commit b929c4e080b5adc603d632354f51b1d6e56726b2
author Austin Schuh <austin.schuh@bluerivertech.com> Mon Jul 12 15:32:53 2021 -0700
committer Austin Schuh <austin.schuh@bluerivertech.com> Mon Jul 12 15:40:50 2021 -0700
tree 89d6069c1c963c7d76cc84360ff17ed8a046177b
parent 0225c547bffdbf98a61924631222dbfedaef3145

Add a Span constructor to SizePrefixedFlatbufferVector

This lets us copy without duplicating the copy code all over the place.

Change-Id: I17e8746ad1186c833a82167fee06efa4c0ffad42
Signed-off-by: Austin Schuh <austin.schuh@bluerivertech.com>

aos/events/logging/logfile_utils.cc

diff --git a/aos/events/logging/logfile_utils.cc b/aos/events/logging/logfile_utils.cc
index f32b337..5f0e372 100644
--- a/aos/events/logging/logfile_utils.cc
+++ b/aos/events/logging/logfile_utils.cc
@@ -411,10 +411,7 @@
   }
 
   // And copy the config so we have it forever, removing the size prefix.
-  ResizeableBuffer data;
-  data.resize(config_data.size());
-  memcpy(data.data(), config_data.begin(), data.size());
-  SizePrefixedFlatbufferVector<LogFileHeader> result(std::move(data));
+  SizePrefixedFlatbufferVector<LogFileHeader> result(config_data);
   if (!result.Verify()) {
     return std::nullopt;
   }
@@ -435,10 +432,7 @@
   }
 
   // And copy the config so we have it forever, removing the size prefix.
-  ResizeableBuffer data;
-  data.resize(data_span.size());
-  memcpy(data.data(), data_span.begin(), data.size());
-  SizePrefixedFlatbufferVector<MessageHeader> result(std::move(data));
+  SizePrefixedFlatbufferVector<MessageHeader> result(data_span);
   if (!result.Verify()) {
     return std::nullopt;
   }
@@ -480,10 +474,7 @@
     return std::nullopt;
   }
 
-  ResizeableBuffer result_buffer;
-  result_buffer.resize(msg_data.size());
-  memcpy(result_buffer.data(), msg_data.begin(), result_buffer.size());
-  SizePrefixedFlatbufferVector<MessageHeader> result(std::move(result_buffer));
+  SizePrefixedFlatbufferVector<MessageHeader> result(msg_data);
 
   const monotonic_clock::time_point timestamp = monotonic_clock::time_point(
       chrono::nanoseconds(result.message().monotonic_sent_time()));

aos/flatbuffers.h

diff --git a/aos/flatbuffers.h b/aos/flatbuffers.h
index 5bef204..90742c3 100644
--- a/aos/flatbuffers.h
+++ b/aos/flatbuffers.h
@@ -413,9 +413,13 @@
       : data_(std::move(data)) {}
 
   // Builds a Flatbuffer by copying the data from the other flatbuffer.
-  SizePrefixedFlatbufferVector(const SizePrefixedFlatbuffer<T> &other) {
-    data_.resize(other.span().size());
-    memcpy(data_.data(), other.span().data(), data_.size());
+  SizePrefixedFlatbufferVector(const SizePrefixedFlatbuffer<T> &other)
+      : SizePrefixedFlatbufferVector(other.span()) {}
+
+  // Builds a flatbuffer by copying the data from the provided span.
+  SizePrefixedFlatbufferVector(const absl::Span<const uint8_t> span) {
+    data_.resize(span.size());
+    memcpy(data_.data(), span.data(), data_.size());
   }
 
   // Copy constructor.