Basic network service implementation for iOS

sky/services/ns_net/url_loader_impl.mm

+// 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 "url_loader_impl.h"
+#include "base/logging.h"
+#include "base/mac/scoped_nsautorelease_pool.h"
+
+#import <Foundation/Foundation.h>
+
+@interface URLLoaderConnectionDelegate : NSObject<NSURLConnectionDataDelegate>
+
+@property(nonatomic) mojo::URLLoaderImpl::StartCallback startCallback;
+
+@end
+
+@implementation URLLoaderConnectionDelegate {
+  mojo::URLResponsePtr _response;

[eseidel, 2015/06/08 20:53:53]

Is objc++ smart enough to run destructors on these?  I would think so, but it's
been probably 10 years since I wrote Obj-c++

[Chinmay, 2015/06/08 22:03:42]

Yeah, unless `-fno-objc-call-cxx-cdtors` is specified

+  mojo::ScopedDataPipeProducerHandle _producer;
+}
+
+@synthesize startCallback = _startCallback;
+
+- (void)connection:(NSURLConnection*)connection
+    didReceiveResponse:(NSHTTPURLResponse*)response {
+  _response = mojo::URLResponse::New();
+  _response->status_code = response.statusCode;
+  _response->url =
+      mojo::String(connection.originalRequest.URL.absoluteString.UTF8String);
+  mojo::DataPipe pipe;
+  _response->body = pipe.consumer_handle.Pass();
+  _producer = pipe.producer_handle.Pass();
+  [self.class updateDelegate:self asPending:YES];
+}
+
+- (void)connection:(NSURLConnection*)connection didReceiveData:(NSData*)data {
+  if (!_startCallback.is_null()) {
+    DCHECK(_response);
+    _startCallback.Run(_response.Pass());
+    _startCallback.reset();
+    _response.reset();
+  }
+  uint32_t length = data.length;
+  MojoResult result = WriteDataRaw(_producer.get(), data.bytes, &length,
+                                   MOJO_WRITE_DATA_FLAG_ALL_OR_NONE);
+  // FIXME(csg): Handle buffers in case of failures
+  DCHECK(result == MOJO_RESULT_OK);
+  DCHECK(length == data.length);
+}
+
+- (void)connectionDidFinishLoading:(NSURLConnection*)connection {
+  DCHECK(_response.is_null());
+  DCHECK(_startCallback.is_null());
+  _producer.reset();
+  [self.class updateDelegate:self asPending:NO];
+}
+
+- (void)connection:(NSURLConnection*)connection
+    didFailWithError:(NSError*)error {
+  if (!_startCallback.is_null()) {
+    if (_response.is_null()) {
+      _response = mojo::URLResponse::New();
+      _response->url = mojo::String(
+          connection.originalRequest.URL.absoluteString.UTF8String);
+    }
+
+    _response->error = mojo::NetworkError::New();
+    _response->error->description =
+        mojo::String(error.localizedDescription.UTF8String);
+
+    _startCallback.Run(_response.Pass());
+    _startCallback.reset();
+  }
+
+  _response.reset();
+  _producer.reset();
+  [self.class updateDelegate:self asPending:NO];
+}
+
+// Since the only reference to the producer end of a data pipe is held by the
+// delegate, which itself has no strong reference, we put the in-flight requests
+// in a collection that references these delegates while they are active.
++ (void)updateDelegate:(URLLoaderConnectionDelegate*)delegate
+             asPending:(BOOL)pending {
+  static NSMutableSet* pendingConnections = nil;
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    pendingConnections = [[NSMutableSet alloc] init];
+  });
+  if (pending) {
+    [pendingConnections addObject:delegate];
+  } else {
+    [pendingConnections removeObject:delegate];
+  }
+}
+
+- (void)dealloc {
+  DCHECK(_response.is_null());
+  DCHECK(_startCallback.is_null());
+  _producer.reset();
+  [super dealloc];
+}
+
+@end
+
+namespace mojo {
+
+URLLoaderImpl::URLLoaderImpl(InterfaceRequest<URLLoader> request)
+    : binding_(this, request.Pass()),
+      connection_delegate_(nullptr),
+      pending_connection_(nullptr) {
+  connection_delegate_ = [[URLLoaderConnectionDelegate alloc] init];
+}
+
+URLLoaderImpl::~URLLoaderImpl() {
+  [(id)connection_delegate_ release];
+
+  [(id)pending_connection_ cancel];
+  [(id)pending_connection_ release];
+}
+
+void URLLoaderImpl::Start(URLRequestPtr request,
+                          const StartCallback& callback) {
+  base::mac::ScopedNSAutoreleasePool pool;
+
+  NSURL* url = [NSURL URLWithString:@(request->url.data())];
+  NSMutableURLRequest* req = [NSMutableURLRequest requestWithURL:url];
+
+  req.HTTPMethod = @(request->method.data());
+
+  if (request->bypass_cache) {
+    req.cachePolicy = NSURLRequestReloadIgnoringLocalCacheData;
+  }
+
+  URLLoaderConnectionDelegate* delegate =
+      (URLLoaderConnectionDelegate*)connection_delegate_;

[eseidel, 2015/06/08 20:53:53]

Are you sure you want to c-style cast here?

+
+  NSURLConnection* connection =
+      [NSURLConnection connectionWithRequest:req delegate:delegate];
+
+  delegate.startCallback = callback;
+
+  [connection start];
+
+  pending_connection_ = [connection retain];
+}
+
+void URLLoaderImpl::FollowRedirect(const FollowRedirectCallback& callback) {
+  base::mac::ScopedNSAutoreleasePool pool;
+  DCHECK(false);
+}
+
+void URLLoaderImpl::QueryStatus(const QueryStatusCallback& callback) {
+  base::mac::ScopedNSAutoreleasePool pool;
+  DCHECK(false);
+}
+
+}  // namespace mojo