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Unified Diff: net/disk_cache/blockfile/block_files.cc

Issue 992733002: Remove //net (except for Android test stuff) and sdch (Closed) Base URL: git@github.com:domokit/mojo.git@master
Patch Set: Created 5 years, 9 months ago
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Index: net/disk_cache/blockfile/block_files.cc
diff --git a/net/disk_cache/blockfile/block_files.cc b/net/disk_cache/blockfile/block_files.cc
deleted file mode 100644
index f46a937534993b78cbadd7326750cc48d25c4227..0000000000000000000000000000000000000000
--- a/net/disk_cache/blockfile/block_files.cc
+++ /dev/null
@@ -1,731 +0,0 @@
-// Copyright (c) 2012 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/blockfile/block_files.h"
-
-#include "base/atomicops.h"
-#include "base/files/file_path.h"
-#include "base/metrics/histogram.h"
-#include "base/strings/string_util.h"
-#include "base/strings/stringprintf.h"
-#include "base/threading/thread_checker.h"
-#include "base/time/time.h"
-#include "net/disk_cache/blockfile/file_lock.h"
-#include "net/disk_cache/blockfile/stress_support.h"
-#include "net/disk_cache/blockfile/trace.h"
-#include "net/disk_cache/cache_util.h"
-
-using base::TimeTicks;
-
-namespace {
-
-const char kBlockName[] = "data_";
-
-// This array is used to perform a fast lookup of the nibble bit pattern to the
-// type of entry that can be stored there (number of consecutive blocks).
-const char s_types[16] = {4, 3, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0};
-
-// Returns the type of block (number of consecutive blocks that can be stored)
-// for a given nibble of the bitmap.
-inline int GetMapBlockType(uint32 value) {
- value &= 0xf;
- return s_types[value];
-}
-
-} // namespace
-
-namespace disk_cache {
-
-BlockHeader::BlockHeader() : header_(NULL) {
-}
-
-BlockHeader::BlockHeader(BlockFileHeader* header) : header_(header) {
-}
-
-BlockHeader::BlockHeader(MappedFile* file)
- : header_(reinterpret_cast<BlockFileHeader*>(file->buffer())) {
-}
-
-BlockHeader::BlockHeader(const BlockHeader& other) : header_(other.header_) {
-}
-
-BlockHeader::~BlockHeader() {
-}
-
-bool BlockHeader::CreateMapBlock(int size, int* index) {
- DCHECK(size > 0 && size <= kMaxNumBlocks);
- int target = 0;
- for (int i = size; i <= kMaxNumBlocks; i++) {
- if (header_->empty[i - 1]) {
- target = i;
- break;
- }
- }
-
- if (!target) {
- STRESS_NOTREACHED();
- return false;
- }
-
- TimeTicks start = TimeTicks::Now();
- // We are going to process the map on 32-block chunks (32 bits), and on every
- // chunk, iterate through the 8 nibbles where the new block can be located.
- int current = header_->hints[target - 1];
- for (int i = 0; i < header_->max_entries / 32; i++, current++) {
- if (current == header_->max_entries / 32)
- current = 0;
- uint32 map_block = header_->allocation_map[current];
-
- for (int j = 0; j < 8; j++, map_block >>= 4) {
- if (GetMapBlockType(map_block) != target)
- continue;
-
- disk_cache::FileLock lock(header_);
- int index_offset = j * 4 + 4 - target;
- *index = current * 32 + index_offset;
- STRESS_DCHECK(*index / 4 == (*index + size - 1) / 4);
- uint32 to_add = ((1 << size) - 1) << index_offset;
- header_->num_entries++;
-
- // Note that there is no race in the normal sense here, but if we enforce
- // the order of memory accesses between num_entries and allocation_map, we
- // can assert that even if we crash here, num_entries will never be less
- // than the actual number of used blocks.
- base::subtle::MemoryBarrier();
- header_->allocation_map[current] |= to_add;
-
- header_->hints[target - 1] = current;
- header_->empty[target - 1]--;
- STRESS_DCHECK(header_->empty[target - 1] >= 0);
- if (target != size) {
- header_->empty[target - size - 1]++;
- }
- LOCAL_HISTOGRAM_TIMES("DiskCache.CreateBlock", TimeTicks::Now() - start);
- return true;
- }
- }
-
- // It is possible to have an undetected corruption (for example when the OS
- // crashes), fix it here.
- LOG(ERROR) << "Failing CreateMapBlock";
- FixAllocationCounters();
- return false;
-}
-
-void BlockHeader::DeleteMapBlock(int index, int size) {
- if (size < 0 || size > kMaxNumBlocks) {
- NOTREACHED();
- return;
- }
- TimeTicks start = TimeTicks::Now();
- int byte_index = index / 8;
- uint8* byte_map = reinterpret_cast<uint8*>(header_->allocation_map);
- uint8 map_block = byte_map[byte_index];
-
- if (index % 8 >= 4)
- map_block >>= 4;
-
- // See what type of block will be available after we delete this one.
- int bits_at_end = 4 - size - index % 4;
- uint8 end_mask = (0xf << (4 - bits_at_end)) & 0xf;
- bool update_counters = (map_block & end_mask) == 0;
- uint8 new_value = map_block & ~(((1 << size) - 1) << (index % 4));
- int new_type = GetMapBlockType(new_value);
-
- disk_cache::FileLock lock(header_);
- STRESS_DCHECK((((1 << size) - 1) << (index % 8)) < 0x100);
- uint8 to_clear = ((1 << size) - 1) << (index % 8);
- STRESS_DCHECK((byte_map[byte_index] & to_clear) == to_clear);
- byte_map[byte_index] &= ~to_clear;
-
- if (update_counters) {
- if (bits_at_end)
- header_->empty[bits_at_end - 1]--;
- header_->empty[new_type - 1]++;
- STRESS_DCHECK(header_->empty[bits_at_end - 1] >= 0);
- }
- base::subtle::MemoryBarrier();
- header_->num_entries--;
- STRESS_DCHECK(header_->num_entries >= 0);
- LOCAL_HISTOGRAM_TIMES("DiskCache.DeleteBlock", TimeTicks::Now() - start);
-}
-
-// Note that this is a simplified version of DeleteMapBlock().
-bool BlockHeader::UsedMapBlock(int index, int size) {
- if (size < 0 || size > kMaxNumBlocks)
- return false;
-
- int byte_index = index / 8;
- uint8* byte_map = reinterpret_cast<uint8*>(header_->allocation_map);
- uint8 map_block = byte_map[byte_index];
-
- if (index % 8 >= 4)
- map_block >>= 4;
-
- STRESS_DCHECK((((1 << size) - 1) << (index % 8)) < 0x100);
- uint8 to_clear = ((1 << size) - 1) << (index % 8);
- return ((byte_map[byte_index] & to_clear) == to_clear);
-}
-
-void BlockHeader::FixAllocationCounters() {
- for (int i = 0; i < kMaxNumBlocks; i++) {
- header_->hints[i] = 0;
- header_->empty[i] = 0;
- }
-
- for (int i = 0; i < header_->max_entries / 32; i++) {
- uint32 map_block = header_->allocation_map[i];
-
- for (int j = 0; j < 8; j++, map_block >>= 4) {
- int type = GetMapBlockType(map_block);
- if (type)
- header_->empty[type -1]++;
- }
- }
-}
-
-bool BlockHeader::NeedToGrowBlockFile(int block_count) const {
- bool have_space = false;
- int empty_blocks = 0;
- for (int i = 0; i < kMaxNumBlocks; i++) {
- empty_blocks += header_->empty[i] * (i + 1);
- if (i >= block_count - 1 && header_->empty[i])
- have_space = true;
- }
-
- if (header_->next_file && (empty_blocks < kMaxBlocks / 10)) {
- // This file is almost full but we already created another one, don't use
- // this file yet so that it is easier to find empty blocks when we start
- // using this file again.
- return true;
- }
- return !have_space;
-}
-
-bool BlockHeader::CanAllocate(int block_count) const {
- DCHECK_GT(block_count, 0);
- for (int i = block_count - 1; i < kMaxNumBlocks; i++) {
- if (header_->empty[i])
- return true;
- }
-
- return false;
-}
-
-int BlockHeader::EmptyBlocks() const {
- int empty_blocks = 0;
- for (int i = 0; i < kMaxNumBlocks; i++) {
- empty_blocks += header_->empty[i] * (i + 1);
- if (header_->empty[i] < 0)
- return 0;
- }
- return empty_blocks;
-}
-
-int BlockHeader::MinimumAllocations() const {
- return header_->empty[kMaxNumBlocks - 1];
-}
-
-int BlockHeader::Capacity() const {
- return header_->max_entries;
-}
-
-bool BlockHeader::ValidateCounters() const {
- if (header_->max_entries < 0 || header_->max_entries > kMaxBlocks ||
- header_->num_entries < 0)
- return false;
-
- int empty_blocks = EmptyBlocks();
- if (empty_blocks + header_->num_entries > header_->max_entries)
- return false;
-
- return true;
-}
-
-int BlockHeader::FileId() const {
- return header_->this_file;
-}
-
-int BlockHeader::NextFileId() const {
- return header_->next_file;
-}
-
-int BlockHeader::Size() const {
- return static_cast<int>(sizeof(*header_));
-}
-
-BlockFileHeader* BlockHeader::Header() {
- return header_;
-}
-
-// ------------------------------------------------------------------------
-
-BlockFiles::BlockFiles(const base::FilePath& path)
- : init_(false), zero_buffer_(NULL), path_(path) {
-}
-
-BlockFiles::~BlockFiles() {
- if (zero_buffer_)
- delete[] zero_buffer_;
- CloseFiles();
-}
-
-bool BlockFiles::Init(bool create_files) {
- DCHECK(!init_);
- if (init_)
- return false;
-
- thread_checker_.reset(new base::ThreadChecker);
-
- block_files_.resize(kFirstAdditionalBlockFile);
- for (int16 i = 0; i < kFirstAdditionalBlockFile; i++) {
- if (create_files)
- if (!CreateBlockFile(i, static_cast<FileType>(i + 1), true))
- return false;
-
- if (!OpenBlockFile(i))
- return false;
-
- // Walk this chain of files removing empty ones.
- if (!RemoveEmptyFile(static_cast<FileType>(i + 1)))
- return false;
- }
-
- init_ = true;
- return true;
-}
-
-MappedFile* BlockFiles::GetFile(Addr address) {
- DCHECK(thread_checker_->CalledOnValidThread());
- DCHECK_GE(block_files_.size(),
- static_cast<size_t>(kFirstAdditionalBlockFile));
- DCHECK(address.is_block_file() || !address.is_initialized());
- if (!address.is_initialized())
- return NULL;
-
- int file_index = address.FileNumber();
- if (static_cast<unsigned int>(file_index) >= block_files_.size() ||
- !block_files_[file_index]) {
- // We need to open the file
- if (!OpenBlockFile(file_index))
- return NULL;
- }
- DCHECK_GE(block_files_.size(), static_cast<unsigned int>(file_index));
- return block_files_[file_index];
-}
-
-bool BlockFiles::CreateBlock(FileType block_type, int block_count,
- Addr* block_address) {
- DCHECK(thread_checker_->CalledOnValidThread());
- DCHECK_NE(block_type, EXTERNAL);
- DCHECK_NE(block_type, BLOCK_FILES);
- DCHECK_NE(block_type, BLOCK_ENTRIES);
- DCHECK_NE(block_type, BLOCK_EVICTED);
- if (block_count < 1 || block_count > kMaxNumBlocks)
- return false;
-
- if (!init_)
- return false;
-
- MappedFile* file = FileForNewBlock(block_type, block_count);
- if (!file)
- return false;
-
- ScopedFlush flush(file);
- BlockHeader file_header(file);
-
- int index;
- if (!file_header.CreateMapBlock(block_count, &index))
- return false;
-
- Addr address(block_type, block_count, file_header.FileId(), index);
- block_address->set_value(address.value());
- Trace("CreateBlock 0x%x", address.value());
- return true;
-}
-
-void BlockFiles::DeleteBlock(Addr address, bool deep) {
- DCHECK(thread_checker_->CalledOnValidThread());
- if (!address.is_initialized() || address.is_separate_file())
- return;
-
- if (!zero_buffer_) {
- zero_buffer_ = new char[Addr::BlockSizeForFileType(BLOCK_4K) * 4];
- memset(zero_buffer_, 0, Addr::BlockSizeForFileType(BLOCK_4K) * 4);
- }
- MappedFile* file = GetFile(address);
- if (!file)
- return;
-
- Trace("DeleteBlock 0x%x", address.value());
-
- size_t size = address.BlockSize() * address.num_blocks();
- size_t offset = address.start_block() * address.BlockSize() +
- kBlockHeaderSize;
- if (deep)
- file->Write(zero_buffer_, size, offset);
-
- BlockHeader file_header(file);
- file_header.DeleteMapBlock(address.start_block(), address.num_blocks());
- file->Flush();
-
- if (!file_header.Header()->num_entries) {
- // This file is now empty. Let's try to delete it.
- FileType type = Addr::RequiredFileType(file_header.Header()->entry_size);
- if (Addr::BlockSizeForFileType(RANKINGS) ==
- file_header.Header()->entry_size) {
- type = RANKINGS;
- }
- RemoveEmptyFile(type); // Ignore failures.
- }
-}
-
-void BlockFiles::CloseFiles() {
- if (init_) {
- DCHECK(thread_checker_->CalledOnValidThread());
- }
- init_ = false;
- for (unsigned int i = 0; i < block_files_.size(); i++) {
- if (block_files_[i]) {
- block_files_[i]->Release();
- block_files_[i] = NULL;
- }
- }
- block_files_.clear();
-}
-
-void BlockFiles::ReportStats() {
- DCHECK(thread_checker_->CalledOnValidThread());
- int used_blocks[kFirstAdditionalBlockFile];
- int load[kFirstAdditionalBlockFile];
- for (int i = 0; i < kFirstAdditionalBlockFile; i++) {
- GetFileStats(i, &used_blocks[i], &load[i]);
- }
- UMA_HISTOGRAM_COUNTS("DiskCache.Blocks_0", used_blocks[0]);
- UMA_HISTOGRAM_COUNTS("DiskCache.Blocks_1", used_blocks[1]);
- UMA_HISTOGRAM_COUNTS("DiskCache.Blocks_2", used_blocks[2]);
- UMA_HISTOGRAM_COUNTS("DiskCache.Blocks_3", used_blocks[3]);
-
- UMA_HISTOGRAM_ENUMERATION("DiskCache.BlockLoad_0", load[0], 101);
- UMA_HISTOGRAM_ENUMERATION("DiskCache.BlockLoad_1", load[1], 101);
- UMA_HISTOGRAM_ENUMERATION("DiskCache.BlockLoad_2", load[2], 101);
- UMA_HISTOGRAM_ENUMERATION("DiskCache.BlockLoad_3", load[3], 101);
-}
-
-bool BlockFiles::IsValid(Addr address) {
-#ifdef NDEBUG
- return true;
-#else
- if (!address.is_initialized() || address.is_separate_file())
- return false;
-
- MappedFile* file = GetFile(address);
- if (!file)
- return false;
-
- BlockHeader header(file);
- bool rv = header.UsedMapBlock(address.start_block(), address.num_blocks());
- DCHECK(rv);
-
- static bool read_contents = false;
- if (read_contents) {
- scoped_ptr<char[]> buffer;
- buffer.reset(new char[Addr::BlockSizeForFileType(BLOCK_4K) * 4]);
- size_t size = address.BlockSize() * address.num_blocks();
- size_t offset = address.start_block() * address.BlockSize() +
- kBlockHeaderSize;
- bool ok = file->Read(buffer.get(), size, offset);
- DCHECK(ok);
- }
-
- return rv;
-#endif
-}
-
-bool BlockFiles::CreateBlockFile(int index, FileType file_type, bool force) {
- base::FilePath name = Name(index);
- int flags = force ? base::File::FLAG_CREATE_ALWAYS : base::File::FLAG_CREATE;
- flags |= base::File::FLAG_WRITE | base::File::FLAG_EXCLUSIVE_WRITE;
-
- scoped_refptr<File> file(new File(base::File(name, flags)));
- if (!file->IsValid())
- return false;
-
- BlockFileHeader header;
- memset(&header, 0, sizeof(header));
- header.magic = kBlockMagic;
- header.version = kBlockVersion2;
- header.entry_size = Addr::BlockSizeForFileType(file_type);
- header.this_file = static_cast<int16>(index);
- DCHECK(index <= kint16max && index >= 0);
-
- return file->Write(&header, sizeof(header), 0);
-}
-
-bool BlockFiles::OpenBlockFile(int index) {
- if (block_files_.size() - 1 < static_cast<unsigned int>(index)) {
- DCHECK(index > 0);
- int to_add = index - static_cast<int>(block_files_.size()) + 1;
- block_files_.resize(block_files_.size() + to_add);
- }
-
- base::FilePath name = Name(index);
- scoped_refptr<MappedFile> file(new MappedFile());
-
- if (!file->Init(name, kBlockHeaderSize)) {
- LOG(ERROR) << "Failed to open " << name.value();
- return false;
- }
-
- size_t file_len = file->GetLength();
- if (file_len < static_cast<size_t>(kBlockHeaderSize)) {
- LOG(ERROR) << "File too small " << name.value();
- return false;
- }
-
- BlockHeader file_header(file.get());
- BlockFileHeader* header = file_header.Header();
- if (kBlockMagic != header->magic || kBlockVersion2 != header->version) {
- LOG(ERROR) << "Invalid file version or magic " << name.value();
- return false;
- }
-
- if (header->updating || !file_header.ValidateCounters()) {
- // Last instance was not properly shutdown, or counters are out of sync.
- if (!FixBlockFileHeader(file.get())) {
- LOG(ERROR) << "Unable to fix block file " << name.value();
- return false;
- }
- }
-
- if (static_cast<int>(file_len) <
- header->max_entries * header->entry_size + kBlockHeaderSize) {
- LOG(ERROR) << "File too small " << name.value();
- return false;
- }
-
- if (index == 0) {
- // Load the links file into memory.
- if (!file->Preload())
- return false;
- }
-
- ScopedFlush flush(file.get());
- DCHECK(!block_files_[index]);
- file.swap(&block_files_[index]);
- return true;
-}
-
-bool BlockFiles::GrowBlockFile(MappedFile* file, BlockFileHeader* header) {
- if (kMaxBlocks == header->max_entries)
- return false;
-
- ScopedFlush flush(file);
- DCHECK(!header->empty[3]);
- int new_size = header->max_entries + 1024;
- if (new_size > kMaxBlocks)
- new_size = kMaxBlocks;
-
- int new_size_bytes = new_size * header->entry_size + sizeof(*header);
-
- if (!file->SetLength(new_size_bytes)) {
- // Most likely we are trying to truncate the file, so the header is wrong.
- if (header->updating < 10 && !FixBlockFileHeader(file)) {
- // If we can't fix the file increase the lock guard so we'll pick it on
- // the next start and replace it.
- header->updating = 100;
- return false;
- }
- return (header->max_entries >= new_size);
- }
-
- FileLock lock(header);
- header->empty[3] = (new_size - header->max_entries) / 4; // 4 blocks entries
- header->max_entries = new_size;
-
- return true;
-}
-
-MappedFile* BlockFiles::FileForNewBlock(FileType block_type, int block_count) {
- static_assert(RANKINGS == 1, "invalid file type");
- MappedFile* file = block_files_[block_type - 1];
- BlockHeader file_header(file);
-
- TimeTicks start = TimeTicks::Now();
- while (file_header.NeedToGrowBlockFile(block_count)) {
- if (kMaxBlocks == file_header.Header()->max_entries) {
- file = NextFile(file);
- if (!file)
- return NULL;
- file_header = BlockHeader(file);
- continue;
- }
-
- if (!GrowBlockFile(file, file_header.Header()))
- return NULL;
- break;
- }
- LOCAL_HISTOGRAM_TIMES("DiskCache.GetFileForNewBlock",
- TimeTicks::Now() - start);
- return file;
-}
-
-MappedFile* BlockFiles::NextFile(MappedFile* file) {
- ScopedFlush flush(file);
- BlockFileHeader* header = reinterpret_cast<BlockFileHeader*>(file->buffer());
- int16 new_file = header->next_file;
- if (!new_file) {
- // RANKINGS is not reported as a type for small entries, but we may be
- // extending the rankings block file.
- FileType type = Addr::RequiredFileType(header->entry_size);
- if (header->entry_size == Addr::BlockSizeForFileType(RANKINGS))
- type = RANKINGS;
-
- new_file = CreateNextBlockFile(type);
- if (!new_file)
- return NULL;
-
- FileLock lock(header);
- header->next_file = new_file;
- }
-
- // Only the block_file argument is relevant for what we want.
- Addr address(BLOCK_256, 1, new_file, 0);
- return GetFile(address);
-}
-
-int16 BlockFiles::CreateNextBlockFile(FileType block_type) {
- for (int16 i = kFirstAdditionalBlockFile; i <= kMaxBlockFile; i++) {
- if (CreateBlockFile(i, block_type, false))
- return i;
- }
- return 0;
-}
-
-// We walk the list of files for this particular block type, deleting the ones
-// that are empty.
-bool BlockFiles::RemoveEmptyFile(FileType block_type) {
- MappedFile* file = block_files_[block_type - 1];
- BlockFileHeader* header = reinterpret_cast<BlockFileHeader*>(file->buffer());
-
- while (header->next_file) {
- // Only the block_file argument is relevant for what we want.
- Addr address(BLOCK_256, 1, header->next_file, 0);
- MappedFile* next_file = GetFile(address);
- if (!next_file)
- return false;
-
- BlockFileHeader* next_header =
- reinterpret_cast<BlockFileHeader*>(next_file->buffer());
- if (!next_header->num_entries) {
- DCHECK_EQ(next_header->entry_size, header->entry_size);
- // Delete next_file and remove it from the chain.
- int file_index = header->next_file;
- header->next_file = next_header->next_file;
- DCHECK(block_files_.size() >= static_cast<unsigned int>(file_index));
- file->Flush();
-
- // We get a new handle to the file and release the old one so that the
- // file gets unmmaped... so we can delete it.
- base::FilePath name = Name(file_index);
- scoped_refptr<File> this_file(new File(false));
- this_file->Init(name);
- block_files_[file_index]->Release();
- block_files_[file_index] = NULL;
-
- int failure = DeleteCacheFile(name) ? 0 : 1;
- UMA_HISTOGRAM_COUNTS("DiskCache.DeleteFailed2", failure);
- if (failure)
- LOG(ERROR) << "Failed to delete " << name.value() << " from the cache.";
- continue;
- }
-
- header = next_header;
- file = next_file;
- }
- return true;
-}
-
-// Note that we expect to be called outside of a FileLock... however, we cannot
-// DCHECK on header->updating because we may be fixing a crash.
-bool BlockFiles::FixBlockFileHeader(MappedFile* file) {
- ScopedFlush flush(file);
- BlockHeader file_header(file);
- int file_size = static_cast<int>(file->GetLength());
- if (file_size < file_header.Size())
- return false; // file_size > 2GB is also an error.
-
- const int kMinHeaderBlockSize = 36;
- const int kMaxHeaderBlockSize = 4096;
- BlockFileHeader* header = file_header.Header();
- if (header->entry_size < kMinHeaderBlockSize ||
- header->entry_size > kMaxHeaderBlockSize || header->num_entries < 0)
- return false;
-
- // Make sure that we survive crashes.
- header->updating = 1;
- int expected = header->entry_size * header->max_entries + file_header.Size();
- if (file_size != expected) {
- int max_expected = header->entry_size * kMaxBlocks + file_header.Size();
- if (file_size < expected || header->empty[3] || file_size > max_expected) {
- NOTREACHED();
- LOG(ERROR) << "Unexpected file size";
- return false;
- }
- // We were in the middle of growing the file.
- int num_entries = (file_size - file_header.Size()) / header->entry_size;
- header->max_entries = num_entries;
- }
-
- file_header.FixAllocationCounters();
- int empty_blocks = file_header.EmptyBlocks();
- if (empty_blocks + header->num_entries > header->max_entries)
- header->num_entries = header->max_entries - empty_blocks;
-
- if (!file_header.ValidateCounters())
- return false;
-
- header->updating = 0;
- return true;
-}
-
-// We are interested in the total number of blocks used by this file type, and
-// the max number of blocks that we can store (reported as the percentage of
-// used blocks). In order to find out the number of used blocks, we have to
-// substract the empty blocks from the total blocks for each file in the chain.
-void BlockFiles::GetFileStats(int index, int* used_count, int* load) {
- int max_blocks = 0;
- *used_count = 0;
- *load = 0;
- for (;;) {
- if (!block_files_[index] && !OpenBlockFile(index))
- return;
-
- BlockFileHeader* header =
- reinterpret_cast<BlockFileHeader*>(block_files_[index]->buffer());
-
- max_blocks += header->max_entries;
- int used = header->max_entries;
- for (int i = 0; i < kMaxNumBlocks; i++) {
- used -= header->empty[i] * (i + 1);
- DCHECK_GE(used, 0);
- }
- *used_count += used;
-
- if (!header->next_file)
- break;
- index = header->next_file;
- }
- if (max_blocks)
- *load = *used_count * 100 / max_blocks;
-}
-
-base::FilePath BlockFiles::Name(int index) {
- // The file format allows for 256 files.
- DCHECK(index < 256 && index >= 0);
- std::string tmp = base::StringPrintf("%s%d", kBlockName, index);
- return path_.AppendASCII(tmp);
-}
-
-} // namespace disk_cache
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