1 files changed, 149 insertions, 0 deletions
diff --git a/chrome/common/file_system/webfilewriter_impl.cc b/chrome/common/file_system/webfilewriter_impl.cc
new file mode 100644
index 0000000..0d04741
--- /dev/null
+++ b/chrome/common/file_system/webfilewriter_impl.cc
@@ -0,0 +1,149 @@
+// Copyright (c) 2010 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 "chrome/common/file_system/webfilewriter_impl.h"
+
+#include "chrome/common/child_thread.h"
+#include "chrome/common/file_system/webfilesystem_impl.h"
+#include "third_party/WebKit/WebKit/chromium/public/WebFileError.h"
+#include "third_party/WebKit/WebKit/chromium/public/WebFileWriterClient.h"
+#include "third_party/WebKit/WebKit/chromium/public/WebURL.h"
+#include "webkit/glue/webkit_glue.h"
+
+WebFileWriterImpl::WebFileWriterImpl(
+     const WebKit::WebString& path, WebKit::WebFileWriterClient* client)
+  : path_(webkit_glue::WebStringToFilePath(path)),
+    client_(client),
+    operation_(kOperationNone),
+    cancel_state_(kCancelNotInProgress) {
+}
+
+WebFileWriterImpl::~WebFileWriterImpl() {
+}
+
+void WebFileWriterImpl::truncate(
+      long long length) {
+  DCHECK(kOperationNone == operation_);
+  DCHECK(kCancelNotInProgress == cancel_state_);
+  operation_ = kOperationTruncate;
+  FileSystemDispatcher* dispatcher =
+      ChildThread::current()->file_system_dispatcher();
+  dispatcher->Truncate(path_, length, &request_id_, this);
+}
+
+void WebFileWriterImpl::write(
+      long long position,
+      const WebKit::WebURL& blob_url) {
+  DCHECK(kOperationNone == operation_);
+  DCHECK(kCancelNotInProgress == cancel_state_);
+  operation_ = kOperationWrite;
+  FileSystemDispatcher* dispatcher =
+      ChildThread::current()->file_system_dispatcher();
+  dispatcher->Write(path_, blob_url, position, &request_id_, this);
+}
+
+// When we cancel a write/truncate, we always get back the result of the write
+// before the result of the cancel, no matter what happens.
+// So we'll get back either
+//   success [of the write/truncate, in a DidWrite(XXX, true)/DidSucceed() call]
+//     followed by failure [of the cancel]; or
+//   failure [of the write, either from cancel or other reasons] followed by
+//     the result of the cancel.
+// In the write case, there could also be queued up non-terminal DidWrite calls
+// before any of that comes back, but there will always be a terminal write
+// response [success or failure] after them, followed by the cancel result, so
+// we can ignore non-terminal write responses, take the terminal write success
+// or the first failure as the last write response, then know that the next
+// thing to come back is the cancel response.  We only notify the
+// AsyncFileWriterClient when it's all over.
+void WebFileWriterImpl::cancel() {
+  DCHECK(kOperationWrite == operation_ || kOperationTruncate == operation_);
+  if (kCancelNotInProgress != cancel_state_)
+    return;
+  cancel_state_ = kCancelSent;
+  FileSystemDispatcher* dispatcher =
+      ChildThread::current()->file_system_dispatcher();
+  dispatcher->Cancel(request_id_, this);
+}
+
+void WebFileWriterImpl::FinishCancel() {
+  DCHECK(kCancelReceivedWriteResponse == cancel_state_);
+  DCHECK(kOperationNone != operation_);
+  cancel_state_ = kCancelNotInProgress;
+  operation_ = kOperationNone;
+  client_->didFail(WebKit::WebFileErrorAbort);
+}
+
+void WebFileWriterImpl::DidSucceed() {
+  // Write never gets a DidSucceed call, so this is either a cancel or truncate
+  // response.
+  switch (cancel_state_) {
+    case kCancelNotInProgress:
+      // A truncate succeeded, with no complications.
+      DCHECK(kOperationTruncate == operation_);
+      operation_ = kOperationNone;
+      client_->didTruncate();
+      break;
+    case kCancelSent:
+      DCHECK(kOperationTruncate == operation_);
+      // This is the success call of the truncate, which we'll eat, even though
+      // it succeeded before the cancel got there.  We accepted the cancel call,
+      // so the truncate will eventually return an error.
+      cancel_state_ = kCancelReceivedWriteResponse;
+      break;
+    case kCancelReceivedWriteResponse:
+      // This is the success of the cancel operation.
+      FinishCancel();
+      break;
+    default:
+      NOTREACHED();
+  }
+}
+
+void WebFileWriterImpl::DidFail(base::PlatformFileError error_code) {
+  DCHECK(kOperationNone != operation_);
+  switch (cancel_state_) {
+    case kCancelNotInProgress:
+      // A write or truncate failed.
+      operation_ = kOperationNone;
+      client_->didFail(
+          webkit_glue::PlatformFileErrorToWebFileError(error_code));
+      break;
+    case kCancelSent:
+      // This is the failure of a write or truncate; the next message should be
+      // the result of the cancel.  We don't assume that it'll be a success, as
+      // the write/truncate could have failed for other reasons.
+      cancel_state_ = kCancelReceivedWriteResponse;
+      break;
+    case kCancelReceivedWriteResponse:
+      // The cancel reported failure, meaning that the write or truncate
+      // finished before the cancel got there.  But we suppressed the
+      // write/truncate's response, and will now report that it was cancelled.
+      FinishCancel();
+      break;
+    default:
+      NOTREACHED();
+  }
+}
+
+void WebFileWriterImpl::DidWrite(int64 bytes, bool complete) {
+  DCHECK(kOperationWrite == operation_);
+  switch (cancel_state_) {
+    case kCancelNotInProgress:
+      if (complete)
+        operation_ = kOperationNone;
+      client_->didWrite(bytes, complete);
+      break;
+    case kCancelSent:
+      // This is the success call of the write, which we'll eat, even though
+      // it succeeded before the cancel got there.  We accepted the cancel call,
+      // so the write will eventually return an error.
+      if (complete)
+        cancel_state_ = kCancelReceivedWriteResponse;
+      break;
+    case kCancelReceivedWriteResponse:
+    default:
+      NOTREACHED();
+  }
+}