Remove partial blockfile v3 disk_cache implementation.

net/disk_cache/blockfile/backend_worker_v3.cc

Index: net/disk_cache/blockfile/backend_worker_v3.cc
diff --git a/net/disk_cache/blockfile/backend_worker_v3.cc b/net/disk_cache/blockfile/backend_worker_v3.cc
deleted file mode 100644
index db74fbad3b40dc5be162292bf8850e31e966c3e1..0000000000000000000000000000000000000000
--- a/net/disk_cache/blockfile/backend_worker_v3.cc
+++ /dev/null
@@ -1,471 +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/backend_worker_v3.h"
-
-#include <stdint.h>
-
-#include <limits>
-
-#include "base/bind.h"
-#include "base/bind_helpers.h"
-#include "base/files/file_path.h"
-#include "base/files/file_util.h"
-#include "base/message_loop/message_loop.h"
-#include "base/strings/string_util.h"
-#include "base/strings/stringprintf.h"
-#include "base/time/time.h"
-#include "base/timer/timer.h"
-#include "net/base/net_errors.h"
-#include "net/disk_cache/blockfile/errors.h"
-#include "net/disk_cache/blockfile/experiments.h"
-#include "net/disk_cache/blockfile/file.h"
-
-using base::Time;
-using base::TimeDelta;
-using base::TimeTicks;
-
-namespace {
-
-#if defined(V3_NOT_JUST_YET_READY)
-
-const char kIndexName[] = "index";
-
-// Seems like ~240 MB correspond to less than 50k entries for 99% of the people.
-// Note that the actual target is to keep the index table load factor under 55%
-// for most users.
-const int k64kEntriesStore = 240 * 1000 * 1000;
-const int kBaseTableLen = 64 * 1024;
-const int kDefaultCacheSize = 80 * 1024 * 1024;
-
-// Avoid trimming the cache for the first 5 minutes (10 timer ticks).
-const int kTrimDelay = 10;
-
-int DesiredIndexTableLen(int32_t storage_size) {
-  if (storage_size <= k64kEntriesStore)
-    return kBaseTableLen;
-  if (storage_size <= k64kEntriesStore * 2)
-    return kBaseTableLen * 2;
-  if (storage_size <= k64kEntriesStore * 4)
-    return kBaseTableLen * 4;
-  if (storage_size <= k64kEntriesStore * 8)
-    return kBaseTableLen * 8;
-
-  // The biggest storage_size for int32_t requires a 4 MB table.
-  return kBaseTableLen * 16;
-}
-
-int MaxStorageSizeForTable(int table_len) {
-  return table_len * (k64kEntriesStore / kBaseTableLen);
-}
-
-size_t GetIndexSize(int table_len) {
-  size_t table_size = sizeof(disk_cache::CacheAddr) * table_len;
-  return sizeof(disk_cache::IndexHeader) + table_size;
-}
-
-// ------------------------------------------------------------------------
-
-// Sets group for the current experiment. Returns false if the files should be
-// discarded.
-bool InitExperiment(disk_cache::IndexHeader* header, bool cache_created) {
-  if (header->experiment == disk_cache::EXPERIMENT_OLD_FILE1 ||
-      header->experiment == disk_cache::EXPERIMENT_OLD_FILE2) {
-    // Discard current cache.
-    return false;
-  }
-
-  if (base::FieldTrialList::FindFullName("SimpleCacheTrial") ==
-          "ExperimentControl") {
-    if (cache_created) {
-      header->experiment = disk_cache::EXPERIMENT_SIMPLE_CONTROL;
-      return true;
-    } else if (header->experiment != disk_cache::EXPERIMENT_SIMPLE_CONTROL) {
-      return false;
-    }
-  }
-
-  header->experiment = disk_cache::NO_EXPERIMENT;
-  return true;
-}
-#endif  // defined(V3_NOT_JUST_YET_READY).
-
-}  // namespace
-
-// ------------------------------------------------------------------------
-
-namespace disk_cache {
-
-BackendImplV3::Worker::Worker(
-    const base::FilePath& path,
-    const scoped_refptr<base::SingleThreadTaskRunner>& main_thread)
-    : path_(path), block_files_(path), init_(false) {
-}
-
-#if defined(V3_NOT_JUST_YET_READY)
-
-int BackendImpl::SyncInit() {
-#if defined(NET_BUILD_STRESS_CACHE)
-  // Start evictions right away.
-  up_ticks_ = kTrimDelay * 2;
-#endif
-  DCHECK(!init_);
-  if (init_)
-    return net::ERR_FAILED;
-
-  bool create_files = false;
-  if (!InitBackingStore(&create_files)) {
-    ReportError(ERR_STORAGE_ERROR);
-    return net::ERR_FAILED;
-  }
-
-  num_refs_ = num_pending_io_ = max_refs_ = 0;
-  entry_count_ = byte_count_ = 0;
-
-  if (!restarted_) {
-    buffer_bytes_ = 0;
-    trace_object_ = TraceObject::GetTraceObject();
-    // Create a recurrent timer of 30 secs.
-    int timer_delay = unit_test_ ? 1000 : 30000;
-    timer_.reset(new base::RepeatingTimer());
-    timer_->Start(FROM_HERE, TimeDelta::FromMilliseconds(timer_delay), this,
-                  &BackendImpl::OnStatsTimer);
-  }
-
-  init_ = true;
-  Trace("Init");
-
-  if (data_->header.experiment != NO_EXPERIMENT &&
-      cache_type_ != net::DISK_CACHE) {
-    // No experiment for other caches.
-    return net::ERR_FAILED;
-  }
-
-  if (!(user_flags_ & kNoRandom)) {
-    // The unit test controls directly what to test.
-    new_eviction_ = (cache_type_ == net::DISK_CACHE);
-  }
-
-  if (!CheckIndex()) {
-    ReportError(ERR_INIT_FAILED);
-    return net::ERR_FAILED;
-  }
-
-  if (!restarted_ && (create_files || !data_->header.num_entries))
-    ReportError(ERR_CACHE_CREATED);
-
-  if (!(user_flags_ & kNoRandom) && cache_type_ == net::DISK_CACHE &&
-      !InitExperiment(&data_->header, create_files)) {
-    return net::ERR_FAILED;
-  }
-
-  // We don't care if the value overflows. The only thing we care about is that
-  // the id cannot be zero, because that value is used as "not dirty".
-  // Increasing the value once per second gives us many years before we start
-  // having collisions.
-  data_->header.this_id++;
-  if (!data_->header.this_id)
-    data_->header.this_id++;
-
-  bool previous_crash = (data_->header.crash != 0);
-  data_->header.crash = 1;
-
-  if (!block_files_.Init(create_files))
-    return net::ERR_FAILED;
-
-  // We want to minimize the changes to cache for an AppCache.
-  if (cache_type() == net::APP_CACHE) {
-    DCHECK(!new_eviction_);
-    read_only_ = true;
-  } else if (cache_type() == net::SHADER_CACHE) {
-    DCHECK(!new_eviction_);
-  }
-
-  eviction_.Init(this);
-
-  // stats_ and rankings_ may end up calling back to us so we better be enabled.
-  disabled_ = false;
-  if (!InitStats())
-    return net::ERR_FAILED;
-
-  disabled_ = !rankings_.Init(this, new_eviction_);
-
-#if defined(STRESS_CACHE_EXTENDED_VALIDATION)
-  trace_object_->EnableTracing(false);
-  int sc = SelfCheck();
-  if (sc < 0 && sc != ERR_NUM_ENTRIES_MISMATCH)
-    NOTREACHED();
-  trace_object_->EnableTracing(true);
-#endif
-
-  if (previous_crash) {
-    ReportError(ERR_PREVIOUS_CRASH);
-  } else if (!restarted_) {
-    ReportError(ERR_NO_ERROR);
-  }
-
-  FlushIndex();
-
-  return disabled_ ? net::ERR_FAILED : net::OK;
-}
-
-void BackendImpl::PrepareForRestart() {
-  // Reset the mask_ if it was not given by the user.
-  if (!(user_flags_ & kMask))
-    mask_ = 0;
-
-  if (!(user_flags_ & kNewEviction))
-    new_eviction_ = false;
-
-  disabled_ = true;
-  data_->header.crash = 0;
-  index_->Flush();
-  index_ = NULL;
-  data_ = NULL;
-  block_files_.CloseFiles();
-  rankings_.Reset();
-  init_ = false;
-  restarted_ = true;
-}
-
-BackendImpl::~BackendImpl() {
-  if (user_flags_ & kNoRandom) {
-    // This is a unit test, so we want to be strict about not leaking entries
-    // and completing all the work.
-    background_queue_.WaitForPendingIO();
-  } else {
-    // This is most likely not a test, so we want to do as little work as
-    // possible at this time, at the price of leaving dirty entries behind.
-    background_queue_.DropPendingIO();
-  }
-
-  if (background_queue_.BackgroundIsCurrentThread()) {
-    // Unit tests may use the same thread for everything.
-    CleanupCache();
-  } else {
-    background_queue_.background_thread()->PostTask(
-        FROM_HERE, base::Bind(&FinalCleanupCallback, base::Unretained(this)));
-    // http://crbug.com/74623
-    base::ThreadRestrictions::ScopedAllowWait allow_wait;
-    done_.Wait();
-  }
-}
-
-void BackendImpl::CleanupCache() {
-  Trace("Backend Cleanup");
-  eviction_.Stop();
-  timer_.reset();
-
-  if (init_) {
-    StoreStats();
-    if (data_)
-      data_->header.crash = 0;
-
-    if (user_flags_ & kNoRandom) {
-      // This is a net_unittest, verify that we are not 'leaking' entries.
-      File::WaitForPendingIO(&num_pending_io_);
-      DCHECK(!num_refs_);
-    } else {
-      File::DropPendingIO();
-    }
-  }
-  block_files_.CloseFiles();
-  FlushIndex();
-  index_ = NULL;
-  ptr_factory_.InvalidateWeakPtrs();
-  done_.Signal();
-}
-
-base::FilePath BackendImpl::GetFileName(Addr address) const {
-  if (!address.is_separate_file() || !address.is_initialized()) {
-    NOTREACHED();
-    return base::FilePath();
-  }
-
-  std::string tmp = base::StringPrintf("f_%06x", address.FileNumber());
-  return path_.AppendASCII(tmp);
-}
-
-// We just created a new file so we're going to write the header and set the
-// file length to include the hash table (zero filled).
-bool BackendImpl::CreateBackingStore(disk_cache::File* file) {
-  AdjustMaxCacheSize(0);
-
-  IndexHeader header;
-  header.table_len = DesiredIndexTableLen(max_size_);
-
-  // We need file version 2.1 for the new eviction algorithm.
-  if (new_eviction_)
-    header.version = 0x20001;
-
-  header.create_time = Time::Now().ToInternalValue();
-
-  if (!file->Write(&header, sizeof(header), 0))
-    return false;
-
-  return file->SetLength(GetIndexSize(header.table_len));
-}
-
-bool BackendImpl::InitBackingStore(bool* file_created) {
-  if (!base::CreateDirectory(path_))
-    return false;
-
-  base::FilePath index_name = path_.AppendASCII(kIndexName);
-
-  int flags = base::PLATFORM_FILE_READ |
-              base::PLATFORM_FILE_WRITE |
-              base::PLATFORM_FILE_OPEN_ALWAYS |
-              base::PLATFORM_FILE_EXCLUSIVE_WRITE;
-  scoped_refptr<disk_cache::File> file(new disk_cache::File(
-      base::CreatePlatformFile(index_name, flags, file_created, NULL)));
-
-  if (!file->IsValid())
-    return false;
-
-  bool ret = true;
-  if (*file_created)
-    ret = CreateBackingStore(file.get());
-
-  file = NULL;
-  if (!ret)
-    return false;
-
-  index_ = new MappedFile();
-  data_ = reinterpret_cast<Index*>(index_->Init(index_name, 0));
-  if (!data_) {
-    LOG(ERROR) << "Unable to map Index file";
-    return false;
-  }
-
-  if (index_->GetLength() < sizeof(Index)) {
-    // We verify this again on CheckIndex() but it's easier to make sure now
-    // that the header is there.
-    LOG(ERROR) << "Corrupt Index file";
-    return false;
-  }
-
-  return true;
-}
-
-void BackendImpl::ReportError(int error) {
-  STRESS_DCHECK(!error || error == ERR_PREVIOUS_CRASH ||
-                error == ERR_CACHE_CREATED);
-
-  // We transmit positive numbers, instead of direct error codes.
-  DCHECK_LE(error, 0);
-  CACHE_UMA(CACHE_ERROR, "Error", 0, error * -1);
-}
-
-
-bool BackendImpl::CheckIndex() {
-  DCHECK(data_);
-
-  size_t current_size = index_->GetLength();
-  if (current_size < sizeof(Index)) {
-    LOG(ERROR) << "Corrupt Index file";
-    return false;
-  }
-
-  if (new_eviction_) {
-    // We support versions 2.0 and 2.1, upgrading 2.0 to 2.1.
-    if (kIndexMagic != data_->header.magic ||
-        kCurrentVersion >> 16 != data_->header.version >> 16) {
-      LOG(ERROR) << "Invalid file version or magic";
-      return false;
-    }
-    if (kCurrentVersion == data_->header.version) {
-      // We need file version 2.1 for the new eviction algorithm.
-      UpgradeTo2_1();
-    }
-  } else {
-    if (kIndexMagic != data_->header.magic ||
-        kCurrentVersion != data_->header.version) {
-      LOG(ERROR) << "Invalid file version or magic";
-      return false;
-    }
-  }
-
-  if (!data_->header.table_len) {
-    LOG(ERROR) << "Invalid table size";
-    return false;
-  }
-
-  if (current_size < GetIndexSize(data_->header.table_len) ||
-      data_->header.table_len & (kBaseTableLen - 1)) {
-    LOG(ERROR) << "Corrupt Index file";
-    return false;
-  }
-
-  AdjustMaxCacheSize(data_->header.table_len);
-
-#if !defined(NET_BUILD_STRESS_CACHE)
-  if (data_->header.num_bytes < 0 ||
-      (max_size_ < std::numeric_limits<int32_t>::max() - kDefaultCacheSize &&
-       data_->header.num_bytes > max_size_ + kDefaultCacheSize)) {
-    LOG(ERROR) << "Invalid cache (current) size";
-    return false;
-  }
-#endif
-
-  if (data_->header.num_entries < 0) {
-    LOG(ERROR) << "Invalid number of entries";
-    return false;
-  }
-
-  if (!mask_)
-    mask_ = data_->header.table_len - 1;
-
-  // Load the table into memory with a single read.
-  std::unique_ptr<char[]> buf(new char[current_size]);
-  return index_->Read(buf.get(), current_size, 0);
-}
-
-bool BackendImpl::InitStats() {
-  Addr address(data_->header.stats);
-  int size = stats_.StorageSize();
-
-  if (!address.is_initialized()) {
-    FileType file_type = Addr::RequiredFileType(size);
-    DCHECK_NE(file_type, EXTERNAL);
-    int num_blocks = Addr::RequiredBlocks(size, file_type);
-
-    if (!CreateBlock(file_type, num_blocks, &address))
-      return false;
-    return stats_.Init(NULL, 0, address);
-  }
-
-  if (!address.is_block_file()) {
-    NOTREACHED();
-    return false;
-  }
-
-  // Load the required data.
-  size = address.num_blocks() * address.BlockSize();
-  MappedFile* file = File(address);
-  if (!file)
-    return false;
-
-  std::unique_ptr<char[]> data(new char[size]);
-  size_t offset = address.start_block() * address.BlockSize() +
-                  kBlockHeaderSize;
-  if (!file->Read(data.get(), size, offset))
-    return false;
-
-  if (!stats_.Init(data.get(), size, address))
-    return false;
-  if (cache_type_ == net::DISK_CACHE && ShouldReportAgain())
-    stats_.InitSizeHistogram();
-  return true;
-}
-
-#endif  // defined(V3_NOT_JUST_YET_READY).
-
-int BackendImplV3::Worker::Init(const CompletionCallback& callback) {
-  return net::ERR_FAILED;
-}
-
-BackendImplV3::Worker::~Worker() {
-}
-
-}  // namespace disk_cache