components/metrics/metrics_hashes.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/metrics/metrics_hashes.h"
   6
   7 #include "base/logging.h"
   8 #include "base/md5.h"
   9 #include "base/sys_byteorder.h"
  10
  11 namespace metrics {
  12
  13 namespace {
  14
  15 // Converts the 8-byte prefix of an MD5 hash into a uint64 value.
  16 inline uint64 DigestToUInt64(const base::MD5Digest& digest) {
  17   uint64 value;
  18   DCHECK_GE(arraysize(digest.a), sizeof(value));
  19   memcpy(&value, digest.a, sizeof(value));
  20   return base::HostToNet64(value);
  21 }
  22
  23 }  // namespace
  24
  25 uint64 HashMetricName(const std::string& name) {
  26   base::MD5Digest digest;
  27   base::MD5Sum(name.c_str(), name.size(), &digest);
  28   return DigestToUInt64(digest);
  29 }
  30
  31 }  // namespace metrics