Initial checkin of gRPC to third_party/

third_party/grpc/src/objective-c/GRPCClient/private/GRPCHost.m

+/*
+ *
+ * Copyright 2015-2016, 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 "GRPCHost.h"
+
+#include <grpc/grpc.h>
+#import <GRPCClient/GRPCCall+ChannelArg.h>
+
+#import "GRPCChannel.h"
+#import "GRPCCompletionQueue.h"
+#import "NSDictionary+GRPC.h"
+
+// TODO(jcanizales): Generate the version in a standalone header, from templates. Like
+// templates/src/core/surface/version.c.template .
+#define GRPC_OBJC_VERSION_STRING @"0.13.0"
+
+@interface GRPCHost ()
+// TODO(mlumish): Investigate whether caching channels with strong links is a good idea.
+@property(nonatomic, strong) GRPCChannel *channel;
+@end
+
+@implementation GRPCHost
+
++ (instancetype)hostWithAddress:(NSString *)address {
+  return [[self alloc] initWithAddress:address];
+}
+
+- (instancetype)init {
+  return [self initWithAddress:nil];
+}
+
+// Default initializer.
+- (instancetype)initWithAddress:(NSString *)address {
+  if (!address) {
+    return nil;
+  }
+
+  // To provide a default port, we try to interpret the address. If it's just a host name without
+  // scheme and without port, we'll use port 443. If it has a scheme, we pass it untouched to the C
+  // gRPC library.
+  // TODO(jcanizales): Add unit tests for the types of addresses we want to let pass untouched.
+  NSURL *hostURL = [NSURL URLWithString:[@"https://" stringByAppendingString:address]];
+  if (hostURL.host && !hostURL.port) {
+    address = [hostURL.host stringByAppendingString:@":443"];
+  }
+
+  // Look up the GRPCHost in the cache.
+  static NSMutableDictionary *hostCache;
+  static dispatch_once_t cacheInitialization;
+  dispatch_once(&cacheInitialization, ^{
+    hostCache = [NSMutableDictionary dictionary];
+  });
+  @synchronized(hostCache) {
+    GRPCHost *cachedHost = hostCache[address];
+    if (cachedHost) {
+      return cachedHost;
+    }
+
+    if ((self = [super init])) {
+      _address = address;
+      _secure = YES;
+      hostCache[address] = self;
+    }
+  }
+  return self;
+}
+
+- (grpc_call *)unmanagedCallWithPath:(NSString *)path completionQueue:(GRPCCompletionQueue *)queue {
+  if (!queue || !path || !self.channel) {
+    return NULL;
+  }
+  return grpc_channel_create_call(self.channel.unmanagedChannel,
+                                  NULL, GRPC_PROPAGATE_DEFAULTS,
+                                  queue.unmanagedQueue,
+                                  path.UTF8String,
+                                  self.hostName.UTF8String,
+                                  gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
+}
+
+- (GRPCChannel *)channel {
+  // Create it lazily, because we don't want to open a connection just because someone is
+  // configuring a host.
+
+  if (!_channel) {
+    NSMutableDictionary *args = [NSMutableDictionary dictionary];
+
+    // TODO(jcanizales): Add OS and device information (see
+    // https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#user-agents ).
+    NSString *userAgent = @"grpc-objc/" GRPC_OBJC_VERSION_STRING;
+    if (_userAgentPrefix) {
+      userAgent = [@[_userAgentPrefix, userAgent] componentsJoinedByString:@" "];
+    }
+    args[@GRPC_ARG_PRIMARY_USER_AGENT_STRING] = userAgent;
+
+    if (_secure) {
+      if (_hostNameOverride) {
+        args[@GRPC_SSL_TARGET_NAME_OVERRIDE_ARG] = _hostNameOverride;
+      }
+
+      _channel = [GRPCChannel secureChannelWithHost:_address
+                                 pathToCertificates:_pathToCertificates
+                                        channelArgs:args];
+    } else {
+      _channel = [GRPCChannel insecureChannelWithHost:_address channelArgs:args];
+    }
+  }
+  return _channel;
+}
+
+- (NSString *)hostName {
+  // TODO(jcanizales): Default to nil instead of _address when Issue #2635 is clarified.
+  return _hostNameOverride ?: _address;
+}
+
+// TODO(jcanizales): Don't let set |secure| to |NO| if |pathToCertificates| or |hostNameOverride|
+// have been set. Don't let set either of the latter if |secure| has been set to |NO|.
+
+@end