PDF: Use a vector instead of a list in DocumentLoader.

pdf/document_loader.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "pdf/document_loader.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/logging.h"
@@ skipping 431 matching lines @@
 
     if (length) {
       if (document_size_ > 0) {
         chunk_stream_.WriteData(current_pos_, start, length);
       } else {
         // If we did not get content-length in the response, we can't
         // preallocate buffer for the entire document. Resizing array causing
         // memory fragmentation issues on the large files and OOM exceptions.
         // To fix this, we collect all chunks of the file to the list and
         // concatenate them together after request is complete.
-        chunk_buffer_.push_back(std::vector<unsigned char>());
-        chunk_buffer_.back().resize(length);
-        memcpy(&(chunk_buffer_.back()[0]), start, length);
+        std::vector<unsigned char> buf(length);
+        memcpy(buf.data(), start, length);
+        chunk_buffer_.push_back(std::move(buf));
       }
       current_pos_ += length;
       current_chunk_read_ += length;
       client_->OnNewDataAvailable();
     }
 
     // Only call the renderer if we allow partial loading.
     if (!partial_document_) {
       ReadMore();
       return;
@@ skipping 39 matching lines @@
 
 void DocumentLoader::ReadComplete() {
   if (!partial_document_) {
     if (document_size_ == 0) {
       // For the document with no 'content-length" specified we've collected all
       // the chunks already. Let's allocate final document buffer and copy them
       // over.
       chunk_stream_.Preallocate(current_pos_);
       uint32_t pos = 0;
       for (auto& chunk : chunk_buffer_) {
-        chunk_stream_.WriteData(pos, &(chunk[0]), chunk.size());
+        chunk_stream_.WriteData(pos, chunk.data(), chunk.size());
         pos += chunk.size();
       }
       chunk_buffer_.clear();
     }
     document_size_ = current_pos_;
     client_->OnDocumentComplete();
     return;
   }
 
   request_pending_ = false;
 
   if (IsDocumentComplete()) {
     client_->OnDocumentComplete();
     return;
   }
 
   UpdateRendering();
   DownloadPendingRequests();
 }
 
 void DocumentLoader::UpdateRendering() {
   if (header_request_)
     client_->OnPartialDocumentLoaded();
   else
     client_->OnPendingRequestComplete();
   header_request_ = false;
 }
 
 }  // namespace chrome_pdf