base/crc32.h

/*
 * libjingle
 * Copyright 2012, Google, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef TALK_BASE_CRC32_H_
#define TALK_BASE_CRC32_H_

#include <string>

#include "talk/base/basictypes.h"

namespace talk_base {

// Updates a CRC32 checksum with |len| bytes from |buf|. |initial| holds the
// checksum result from the previous update; for the first call, it should be 0.
uint32 UpdateCrc32(uint32 initial, const void* buf, size_t len);

// Computes a CRC32 checksum using |len| bytes from |buf|.
inline uint32 ComputeCrc32(const void* buf, size_t len) {
  return UpdateCrc32(0, buf, len);
}
inline uint32 ComputeCrc32(const std::string& str) {
  return ComputeCrc32(str.c_str(), str.size());
}

}  // namespace talk_base

#endif  // TALK_BASE_CRC32_H_