From cc26fef5b2baf8f86cecb60bdc288a9d50d76b6a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niels=20M=C3=B6ller?= <nisse@webrtc.org>
Date: Tue, 19 Feb 2019 15:42:15 +0100
Subject: [PATCH] Use a CopyOnWriteBuffer to back EncodedImage data

Intended to make copy construction and assignment of EncodedImage
cheaper, but otherwise not have any effect on users of the class.

Bug: webrtc:9378, chromium:931692
Change-Id: I22cf8c05f6ef7b7b5cf7ef08fd0dfc5c61211196
Reviewed-on: https://webrtc-review.googlesource.com/c/123442
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26760}
---
 api/video/DEPS             | 5 +++++
 api/video/encoded_image.cc | 3 +--
 api/video/encoded_image.h  | 8 ++++----
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/api/video/DEPS b/api/video/DEPS
index 4bc9a3901b..6cecc23576 100644
--- a/api/video/DEPS
+++ b/api/video/DEPS
@@ -6,6 +6,11 @@ specific_include_rules = {
     "+modules/video_coding/encoded_frame.h",
   ],
 
+  # Used for a private member variable.
+  "encoded_image\.h": [
+    "+rtc_base/copy_on_write_buffer.h",
+  ],
+
   "i010_buffer\.h": [
     "+rtc_base/memory/aligned_malloc.h",
   ],
diff --git a/api/video/encoded_image.cc b/api/video/encoded_image.cc
index f96b9c2783..d1fa046472 100644
--- a/api/video/encoded_image.cc
+++ b/api/video/encoded_image.cc
@@ -42,8 +42,7 @@ EncodedImage& EncodedImage::operator=(const EncodedImage&) = default;
 
 void EncodedImage::Retain() {
   if (buffer_) {
-    encoded_data_ = std::vector<uint8_t>(size_);
-    memcpy(encoded_data_.data(), buffer_, size_);
+    encoded_data_.SetData(buffer_, size_);
     buffer_ = nullptr;
   }
 }
diff --git a/api/video/encoded_image.h b/api/video/encoded_image.h
index 1c91400c89..1d3bd46ef5 100644
--- a/api/video/encoded_image.h
+++ b/api/video/encoded_image.h
@@ -12,7 +12,6 @@
 #define API_VIDEO_ENCODED_IMAGE_H_
 
 #include <stdint.h>
-#include <vector>
 
 #include "absl/types/optional.h"
 #include "api/video/color_space.h"
@@ -23,6 +22,7 @@
 #include "api/video/video_timing.h"
 #include "common_types.h"  // NOLINT(build/include)
 #include "rtc_base/checks.h"
+#include "rtc_base/copy_on_write_buffer.h"
 #include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
@@ -88,13 +88,13 @@ class RTC_EXPORT EncodedImage {
   }
 
   void Allocate(size_t capacity) {
-    encoded_data_.resize(capacity);
+    encoded_data_.SetSize(capacity);
     buffer_ = nullptr;
   }
 
   uint8_t* data() { return buffer_ ? buffer_ : encoded_data_.data(); }
   const uint8_t* data() const {
-    return buffer_ ? buffer_ : encoded_data_.data();
+    return buffer_ ? buffer_ : encoded_data_.cdata();
   }
   // TODO(nisse): At some places, code accepts a const ref EncodedImage, but
   // still writes to it, to clear padding at the end of the encoded data.
@@ -141,7 +141,7 @@ class RTC_EXPORT EncodedImage {
  private:
   // TODO(bugs.webrtc.org/9378): We're transitioning to always owning the
   // encoded data.
-  std::vector<uint8_t> encoded_data_;
+  rtc::CopyOnWriteBuffer encoded_data_;
   size_t size_;      // Size of encoded frame data.
   // Non-null when used with an un-owned buffer.
   uint8_t* buffer_;