Remove the code to store and load QUIC server configs in the disk cache.

net/http/disk_cache_based_quic_server_info.cc

Index: net/http/disk_cache_based_quic_server_info.cc
diff --git a/net/http/disk_cache_based_quic_server_info.cc b/net/http/disk_cache_based_quic_server_info.cc
deleted file mode 100644
index b149fc95ae211e39a78ef9fa35e31add15508f28..0000000000000000000000000000000000000000
--- a/net/http/disk_cache_based_quic_server_info.cc
+++ /dev/null
@@ -1,450 +0,0 @@
-// Copyright 2014 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/http/disk_cache_based_quic_server_info.h"
-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "base/callback_helpers.h"
-#include "base/logging.h"
-#include "base/metrics/histogram_macros.h"
-#include "base/stl_util.h"
-#include "base/trace_event/memory_usage_estimator.h"
-#include "net/base/completion_callback.h"
-#include "net/base/io_buffer.h"
-#include "net/base/net_errors.h"
-#include "net/http/http_cache.h"
-#include "net/http/http_network_session.h"
-#include "net/quic/core/quic_server_id.h"
-
-namespace net {
-
-// Some APIs inside disk_cache take a handle that the caller must keep alive
-// until the API has finished its asynchronous execution.
-//
-// Unfortunately, DiskCacheBasedQuicServerInfo may be deleted before the
-// operation completes causing a use-after-free.
-//
-// This data shim struct is meant to provide a location for the disk_cache
-// APIs to write into even if the originating DiskCacheBasedQuicServerInfo
-// object has been deleted.  The lifetime for instances of this struct
-// should be bound to the CompletionCallback that is passed to the disk_cache
-// API.  We do this by binding an instance of this struct to an unused
-// parameter for OnIOComplete() using base::Owned().
-//
-// This is a hack. A better fix is to make it so that the disk_cache APIs
-// take a Callback to a mutator for setting the output value rather than
-// writing into a raw handle. Then the caller can just pass in a Callback
-// bound to WeakPtr for itself. This callback would correctly "no-op" itself
-// when the DiskCacheBasedQuicServerInfo object is deleted.
-//
-// TODO(ajwong): Change disk_cache's API to return results via Callback.
-struct DiskCacheBasedQuicServerInfo::CacheOperationDataShim {
-  CacheOperationDataShim() : backend(NULL), entry(NULL) {}
-
-  disk_cache::Backend* backend;
-  disk_cache::Entry* entry;
-};
-
-DiskCacheBasedQuicServerInfo::DiskCacheBasedQuicServerInfo(
-    const QuicServerId& server_id,
-    HttpCache* http_cache)
-    : QuicServerInfo(server_id),
-      data_shim_(new CacheOperationDataShim()),
-      state_(GET_BACKEND),
-      ready_(false),
-      found_entry_(false),
-      server_id_(server_id),
-      http_cache_(http_cache),
-      backend_(NULL),
-      entry_(NULL),
-      last_failure_(NO_FAILURE),
-      weak_factory_(this) {
-      io_callback_ =
-          base::Bind(&DiskCacheBasedQuicServerInfo::OnIOComplete,
-                     weak_factory_.GetWeakPtr(),
-                     base::Owned(data_shim_));  // Ownership assigned.
-}
-
-DiskCacheBasedQuicServerInfo::~DiskCacheBasedQuicServerInfo() {
-  DCHECK(wait_for_ready_callback_.is_null());
-  if (entry_)
-    entry_->Close();
-}
-
-void DiskCacheBasedQuicServerInfo::Start() {
-  DCHECK(CalledOnValidThread());
-  DCHECK_EQ(GET_BACKEND, state_);
-  DCHECK_EQ(last_failure_, NO_FAILURE);
-  RecordQuicServerInfoStatus(QUIC_SERVER_INFO_START);
-  load_start_time_ = base::TimeTicks::Now();
-  DoLoop(OK);
-}
-
-int DiskCacheBasedQuicServerInfo::WaitForDataReady(
-    const CompletionCallback& callback) {
-  DCHECK(CalledOnValidThread());
-  DCHECK_NE(GET_BACKEND, state_);
-  wait_for_data_start_time_ = base::TimeTicks::Now();
-
-  RecordQuicServerInfoStatus(QUIC_SERVER_INFO_WAIT_FOR_DATA_READY);
-  if (ready_) {
-    wait_for_data_end_time_ = base::TimeTicks::Now();
-    RecordLastFailure();
-    return OK;
-  }
-
-  if (!callback.is_null()) {
-    // Prevent a new callback for WaitForDataReady overwriting an existing
-    // pending callback (|wait_for_ready_callback_|).
-    if (!wait_for_ready_callback_.is_null()) {
-      RecordQuicServerInfoFailure(WAIT_FOR_DATA_READY_INVALID_ARGUMENT_FAILURE);
-      return ERR_INVALID_ARGUMENT;
-    }
-    wait_for_ready_callback_ = callback;
-  }
-
-  return ERR_IO_PENDING;
-}
-
-void DiskCacheBasedQuicServerInfo::ResetWaitForDataReadyCallback() {
-  DCHECK(CalledOnValidThread());
-  wait_for_ready_callback_.Reset();
-}
-
-void DiskCacheBasedQuicServerInfo::CancelWaitForDataReadyCallback() {
-  DCHECK(CalledOnValidThread());
-
-  RecordQuicServerInfoStatus(QUIC_SERVER_INFO_WAIT_FOR_DATA_READY_CANCEL);
-  if (!wait_for_ready_callback_.is_null()) {
-    RecordLastFailure();
-    wait_for_ready_callback_.Reset();
-  }
-}
-
-bool DiskCacheBasedQuicServerInfo::IsDataReady() {
-  return ready_;
-}
-
-bool DiskCacheBasedQuicServerInfo::IsReadyToPersist() {
-  // The data can be persisted if it has been loaded from the disk cache
-  // and there are no pending writes.
-  RecordQuicServerInfoStatus(QUIC_SERVER_INFO_READY_TO_PERSIST);
-  if (ready_ && new_data_.empty())
-    return true;
-  RecordQuicServerInfoFailure(READY_TO_PERSIST_FAILURE);
-  return false;
-}
-
-void DiskCacheBasedQuicServerInfo::Persist() {
-  DCHECK(CalledOnValidThread());
-  if (!IsReadyToPersist()) {
-    // Handle updates while a write is pending or if we haven't loaded from disk
-    // cache. Save the data to be written into a temporary buffer and then
-    // persist that data when we are ready to persist.
-    pending_write_data_ = Serialize();
-    return;
-  }
-  PersistInternal();
-}
-
-void DiskCacheBasedQuicServerInfo::PersistInternal() {
-  DCHECK(CalledOnValidThread());
-  DCHECK_NE(GET_BACKEND, state_);
-  DCHECK(new_data_.empty());
-  CHECK(ready_);
-  DCHECK(wait_for_ready_callback_.is_null());
-
-  if (pending_write_data_.empty()) {
-    new_data_ = Serialize();
-  } else {
-    new_data_ = pending_write_data_;
-    base::STLClearObject(&pending_write_data_);
-  }
-
-  RecordQuicServerInfoStatus(QUIC_SERVER_INFO_PERSIST);
-  if (!backend_) {
-    RecordQuicServerInfoFailure(PERSIST_NO_BACKEND_FAILURE);
-    return;
-  }
-
-  state_ = CREATE_OR_OPEN;
-  DoLoop(OK);
-}
-
-void DiskCacheBasedQuicServerInfo::OnExternalCacheHit() {
-  DCHECK(CalledOnValidThread());
-  DCHECK_NE(GET_BACKEND, state_);
-
-  RecordQuicServerInfoStatus(QUIC_SERVER_INFO_EXTERNAL_CACHE_HIT);
-  if (!backend_) {
-    RecordQuicServerInfoFailure(PERSIST_NO_BACKEND_FAILURE);
-    return;
-  }
-
-  backend_->OnExternalCacheHit(key());
-}
-
-size_t DiskCacheBasedQuicServerInfo::EstimateMemoryUsage() const {
-  return base::trace_event::EstimateMemoryUsage(new_data_) +
-         base::trace_event::EstimateMemoryUsage(pending_write_data_) +
-         base::trace_event::EstimateMemoryUsage(server_id_) +
-         (read_buffer_ == nullptr ? 0 : read_buffer_->size()) +
-         (write_buffer_ == nullptr ? 0 : write_buffer_->size()) +
-         base::trace_event::EstimateMemoryUsage(data_);
-}
-
-std::string DiskCacheBasedQuicServerInfo::key() const {
-  return "quicserverinfo:" + server_id_.ToString();
-}
-
-void DiskCacheBasedQuicServerInfo::OnIOComplete(CacheOperationDataShim* unused,
-                                                int rv) {
-  DCHECK_NE(NONE, state_);
-  rv = DoLoop(rv);
-  if (rv == ERR_IO_PENDING)
-    return;
-
-  base::WeakPtr<DiskCacheBasedQuicServerInfo> weak_this =
-      weak_factory_.GetWeakPtr();
-
-  if (!wait_for_ready_callback_.is_null()) {
-    wait_for_data_end_time_ = base::TimeTicks::Now();
-    RecordLastFailure();
-    base::ResetAndReturn(&wait_for_ready_callback_).Run(rv);
-  }
-  // |wait_for_ready_callback_| could delete the object if there is an error.
-  // Check if |weak_this| still exists before accessing it.
-  if (weak_this.get() && ready_ && !pending_write_data_.empty()) {
-    DCHECK_EQ(NONE, state_);
-    PersistInternal();
-  }
-}
-
-int DiskCacheBasedQuicServerInfo::DoLoop(int rv) {
-  do {
-    switch (state_) {
-      case GET_BACKEND:
-        rv = DoGetBackend();
-        break;
-      case GET_BACKEND_COMPLETE:
-        rv = DoGetBackendComplete(rv);
-        break;
-      case OPEN:
-        rv = DoOpen();
-        break;
-      case OPEN_COMPLETE:
-        rv = DoOpenComplete(rv);
-        break;
-      case READ:
-        rv = DoRead();
-        break;
-      case READ_COMPLETE:
-        rv = DoReadComplete(rv);
-        break;
-      case WAIT_FOR_DATA_READY_DONE:
-        rv = DoWaitForDataReadyDone();
-        break;
-      case CREATE_OR_OPEN:
-        rv = DoCreateOrOpen();
-        break;
-      case CREATE_OR_OPEN_COMPLETE:
-        rv = DoCreateOrOpenComplete(rv);
-        break;
-      case WRITE:
-        rv = DoWrite();
-        break;
-      case WRITE_COMPLETE:
-        rv = DoWriteComplete(rv);
-        break;
-      case SET_DONE:
-        rv = DoSetDone();
-        break;
-      default:
-        rv = OK;
-        NOTREACHED();
-    }
-  } while (rv != ERR_IO_PENDING && state_ != NONE);
-
-  return rv;
-}
-
-int DiskCacheBasedQuicServerInfo::DoGetBackendComplete(int rv) {
-  if (rv == OK) {
-    backend_ = data_shim_->backend;
-    state_ = OPEN;
-  } else {
-    RecordQuicServerInfoFailure(GET_BACKEND_FAILURE);
-    state_ = WAIT_FOR_DATA_READY_DONE;
-  }
-  return OK;
-}
-
-int DiskCacheBasedQuicServerInfo::DoOpenComplete(int rv) {
-  if (rv == OK) {
-    entry_ = data_shim_->entry;
-    state_ = READ;
-    found_entry_ = true;
-  } else {
-    RecordQuicServerInfoFailure(OPEN_FAILURE);
-    state_ = WAIT_FOR_DATA_READY_DONE;
-  }
-
-  return OK;
-}
-
-int DiskCacheBasedQuicServerInfo::DoReadComplete(int rv) {
-  if (rv > 0)
-    data_.assign(read_buffer_->data(), rv);
-  else if (rv < 0)
-    RecordQuicServerInfoFailure(READ_FAILURE);
-
-  read_buffer_ = nullptr;
-  state_ = WAIT_FOR_DATA_READY_DONE;
-  return OK;
-}
-
-int DiskCacheBasedQuicServerInfo::DoWriteComplete(int rv) {
-  if (rv < 0)
-    RecordQuicServerInfoFailure(WRITE_FAILURE);
-  write_buffer_ = nullptr;
-  state_ = SET_DONE;
-  return OK;
-}
-
-int DiskCacheBasedQuicServerInfo::DoCreateOrOpenComplete(int rv) {
-  if (rv != OK) {
-    RecordQuicServerInfoFailure(CREATE_OR_OPEN_FAILURE);
-    state_ = SET_DONE;
-  } else {
-    if (!entry_) {
-      entry_ = data_shim_->entry;
-      found_entry_ = true;
-    }
-    DCHECK(entry_);
-    state_ = WRITE;
-  }
-  return OK;
-}
-
-int DiskCacheBasedQuicServerInfo::DoGetBackend() {
-  state_ = GET_BACKEND_COMPLETE;
-  return http_cache_->GetBackend(&data_shim_->backend, io_callback_);
-}
-
-int DiskCacheBasedQuicServerInfo::DoOpen() {
-  state_ = OPEN_COMPLETE;
-  return backend_->OpenEntry(key(), &data_shim_->entry, io_callback_);
-}
-
-int DiskCacheBasedQuicServerInfo::DoRead() {
-  const int32_t size = entry_->GetDataSize(0 /* index */);
-  if (!size) {
-    state_ = WAIT_FOR_DATA_READY_DONE;
-    return OK;
-  }
-
-  read_buffer_ = new IOBufferWithSize(size);
-  state_ = READ_COMPLETE;
-  return entry_->ReadData(
-      0 /* index */, 0 /* offset */, read_buffer_.get(), size, io_callback_);
-}
-
-int DiskCacheBasedQuicServerInfo::DoWrite() {
-  write_buffer_ = new IOBufferWithSize(new_data_.size());
-  memcpy(write_buffer_->data(), new_data_.data(), new_data_.size());
-  state_ = WRITE_COMPLETE;
-
-  return entry_->WriteData(0 /* index */,
-                           0 /* offset */,
-                           write_buffer_.get(),
-                           new_data_.size(),
-                           io_callback_,
-                           true /* truncate */);
-}
-
-int DiskCacheBasedQuicServerInfo::DoCreateOrOpen() {
-  state_ = CREATE_OR_OPEN_COMPLETE;
-  if (entry_)
-    return OK;
-
-  if (found_entry_) {
-    return backend_->OpenEntry(key(), &data_shim_->entry, io_callback_);
-  }
-
-  return backend_->CreateEntry(key(), &data_shim_->entry, io_callback_);
-}
-
-int DiskCacheBasedQuicServerInfo::DoWaitForDataReadyDone() {
-  DCHECK(!ready_);
-  state_ = NONE;
-  ready_ = true;
-  // We close the entry because, if we shutdown before ::Persist is called,
-  // then we might leak a cache reference, which causes a DCHECK on shutdown.
-  if (entry_)
-    entry_->Close();
-  entry_ = NULL;
-
-  RecordQuicServerInfoStatus(QUIC_SERVER_INFO_PARSE);
-  if (!Parse(data_)) {
-    if (data_.empty())
-      RecordQuicServerInfoFailure(PARSE_NO_DATA_FAILURE);
-    else
-      RecordQuicServerInfoFailure(PARSE_FAILURE);
-  }
-
-  UMA_HISTOGRAM_TIMES("Net.QuicServerInfo.DiskCacheLoadTime",
-                      base::TimeTicks::Now() - load_start_time_);
-  return OK;
-}
-
-int DiskCacheBasedQuicServerInfo::DoSetDone() {
-  if (entry_)
-    entry_->Close();
-  entry_ = NULL;
-  base::STLClearObject(&new_data_);
-  state_ = NONE;
-  return OK;
-}
-
-void DiskCacheBasedQuicServerInfo::RecordQuicServerInfoStatus(
-    QuicServerInfoAPICall call) {
-  if (!backend_) {
-    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.APICall.NoBackend", call,
-                              QUIC_SERVER_INFO_NUM_OF_API_CALLS);
-  } else if (backend_->GetCacheType() == MEMORY_CACHE) {
-    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.APICall.MemoryCache", call,
-                              QUIC_SERVER_INFO_NUM_OF_API_CALLS);
-  } else {
-    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.APICall.DiskCache", call,
-                              QUIC_SERVER_INFO_NUM_OF_API_CALLS);
-  }
-}
-
-void DiskCacheBasedQuicServerInfo::RecordLastFailure() {
-  if (last_failure_ != NO_FAILURE) {
-    UMA_HISTOGRAM_ENUMERATION(
-        "Net.QuicDiskCache.FailureReason.WaitForDataReady",
-        last_failure_, NUM_OF_FAILURES);
-  }
-  last_failure_ = NO_FAILURE;
-}
-
-void DiskCacheBasedQuicServerInfo::RecordQuicServerInfoFailure(
-    FailureReason failure) {
-  last_failure_ = failure;
-
-  if (!backend_) {
-    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.FailureReason.NoBackend",
-                              failure, NUM_OF_FAILURES);
-  } else if (backend_->GetCacheType() == MEMORY_CACHE) {
-    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.FailureReason.MemoryCache",
-                              failure, NUM_OF_FAILURES);
-  } else {
-    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.FailureReason.DiskCache",
-                              failure, NUM_OF_FAILURES);
-  }
-}
-
-}  // namespace net