Alpha 1 drop of Google's Objective C plugin and runtime support for protobufs.
diff --git a/objectivec/GPBExtensionRegistry.m b/objectivec/GPBExtensionRegistry.m
new file mode 100644
index 0000000..a191dac
--- /dev/null
+++ b/objectivec/GPBExtensionRegistry.m
@@ -0,0 +1,98 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc. All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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 "GPBExtensionRegistry_PackagePrivate.h"
+
+#import "GPBBootstrap.h"
+#import "GPBDescriptor.h"
+#import "GPBExtensionField.h"
+
+@implementation GPBExtensionRegistry {
+ // TODO(dmaclach): Reimplement with CFDictionaries that don't use
+ // objects as keys.
+ NSMutableDictionary *mutableClassMap_;
+}
+
+- (instancetype)init {
+ if ((self = [super init])) {
+ mutableClassMap_ = [[NSMutableDictionary alloc] init];
+ }
+ return self;
+}
+
+- (void)dealloc {
+ [mutableClassMap_ release];
+ [super dealloc];
+}
+
+- (NSMutableDictionary *)extensionMapForContainingType:
+ (GPBDescriptor *)containingType {
+ NSMutableDictionary *extensionMap =
+ [mutableClassMap_ objectForKey:containingType];
+ if (extensionMap == nil) {
+ extensionMap = [NSMutableDictionary dictionary];
+ [mutableClassMap_ setObject:extensionMap forKey:containingType];
+ }
+ return extensionMap;
+}
+
+- (void)addExtension:(GPBExtensionField *)extension {
+ if (extension == nil) {
+ return;
+ }
+
+ GPBDescriptor *containingType = [extension containingType];
+ NSMutableDictionary *extensionMap =
+ [self extensionMapForContainingType:containingType];
+ [extensionMap setObject:extension forKey:@([extension fieldNumber])];
+}
+
+- (GPBExtensionField *)getExtension:(GPBDescriptor *)containingType
+ fieldNumber:(NSInteger)fieldNumber {
+ NSDictionary *extensionMap = [mutableClassMap_ objectForKey:containingType];
+ return [extensionMap objectForKey:@(fieldNumber)];
+}
+
+- (void)addExtensions:(GPBExtensionRegistry *)registry {
+ if (registry == nil) {
+ // In the case where there are no extensions just ignore.
+ return;
+ }
+ NSMutableDictionary *otherClassMap = registry->mutableClassMap_;
+ for (GPBDescriptor *containingType in otherClassMap) {
+ NSMutableDictionary *extensionMap =
+ [self extensionMapForContainingType:containingType];
+ NSMutableDictionary *otherExtensionMap =
+ [registry extensionMapForContainingType:containingType];
+ [extensionMap addEntriesFromDictionary:otherExtensionMap];
+ }
+}
+
+@end
