netwerk/base/SimpleBuffer.h
author Wes Kocher <wkocher@mozilla.com>
Fri, 12 May 2017 18:24:42 -0700
changeset 358155 d7711b69b0136381c4da5cd292619d514ffee1ee
parent 356003 6fddc78b430a8da96dba18d24827215b85e7b00c
child 416428 17e1f96d453f869f9bb64cc1d889320ca2b4adba
permissions -rw-r--r--
Backed out changeset 95ff98f1c2e5 (bug 1319111) for talos failures a=backout MozReview-Commit-ID: Gs09moFm5rQ

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef SimpleBuffer_h__
#define SimpleBuffer_h__

/*
  This class is similar to a nsPipe except it does not have any locking, stores
  an unbounded amount of data, can only be used on one thread, and has much
  simpler result code semantics to deal with.
*/

#include "prtypes.h"
#include "mozilla/LinkedList.h"
#include "nsIThreadInternal.h"

namespace mozilla {
namespace net {

class SimpleBufferPage : public LinkedListElement<SimpleBufferPage>
{
public:
  SimpleBufferPage() : mReadOffset(0), mWriteOffset(0) {}
  static const size_t kSimpleBufferPageSize = 32000;

private:
  friend class SimpleBuffer;
  char mBuffer[kSimpleBufferPageSize];
  size_t mReadOffset;
  size_t mWriteOffset;
};

class SimpleBuffer
{
public:
  SimpleBuffer();
  ~SimpleBuffer() {}

  nsresult Write(char *stc, size_t len); // return OK or OUT_OF_MEMORY
  size_t Read(char *dest, size_t maxLen); // return bytes read
  size_t Available();
  void Clear();

private:
  NS_DECL_OWNINGTHREAD

  nsresult mStatus;
  AutoCleanLinkedList<SimpleBufferPage> mBufferList;
  size_t mAvailable;
};

} // namespace net
} // namespace mozilla

#endif