localStorage: Aggressively flush to disk for Android WebView.

content/browser/dom_storage/dom_storage_area.cc

 // Copyright 2013 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 "content/browser/dom_storage/dom_storage_area.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 24 matching lines @@
 // of other values being set, so changes are batched.
 const int kCommitDefaultDelaySecs = 5;
 
 // To avoid excessive IO we apply limits to the amount of data being written
 // and the frequency of writes. The specific values used are somewhat arbitrary.
 const int kMaxBytesPerDay = kPerStorageAreaQuota * 2;
 const int kMaxCommitsPerHour = 6;
 
 }  // namespace
 
+bool DOMStorageArea::s_aggressive_flushing_enabled_ = false;
+
 DOMStorageArea::RateLimiter::RateLimiter(size_t desired_rate,
                                          base::TimeDelta time_quantum)
     : rate_(desired_rate), samples_(0), time_quantum_(time_quantum) {
   DCHECK_GT(desired_rate, 0ul);
 }
 
 base::TimeDelta DOMStorageArea::RateLimiter::ComputeTimeNeeded() const {
   return time_quantum_ * (samples_ / rate_);
 }
 
@@ skipping 28 matching lines @@
 }
 
 // static
 GURL DOMStorageArea::OriginFromDatabaseFileName(const base::FilePath& name) {
   DCHECK(name.MatchesExtension(kDatabaseFileExtension));
   std::string origin_id =
       name.BaseName().RemoveExtension().MaybeAsASCII();
   return storage::GetOriginFromIdentifier(origin_id);
 }
 
+void DOMStorageArea::EnableAggressiveCommitDelay() {
+  s_aggressive_flushing_enabled_ = true;
+}
+
 DOMStorageArea::DOMStorageArea(const GURL& origin,
                                const base::FilePath& directory,
                                DOMStorageTaskRunner* task_runner)
     : namespace_id_(kLocalStorageNamespaceId),
       origin_(origin),
       directory_(directory),
       task_runner_(task_runner),
       map_(new DOMStorageMap(kPerStorageAreaQuota +
                              kPerStorageAreaOverQuotaAllowance)),
       is_initial_import_done_(true),
@@ skipping 278 matching lines @@
   // started after the commits have happened.
   if (commit_batches_in_flight_)
     return;
 
   task_runner_->PostDelayedTask(
       FROM_HERE, base::Bind(&DOMStorageArea::OnCommitTimer, this),
       ComputeCommitDelay());
 }
 
 base::TimeDelta DOMStorageArea::ComputeCommitDelay() const {
+  if (s_aggressive_flushing_enabled_)
+    return base::TimeDelta::FromSeconds(1);
+
   base::TimeDelta elapsed_time = base::TimeTicks::Now() - start_time_;
   base::TimeDelta delay = std::max(
       base::TimeDelta::FromSeconds(kCommitDefaultDelaySecs),
       std::max(commit_rate_limiter_.ComputeDelayNeeded(elapsed_time),
                data_rate_limiter_.ComputeDelayNeeded(elapsed_time)));
   UMA_HISTOGRAM_LONG_TIMES("LocalStorage.CommitDelay", delay);
   return delay;
 }
 
 void DOMStorageArea::OnCommitTimer() {
@@ skipping 65 matching lines @@
         commit_batch_->clear_all_first,
         commit_batch_->changed_values);
     DCHECK(success);
   }
   commit_batch_.reset();
   backing_.reset();
   session_storage_backing_ = NULL;
 }
 
 }  // namespace content