Pepper quota support

webkit/plugins/ppapi/quota_file_io.cc

+// Copyright (c) 2011 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/plugins/ppapi/quota_file_io.h"
+
+#include "base/stl_util.h"
+#include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
+
+using base::PlatformFile;
+using base::PlatformFileError;
+using quota::StorageType;
+
+namespace webkit {
+namespace ppapi {
+
+namespace {
+StorageType PPFileSystemTypeToQuotaStorageType(PP_FileSystemType type) {
+  switch (type) {
+    case PP_FILESYSTEMTYPE_LOCALPERSISTENT:
+      return quota::kStorageTypePersistent;
+    case PP_FILESYSTEMTYPE_LOCALTEMPORARY:
+      return quota::kStorageTypeTemporary;
+    default:
+      return quota::kStorageTypeUnknown;
+  }
+  NOTREACHED();
+}
+}  // namespace
+
+class QuotaFileIO::PendingOperationBase {
+ public:
+  virtual ~PendingOperationBase() {}
+
+  // Either one of Run() or DidFail() is called (the latter is called when
+  // there was more than one error during quota queries).
+  virtual void Run() = 0;
+  virtual void DidFail(PlatformFileError error) = 0;
+
+ protected:
+  PendingOperationBase(QuotaFileIO* quota_io, bool is_will_operation)
+      : quota_io_(quota_io), is_will_operation_(is_will_operation) {
+    DCHECK(quota_io_);
+    quota_io_->WillUpdate();
+  }
+
+  QuotaFileIO* quota_io_;
+  const bool is_will_operation_;
+};
+
+class QuotaFileIO::WriteOperation : public PendingOperationBase {
+ public:
+  WriteOperation(QuotaFileIO* quota_io,
+                 bool is_will_operation,
+                 int64_t offset,
+                 const char* buffer,
+                 int32_t bytes_to_write,
+                 WriteCallback* callback)
+      : PendingOperationBase(quota_io, is_will_operation),
+        offset_(offset),
+        bytes_to_write_(bytes_to_write),
+        callback_(callback),
+        finished_(false),
+        status_(base::PLATFORM_FILE_OK),
+        bytes_written_(0),
+        callback_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
+    if (!is_will_operation) {
+      // TODO(kinuko): check the API convention if we really need to keep a
+      // copy of the buffer during the async write operations.
+      buffer_.reset(new char[bytes_to_write]);
+      memcpy(buffer_.get(), buffer, bytes_to_write);
+    }
+  }
+  virtual ~WriteOperation() {}
+  virtual void Run() OVERRIDE {
+    DCHECK(quota_io_);
+    if (quota_io_->CheckIfExceedsQuota(offset_ + bytes_to_write_)) {
+      DidFail(base::PLATFORM_FILE_ERROR_NO_SPACE);
+      return;
+    }
+    if (is_will_operation_) {
+      // Assuming the write will succeed.
+      DidFinish(base::PLATFORM_FILE_OK, bytes_to_write_);
+      return;
+    }
+    DCHECK(buffer_.get());
+    if (!base::FileUtilProxy::Write(
+            quota_io_->instance_->delegate()->GetFileThreadMessageLoopProxy(),
+            quota_io_->file_, offset_, buffer_.get(), bytes_to_write_,
+            callback_factory_.NewCallback(&WriteOperation::DidFinish))) {
+      DidFail(base::PLATFORM_FILE_ERROR_FAILED);
+      return;
+    }
+  }
+
+  virtual void DidFail(PlatformFileError error) OVERRIDE {
+    DidFinish(error, 0);
+  }
+
+  bool finished() const { return finished_; }
+
+  void RunCallback() {
+    DCHECK(callback_.get());
+    callback_->Run(status_, bytes_written_);
+    callback_.reset();
+    delete this;
+  }
+
+ private:
+  void DidFinish(PlatformFileError status, int bytes_written) {
+    finished_ = true;
+    status_ = status;
+    bytes_written_ = bytes_written;
+    int64_t max_offset =
+        (status != base::PLATFORM_FILE_OK) ? 0 : offset_ + bytes_written;
+    // This may delete itself by calling RunCallback.
+    quota_io_->DidWrite(this, max_offset);
+  }
+
+  const int64_t offset_;
+  scoped_array<char> buffer_;
+  const int32_t bytes_to_write_;
+  scoped_ptr<WriteCallback> callback_;
+  bool finished_;
+  PlatformFileError status_;
+  int64_t bytes_written_;
+  base::ScopedCallbackFactory<QuotaFileIO::WriteOperation> callback_factory_;
+};
+
+class QuotaFileIO::SetLengthOperation : public PendingOperationBase {
+ public:
+  SetLengthOperation(QuotaFileIO* quota_io,
+                     bool is_will_operation,
+                     int64_t length,
+                     StatusCallback* callback)
+      : PendingOperationBase(quota_io, is_will_operation),
+        length_(length),
+        callback_(callback),
+        callback_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {}
+  virtual ~SetLengthOperation() {}
+
+  virtual void Run() OVERRIDE {
+    DCHECK(quota_io_);
+    if (quota_io_->CheckIfExceedsQuota(length_)) {
+      DidFail(base::PLATFORM_FILE_ERROR_NO_SPACE);
+      return;
+    }
+    if (is_will_operation_) {
+      DidFinish(base::PLATFORM_FILE_OK);
+      return;
+    }
+    if (!base::FileUtilProxy::Truncate(
+            quota_io_->instance_->delegate()->GetFileThreadMessageLoopProxy(),
+            quota_io_->file_, length_,
+            callback_factory_.NewCallback(&SetLengthOperation::DidFinish))) {
+      DidFail(base::PLATFORM_FILE_ERROR_FAILED);
+      return;
+    }
+  }
+
+  virtual void DidFail(PlatformFileError error) OVERRIDE {
+    DidFinish(error);
+  }
+
+ private:
+  void DidFinish(PlatformFileError status) {
+    quota_io_->DidSetLength(status, length_);
+    DCHECK(callback_.get());
+    callback_->Run(status);
+    callback_.reset();
+    delete this;
+  }
+
+  int64_t length_;
+  scoped_ptr<StatusCallback> callback_;
+  base::ScopedCallbackFactory<QuotaFileIO::SetLengthOperation>
+      callback_factory_;
+};
+
+// QuotaFileIO --------------------------------------------------------------
+
+QuotaFileIO::QuotaFileIO(
+    PluginInstance* instance,
+    PlatformFile file,
+    const GURL& file_url,
+    PP_FileSystemType type)
+    : instance_(instance),
+      file_(file),
+      file_url_(file_url),
+      storage_type_(PPFileSystemTypeToQuotaStorageType(type)),
+      cached_file_size_(0),
+      cached_available_space_(0),
+      outstanding_quota_queries_(0),
+      outstanding_errors_(0),
+      max_written_offset_(0),
+      inflight_operations_(0),
+      callback_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
+  DCHECK(instance_);
+  DCHECK_NE(base::kInvalidPlatformFileValue, file_);
+  DCHECK_NE(quota::kStorageTypeUnknown, storage_type_);
+}
+
+QuotaFileIO::~QuotaFileIO() {
+  // Note that this doesn't dispatch pending callbacks.
+  STLDeleteContainerPointers(pending_operations_.begin(),
+                             pending_operations_.end());
+}
+
+bool QuotaFileIO::Write(
+    int64_t offset, const char* buffer, int32_t bytes_to_write,
+    WriteCallback* callback) {
+  WriteOperation* op = new WriteOperation(
+      this, false, offset, buffer, bytes_to_write, callback);
+  return RegisterOperationForQuotaChecks(op);
+}
+
+bool QuotaFileIO::SetLength(int64_t length, StatusCallback* callback) {
+  DCHECK(pending_operations_.empty());
+  SetLengthOperation* op = new SetLengthOperation(
+      this, false, length, callback);
+  return RegisterOperationForQuotaChecks(op);
+}
+
+bool QuotaFileIO::WillWrite(
+    int64_t offset, int32_t bytes_to_write, WriteCallback* callback) {
+  WriteOperation* op = new WriteOperation(
+      this, true, offset, NULL, bytes_to_write, callback);
+  return RegisterOperationForQuotaChecks(op);
+}
+
+bool QuotaFileIO::WillSetLength(int64_t length, StatusCallback* callback) {
+  DCHECK(pending_operations_.empty());
+  SetLengthOperation* op = new SetLengthOperation(this, true, length, callback);
+  return RegisterOperationForQuotaChecks(op);
+}
+
+bool QuotaFileIO::RegisterOperationForQuotaChecks(
+    PendingOperationBase* op_ptr) {
+  scoped_ptr<PendingOperationBase> op(op_ptr);
+  if (pending_operations_.empty()) {
+    // This is the first pending quota check. Run querying the file size
+    // and available space.
+    outstanding_quota_queries_ = 0;
+    outstanding_errors_ = 0;
+
+    // Query the file size.
+    ++outstanding_quota_queries_;
+    if (!base::FileUtilProxy::GetFileInfoFromPlatformFile(
+            instance_->delegate()->GetFileThreadMessageLoopProxy(), file_,
+            callback_factory_.NewCallback(
+                &QuotaFileIO::DidQueryInfoForQuota))) {
+      // This makes the call fail synchronously; we do not fire the callback
+      // here but just delete the operation and return false.
+      return false;
+    }
+
+    // Query the current available space.
+    ++outstanding_quota_queries_;
+    instance_->delegate()->QueryAvailableSpace(
+        GURL(file_url_.path()).GetOrigin(), storage_type_,
+        callback_factory_.NewCallback(&QuotaFileIO::DidQueryAvailableSpace));
+  }
+  pending_operations_.push_back(op.release());
+  return true;
+}
+
+void QuotaFileIO::DidQueryInfoForQuota(
+    base::PlatformFileError error_code,
+    const base::PlatformFileInfo& file_info) {
+  if (error_code != base::PLATFORM_FILE_OK)
+    ++outstanding_errors_;
+  cached_file_size_ = file_info.size;
+  DCHECK_GT(outstanding_quota_queries_, 0);
+  if (--outstanding_quota_queries_ == 0)
+    DidQueryForQuotaCheck();
+}
+
+void QuotaFileIO::DidQueryAvailableSpace(int64_t avail_space) {
+  cached_available_space_ = avail_space;
+  DCHECK_GT(outstanding_quota_queries_, 0);
+  if (--outstanding_quota_queries_ == 0)
+    DidQueryForQuotaCheck();
+}
+
+void QuotaFileIO::DidQueryForQuotaCheck() {
+  DCHECK(!pending_operations_.empty());
+  DCHECK_GT(inflight_operations_, 0);
+  for (std::deque<PendingOperationBase*>::iterator iter =
+           pending_operations_.begin();
+       iter != pending_operations_.end();
+       ++iter) {
+    PendingOperationBase* op = *iter;
+    if (outstanding_errors_ > 0) {
+      op->DidFail(base::PLATFORM_FILE_ERROR_FAILED);
+      continue;
+    }
+    op->Run();
+  }
+}
+
+bool QuotaFileIO::CheckIfExceedsQuota(int64_t new_file_size) const {
+  DCHECK_GE(cached_file_size_, 0);
+  DCHECK_GE(cached_available_space_, 0);
+  return new_file_size - cached_file_size_ > cached_available_space_;
+}
+
+void QuotaFileIO::WillUpdate() {
+  if (inflight_operations_++ == 0) {
+    instance_->delegate()->WillUpdateFile(file_url_);
+    DCHECK_EQ(0, max_written_offset_);
+  }
+}
+
+void QuotaFileIO::DidWrite(WriteOperation* op,
+                           int64_t written_offset_end) {
+  max_written_offset_ = std::max(max_written_offset_, written_offset_end);
+  DCHECK_GT(inflight_operations_, 0);
+  DCHECK(!pending_operations_.empty());
+  // Fire callbacks for finished operations.
+  while (!pending_operations_.empty()) {
+    WriteOperation* op = static_cast<WriteOperation*>(
+        pending_operations_.front());
+    if (!op->finished())
+      break;
+    op->RunCallback();
+    pending_operations_.pop_front();
+  }
+  // If we have no more pending writes, notify the browser that we did
+  // update the file.
+  if (--inflight_operations_ == 0) {
+    DCHECK(pending_operations_.empty());
+    int64_t growth = max_written_offset_ - cached_file_size_;
+    growth = growth < 0 ? 0 : growth;
+    instance_->delegate()->DidUpdateFile(file_url_, growth);
+    max_written_offset_ = 0;
+  }
+}
+
+void QuotaFileIO::DidSetLength(PlatformFileError error, int64_t new_file_size) {
+  DCHECK_EQ(1, inflight_operations_);
+  pending_operations_.pop_front();
+  DCHECK(pending_operations_.empty());
+  int64_t delta = (error != base::PLATFORM_FILE_OK) ? 0 :
+      new_file_size - cached_file_size_;
+  instance_->delegate()->DidUpdateFile(file_url_, delta);
+  inflight_operations_ = 0;
+}
+
+}  // namespace ppapi
+}  // namespace webkit