Squashed 'third_party/flatbuffers/' content from commit acc9990ab
Change-Id: I48550d40d78fea996ebe74e9723a5d1f910de491
git-subtree-dir: third_party/flatbuffers
git-subtree-split: acc9990abd2206491480291b0f85f925110102ea
diff --git a/rust/flatbuffers/src/push.rs b/rust/flatbuffers/src/push.rs
new file mode 100644
index 0000000..1863058
--- /dev/null
+++ b/rust/flatbuffers/src/push.rs
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2018 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use std::cmp::max;
+use std::mem::{align_of, size_of};
+
+use endian_scalar::emplace_scalar;
+
+/// Trait to abstract over functionality needed to write values (either owned
+/// or referenced). Used in FlatBufferBuilder and implemented for generated
+/// types.
+pub trait Push: Sized {
+ type Output;
+ fn push(&self, dst: &mut [u8], _rest: &[u8]);
+ #[inline]
+ fn size() -> usize {
+ size_of::<Self::Output>()
+ }
+ #[inline]
+ fn alignment() -> PushAlignment {
+ PushAlignment::new(align_of::<Self::Output>())
+ }
+}
+
+/// Ensure Push alignment calculations are typesafe (because this helps reduce
+/// implementation issues when using FlatBufferBuilder::align).
+pub struct PushAlignment(usize);
+impl PushAlignment {
+ #[inline]
+ pub fn new(x: usize) -> Self {
+ PushAlignment { 0: x }
+ }
+ #[inline]
+ pub fn value(&self) -> usize {
+ self.0
+ }
+ #[inline]
+ pub fn max_of(&self, o: usize) -> Self {
+ PushAlignment::new(max(self.0, o))
+ }
+}
+
+/// Macro to implement Push for EndianScalar types.
+macro_rules! impl_push_for_endian_scalar {
+ ($ty:ident) => {
+ impl Push for $ty {
+ type Output = $ty;
+
+ #[inline]
+ fn push(&self, dst: &mut [u8], _rest: &[u8]) {
+ emplace_scalar::<$ty>(dst, *self);
+ }
+ }
+ };
+}
+
+impl_push_for_endian_scalar!(bool);
+impl_push_for_endian_scalar!(u8);
+impl_push_for_endian_scalar!(i8);
+impl_push_for_endian_scalar!(u16);
+impl_push_for_endian_scalar!(i16);
+impl_push_for_endian_scalar!(u32);
+impl_push_for_endian_scalar!(i32);
+impl_push_for_endian_scalar!(u64);
+impl_push_for_endian_scalar!(i64);
+impl_push_for_endian_scalar!(f32);
+impl_push_for_endian_scalar!(f64);