initial drop of a few sources to start things out

1 files changed, 246 insertions, 0 deletions

diff --git a/Foundation/GTMNSData+zlib.m b/Foundation/GTMNSData+zlib.m
new file mode 100644
index 0000000..89a906a
--- /dev/null
+++ b/Foundation/GTMNSData+zlib.m
@@ -0,0 +1,246 @@
+//
+//  GTMNSData+zlib.m
+//
+//  Copyright 2007-2008 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+zlib.h"
+#import <zlib.h>
+
+#define kChunkSize 1024
+
+@interface NSData (GTMZlibAdditionsPrivate)
++ (NSData *)gtm_dataByCompressingBytes:(const void *)bytes
+                                length:(unsigned)length
+                      compressionLevel:(int)level
+                               useGzip:(BOOL)useGzip;
+@end
+
+@implementation NSData (GTMZlibAdditionsPrivate)
++ (NSData *)gtm_dataByCompressingBytes:(const void *)bytes
+                                length:(unsigned)length
+                      compressionLevel:(int)level
+                               useGzip:(BOOL)useGzip {
+  if (!bytes || !length) return nil;
+
+  if (level < Z_BEST_SPEED)
+    level = Z_BEST_SPEED;
+  else if (level > Z_BEST_COMPRESSION)
+    level = Z_BEST_COMPRESSION;
+
+  z_stream strm;
+  bzero(&strm, sizeof(z_stream));
+
+  int windowBits = 15; // the default
+  int memLevel = 8; // the default
+  if (useGzip)
+    windowBits += 16; // enable gzip header instead of zlib header
+  int retCode;
+  if ((retCode = deflateInit2(&strm, level, Z_DEFLATED, windowBits,
+                              memLevel, Z_DEFAULT_STRATEGY)) != Z_OK) {
+#ifdef DEBUG
+    NSLog(@"Failed to init for deflate w/ level %d, error %d",
+          level, retCode);
+#endif
+    return nil;
+  }
+
+  // hint the size at 1/4 the input size
+  NSMutableData *result = [NSMutableData dataWithCapacity:(length/4)];
+  unsigned char output[kChunkSize];
+
+  // setup the input
+  strm.avail_in = length;
+  strm.next_in = (unsigned char*)bytes;
+
+  // loop to collect the data
+  do {
+    // update what we're passing in
+    strm.avail_out = kChunkSize;
+    strm.next_out = output;
+    retCode = deflate(&strm, Z_FINISH);
+    if ((retCode != Z_OK) && (retCode != Z_STREAM_END)) {
+#ifdef DEBUG
+      NSLog(@"Error trying to deflate some of the payload, error %d",
+            retCode);
+#endif
+      deflateEnd(&strm);
+      return nil;
+    }
+    // collect what we got
+    unsigned gotBack = kChunkSize - strm.avail_out;
+    if (gotBack > 0) {
+      [result appendBytes:output length:gotBack];
+    }
+
+  } while (retCode == Z_OK);
+
+#ifdef DEBUG
+  if (strm.avail_in != 0) {
+    NSLog(@"thought we finished deflate w/o using all input, %u bytes left",
+          strm.avail_in);
+  }
+  if (retCode != Z_STREAM_END) {
+    NSLog(@"thought we finished deflate w/o getting a result of stream end, code %d",
+          retCode);
+  }
+#endif
+
+  // clean up
+  deflateEnd(&strm);
+
+  return result;
+} // gtm_dataByCompressingBytes:length:compressionLevel:useGzip:
+  
+
+@end
+
+
+@implementation NSData (GTMZLibAdditions)
+
++ (NSData *)gtm_dataByGzippingBytes:(const void *)bytes
+                             length:(unsigned)length {
+  return [self gtm_dataByCompressingBytes:bytes
+                                   length:length
+                         compressionLevel:Z_DEFAULT_COMPRESSION
+                                  useGzip:YES];
+} // gtm_dataByGzippingBytes:length:
+
++ (NSData *)gtm_dataByGzippingData:(NSData *)data {
+  return [self gtm_dataByCompressingBytes:[data bytes]
+                                   length:[data length]
+                         compressionLevel:Z_DEFAULT_COMPRESSION
+                                  useGzip:YES];
+} // gtm_dataByGzippingData:
+
++ (NSData *)gtm_dataByGzippingBytes:(const void *)bytes
+                             length:(unsigned)length
+                   compressionLevel:(int)level {
+  return [self gtm_dataByCompressingBytes:bytes
+                                   length:length
+                         compressionLevel:level
+                                  useGzip:YES];
+} // gtm_dataByGzippingBytes:length:level:
+
++ (NSData *)gtm_dataByGzippingData:(NSData *)data
+                  compressionLevel:(int)level {
+  return [self gtm_dataByCompressingBytes:[data bytes]
+                                   length:[data length]
+                         compressionLevel:level
+                                  useGzip:YES];
+} // gtm_dataByGzippingData:level:
+
++ (NSData *)gtm_dataByDeflatingBytes:(const void *)bytes
+                              length:(unsigned)length {
+  return [self gtm_dataByCompressingBytes:bytes
+                                   length:length
+                         compressionLevel:Z_DEFAULT_COMPRESSION
+                                  useGzip:NO];
+} // gtm_dataByDeflatingBytes:length:
+
++ (NSData *)gtm_dataByDeflatingData:(NSData *)data {
+  return [self gtm_dataByCompressingBytes:[data bytes]
+                                   length:[data length]
+                         compressionLevel:Z_DEFAULT_COMPRESSION
+                                  useGzip:NO];
+} // gtm_dataByDeflatingData:
+
++ (NSData *)gtm_dataByDeflatingBytes:(const void *)bytes
+                              length:(unsigned)length
+                    compressionLevel:(int)level {
+  return [self gtm_dataByCompressingBytes:bytes
+                                   length:length
+                         compressionLevel:level
+                                  useGzip:NO];
+} // gtm_dataByDeflatingBytes:length:level:
+
++ (NSData *)gtm_dataByDeflatingData:(NSData *)data
+                   compressionLevel:(int)level {
+  return [self gtm_dataByCompressingBytes:[data bytes]
+                                   length:[data length]
+                         compressionLevel:level
+                                  useGzip:NO];
+} // gtm_dataByDeflatingData:level:
+
++ (NSData *)gtm_dataByInflatingBytes:(const void *)bytes
+                              length:(unsigned)length {
+  if (!bytes || !length) return nil;
+
+  z_stream strm;
+  bzero(&strm, sizeof(z_stream));
+
+  // setup the input
+  strm.avail_in = length;
+  strm.next_in = (unsigned char*)bytes;
+
+  int windowBits = 15; // 15 to enable any window size
+  windowBits += 32; // and +32 to enable zlib or gzip header detection.
+  int retCode;
+  if ((retCode = inflateInit2(&strm, windowBits)) != Z_OK) {
+#ifdef DEBUG
+    NSLog(@"Failed to init for inflate, error %d", retCode);
+#endif
+    return nil;
+  }
+
+  // hint the size at 4x the input size
+  NSMutableData *result = [NSMutableData dataWithCapacity:(length*4)];
+  unsigned char output[kChunkSize];
+
+  // loop to collect the data
+  do {
+    // update what we're passing in
+    strm.avail_out = kChunkSize;
+    strm.next_out = output;
+    retCode = inflate(&strm, Z_NO_FLUSH);
+    if ((retCode != Z_OK) && (retCode != Z_STREAM_END)) {
+#ifdef DEBUG
+      NSLog(@"Error trying to inflate some of the payload, error %d",
+            retCode);
+#endif
+      inflateEnd(&strm);
+      return nil;
+    }
+    // collect what we got
+    unsigned gotBack = kChunkSize - strm.avail_out;
+    if (gotBack > 0) {
+      [result appendBytes:output length:gotBack];
+    }
+
+  } while (retCode == Z_OK);
+
+#ifdef DEBUG
+  if (strm.avail_in != 0) {
+    NSLog(@"thought we finished inflate w/o using all input, %u bytes left",
+          strm.avail_in);
+  }
+  if (retCode != Z_STREAM_END) {
+    NSLog(@"thought we finished inflate w/o getting a result of stream end, code %d",
+          retCode);
+  }
+#endif
+
+  // clean up
+  inflateEnd(&strm);
+
+  return result;
+} // gtm_dataByInflatingBytes:length:
+
++ (NSData *)gtm_dataByInflatingData:(NSData *)data {
+  return [self gtm_dataByInflatingBytes:[data bytes]
+                                 length:[data length]];
+} // gtm_dataByInflatingData:
+
+@end