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. 4 5 #ifndef MOJO_BINDINGS_JS_DRAIN_DATA_H_ 6 #define MOJO_BINDINGS_JS_DRAIN_DATA_H_ 7 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" 13 14 namespace mojo { 15 namespace js { 16 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. 22 23 class DrainData { 24 public: 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); 28 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(); 32 33 private: 34 ~DrainData(); 35 36 // Registers an "async waiter" that calls DataReady() via WaitCompleted(). 37 void WaitForData(); WaitCompleted(void * self,MojoResult result)38 static void WaitCompleted(void* self, MojoResult result) { 39 static_cast<DrainData*>(self)->DataReady(result); 40 } 41 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(); 46 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); 50 51 typedef std::vector<char> DataBuffer; 52 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_; 59 }; 60 61 } // namespace js 62 } // namespace mojo 63 64 #endif // MOJO_BINDINGS_JS_DRAIN_DATA_H_ 65