Initial implementation of ServiceWorkerCache.

net/base/io_buffer.h

 // Copyright (c) 2012 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.
 
 #ifndef NET_BASE_IO_BUFFER_H_
 #define NET_BASE_IO_BUFFER_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 105 matching lines @@
   explicit StringIOBuffer(const std::string& s);
 
   int size() const { return static_cast<int>(string_data_.size()); }
 
  private:
   virtual ~StringIOBuffer();
 
   std::string string_data_;
 };
 
+// This versions allows a string to be used as the storage for a write-style
+// operation, avoiding an extra data copy.
+class NET_EXPORT ZeroCopyStringIOBuffer : public IOBuffer {
+ public:
+  ZeroCopyStringIOBuffer();
+
+  std::string* string() { return &string_; }
+
+  // Signals that we are done writing to the string and we can use it for a
+  // write-style IO operation.
+  void Done();
+
+ private:
+  virtual ~ZeroCopyStringIOBuffer();
+
+  std::string string_;
+};
+
 // This version wraps an existing IOBuffer and provides convenient functions
 // to progressively read all the data.
 //
 // DrainableIOBuffer is useful when you have an IOBuffer that contains data
 // to be written progressively, and Write() function takes an IOBuffer rather
 // than char*. DrainableIOBuffer can be used as follows:
 //
 // // payload is the IOBuffer containing the data to be written.
 // buf = new DrainableIOBuffer(payload, payload_size);
 //
@@ skipping 99 matching lines @@
  public:
   explicit WrappedIOBuffer(const char* data);
 
  protected:
   virtual ~WrappedIOBuffer();
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_IO_BUFFER_H_