Initial checkin of gRPC to third_party/

third_party/grpc/src/objective-c/ProtoRPC/ProtoRPC.m

+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#import "ProtoRPC.h"
+
+#import <GPBProtocolBuffers.h>
+#import <RxLibrary/GRXWriteable.h>
+#import <RxLibrary/GRXWriter+Transformations.h>
+
+static NSError *ErrorForBadProto(id proto, Class expectedClass, NSError *parsingError) {
+  NSDictionary *info = @{
+                         NSLocalizedDescriptionKey: @"Unable to parse response from the server",
+                         NSLocalizedRecoverySuggestionErrorKey: @"If this RPC is idempotent, retry "
+                         @"with exponential backoff. Otherwise, query the server status before "
+                         @"retrying.",
+                         NSUnderlyingErrorKey: parsingError,
+                         @"Expected class": expectedClass,
+                         @"Received value": proto,
+                         };
+  // TODO(jcanizales): Use kGRPCErrorDomain and GRPCErrorCodeInternal when they're public.
+  return [NSError errorWithDomain:@"io.grpc"
+                             code:13
+                         userInfo:info];
+}
+
+@implementation ProtoRPC {
+  id<GRXWriteable> _responseWriteable;
+}
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wobjc-designated-initializers"
+- (instancetype)initWithHost:(NSString *)host
+                        path:(NSString *)path
+              requestsWriter:(GRXWriter *)requestsWriter {
+  [NSException raise:NSInvalidArgumentException
+              format:@"Please use ProtoRPC's designated initializer instead."];
+  return nil;
+}
+#pragma clang diagnostic pop
+
+// Designated initializer
+- (instancetype)initWithHost:(NSString *)host
+                      method:(ProtoMethod *)method
+              requestsWriter:(GRXWriter *)requestsWriter
+               responseClass:(Class)responseClass
+          responsesWriteable:(id<GRXWriteable>)responsesWriteable {
+  // Because we can't tell the type system to constrain the class, we need to check at runtime:
+  if (![responseClass respondsToSelector:@selector(parseFromData:error:)]) {
+    [NSException raise:NSInvalidArgumentException
+                format:@"A protobuf class to parse the responses must be provided."];
+  }
+  // A writer that serializes the proto messages to send.
+  GRXWriter *bytesWriter = [requestsWriter map:^id(GPBMessage *proto) {
+    if (![proto isKindOfClass:GPBMessage.class]) {
+      [NSException raise:NSInvalidArgumentException
+                  format:@"Request must be a proto message: %@", proto];
+    }
+    return [proto data];
+  }];
+  if ((self = [super initWithHost:host path:method.HTTPPath requestsWriter:bytesWriter])) {
+    __weak ProtoRPC *weakSelf = self;
+
+    // A writeable that parses the proto messages received.
+    _responseWriteable = [[GRXWriteable alloc] initWithValueHandler:^(NSData *value) {
+      // TODO(jcanizales): This is done in the main thread, and needs to happen in another thread.
+      NSError *error = nil;
+      id parsed = [responseClass parseFromData:value error:&error];
+      if (parsed) {
+        [responsesWriteable writeValue:parsed];
+      } else {
+        [weakSelf finishWithError:ErrorForBadProto(value, responseClass, error)];
+      }
+    } completionHandler:^(NSError *errorOrNil) {
+      [responsesWriteable writesFinishedWithError:errorOrNil];
+    }];
+  }
+  return self;
+}
+
+- (void)start {
+  [self startWithWriteable:_responseWriteable];
+}
+
+- (void)startWithWriteable:(id<GRXWriteable>)writeable {
+  [super startWithWriteable:writeable];
+  // Break retain cycles.
+  _responseWriteable = nil;
+}
+@end