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 |