > parent->finish());
+ do {
+ node = parent;
+ pos = node->position();
+ parent = node->parent();
+ node->value_destroy_n(node->start(), node->count(), alloc);
+ deallocate(InternalSize(), node, alloc);
+ if (parent == delete_root_parent) return;
+ ++pos;
+ } while (pos > parent->finish());
}
-
- // Move values that can't be swapped.
- const size_type to_move = larger->count() - smaller->count();
- larger->uninitialized_move_n(to_move, smaller->count(), smaller->count(),
- smaller, alloc);
- larger->value_destroy_n(smaller->count(), to_move, alloc);
-
- if (!leaf()) {
- // Swap the child pointers.
- std::swap_ranges(&smaller->mutable_child(0),
- &smaller->mutable_child(smaller->count() + 1),
- &larger->mutable_child(0));
- // Update swapped children's parent pointers.
- int i = 0;
- for (; i <= smaller->count(); ++i) {
- smaller->child(i)->set_parent(smaller);
- larger->child(i)->set_parent(larger);
- }
- // Move the child pointers that couldn't be swapped.
- for (; i <= larger->count(); ++i) {
- smaller->init_child(i, larger->child(i));
- larger->clear_child(i);
- }
- }
-
- // Swap the counts.
- swap(mutable_count(), x->mutable_count());
}
////
@@ -1761,23 +1809,24 @@
template <typename N, typename R, typename P>
void btree_iterator<N, R, P>::increment_slow() {
if (node->leaf()) {
- assert(position >= node->count());
+ assert(position >= node->finish());
btree_iterator save(*this);
- while (position == node->count() && !node->is_root()) {
+ while (position == node->finish() && !node->is_root()) {
assert(node->parent()->child(node->position()) == node);
position = node->position();
node = node->parent();
}
- if (position == node->count()) {
+ // TODO(ezb): assert we aren't incrementing end() instead of handling.
+ if (position == node->finish()) {
*this = save;
}
} else {
- assert(position < node->count());
+ assert(position < node->finish());
node = node->child(position + 1);
while (!node->leaf()) {
- node = node->child(0);
+ node = node->start_child();
}
- position = 0;
+ position = node->start();
}
}
@@ -1786,21 +1835,22 @@
if (node->leaf()) {
assert(position <= -1);
btree_iterator save(*this);
- while (position < 0 && !node->is_root()) {
+ while (position < node->start() && !node->is_root()) {
assert(node->parent()->child(node->position()) == node);
position = node->position() - 1;
node = node->parent();
}
- if (position < 0) {
+ // TODO(ezb): assert we aren't decrementing begin() instead of handling.
+ if (position < node->start()) {
*this = save;
}
} else {
- assert(position >= 0);
+ assert(position >= node->start());
node = node->child(position);
while (!node->leaf()) {
- node = node->child(node->count());
+ node = node->child(node->finish());
}
- position = node->count() - 1;
+ position = node->finish() - 1;
}
}
@@ -1808,7 +1858,7 @@
// btree methods
template <typename P>
template <typename Btree>
-void btree<P>::copy_or_move_values_in_order(Btree *x) {
+void btree<P>::copy_or_move_values_in_order(Btree &other) {
static_assert(std::is_same<btree, Btree>::value ||
std::is_same<const btree, Btree>::value,
"Btree type must be same or const.");
@@ -1816,11 +1866,11 @@
// We can avoid key comparisons because we know the order of the
// values is the same order we'll store them in.
- auto iter = x->begin();
- if (iter == x->end()) return;
+ auto iter = other.begin();
+ if (iter == other.end()) return;
insert_multi(maybe_move_from_iterator(iter));
++iter;
- for (; iter != x->end(); ++iter) {
+ for (; iter != other.end(); ++iter) {
// If the btree is not empty, we can just insert the new value at the end
// of the tree.
internal_emplace(end(), maybe_move_from_iterator(iter));
@@ -1859,24 +1909,57 @@
}
template <typename P>
-btree<P>::btree(const key_compare &comp, const allocator_type &alloc)
- : root_(comp, alloc, EmptyNode()), rightmost_(EmptyNode()), size_(0) {}
-
-template <typename P>
-btree<P>::btree(const btree &x) : btree(x.key_comp(), x.allocator()) {
- copy_or_move_values_in_order(&x);
+template <typename K>
+auto btree<P>::lower_bound_equal(const K &key) const
+ -> std::pair<iterator, bool> {
+ const SearchResult<iterator, is_key_compare_to::value> res =
+ internal_lower_bound(key);
+ const iterator lower = iterator(internal_end(res.value));
+ const bool equal = res.HasMatch()
+ ? res.IsEq()
+ : lower != end() && !compare_keys(key, lower.key());
+ return {lower, equal};
}
template <typename P>
-template <typename... Args>
-auto btree<P>::insert_unique(const key_type &key, Args &&... args)
+template <typename K>
+auto btree<P>::equal_range(const K &key) -> std::pair<iterator, iterator> {
+ const std::pair<iterator, bool> lower_and_equal = lower_bound_equal(key);
+ const iterator lower = lower_and_equal.first;
+ if (!lower_and_equal.second) {
+ return {lower, lower};
+ }
+
+ const iterator next = std::next(lower);
+ if (!params_type::template can_have_multiple_equivalent_keys<K>()) {
+ // The next iterator after lower must point to a key greater than `key`.
+ // Note: if this assert fails, then it may indicate that the comparator does
+ // not meet the equivalence requirements for Compare
+ // (see https://en.cppreference.com/w/cpp/named_req/Compare).
+ assert(next == end() || compare_keys(key, next.key()));
+ return {lower, next};
+ }
+ // Try once more to avoid the call to upper_bound() if there's only one
+ // equivalent key. This should prevent all calls to upper_bound() in cases of
+ // unique-containers with heterogeneous comparators in which all comparison
+ // operators have the same equivalence classes.
+ if (next == end() || compare_keys(key, next.key())) return {lower, next};
+
+ // In this case, we need to call upper_bound() to avoid worst case O(N)
+ // behavior if we were to iterate over equal keys.
+ return {lower, upper_bound(key)};
+}
+
+template <typename P>
+template <typename K, typename... Args>
+auto btree<P>::insert_unique(const K &key, Args &&... args)
-> std::pair<iterator, bool> {
if (empty()) {
mutable_root() = rightmost_ = new_leaf_root_node(1);
}
- auto res = internal_locate(key);
- iterator &iter = res.value;
+ SearchResult<iterator, is_key_compare_to::value> res = internal_locate(key);
+ iterator iter = res.value;
if (res.HasMatch()) {
if (res.IsEq()) {
@@ -1894,14 +1977,13 @@
}
template <typename P>
-template <typename... Args>
-inline auto btree<P>::insert_hint_unique(iterator position, const key_type &key,
+template <typename K, typename... Args>
+inline auto btree<P>::insert_hint_unique(iterator position, const K &key,
Args &&... args)
-> std::pair<iterator, bool> {
if (!empty()) {
if (position == end() || compare_keys(key, position.key())) {
- iterator prev = position;
- if (position == begin() || compare_keys((--prev).key(), key)) {
+ if (position == begin() || compare_keys(std::prev(position).key(), key)) {
// prev.key() < key < position.key()
return {internal_emplace(position, std::forward<Args>(args)...), true};
}
@@ -1920,14 +2002,23 @@
}
template <typename P>
-template <typename InputIterator>
-void btree<P>::insert_iterator_unique(InputIterator b, InputIterator e) {
+template <typename InputIterator, typename>
+void btree<P>::insert_iterator_unique(InputIterator b, InputIterator e, int) {
for (; b != e; ++b) {
insert_hint_unique(end(), params_type::key(*b), *b);
}
}
template <typename P>
+template <typename InputIterator>
+void btree<P>::insert_iterator_unique(InputIterator b, InputIterator e, char) {
+ for (; b != e; ++b) {
+ init_type value(*b);
+ insert_hint_unique(end(), params_type::key(value), std::move(value));
+ }
+}
+
+template <typename P>
template <typename ValueType>
auto btree<P>::insert_multi(const key_type &key, ValueType &&v) -> iterator {
if (empty()) {
@@ -1947,17 +2038,16 @@
if (!empty()) {
const key_type &key = params_type::key(v);
if (position == end() || !compare_keys(position.key(), key)) {
- iterator prev = position;
- if (position == begin() || !compare_keys(key, (--prev).key())) {
+ if (position == begin() ||
+ !compare_keys(key, std::prev(position).key())) {
// prev.key() <= key <= position.key()
return internal_emplace(position, std::forward<ValueType>(v));
}
} else {
- iterator next = position;
- ++next;
- if (next == end() || !compare_keys(next.key(), key)) {
- // position.key() < key <= next.key()
- return internal_emplace(next, std::forward<ValueType>(v));
+ ++position;
+ if (position == end() || !compare_keys(position.key(), key)) {
+ // {original `position`}.key() < key < {current `position`}.key()
+ return internal_emplace(position, std::forward<ValueType>(v));
}
}
}
@@ -1973,46 +2063,47 @@
}
template <typename P>
-auto btree<P>::operator=(const btree &x) -> btree & {
- if (this != &x) {
+auto btree<P>::operator=(const btree &other) -> btree & {
+ if (this != &other) {
clear();
- *mutable_key_comp() = x.key_comp();
+ *mutable_key_comp() = other.key_comp();
if (absl::allocator_traits<
allocator_type>::propagate_on_container_copy_assignment::value) {
- *mutable_allocator() = x.allocator();
+ *mutable_allocator() = other.allocator();
}
- copy_or_move_values_in_order(&x);
+ copy_or_move_values_in_order(other);
}
return *this;
}
template <typename P>
-auto btree<P>::operator=(btree &&x) noexcept -> btree & {
- if (this != &x) {
+auto btree<P>::operator=(btree &&other) noexcept -> btree & {
+ if (this != &other) {
clear();
using std::swap;
if (absl::allocator_traits<
allocator_type>::propagate_on_container_copy_assignment::value) {
// Note: `root_` also contains the allocator and the key comparator.
- swap(root_, x.root_);
- swap(rightmost_, x.rightmost_);
- swap(size_, x.size_);
+ swap(root_, other.root_);
+ swap(rightmost_, other.rightmost_);
+ swap(size_, other.size_);
} else {
- if (allocator() == x.allocator()) {
- swap(mutable_root(), x.mutable_root());
- swap(*mutable_key_comp(), *x.mutable_key_comp());
- swap(rightmost_, x.rightmost_);
- swap(size_, x.size_);
+ if (allocator() == other.allocator()) {
+ swap(mutable_root(), other.mutable_root());
+ swap(*mutable_key_comp(), *other.mutable_key_comp());
+ swap(rightmost_, other.rightmost_);
+ swap(size_, other.size_);
} else {
// We aren't allowed to propagate the allocator and the allocator is
// different so we can't take over its memory. We must move each element
- // individually. We need both `x` and `this` to have `x`s key comparator
- // while moving the values so we can't swap the key comparators.
- *mutable_key_comp() = x.key_comp();
- copy_or_move_values_in_order(&x);
+ // individually. We need both `other` and `this` to have `other`s key
+ // comparator while moving the values so we can't swap the key
+ // comparators.
+ *mutable_key_comp() = other.key_comp();
+ copy_or_move_values_in_order(other);
}
}
}
@@ -2024,20 +2115,19 @@
bool internal_delete = false;
if (!iter.node->leaf()) {
// Deletion of a value on an internal node. First, move the largest value
- // from our left child here, then delete that position (in remove_value()
+ // from our left child here, then delete that position (in remove_values()
// below). We can get to the largest value from our left child by
// decrementing iter.
iterator internal_iter(iter);
--iter;
assert(iter.node->leaf());
- assert(!compare_keys(internal_iter.key(), iter.key()));
params_type::move(mutable_allocator(), iter.node->slot(iter.position),
internal_iter.node->slot(internal_iter.position));
internal_delete = true;
}
// Delete the key from the leaf.
- iter.node->remove_value(iter.position, mutable_allocator());
+ iter.node->remove_values(iter.position, /*to_erase=*/1, mutable_allocator());
--size_;
// We want to return the next value after the one we just erased. If we
@@ -2088,8 +2178,8 @@
// Adjust our return value. If we're pointing at the end of a node, advance
// the iterator.
- if (res.position == res.node->count()) {
- res.position = res.node->count() - 1;
+ if (res.position == res.node->finish()) {
+ res.position = res.node->finish() - 1;
++res;
}
@@ -2097,7 +2187,7 @@
}
template <typename P>
-auto btree<P>::erase(iterator begin, iterator end)
+auto btree<P>::erase_range(iterator begin, iterator end)
-> std::pair<size_type, iterator> {
difference_type count = std::distance(begin, end);
assert(count >= 0);
@@ -2112,7 +2202,9 @@
}
if (begin.node == end.node) {
- erase_same_node(begin, end);
+ assert(end.position > begin.position);
+ begin.node->remove_values(begin.position, end.position - begin.position,
+ mutable_allocator());
size_ -= count;
return {count, rebalance_after_delete(begin)};
}
@@ -2121,9 +2213,12 @@
while (size_ > target_size) {
if (begin.node->leaf()) {
const size_type remaining_to_erase = size_ - target_size;
- const size_type remaining_in_node = begin.node->count() - begin.position;
- begin = erase_from_leaf_node(
- begin, (std::min)(remaining_to_erase, remaining_in_node));
+ const size_type remaining_in_node = begin.node->finish() - begin.position;
+ const size_type to_erase =
+ (std::min)(remaining_to_erase, remaining_in_node);
+ begin.node->remove_values(begin.position, to_erase, mutable_allocator());
+ size_ -= to_erase;
+ begin = rebalance_after_delete(begin);
} else {
begin = erase(begin);
}
@@ -2132,78 +2227,9 @@
}
template <typename P>
-void btree<P>::erase_same_node(iterator begin, iterator end) {
- assert(begin.node == end.node);
- assert(end.position > begin.position);
-
- node_type *node = begin.node;
- size_type to_erase = end.position - begin.position;
- if (!node->leaf()) {
- // Delete all children between begin and end.
- for (size_type i = 0; i < to_erase; ++i) {
- internal_clear(node->child(begin.position + i + 1));
- }
- // Rotate children after end into new positions.
- for (size_type i = begin.position + to_erase + 1; i <= node->count(); ++i) {
- node->set_child(i - to_erase, node->child(i));
- node->clear_child(i);
- }
- }
- node->remove_values_ignore_children(begin.position, to_erase,
- mutable_allocator());
-
- // Do not need to update rightmost_, because
- // * either end == this->end(), and therefore node == rightmost_, and still
- // exists
- // * or end != this->end(), and therefore rightmost_ hasn't been erased, since
- // it wasn't covered in [begin, end)
-}
-
-template <typename P>
-auto btree<P>::erase_from_leaf_node(iterator begin, size_type to_erase)
- -> iterator {
- node_type *node = begin.node;
- assert(node->leaf());
- assert(node->count() > begin.position);
- assert(begin.position + to_erase <= node->count());
-
- node->remove_values_ignore_children(begin.position, to_erase,
- mutable_allocator());
-
- size_ -= to_erase;
-
- return rebalance_after_delete(begin);
-}
-
-template <typename P>
-template <typename K>
-auto btree<P>::erase_unique(const K &key) -> size_type {
- const iterator iter = internal_find(key);
- if (iter.node == nullptr) {
- // The key doesn't exist in the tree, return nothing done.
- return 0;
- }
- erase(iter);
- return 1;
-}
-
-template <typename P>
-template <typename K>
-auto btree<P>::erase_multi(const K &key) -> size_type {
- const iterator begin = internal_lower_bound(key);
- if (begin.node == nullptr) {
- // The key doesn't exist in the tree, return nothing done.
- return 0;
- }
- // Delete all of the keys between begin and upper_bound(key).
- const iterator end = internal_end(internal_upper_bound(key));
- return erase(begin, end).first;
-}
-
-template <typename P>
void btree<P>::clear() {
if (!empty()) {
- internal_clear(root());
+ node_type::clear_and_delete(root(), mutable_allocator());
}
mutable_root() = EmptyNode();
rightmost_ = EmptyNode();
@@ -2211,20 +2237,20 @@
}
template <typename P>
-void btree<P>::swap(btree &x) {
+void btree<P>::swap(btree &other) {
using std::swap;
if (absl::allocator_traits<
allocator_type>::propagate_on_container_swap::value) {
// Note: `root_` also contains the allocator and the key comparator.
- swap(root_, x.root_);
+ swap(root_, other.root_);
} else {
// It's undefined behavior if the allocators are unequal here.
- assert(allocator() == x.allocator());
- swap(mutable_root(), x.mutable_root());
- swap(*mutable_key_comp(), *x.mutable_key_comp());
+ assert(allocator() == other.allocator());
+ swap(mutable_root(), other.mutable_root());
+ swap(*mutable_key_comp(), *other.mutable_key_comp());
}
- swap(rightmost_, x.rightmost_);
- swap(size_, x.size_);
+ swap(rightmost_, other.rightmost_);
+ swap(size_, other.size_);
}
template <typename P>
@@ -2234,7 +2260,7 @@
assert(rightmost_ != nullptr);
assert(empty() || size() == internal_verify(root(), nullptr, nullptr));
assert(leftmost() == (++const_iterator(root(), -1)).node);
- assert(rightmost_ == (--const_iterator(root(), root()->count())).node);
+ assert(rightmost_ == (--const_iterator(root(), root()->finish())).node);
assert(leftmost()->leaf());
assert(rightmost_->leaf());
}
@@ -2249,7 +2275,7 @@
// First try to make room on the node by rebalancing.
node_type *parent = node->parent();
if (node != root()) {
- if (node->position() > 0) {
+ if (node->position() > parent->start()) {
// Try rebalancing with our left sibling.
node_type *left = parent->child(node->position() - 1);
assert(left->max_count() == kNodeValues);
@@ -2258,16 +2284,16 @@
// inserting at the end of the right node then we bias rebalancing to
// fill up the left node.
int to_move = (kNodeValues - left->count()) /
- (1 + (insert_position < kNodeValues));
+ (1 + (insert_position < static_cast<int>(kNodeValues)));
to_move = (std::max)(1, to_move);
- if (((insert_position - to_move) >= 0) ||
- ((left->count() + to_move) < kNodeValues)) {
+ if (insert_position - to_move >= node->start() ||
+ left->count() + to_move < static_cast<int>(kNodeValues)) {
left->rebalance_right_to_left(to_move, node, mutable_allocator());
assert(node->max_count() - node->count() == to_move);
insert_position = insert_position - to_move;
- if (insert_position < 0) {
+ if (insert_position < node->start()) {
insert_position = insert_position + left->count() + 1;
node = left;
}
@@ -2278,7 +2304,7 @@
}
}
- if (node->position() < parent->count()) {
+ if (node->position() < parent->finish()) {
// Try rebalancing with our right sibling.
node_type *right = parent->child(node->position() + 1);
assert(right->max_count() == kNodeValues);
@@ -2286,15 +2312,15 @@
// We bias rebalancing based on the position being inserted. If we're
// inserting at the beginning of the left node then we bias rebalancing
// to fill up the right node.
- int to_move =
- (kNodeValues - right->count()) / (1 + (insert_position > 0));
+ int to_move = (static_cast<int>(kNodeValues) - right->count()) /
+ (1 + (insert_position > node->start()));
to_move = (std::max)(1, to_move);
- if ((insert_position <= (node->count() - to_move)) ||
- ((right->count() + to_move) < kNodeValues)) {
+ if (insert_position <= node->finish() - to_move ||
+ right->count() + to_move < static_cast<int>(kNodeValues)) {
node->rebalance_left_to_right(to_move, right, mutable_allocator());
- if (insert_position > node->count()) {
+ if (insert_position > node->finish()) {
insert_position = insert_position - node->count() - 1;
node = right;
}
@@ -2317,10 +2343,11 @@
// Create a new root node and set the current root node as the child of the
// new root.
parent = new_internal_node(parent);
- parent->init_child(0, root());
+ parent->init_child(parent->start(), root());
mutable_root() = parent;
// If the former root was a leaf node, then it's now the rightmost node.
- assert(!parent->child(0)->leaf() || parent->child(0) == rightmost_);
+ assert(!parent->start_child()->leaf() ||
+ parent->start_child() == rightmost_);
}
// Split the node.
@@ -2334,7 +2361,7 @@
node->split(insert_position, split_node, mutable_allocator());
}
- if (insert_position > node->count()) {
+ if (insert_position > node->finish()) {
insert_position = insert_position - node->count() - 1;
node = split_node;
}
@@ -2343,33 +2370,28 @@
template <typename P>
void btree<P>::merge_nodes(node_type *left, node_type *right) {
left->merge(right, mutable_allocator());
- if (right->leaf()) {
- if (rightmost_ == right) rightmost_ = left;
- delete_leaf_node(right);
- } else {
- delete_internal_node(right);
- }
+ if (rightmost_ == right) rightmost_ = left;
}
template <typename P>
bool btree<P>::try_merge_or_rebalance(iterator *iter) {
node_type *parent = iter->node->parent();
- if (iter->node->position() > 0) {
+ if (iter->node->position() > parent->start()) {
// Try merging with our left sibling.
node_type *left = parent->child(iter->node->position() - 1);
assert(left->max_count() == kNodeValues);
- if ((1 + left->count() + iter->node->count()) <= kNodeValues) {
+ if (1U + left->count() + iter->node->count() <= kNodeValues) {
iter->position += 1 + left->count();
merge_nodes(left, iter->node);
iter->node = left;
return true;
}
}
- if (iter->node->position() < parent->count()) {
+ if (iter->node->position() < parent->finish()) {
// Try merging with our right sibling.
node_type *right = parent->child(iter->node->position() + 1);
assert(right->max_count() == kNodeValues);
- if ((1 + iter->node->count() + right->count()) <= kNodeValues) {
+ if (1U + iter->node->count() + right->count() <= kNodeValues) {
merge_nodes(iter->node, right);
return true;
}
@@ -2377,24 +2399,22 @@
// we deleted the first element from iter->node and the node is not
// empty. This is a small optimization for the common pattern of deleting
// from the front of the tree.
- if ((right->count() > kMinNodeValues) &&
- ((iter->node->count() == 0) ||
- (iter->position > 0))) {
+ if (right->count() > kMinNodeValues &&
+ (iter->node->count() == 0 || iter->position > iter->node->start())) {
int to_move = (right->count() - iter->node->count()) / 2;
to_move = (std::min)(to_move, right->count() - 1);
iter->node->rebalance_right_to_left(to_move, right, mutable_allocator());
return false;
}
}
- if (iter->node->position() > 0) {
+ if (iter->node->position() > parent->start()) {
// Try rebalancing with our left sibling. We don't perform rebalancing if
// we deleted the last element from iter->node and the node is not
// empty. This is a small optimization for the common pattern of deleting
// from the back of the tree.
node_type *left = parent->child(iter->node->position() - 1);
- if ((left->count() > kMinNodeValues) &&
- ((iter->node->count() == 0) ||
- (iter->position < iter->node->count()))) {
+ if (left->count() > kMinNodeValues &&
+ (iter->node->count() == 0 || iter->position < iter->node->finish())) {
int to_move = (left->count() - iter->node->count()) / 2;
to_move = (std::min)(to_move, left->count() - 1);
left->rebalance_left_to_right(to_move, iter->node, mutable_allocator());
@@ -2407,28 +2427,27 @@
template <typename P>
void btree<P>::try_shrink() {
- if (root()->count() > 0) {
+ node_type *orig_root = root();
+ if (orig_root->count() > 0) {
return;
}
// Deleted the last item on the root node, shrink the height of the tree.
- if (root()->leaf()) {
+ if (orig_root->leaf()) {
assert(size() == 0);
- delete_leaf_node(root());
- mutable_root() = EmptyNode();
- rightmost_ = EmptyNode();
+ mutable_root() = rightmost_ = EmptyNode();
} else {
- node_type *child = root()->child(0);
+ node_type *child = orig_root->start_child();
child->make_root();
- delete_internal_node(root());
mutable_root() = child;
}
+ node_type::clear_and_delete(orig_root, mutable_allocator());
}
template <typename P>
template <typename IterType>
inline IterType btree<P>::internal_last(IterType iter) {
assert(iter.node != nullptr);
- while (iter.position == iter.node->count()) {
+ while (iter.position == iter.node->finish()) {
iter.position = iter.node->position();
iter.node = iter.node->parent();
if (iter.node->leaf()) {
@@ -2449,7 +2468,8 @@
--iter;
++iter.position;
}
- const int max_count = iter.node->max_count();
+ const field_type max_count = iter.node->max_count();
+ allocator_type *alloc = mutable_allocator();
if (iter.node->count() == max_count) {
// Make room in the leaf for the new item.
if (max_count < kNodeValues) {
@@ -2458,16 +2478,20 @@
assert(iter.node == root());
iter.node =
new_leaf_root_node((std::min<int>)(kNodeValues, 2 * max_count));
- iter.node->swap(root(), mutable_allocator());
- delete_leaf_node(root());
- mutable_root() = iter.node;
- rightmost_ = iter.node;
+ // Transfer the values from the old root to the new root.
+ node_type *old_root = root();
+ node_type *new_root = iter.node;
+ new_root->transfer_n(old_root->count(), new_root->start(),
+ old_root->start(), old_root, alloc);
+ new_root->set_finish(old_root->finish());
+ old_root->set_finish(old_root->start());
+ node_type::clear_and_delete(old_root, alloc);
+ mutable_root() = rightmost_ = new_root;
} else {
rebalance_or_split(&iter);
}
}
- iter.node->emplace_value(iter.position, mutable_allocator(),
- std::forward<Args>(args)...);
+ iter.node->emplace_value(iter.position, alloc, std::forward<Args>(args)...);
++size_;
return iter;
}
@@ -2476,67 +2500,57 @@
template <typename K>
inline auto btree<P>::internal_locate(const K &key) const
-> SearchResult<iterator, is_key_compare_to::value> {
- return internal_locate_impl(key, is_key_compare_to());
-}
-
-template <typename P>
-template <typename K>
-inline auto btree<P>::internal_locate_impl(
- const K &key, std::false_type /* IsCompareTo */) const
- -> SearchResult<iterator, false> {
- iterator iter(const_cast<node_type *>(root()), 0);
+ iterator iter(const_cast<node_type *>(root()));
for (;;) {
- iter.position = iter.node->lower_bound(key, key_comp()).value;
- // NOTE: we don't need to walk all the way down the tree if the keys are
- // equal, but determining equality would require doing an extra comparison
- // on each node on the way down, and we will need to go all the way to the
- // leaf node in the expected case.
- if (iter.node->leaf()) {
- break;
- }
- iter.node = iter.node->child(iter.position);
- }
- return {iter};
-}
-
-template <typename P>
-template <typename K>
-inline auto btree<P>::internal_locate_impl(
- const K &key, std::true_type /* IsCompareTo */) const
- -> SearchResult<iterator, true> {
- iterator iter(const_cast<node_type *>(root()), 0);
- for (;;) {
- SearchResult<int, true> res = iter.node->lower_bound(key, key_comp());
+ SearchResult<int, is_key_compare_to::value> res =
+ iter.node->lower_bound(key, key_comp());
iter.position = res.value;
- if (res.match == MatchKind::kEq) {
+ if (res.IsEq()) {
return {iter, MatchKind::kEq};
}
+ // Note: in the non-key-compare-to case, we don't need to walk all the way
+ // down the tree if the keys are equal, but determining equality would
+ // require doing an extra comparison on each node on the way down, and we
+ // will need to go all the way to the leaf node in the expected case.
if (iter.node->leaf()) {
break;
}
iter.node = iter.node->child(iter.position);
}
+ // Note: in the non-key-compare-to case, the key may actually be equivalent
+ // here (and the MatchKind::kNe is ignored).
return {iter, MatchKind::kNe};
}
template <typename P>
template <typename K>
-auto btree<P>::internal_lower_bound(const K &key) const -> iterator {
- iterator iter(const_cast<node_type *>(root()), 0);
+auto btree<P>::internal_lower_bound(const K &key) const
+ -> SearchResult<iterator, is_key_compare_to::value> {
+ if (!params_type::template can_have_multiple_equivalent_keys<K>()) {
+ SearchResult<iterator, is_key_compare_to::value> ret = internal_locate(key);
+ ret.value = internal_last(ret.value);
+ return ret;
+ }
+ iterator iter(const_cast<node_type *>(root()));
+ SearchResult<int, is_key_compare_to::value> res;
+ bool seen_eq = false;
for (;;) {
- iter.position = iter.node->lower_bound(key, key_comp()).value;
+ res = iter.node->lower_bound(key, key_comp());
+ iter.position = res.value;
if (iter.node->leaf()) {
break;
}
+ seen_eq = seen_eq || res.IsEq();
iter.node = iter.node->child(iter.position);
}
- return internal_last(iter);
+ if (res.IsEq()) return {iter, MatchKind::kEq};
+ return {internal_last(iter), seen_eq ? MatchKind::kEq : MatchKind::kNe};
}
template <typename P>
template <typename K>
auto btree<P>::internal_upper_bound(const K &key) const -> iterator {
- iterator iter(const_cast<node_type *>(root()), 0);
+ iterator iter(const_cast<node_type *>(root()));
for (;;) {
iter.position = iter.node->upper_bound(key, key_comp());
if (iter.node->leaf()) {
@@ -2550,7 +2564,7 @@
template <typename P>
template <typename K>
auto btree<P>::internal_find(const K &key) const -> iterator {
- auto res = internal_locate(key);
+ SearchResult<iterator, is_key_compare_to::value> res = internal_locate(key);
if (res.HasMatch()) {
if (res.IsEq()) {
return res.value;
@@ -2565,47 +2579,35 @@
}
template <typename P>
-void btree<P>::internal_clear(node_type *node) {
- if (!node->leaf()) {
- for (int i = 0; i <= node->count(); ++i) {
- internal_clear(node->child(i));
- }
- delete_internal_node(node);
- } else {
- delete_leaf_node(node);
- }
-}
-
-template <typename P>
-int btree<P>::internal_verify(
- const node_type *node, const key_type *lo, const key_type *hi) const {
+int btree<P>::internal_verify(const node_type *node, const key_type *lo,
+ const key_type *hi) const {
assert(node->count() > 0);
assert(node->count() <= node->max_count());
if (lo) {
- assert(!compare_keys(node->key(0), *lo));
+ assert(!compare_keys(node->key(node->start()), *lo));
}
if (hi) {
- assert(!compare_keys(*hi, node->key(node->count() - 1)));
+ assert(!compare_keys(*hi, node->key(node->finish() - 1)));
}
- for (int i = 1; i < node->count(); ++i) {
+ for (int i = node->start() + 1; i < node->finish(); ++i) {
assert(!compare_keys(node->key(i), node->key(i - 1)));
}
int count = node->count();
if (!node->leaf()) {
- for (int i = 0; i <= node->count(); ++i) {
+ for (int i = node->start(); i <= node->finish(); ++i) {
assert(node->child(i) != nullptr);
assert(node->child(i)->parent() == node);
assert(node->child(i)->position() == i);
- count += internal_verify(
- node->child(i),
- (i == 0) ? lo : &node->key(i - 1),
- (i == node->count()) ? hi : &node->key(i));
+ count += internal_verify(node->child(i),
+ i == node->start() ? lo : &node->key(i - 1),
+ i == node->finish() ? hi : &node->key(i));
}
}
return count;
}
} // namespace container_internal
+ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_BTREE_H_