[Author: iwade]

Add NSData hex conversion routines.

Add a case-insensitive NSDictionary constructor.

I have a need for both pieces of functionality in an iPhone app I'm developing.

R=dmaclach,thomasvl
APPROVED=dmaclach
DELTA=521  (521 added, 0 deleted, 0 changed)

6 files changed, 474 insertions, 0 deletions

diff --git a/Foundation/GTMNSData+Hex.h b/Foundation/GTMNSData+Hex.h
new file mode 100644
index 0000000..b1e668d
--- /dev/null
+++ b/Foundation/GTMNSData+Hex.h
@@ -0,0 +1,37 @@
+//
+//  GTMNSData+Hex.h
+//
+//  Copyright 2009 Google Inc.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License"); you may not
+//  use this file except in compliance with the License.  You may obtain a copy
+//  of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+//  License for the specific language governing permissions and limitations under
+//  the License.
+//
+
+#import <Foundation/Foundation.h>
+
+/// Helpers for dealing w/ hex encoded strings.
+@interface NSData (GTMHexAdditions)
+
+/// Return an autoreleased NSData w/ the result of decoding |hexString| to
+/// binary data.
+///
+/// Will return |nil| if |hexString| contains any non-hex characters (i.e.
+/// 0-9, a-f, A-F) or if the length of |hexString| is not cleanly divisible by
+/// two.
+/// Leading 0x prefix is not supported and will result in a |nil| return value.
++ (NSData *)gtm_dataWithHexString:(NSString *)hexString;
+
+/// Return an autoreleased NSString w/ the result of encoding the NSData bytes
+/// as hex. No leading 0x prefix is included.
+- (NSString *)gtm_hexString;
+
+@end
diff --git a/Foundation/GTMNSData+Hex.m b/Foundation/GTMNSData+Hex.m
new file mode 100644
index 0000000..c7e740d
--- /dev/null
+++ b/Foundation/GTMNSData+Hex.m
@@ -0,0 +1,102 @@
+//
+//  GTMNSData+Hex.m
+//
+//  Copyright 2009 Google Inc.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License"); you may not
+//  use this file except in compliance with the License.  You may obtain a copy
+//  of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+//  License for the specific language governing permissions and limitations under
+//  the License.
+//
+
+#import "GTMNSData+Hex.h"
+#import "GTMDefines.h"
+
+@implementation NSData (GTMHexAdditions)
+
++ (NSData *)gtm_dataWithHexString:(NSString *)hexString {
+  NSData *hexData = [hexString dataUsingEncoding:NSASCIIStringEncoding];
+  const char *hexBuf = [hexData bytes];
+  NSUInteger hexLen = [hexData length];
+
+  // This indicates an error converting to ASCII.
+  if (hexString && !hexData) {
+    return nil;
+  }
+
+  if ((hexLen % 2) != 0) {
+    return nil;
+  }
+
+  NSMutableData *binaryData = [NSMutableData dataWithLength:(hexLen / 2)];
+  unsigned char *binaryPtr = [binaryData mutableBytes];
+  unsigned char value = 0;
+  for (NSUInteger i = 0; i < hexLen; i++) {
+    char c = hexBuf[i];
+
+    if (!isxdigit(c)) {
+      return nil;
+    }
+
+    if (isdigit(c)) {
+      value += c - '0';
+    } else if (islower(c)) {
+      value += 10 + c - 'a';
+    } else {
+      value += 10 + c - 'A';
+    }
+
+    if (i & 1) {
+      *binaryPtr++ = value;
+      value = 0;
+    } else {
+      value <<= 4;
+    }
+  }
+
+  return [NSData dataWithData:binaryData];
+}
+
+- (NSString *)gtm_hexString {
+  static const char kHexTable[] =
+    "000102030405060708090a0b0c0d0e0f"
+    "101112131415161718191a1b1c1d1e1f"
+    "202122232425262728292a2b2c2d2e2f"
+    "303132333435363738393a3b3c3d3e3f"
+    "404142434445464748494a4b4c4d4e4f"
+    "505152535455565758595a5b5c5d5e5f"
+    "606162636465666768696a6b6c6d6e6f"
+    "707172737475767778797a7b7c7d7e7f"
+    "808182838485868788898a8b8c8d8e8f"
+    "909192939495969798999a9b9c9d9e9f"
+    "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf"
+    "b0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
+    "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
+    "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
+    "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
+    "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
+
+  const unsigned char *binaryPtr = [self bytes];
+  NSUInteger binaryLen = [self length];
+
+  NSMutableData *hexData = [NSMutableData dataWithLength:(2 * binaryLen)];
+  char *hexPtr = [hexData mutableBytes];
+
+  for (NSUInteger i = 0; i < binaryLen; i++) {
+    *hexPtr++ = kHexTable[(*binaryPtr)*2];
+    *hexPtr++ = kHexTable[(*binaryPtr)*2 + 1];
+    ++binaryPtr;
+  }
+
+  return [[[NSString alloc] initWithData:hexData
+                                encoding:NSASCIIStringEncoding] autorelease];
+}
+
+@end
diff --git a/Foundation/GTMNSData+HexTest.m b/Foundation/GTMNSData+HexTest.m
new file mode 100644
index 0000000..6bc1608
--- /dev/null
+++ b/Foundation/GTMNSData+HexTest.m
@@ -0,0 +1,58 @@
+//
+//  GTMNSData+HexTest.m
+//
+//  Copyright 2009 Google Inc.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License"); you may not
+//  use this file except in compliance with the License.  You may obtain a copy
+//  of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+//  License for the specific language governing permissions and limitations under
+//  the License.
+//
+
+#import "GTMSenTestCase.h"
+#import "GTMNSData+Hex.h"
+
+@interface GTMNSData_HexTest : GTMTestCase
+@end
+
+@implementation GTMNSData_HexTest
+
+- (void)testNSDataHexAdditions {
+  NSString *testString = @"1c2f0032f40123456789abcdef";
+  char testBytes[] = { 0x1c, 0x2f, 0x00, 0x32, 0xf4, 0x01, 0x23,
+                       0x45, 0x67, 0x89, 0xab, 0xcd, 0xef };
+  NSData *testData = [NSData dataWithBytes:testBytes length:sizeof(testBytes)];
+
+  STAssertTrue([[testData gtm_hexString] isEqual:testString],
+               @"gtm_hexString doesn't encode as expected");
+
+  STAssertEqualStrings([[NSData data] gtm_hexString], @"",
+                       @"gtm_hexString empty data should return empty string");
+
+  STAssertTrue([[NSData gtm_dataWithHexString:testString] isEqual:testData],
+               @"gtm_dataWithHexString: doesn't decode as expected");
+
+  STAssertNil([NSData gtm_dataWithHexString:@"1c2f003"],
+              @"gtm_dataWithHexString: parsed hex from an odd size string");
+
+  STAssertNil([NSData gtm_dataWithHexString:@"1c2f00ft"],
+              @"gtm_dataWithHexString: parsed hex from a non hex string");
+
+  STAssertNil([NSData gtm_dataWithHexString:@"abcdéf"],
+              @"gtm_dataWithHexString: parsed a non-ASCII character");
+
+  STAssertNotNil([NSData gtm_dataWithHexString:@""],
+                 @"gtm_dataWithHexString: empty input resulted in nil output");
+
+  STAssertNotNil([NSData gtm_dataWithHexString:nil],
+                 @"gtm_dataWithHexString: nil input resulted in nil output");
+}
+
+@end
diff --git a/Foundation/GTMNSDictionary+CaseInsensitive.h b/Foundation/GTMNSDictionary+CaseInsensitive.h
new file mode 100644
index 0000000..a31e81c
--- /dev/null
+++ b/Foundation/GTMNSDictionary+CaseInsensitive.h
@@ -0,0 +1,42 @@
+//
+//  GTMNSDictionary+CaseInsensitive.h
+//
+//  Copyright 2009 Google Inc.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License"); you may not
+//  use this file except in compliance with the License.  You may obtain a copy
+//  of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+//  License for the specific language governing permissions and limitations under
+//  the License.
+//
+
+#import <Foundation/Foundation.h>
+
+/// Utility for building case-insensitive NSDictionary objects.
+@interface NSDictionary (GTMNSDictionaryCaseInsensitiveAdditions)
+
+/// Initializes an NSDictionary with a case-insensitive comparison function
+/// for NSString keys, while non-NSString keys are treated normally.
+///
+/// The case for NSString keys is preserved, though duplicate keys (when
+/// compared in a case-insensitive fashion) have one of their values dropped
+/// arbitrarily.
+///
+/// An example of use with HTTP headers in an NSHTTPURLResponse object:
+///
+/// NSDictionary *headers =
+///     [NSDictionary gtm_dictionaryWithDictionaryCaseInsensitive:
+///      [response allHeaderFields]];
+/// NSString *contentType = [headers objectForKey:@"Content-Type"];
+- (id)gtm_initWithDictionaryCaseInsensitive:(NSDictionary *)dictionary;
+
+/// Returns a newly created and autoreleased NSDictionary object as above.
++ (id)gtm_dictionaryWithDictionaryCaseInsensitive:(NSDictionary *)dictionary;
+
+@end
diff --git a/Foundation/GTMNSDictionary+CaseInsensitive.m b/Foundation/GTMNSDictionary+CaseInsensitive.m
new file mode 100644
index 0000000..96494c2
--- /dev/null
+++ b/Foundation/GTMNSDictionary+CaseInsensitive.m
@@ -0,0 +1,116 @@
+//
+//  GTMNSDictionary+CaseInsensitive.m
+//
+//  Copyright 2009 Google Inc.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License"); you may not
+//  use this file except in compliance with the License.  You may obtain a copy
+//  of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+//  License for the specific language governing permissions and limitations under
+//  the License.
+//
+
+#import "GTMNSDictionary+CaseInsensitive.h"
+#import "GTMDefines.h"
+#import <CoreFoundation/CoreFoundation.h>
+
+@interface NSMutableDictionary (GTMNSMutableDictionaryCaseInsensitiveAdditions)
+
+// Returns a mutable equivalent to GTMNSDictionaryCaseInsensitiveAdditions.
+- (id)gtm_initWithDictionaryCaseInsensitive:(NSDictionary *)dictionary;
+
+@end
+
+static Boolean CaseInsensitiveEqualCallback(const void *a, const void *b) {
+  id idA = (id)a;
+  id idB = (id)b;
+  Boolean ret = FALSE;
+  if ([idA isKindOfClass:[NSString class]] &&
+      [idB isKindOfClass:[NSString class]]) {
+    ret = ([idA compare:idB options:NSCaseInsensitiveSearch|NSLiteralSearch]
+           == NSOrderedSame);
+  } else {
+    ret = [idA isEqual:idB];
+  }
+  return ret;
+}
+
+static CFHashCode CaseInsensitiveHashCallback(const void *value) {
+  id idValue = (id)value;
+  CFHashCode ret = 0;
+  if ([idValue isKindOfClass:[NSString class]]) {
+    ret = [[idValue lowercaseString] hash];
+  } else {
+    ret = [idValue hash];
+  }
+  return ret;
+}
+
+@implementation NSDictionary (GTMNSDictionaryCaseInsensitiveAdditions)
+
+- (id)gtm_initWithDictionaryCaseInsensitive:(NSDictionary *)dictionary {
+  [self release];
+  self = nil;
+
+  CFIndex count = 0;
+  void *keys = NULL;
+  void *values = NULL;
+
+  if (dictionary) {
+    count = CFDictionaryGetCount((CFDictionaryRef)dictionary);
+
+    if (count) {
+      keys = malloc(count * sizeof(void *));
+      values = malloc(count * sizeof(void *));
+      if (!keys || !values) {
+        free(keys);
+        free(values);
+        return self;
+      }
+
+      CFDictionaryGetKeysAndValues((CFDictionaryRef)dictionary, keys, values);
+    }
+  }
+
+  CFDictionaryKeyCallBacks keyCallbacks = kCFCopyStringDictionaryKeyCallBacks;
+  _GTMDevAssert(keyCallbacks.version == 0,
+                @"CFDictionaryKeyCallBacks structure updated");
+  keyCallbacks.equal = CaseInsensitiveEqualCallback;
+  keyCallbacks.hash = CaseInsensitiveHashCallback;
+
+  self = (id)CFDictionaryCreate(kCFAllocatorDefault,
+                                keys, values, count, &keyCallbacks,
+                                &kCFTypeDictionaryValueCallBacks);
+
+  free(keys);
+  free(values);
+
+  return self;
+}
+
++ (id)gtm_dictionaryWithDictionaryCaseInsensitive:(NSDictionary *)dictionary {
+  return [[[self alloc]
+           gtm_initWithDictionaryCaseInsensitive:dictionary] autorelease];
+}
+
+@end
+
+@implementation NSMutableDictionary (GTMNSMutableDictionaryCaseInsensitiveAdditions)
+
+- (id)gtm_initWithDictionaryCaseInsensitive:(NSDictionary *)dictionary {
+  if ((self = [super gtm_initWithDictionaryCaseInsensitive:dictionary])) {
+    id copy = (id)CFDictionaryCreateMutableCopy(kCFAllocatorDefault, 0,
+                                                (CFDictionaryRef)self);
+    [self release];
+    self = copy;
+  }
+  return self;
+}
+
+@end
diff --git a/Foundation/GTMNSDictionary+CaseInsensitiveTest.m b/Foundation/GTMNSDictionary+CaseInsensitiveTest.m
new file mode 100644
index 0000000..67584ff
--- /dev/null
+++ b/Foundation/GTMNSDictionary+CaseInsensitiveTest.m
@@ -0,0 +1,119 @@
+//
+//  GTMNSDictionary+CaseInsensitiveTest.m
+//
+//  Copyright 2009 Google Inc.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License"); you may not
+//  use this file except in compliance with the License.  You may obtain a copy
+//  of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+//  License for the specific language governing permissions and limitations under
+//  the License.
+//
+
+#import "GTMSenTestCase.h"
+#import "GTMNSDictionary+CaseInsensitive.h"
+
+@interface GTMNSDictionary_CaseInsensitiveTest : GTMTestCase
+@end
+
+@implementation GTMNSDictionary_CaseInsensitiveTest
+
+- (void)testNSDictionaryCaseInsensitiveAdditions {
+  NSURL *objKey = [NSURL URLWithString:@"http://WWW.Google.COM/"];
+  NSURL *lcObjKey = [NSURL URLWithString:[[objKey absoluteString]
+                                          lowercaseString]];
+
+  NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:
+                        @"value", @"key",
+                        @"value", @"KEY",
+                        @"bar", @"FOO",
+                        @"yes", objKey,
+                        nil];
+
+  NSDictionary *ciDict =
+      [NSDictionary gtm_dictionaryWithDictionaryCaseInsensitive:dict];
+
+  STAssertNotNil(ciDict, @"gtm_dictionaryWithDictionaryCaseInsensitive failed");
+
+  STAssertTrue([ciDict count] == 3,
+               @"wrong count, multiple 'key' entries should be folded.");
+
+  STAssertEqualStrings([ciDict objectForKey:@"foo"], @"bar",
+                       @"case insensitive key lookup failed");
+
+  STAssertEqualStrings([ciDict objectForKey:@"kEy"], @"value",
+                       @"case insensitive key lookup failed");
+
+  STAssertNotNil([ciDict objectForKey:objKey],
+                 @"exact matches on non-NSString objects should still work.");
+
+  STAssertNil([ciDict objectForKey:lcObjKey],
+              @"only NSString and subclasses are case-insensitive.");
+
+  STAssertNotNil([NSDictionary gtm_dictionaryWithDictionaryCaseInsensitive:
+                  [NSDictionary dictionary]],
+                 @"empty dictionary should not return nil");
+
+  STAssertNotNil([NSDictionary gtm_dictionaryWithDictionaryCaseInsensitive:
+                  nil],
+                 @"nil dictionary should return empty dictionary");
+
+  STAssertNotNil([[[NSDictionary alloc] gtm_initWithDictionaryCaseInsensitive:
+                   nil] autorelease],
+                 @"nil dictionary should return empty dictionary");
+}
+
+- (void)testNSMutableDictionaryCaseInsensitiveAdditions {
+  NSURL *objKey = [NSURL URLWithString:@"http://WWW.Google.COM/"];
+  NSURL *lcObjKey = [NSURL URLWithString:[[objKey absoluteString]
+                                          lowercaseString]];
+
+  NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:
+                        @"value", @"key",
+                        @"value", @"KEY",
+                        @"bar", @"FOO",
+                        @"yes", objKey,
+                        nil];
+
+  NSMutableDictionary *ciDict =
+      [NSMutableDictionary gtm_dictionaryWithDictionaryCaseInsensitive:dict];
+
+  STAssertNotNil(ciDict, @"gtm_dictionaryWithDictionaryCaseInsensitive failed");
+
+  STAssertTrue([ciDict count] == 3,
+               @"wrong count, multiple 'key' entries should be folded.");
+
+  STAssertEqualStrings([ciDict objectForKey:@"foo"], @"bar",
+                       @"case insensitive key lookup failed");
+
+  STAssertEqualStrings([ciDict objectForKey:@"kEy"], @"value",
+                       @"case insensitive key lookup failed");
+
+  STAssertNotNil([ciDict objectForKey:objKey],
+                 @"exact matches on non-NSString objects should still work.");
+
+  STAssertNil([ciDict objectForKey:lcObjKey],
+              @"only NSString and subclasses are case-insensitive.");
+
+  NSObject *obj = [[[NSObject alloc] init] autorelease];
+  [ciDict setObject:obj forKey:@"kEy"];
+  STAssertEquals([ciDict objectForKey:@"key"], obj,
+                 @"mutable dictionary value not overwritten");
+
+  STAssertNotNil(
+      [NSMutableDictionary gtm_dictionaryWithDictionaryCaseInsensitive:
+       [NSDictionary dictionary]],
+      @"empty dictionary should not return nil");
+
+  STAssertNotNil(
+      [NSMutableDictionary gtm_dictionaryWithDictionaryCaseInsensitive:nil],
+      @"nil dictionary should return empty dictionary");
+}
+
+@end