Mojo service implementation for HTTP server - part 2

mojo/services/network/http_connection_impl.cc

 // Copyright 2015 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 "mojo/services/network/http_connection_impl.h"
 
 #include <limits>
 
+#include "base/bind_helpers.h"
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/strings/string_util.h"
+#include "mojo/common/handle_watcher.h"
 #include "mojo/services/network/http_server_impl.h"
 #include "mojo/services/network/net_adapters.h"
 #include "net/base/net_errors.h"
+#include "net/http/http_request_headers.h"
+#include "net/http/http_status_code.h"
 #include "net/server/http_server.h"
 #include "net/server/http_server_request_info.h"
+#include "net/server/http_server_response_info.h"
+#include "third_party/mojo/src/mojo/public/cpp/bindings/type_converter.h"
+#include "third_party/mojo/src/mojo/public/cpp/system/data_pipe.h"
 
 namespace mojo {
 
+// SimpleDataPipeReader reads till end-of-file, stores the data in a string and
+// notifies completion.
+class HttpConnectionImpl::SimpleDataPipeReader {
+ public:
+  using CompletionCallback =
+      base::Callback<void(SimpleDataPipeReader*, scoped_ptr<std::string>)>;
+
+  SimpleDataPipeReader() {}
+  ~SimpleDataPipeReader() {}
+
+  void Start(ScopedDataPipeConsumerHandle consumer,
+             const CompletionCallback& completion_callback) {
+    DCHECK(consumer.is_valid() && !consumer_.is_valid());
+    consumer_ = consumer.Pass();
+    completion_callback_ = completion_callback;
+    buffer_.reset(new std::string);
+    ReadMore();
+  }
+
+ private:
+  void ReadMore() {
+    const void* buf;
+    uint32_t buf_size;
+    MojoResult rv = BeginReadDataRaw(consumer_.get(), &buf, &buf_size,
+                                     MOJO_READ_DATA_FLAG_NONE);
+    if (rv == MOJO_RESULT_OK) {
+      buffer_->append(static_cast<const char*>(buf), buf_size);
+      EndReadDataRaw(consumer_.get(), buf_size);
+      WaitToReadMore();
+    } else if (rv == MOJO_RESULT_SHOULD_WAIT) {
+      WaitToReadMore();
+    } else if (rv == MOJO_RESULT_FAILED_PRECONDITION) {
+      // We reached end-of-file.
+      completion_callback_.Run(this, buffer_.Pass());
+      // Note: This object may have been destroyed in the callback.
+    } else {
+      CHECK(false);
+    }
+  }
+
+  void WaitToReadMore() {
+    watcher_.Start(consumer_.get(), MOJO_HANDLE_SIGNAL_READABLE,
+                   MOJO_DEADLINE_INDEFINITE,
+                   base::Bind(&SimpleDataPipeReader::OnHandleReady,
+                              base::Unretained(this)));
+  }
+
+  void OnHandleReady(MojoResult result) { ReadMore(); }
+
+  ScopedDataPipeConsumerHandle consumer_;
+  common::HandleWatcher watcher_;
+  CompletionCallback completion_callback_;
+  scoped_ptr<std::string> buffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(SimpleDataPipeReader);
+};
+
+template <>
+struct TypeConverter<URLRequestPtr, net::HttpServerRequestInfo> {
+  static URLRequestPtr Convert(const net::HttpServerRequestInfo& obj) {
+    URLRequestPtr request(URLRequest::New());
+    request->url = obj.path;
+    request->method = obj.method;
+    request->headers.resize(obj.headers.size());
+    size_t index = 0;
+    for (const auto& item : obj.headers) {
+      HTTPHeaderPtr header(HTTPHeader::New());
+      header->name = item.first;
+      header->value = item.second;
+      request->headers[index++] = header.Pass();
+    }
+    if (!obj.data.empty()) {
+      uint32_t num_bytes = static_cast<uint32_t>(obj.data.size());
+      MojoCreateDataPipeOptions options;
+      options.struct_size = sizeof(MojoCreateDataPipeOptions);
+      options.flags = MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_NONE;
+      options.element_num_bytes = 1;
+      options.capacity_num_bytes = num_bytes;
+      DataPipe data_pipe(options);
+      request->body.push_back(data_pipe.consumer_handle.Pass());
+      MojoResult result =
+          WriteDataRaw(data_pipe.producer_handle.get(), obj.data.data(),
+                       &num_bytes, MOJO_WRITE_DATA_FLAG_ALL_OR_NONE);
+      DCHECK_EQ(MOJO_RESULT_OK, result);

[jam, 2015/05/15 06:46:43]

nit: perhaps CHECK so that we know if we have to hit MOJO_RESULT_SHOULD_WAIT
later?

[yzshen1, 2015/05/15 17:22:54]

Done.

+    }
+    return request.Pass();
+  }
+};
+
 HttpConnectionImpl::HttpConnectionImpl(int connection_id,
                                        HttpServerImpl* owner,
                                        HttpConnectionDelegatePtr delegate,
                                        HttpConnectionPtr* connection)
     : connection_id_(connection_id),
       owner_(owner),
       delegate_(delegate.Pass()),
-      binding_(this, connection) {
+      binding_(this, connection),
+      encountered_connection_error_(false) {
+
   binding_.set_error_handler(this);
   delegate_.set_error_handler(this);
 }
 
-HttpConnectionImpl::~HttpConnectionImpl() {}
+HttpConnectionImpl::~HttpConnectionImpl() {
+  for (const auto& reader : response_body_readers_)

[jam, 2015/05/15 06:46:43]

nit: STLDeleteElements

[yzshen1, 2015/05/15 17:22:54]

Done.

+    delete reader;
+}
 
 void HttpConnectionImpl::OnReceivedHttpRequest(
     const net::HttpServerRequestInfo& info) {
-  // TODO(yzshen): implement it.
+  if (!delegate_)
+    return;
+
+  delegate_->OnReceivedRequest(
+      URLRequest::From(info), [this](URLResponsePtr response) {
+        if (response->body.is_valid()) {
+          SimpleDataPipeReader* reader = new SimpleDataPipeReader;
+          response_body_readers_.insert(reader);
+          reader->Start(
+              response->body.Pass(),
+              base::Bind(&HttpConnectionImpl::OnFinishedReadingResponseBody,
+                         base::Unretained(this), base::Passed(&response)));
+        } else {
+          OnFinishedReadingResponseBody(response.Pass(), nullptr, nullptr);
+        }
+      });
 }
 
 void HttpConnectionImpl::OnReceivedWebSocketRequest(
     const net::HttpServerRequestInfo& info) {
   // TODO(yzshen): implement it.
 }
 
 void HttpConnectionImpl::OnReceivedWebSocketMessage(const std::string& data) {
   // TODO(yzshen): implement it.
 }
@@ skipping 14 matching lines @@
     const SetReceiveBufferSizeCallback& callback) {
   if (size > static_cast<uint32_t>(std::numeric_limits<int32_t>::max()))
     size = std::numeric_limits<int32_t>::max();
 
   owner_->server()->SetReceiveBufferSize(
       connection_id_, static_cast<int32_t>(size));
   callback.Run(MakeNetworkError(net::OK));
 }
 
 void HttpConnectionImpl::OnConnectionError() {
-  // The proxy side of |binding_| or the impl side of |delegate_| has closed the
-  // pipe. The connection is not needed anymore.
-  owner_->server()->Close(connection_id_);
+  if (!encountered_connection_error_) {

[jam, 2015/05/15 06:46:43]

why is this boolean needed? perhaps document why it would get called twice

nit: change this so that it early returns if the bool is set, that way you have
less indentation

[yzshen1, 2015/05/15 17:22:54]

I realized that based on the current code it won't be called twice. Although
this error handler is set for both |binding_| and |delegate_|, we reset the two
when this method is called for the first time.

I replaced the boolean with a method EncounteredConnectionError(), and updated
comments. Thanks! 

+    // The proxy side of |binding_| or the impl side of |delegate_| has closed
+    // the pipe.
+    encountered_connection_error_ = true;
+    binding_.Close();
+    delegate_.reset();
+
+    // Don't close the connection until all pending responses are sent.
+    if (response_body_readers_.empty())
+      owner_->server()->Close(connection_id_);
+  }
+}
+
+void HttpConnectionImpl::OnFinishedReadingResponseBody(
+    URLResponsePtr response,
+    SimpleDataPipeReader* reader,
+    scoped_ptr<std::string> body) {
+  if (reader) {
+    delete reader;
+    response_body_readers_.erase(reader);
+  }
+
+  net::HttpServerResponseInfo info(
+      static_cast<net::HttpStatusCode>(response->status_code));
+
+  std::string content_type;
+  for (size_t i = 0; i < response->headers.size(); ++i) {
+    const HTTPHeader& header = *(response->headers[i]);
+
+    if (body) {
+      // net::HttpServerResponseInfo::SetBody() automatically sets
+      // Content-Length and Content-Types, so skip the two here.
+      //
+      // TODO(yzshen): Consider adding to net::HttpServerResponseInfo a simple
+      // setter for body which doesn't fiddle with headers.
+      if (base::strcasecmp(header.name.data(),
+                           net::HttpRequestHeaders::kContentLength) == 0) {
+        continue;
+      } else if (base::strcasecmp(header.name.data(),
+                                  net::HttpRequestHeaders::kContentType) == 0) {
+        content_type = header.value;
+        continue;
+      }
+    }
+    info.AddHeader(header.name, header.value);
+  }
+
+  if (body)
+    info.SetBody(*body, content_type);
+
+  owner_->server()->SendResponse(connection_id_, info);
+
+  if (response_body_readers_.empty() && encountered_connection_error_)
+    owner_->server()->Close(connection_id_);
 }
 
 }  // namespace mojo