Reorganize net/disk_cache into backend specific directories.

net/disk_cache/stats.cc

Index: net/disk_cache/stats.cc
diff --git a/net/disk_cache/stats.cc b/net/disk_cache/stats.cc
deleted file mode 100644
index b05ecc6ec0bc47153cf583a11fc9d78f60aedf30..0000000000000000000000000000000000000000
--- a/net/disk_cache/stats.cc
+++ /dev/null
@@ -1,312 +0,0 @@
-// Copyright (c) 2011 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.
-
-#include "net/disk_cache/stats.h"
-
-#include "base/format_macros.h"
-#include "base/logging.h"
-#include "base/metrics/histogram_samples.h"
-#include "base/strings/string_util.h"
-#include "base/strings/stringprintf.h"
-
-namespace {
-
-const int32 kDiskSignature = 0xF01427E0;
-
-struct OnDiskStats {
-  int32 signature;
-  int size;
-  int data_sizes[disk_cache::Stats::kDataSizesLength];
-  int64 counters[disk_cache::Stats::MAX_COUNTER];
-};
-COMPILE_ASSERT(sizeof(OnDiskStats) < 512, needs_more_than_2_blocks);
-
-// Returns the "floor" (as opposed to "ceiling") of log base 2 of number.
-int LogBase2(int32 number) {
-  unsigned int value = static_cast<unsigned int>(number);
-  const unsigned int mask[] = {0x2, 0xC, 0xF0, 0xFF00, 0xFFFF0000};
-  const unsigned int s[] = {1, 2, 4, 8, 16};
-
-  unsigned int result = 0;
-  for (int i = 4; i >= 0; i--) {
-    if (value & mask[i]) {
-      value >>= s[i];
-      result |= s[i];
-    }
-  }
-  return static_cast<int>(result);
-}
-
-// WARNING: Add new stats only at the end, or change LoadStats().
-static const char* kCounterNames[] = {
-  "Open miss",
-  "Open hit",
-  "Create miss",
-  "Create hit",
-  "Resurrect hit",
-  "Create error",
-  "Trim entry",
-  "Doom entry",
-  "Doom cache",
-  "Invalid entry",
-  "Open entries",
-  "Max entries",
-  "Timer",
-  "Read data",
-  "Write data",
-  "Open rankings",
-  "Get rankings",
-  "Fatal error",
-  "Last report",
-  "Last report timer",
-  "Doom recent entries",
-  "unused"
-};
-COMPILE_ASSERT(arraysize(kCounterNames) == disk_cache::Stats::MAX_COUNTER,
-               update_the_names);
-
-}  // namespace
-
-namespace disk_cache {
-
-bool VerifyStats(OnDiskStats* stats) {
-  if (stats->signature != kDiskSignature)
-    return false;
-
-  // We don't want to discard the whole cache every time we have one extra
-  // counter; we keep old data if we can.
-  if (static_cast<unsigned int>(stats->size) > sizeof(*stats)) {
-    memset(stats, 0, sizeof(*stats));
-    stats->signature = kDiskSignature;
-  } else if (static_cast<unsigned int>(stats->size) != sizeof(*stats)) {
-    size_t delta = sizeof(*stats) - static_cast<unsigned int>(stats->size);
-    memset(reinterpret_cast<char*>(stats) + stats->size, 0, delta);
-    stats->size = sizeof(*stats);
-  }
-
-  return true;
-}
-
-Stats::Stats() : size_histogram_(NULL) {
-}
-
-Stats::~Stats() {
-  if (size_histogram_) {
-    size_histogram_->Disable();
-  }
-}
-
-bool Stats::Init(void* data, int num_bytes, Addr address) {
-  OnDiskStats local_stats;
-  OnDiskStats* stats = &local_stats;
-  if (!num_bytes) {
-    memset(stats, 0, sizeof(local_stats));
-    local_stats.signature = kDiskSignature;
-    local_stats.size = sizeof(local_stats);
-  } else if (num_bytes >= static_cast<int>(sizeof(*stats))) {
-    stats = reinterpret_cast<OnDiskStats*>(data);
-    if (!VerifyStats(stats))
-      return false;
-  } else {
-    return false;
-  }
-
-  storage_addr_ = address;
-
-  memcpy(data_sizes_, stats->data_sizes, sizeof(data_sizes_));
-  memcpy(counters_, stats->counters, sizeof(counters_));
-
-  // Clean up old value.
-  SetCounter(UNUSED, 0);
-  return true;
-}
-
-void Stats::InitSizeHistogram() {
-  // It seems impossible to support this histogram for more than one
-  // simultaneous objects with the current infrastructure.
-  static bool first_time = true;
-  if (first_time) {
-    first_time = false;
-    if (!size_histogram_) {
-      // Stats may be reused when the cache is re-created, but we want only one
-      // histogram at any given time.
-      size_histogram_ = StatsHistogram::FactoryGet("DiskCache.SizeStats", this);
-    }
-  }
-}
-
-int Stats::StorageSize() {
-  // If we have more than 512 bytes of counters, change kDiskSignature so we
-  // don't overwrite something else (LoadStats must fail).
-  COMPILE_ASSERT(sizeof(OnDiskStats) <= 256 * 2, use_more_blocks);
-  return 256 * 2;
-}
-
-void Stats::ModifyStorageStats(int32 old_size, int32 new_size) {
-  // We keep a counter of the data block size on an array where each entry is
-  // the adjusted log base 2 of the size. The first entry counts blocks of 256
-  // bytes, the second blocks up to 512 bytes, etc. With 20 entries, the last
-  // one stores entries of more than 64 MB
-  int new_index = GetStatsBucket(new_size);
-  int old_index = GetStatsBucket(old_size);
-
-  if (new_size)
-    data_sizes_[new_index]++;
-
-  if (old_size)
-    data_sizes_[old_index]--;
-}
-
-void Stats::OnEvent(Counters an_event) {
-  DCHECK(an_event >= MIN_COUNTER && an_event < MAX_COUNTER);
-  counters_[an_event]++;
-}
-
-void Stats::SetCounter(Counters counter, int64 value) {
-  DCHECK(counter >= MIN_COUNTER && counter < MAX_COUNTER);
-  counters_[counter] = value;
-}
-
-int64 Stats::GetCounter(Counters counter) const {
-  DCHECK(counter >= MIN_COUNTER && counter < MAX_COUNTER);
-  return counters_[counter];
-}
-
-void Stats::GetItems(StatsItems* items) {
-  std::pair<std::string, std::string> item;
-  for (int i = 0; i < kDataSizesLength; i++) {
-    item.first = base::StringPrintf("Size%02d", i);
-    item.second = base::StringPrintf("0x%08x", data_sizes_[i]);
-    items->push_back(item);
-  }
-
-  for (int i = MIN_COUNTER; i < MAX_COUNTER; i++) {
-    item.first = kCounterNames[i];
-    item.second = base::StringPrintf("0x%" PRIx64, counters_[i]);
-    items->push_back(item);
-  }
-}
-
-int Stats::GetHitRatio() const {
-  return GetRatio(OPEN_HIT, OPEN_MISS);
-}
-
-int Stats::GetResurrectRatio() const {
-  return GetRatio(RESURRECT_HIT, CREATE_HIT);
-}
-
-void Stats::ResetRatios() {
-  SetCounter(OPEN_HIT, 0);
-  SetCounter(OPEN_MISS, 0);
-  SetCounter(RESURRECT_HIT, 0);
-  SetCounter(CREATE_HIT, 0);
-}
-
-int Stats::GetLargeEntriesSize() {
-  int total = 0;
-  // data_sizes_[20] stores values between 512 KB and 1 MB (see comment before
-  // GetStatsBucket()).
-  for (int bucket = 20; bucket < kDataSizesLength; bucket++)
-    total += data_sizes_[bucket] * GetBucketRange(bucket);
-
-  return total;
-}
-
-int Stats::SerializeStats(void* data, int num_bytes, Addr* address) {
-  OnDiskStats* stats = reinterpret_cast<OnDiskStats*>(data);
-  if (num_bytes < static_cast<int>(sizeof(*stats)))
-    return 0;
-
-  stats->signature = kDiskSignature;
-  stats->size = sizeof(*stats);
-  memcpy(stats->data_sizes, data_sizes_, sizeof(data_sizes_));
-  memcpy(stats->counters, counters_, sizeof(counters_));
-
-  *address = storage_addr_;
-  return sizeof(*stats);
-}
-
-int Stats::GetBucketRange(size_t i) const {
-  if (i < 2)
-    return static_cast<int>(1024 * i);
-
-  if (i < 12)
-    return static_cast<int>(2048 * (i - 1));
-
-  if (i < 17)
-    return static_cast<int>(4096 * (i - 11)) + 20 * 1024;
-
-  int n = 64 * 1024;
-  if (i > static_cast<size_t>(kDataSizesLength)) {
-    NOTREACHED();
-    i = kDataSizesLength;
-  }
-
-  i -= 17;
-  n <<= i;
-  return n;
-}
-
-void Stats::Snapshot(base::HistogramSamples* samples) const {
-  for (int i = 0; i < kDataSizesLength; i++) {
-    int count = data_sizes_[i];
-    if (count < 0)
-      count = 0;
-    samples->Accumulate(GetBucketRange(i), count);
-  }
-}
-
-// The array will be filled this way:
-//  index      size
-//    0       [0, 1024)
-//    1    [1024, 2048)
-//    2    [2048, 4096)
-//    3      [4K, 6K)
-//      ...
-//   10     [18K, 20K)
-//   11     [20K, 24K)
-//   12     [24k, 28K)
-//      ...
-//   15     [36k, 40K)
-//   16     [40k, 64K)
-//   17     [64K, 128K)
-//   18    [128K, 256K)
-//      ...
-//   23      [4M, 8M)
-//   24      [8M, 16M)
-//   25     [16M, 32M)
-//   26     [32M, 64M)
-//   27     [64M, ...)
-int Stats::GetStatsBucket(int32 size) {
-  if (size < 1024)
-    return 0;
-
-  // 10 slots more, until 20K.
-  if (size < 20 * 1024)
-    return size / 2048 + 1;
-
-  // 5 slots more, from 20K to 40K.
-  if (size < 40 * 1024)
-    return (size - 20 * 1024) / 4096 + 11;
-
-  // From this point on, use a logarithmic scale.
-  int result =  LogBase2(size) + 1;
-
-  COMPILE_ASSERT(kDataSizesLength > 16, update_the_scale);
-  if (result >= kDataSizesLength)
-    result = kDataSizesLength - 1;
-
-  return result;
-}
-
-int Stats::GetRatio(Counters hit, Counters miss) const {
-  int64 ratio = GetCounter(hit) * 100;
-  if (!ratio)
-    return 0;
-
-  ratio /= (GetCounter(hit) + GetCounter(miss));
-  return static_cast<int>(ratio);
-}
-
-}  // namespace disk_cache