Quota: Implement QuotaBackendImpl

webkit/browser/fileapi/quota/quota_backend_impl.cc

Index: webkit/browser/fileapi/quota/quota_backend_impl.cc
diff --git a/webkit/browser/fileapi/quota/quota_backend_impl.cc b/webkit/browser/fileapi/quota/quota_backend_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..defdb341641c3b9f1f1928ff6a33420c44b5668c
--- /dev/null
+++ b/webkit/browser/fileapi/quota/quota_backend_impl.cc
@@ -0,0 +1,190 @@
+// 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 "webkit/browser/fileapi/quota/quota_backend_impl.h"
+
+#include <string>
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/sequenced_task_runner.h"
+#include "webkit/browser/fileapi/file_system_usage_cache.h"
+#include "webkit/browser/quota/quota_client.h"
+#include "webkit/browser/quota/quota_manager.h"
+#include "webkit/common/fileapi/file_system_util.h"
+
+namespace fileapi {
+
+QuotaBackendImpl::QuotaBackendImpl(
+    base::SequencedTaskRunner* file_task_runner,
+    ObfuscatedFileUtil* obfuscated_file_util,
+    FileSystemUsageCache* file_system_usage_cache,
+    quota::QuotaManagerProxy* quota_manager_proxy)
+    : file_task_runner_(file_task_runner),
+      obfuscated_file_util_(obfuscated_file_util),
+      file_system_usage_cache_(file_system_usage_cache),
+      quota_manager_proxy_(quota_manager_proxy),
+      weak_ptr_factory_(this) {
+}
+
+QuotaBackendImpl::~QuotaBackendImpl() {
+}
+
+void QuotaBackendImpl::ReserveQuota(const GURL& origin,
+                                    FileSystemType type,
+                                    int64 delta,
+                                    const ReserveQuotaCallback& callback) {
+  DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  if (!delta) {
+    callback.Run(base::PLATFORM_FILE_OK);
+    return;
+  }
+  DCHECK(quota_manager_proxy_);
+  quota_manager_proxy_->GetUsageAndQuota(
+      file_task_runner_, origin, FileSystemTypeToQuotaStorageType(type),
+      base::Bind(&QuotaBackendImpl::DidGetUsageAndQuotaForReserveQuota,
+                 weak_ptr_factory_.GetWeakPtr(),
+                 QuotaReservationInfo(origin, type, delta), callback));
+}
+
+void QuotaBackendImpl::ReleaseReservedQuota(const GURL& origin,
+                                            FileSystemType type,
+                                            int64 size) {
+  DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK_LE(0, size);
+  if (!size)
+    return;
+  ReserveQuotaInternal(QuotaReservationInfo(origin, type, -size));
+}
+
+void QuotaBackendImpl::CommitQuotaUsage(const GURL& origin,
+                                        FileSystemType type,
+                                        int64 delta,
+                                        const StatusCallback& callback) {
+  DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  if (!delta) {
+    callback.Run(base::PLATFORM_FILE_OK);
+    return;
+  }
+  DCHECK(quota_manager_proxy_);
+  quota_manager_proxy_->GetUsageAndQuota(
+      file_task_runner_, origin, FileSystemTypeToQuotaStorageType(type),
+      base::Bind(&QuotaBackendImpl::DidGetUsageAndQuotaForCommitQuotaUsage,
+                 weak_ptr_factory_.GetWeakPtr(),
+                 QuotaReservationInfo(origin, type, delta), callback));
+}
+
+void QuotaBackendImpl::IncrementDirtyCount(const GURL& origin,
+                                           FileSystemType type) {
+  DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  base::FilePath path;
+  if (GetUsageCachePath(origin, type, &path) != base::PLATFORM_FILE_OK)
+    return;
+  DCHECK(file_system_usage_cache_);
+  file_system_usage_cache_->IncrementDirty(path);
+}
+
+void QuotaBackendImpl::DecrementDirtyCount(const GURL& origin,
+                                           FileSystemType type) {
+  DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  base::FilePath path;
+  if (GetUsageCachePath(origin, type, &path) != base::PLATFORM_FILE_OK)
+    return;
+  DCHECK(file_system_usage_cache_);
+  file_system_usage_cache_->DecrementDirty(path);
+}
+
+void QuotaBackendImpl::DidGetUsageAndQuotaForReserveQuota(
+    const QuotaReservationInfo& info,
+    const ReserveQuotaCallback& callback,
+    quota::QuotaStatusCode status, int64 usage, int64 quota) {
+  DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  if (status != quota::kQuotaStatusOk) {
+    callback.Run(base::PLATFORM_FILE_ERROR_FAILED);
+    return;
+  }
+
+  if (quota < usage + info.delta) {
+    callback.Run(base::PLATFORM_FILE_ERROR_NO_SPACE);
+    return;
+  }
+
+  ReserveQuotaInternal(info);
+  if (callback.Run(base::PLATFORM_FILE_OK))
+    return;
+  // The requester could not accept the reserved quota. Revert it.
+  ReserveQuotaInternal(
+      QuotaReservationInfo(info.origin, info.type, -info.delta));
+}
+
+void QuotaBackendImpl::DidGetUsageAndQuotaForCommitQuotaUsage(
+    const QuotaReservationInfo& info,
+    const StatusCallback& callback,
+    quota::QuotaStatusCode status, int64 usage, int64 quota) {
+  DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  if (status != quota::kQuotaStatusOk) {
+    callback.Run(base::PLATFORM_FILE_ERROR_FAILED);
+    return;
+  }
+
+  if (quota < usage + info.delta) {
+    callback.Run(base::PLATFORM_FILE_ERROR_NO_SPACE);

[kinuko, 2013/11/07 10:10:09]

I don't think querying first and returning here really makes sense, since at
this point we've already written data into the disk?

[nhiroki, 2013/11/08 00:12:05]

Removed the querying part.

+    return;
+  }
+
+  ReserveQuotaInternal(info);
+  base::PlatformFileError error = CommitQuotaUsageInternal(info);
+  if (error != base::PLATFORM_FILE_OK) {
+    // Failed to update usage. Revert it.
+    ReserveQuotaInternal(
+        QuotaReservationInfo(info.origin, info.type, -info.delta));
+  }
+  callback.Run(error);
+}
+
+void QuotaBackendImpl::ReserveQuotaInternal(const QuotaReservationInfo& info) {
+  DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK(quota_manager_proxy_);
+  quota_manager_proxy_->NotifyStorageModified(
+      quota::QuotaClient::kFileSystem, info.origin,
+      FileSystemTypeToQuotaStorageType(info.type), info.delta);
+}
+
+base::PlatformFileError QuotaBackendImpl::CommitQuotaUsageInternal(
+    const QuotaReservationInfo& info) {
+  DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  base::FilePath path;
+  base::PlatformFileError error =
+      GetUsageCachePath(info.origin, info.type, &path);
+  if (error != base::PLATFORM_FILE_OK)
+    return error;
+  bool result =
+      file_system_usage_cache_->AtomicUpdateUsageByDelta(path, info.delta);
+  return result ? base::PLATFORM_FILE_OK
+                : base::PLATFORM_FILE_ERROR_FAILED;

[kinuko, 2013/11/07 10:10:09]

The quota reservation code doesn't seem to handle failure case for
CommitQuotaUsage. I need to look into what other code is doing when
AtomicUpdateUsage fails (it shouldn't usually fail, I guess) but maybe we should
increment dirty count to force recalculation in the next time??  (tzik@, WDYT?)

[tzik, 2013/11/07 11:45:15]

Ah right, it ignores the result. CommitQuotaUsage shouldn't take a callback.

For errors on updating usage cache, I think it fails only on unrecoverable
disaster, so it's OK to ignore. :p

[nhiroki, 2013/11/08 00:12:05]

Okay, removed them. That looks simpler :)

+}
+
+base::PlatformFileError QuotaBackendImpl::GetUsageCachePath(
+    const GURL& origin,
+    FileSystemType type,
+    base::FilePath* usage_file_path) {
+  DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK(usage_file_path);
+  base::PlatformFileError error = base::PLATFORM_FILE_OK;
+  *usage_file_path =
+      SandboxFileSystemBackendDelegate::GetUsageCachePathForOriginAndType(
+          obfuscated_file_util_, origin, type, &error);
+  return error;
+}
+
+QuotaBackendImpl::QuotaReservationInfo::QuotaReservationInfo(
+    const GURL& origin, FileSystemType type, int64 delta)
+    : origin(origin), type(type), delta(delta) {
+}
+
+QuotaBackendImpl::QuotaReservationInfo::~QuotaReservationInfo() {
+}
+
+}  // namespace fileapi