1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef MOJO_BINDINGS_JS_DRAIN_DATA_H_
6 #define MOJO_BINDINGS_JS_DRAIN_DATA_H_
8 #include "base/memory/scoped_vector.h"
9 #include "gin/runner.h"
10 #include "mojo/public/c/environment/async_waiter.h"
11 #include "mojo/public/cpp/system/core.h"
12 #include "v8/include/v8.h"
17 // This class is the implementation of the Mojo JavaScript core module's
18 // drainData() method. It is not intended to be used directly. The caller
19 // allocates a DrainData on the heap and returns GetPromise() to JS. The
20 // implementation deletes itself after reading as much data as possible
21 // and rejecting or resolving the Promise.
25 // Starts waiting for data on the specified data pipe consumer handle.
26 // See WaitForData(). The constructor does not block.
27 DrainData(v8::Isolate* isolate, mojo::Handle handle);
29 // Returns a Promise that will be settled when no more data can be read.
30 // Should be called just once on a newly allocated DrainData object.
31 v8::Handle<v8::Value> GetPromise();
36 // Registers an "async waiter" that calls DataReady() via WaitCompleted().
38 static void WaitCompleted(void* self, MojoResult result) {
39 static_cast<DrainData*>(self)->DataReady(result);
42 // Use ReadData() to read whatever is availble now on handle_ and save
43 // it in data_buffers_.
44 void DataReady(MojoResult result);
45 MojoResult ReadData();
47 // When the remote data pipe handle is closed, or an error occurs, deliver
48 // all of the buffered data to the JS Promise and then delete this.
49 void DeliverData(MojoResult result);
51 typedef std::vector<char> DataBuffer;
53 v8::Isolate* isolate_;
54 ScopedDataPipeConsumerHandle handle_;
55 MojoAsyncWaitID wait_id_;
56 base::WeakPtr<gin::Runner> runner_;
57 v8::UniquePersistent<v8::Promise::Resolver> resolver_;
58 ScopedVector<DataBuffer> data_buffers_;
64 #endif // MOJO_BINDINGS_JS_DRAIN_DATA_H_