--- /dev/null
+// Copyright 2018 Google
+//
+// 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 "GULNSData+zlib.h"
+
+#import <zlib.h>
+
+#define kChunkSize 1024
+#define Z_DEFAULT_COMPRESSION (-1)
+
+NSString *const GULNSDataZlibErrorDomain = @"com.google.GULNSDataZlibErrorDomain";
+NSString *const GULNSDataZlibErrorKey = @"GULNSDataZlibErrorKey";
+NSString *const GULNSDataZlibRemainingBytesKey = @"GULNSDataZlibRemainingBytesKey";
+
+@implementation NSData (GULGzip)
+
++ (NSData *)gul_dataByInflatingGzippedData:(NSData *)data error:(NSError **)error {
+ const void *bytes = [data bytes];
+ NSUInteger length = [data length];
+ if (!bytes || !length) {
+ return nil;
+ }
+
+#if defined(__LP64__) && __LP64__
+ // Don't support > 32bit length for 64 bit, see note in header.
+ if (length > UINT_MAX) {
+ return nil;
+ }
+#endif
+
+ z_stream strm;
+ bzero(&strm, sizeof(z_stream));
+
+ // Setup the input.
+ strm.avail_in = (unsigned int)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) {
+ if (error) {
+ NSDictionary *userInfo = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:retCode]
+ forKey:GULNSDataZlibErrorKey];
+ *error = [NSError errorWithDomain:GULNSDataZlibErrorDomain
+ code:GULNSDataZlibErrorInternal
+ userInfo:userInfo];
+ }
+ 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)) {
+ if (error) {
+ NSMutableDictionary *userInfo =
+ [NSMutableDictionary dictionaryWithObject:[NSNumber numberWithInt:retCode]
+ forKey:GULNSDataZlibErrorKey];
+ if (strm.msg) {
+ NSString *message = [NSString stringWithUTF8String:strm.msg];
+ if (message) {
+ [userInfo setObject:message forKey:NSLocalizedDescriptionKey];
+ }
+ }
+ *error = [NSError errorWithDomain:GULNSDataZlibErrorDomain
+ code:GULNSDataZlibErrorInternal
+ userInfo:userInfo];
+ }
+ 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);
+
+ // Make sure there wasn't more data tacked onto the end of a valid compressed stream.
+ if (strm.avail_in != 0) {
+ if (error) {
+ NSDictionary *userInfo =
+ [NSDictionary dictionaryWithObject:[NSNumber numberWithUnsignedInt:strm.avail_in]
+ forKey:GULNSDataZlibRemainingBytesKey];
+ *error = [NSError errorWithDomain:GULNSDataZlibErrorDomain
+ code:GULNSDataZlibErrorDataRemaining
+ userInfo:userInfo];
+ }
+ result = nil;
+ }
+ // The only way out of the loop was by hitting the end of the stream.
+ NSAssert(retCode == Z_STREAM_END,
+ @"Thought we finished inflate w/o getting a result of stream end, code %d", retCode);
+
+ // Clean up.
+ inflateEnd(&strm);
+
+ return result;
+}
+
++ (NSData *)gul_dataByGzippingData:(NSData *)data error:(NSError **)error {
+ const void *bytes = [data bytes];
+ NSUInteger length = [data length];
+
+ int level = Z_DEFAULT_COMPRESSION;
+ if (!bytes || !length) {
+ return nil;
+ }
+
+#if defined(__LP64__) && __LP64__
+ // Don't support > 32bit length for 64 bit, see note in header.
+ if (length > UINT_MAX) {
+ if (error) {
+ *error = [NSError errorWithDomain:GULNSDataZlibErrorDomain
+ code:GULNSDataZlibErrorGreaterThan32BitsToCompress
+ userInfo:nil];
+ }
+ return nil;
+ }
+#endif
+
+ z_stream strm;
+ bzero(&strm, sizeof(z_stream));
+
+ int memLevel = 8; // Default.
+ int windowBits = 15 + 16; // Enable gzip header instead of zlib header.
+
+ int retCode;
+ if ((retCode = deflateInit2(&strm, level, Z_DEFLATED, windowBits, memLevel,
+ Z_DEFAULT_STRATEGY)) != Z_OK) {
+ if (error) {
+ NSDictionary *userInfo = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:retCode]
+ forKey:GULNSDataZlibErrorKey];
+ *error = [NSError errorWithDomain:GULNSDataZlibErrorDomain
+ code:GULNSDataZlibErrorInternal
+ userInfo:userInfo];
+ }
+ 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 = (unsigned int)length;
+ strm.next_in = (unsigned char *)bytes;
+
+ // 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)) {
+ if (error) {
+ NSDictionary *userInfo = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:retCode]
+ forKey:GULNSDataZlibErrorKey];
+ *error = [NSError errorWithDomain:GULNSDataZlibErrorDomain
+ code:GULNSDataZlibErrorInternal
+ userInfo:userInfo];
+ }
+ 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);
+
+ // If the loop exits, it used all input and the stream ended.
+ NSAssert(strm.avail_in == 0,
+ @"Should have finished deflating without using all input, %u bytes left", strm.avail_in);
+ NSAssert(retCode == Z_STREAM_END,
+ @"thought we finished deflate w/o getting a result of stream end, code %d", retCode);
+
+ // Clean up.
+ deflateEnd(&strm);
+
+ return result;
+}
+
+@end
fnp / wl-app.git / blobdiff