Move webrtc/{base => rtc_base}

webrtc/base/crc32.cc

-/*
- *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#include "webrtc/base/crc32.h"
-
-#include "webrtc/base/arraysize.h"
-
-namespace rtc {
-
-// This implementation is based on the sample implementation in RFC 1952.
-
-// CRC32 polynomial, in reversed form.
-// See RFC 1952, or http://en.wikipedia.org/wiki/Cyclic_redundancy_check
-static const uint32_t kCrc32Polynomial = 0xEDB88320;
-static uint32_t kCrc32Table[256] = {0};
-
-static void EnsureCrc32TableInited() {
-  if (kCrc32Table[arraysize(kCrc32Table) - 1])
-    return;  // already inited
-  for (uint32_t i = 0; i < arraysize(kCrc32Table); ++i) {
-    uint32_t c = i;
-    for (size_t j = 0; j < 8; ++j) {
-      if (c & 1) {
-        c = kCrc32Polynomial ^ (c >> 1);
-      } else {
-        c >>= 1;
-      }
-    }
-    kCrc32Table[i] = c;
-  }
-}
-
-uint32_t UpdateCrc32(uint32_t start, const void* buf, size_t len) {
-  EnsureCrc32TableInited();
-
-  uint32_t c = start ^ 0xFFFFFFFF;
-  const uint8_t* u = static_cast<const uint8_t*>(buf);
-  for (size_t i = 0; i < len; ++i) {
-    c = kCrc32Table[(c ^ u[i]) & 0xFF] ^ (c >> 8);
-  }
-  return c ^ 0xFFFFFFFF;
-}
-
-}  // namespace rtc
-