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NSData+GZIP from https://github.com/nicklockwood/GZIP minified for Segment
//
// GZIP.h
//
// Version 1.1.1
//
// Created by Nick Lockwood on 03/06/2012.
// Copyright (C) 2012 Charcoal Design
//
// Distributed under the permissive zlib License
// Get the latest version from here:
//
// https://github.com/nicklockwood/GZIP
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
#import <Foundation/Foundation.h>
@interface NSData (GZIP)
- (nullable NSData *)gzippedData;
@end
//
// GZIP.m
//
// Version 1.1.1
//
// Created by Nick Lockwood on 03/06/2012.
// Copyright (C) 2012 Charcoal Design
//
// Distributed under the permissive zlib License
// Get the latest version from here:
//
// https://github.com/nicklockwood/GZIP
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
#import "NSData+GZIP.h"
#import <zlib.h>
#import <dlfcn.h>
#pragma clang diagnostic ignored "-Wcast-qual"
@implementation NSData (GZIP)
static void *libzOpen()
{
static void *libz;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
libz = dlopen("/usr/lib/libz.dylib", RTLD_LAZY);
});
return libz;
}
- (NSData *)gzippedDataWithCompressionLevel:(float)level
{
if (self.length == 0 || [self isGzippedData]) {
return self;
}
void *libz = libzOpen();
int (*deflateInit2_)(z_streamp, int, int, int, int, int, const char *, int) =
(int (*)(z_streamp, int, int, int, int, int, const char *, int))dlsym(libz, "deflateInit2_");
int (*deflate)(z_streamp, int) = (int (*)(z_streamp, int))dlsym(libz, "deflate");
int (*deflateEnd)(z_streamp) = (int (*)(z_streamp))dlsym(libz, "deflateEnd");
z_stream stream;
stream.zalloc = Z_NULL;
stream.zfree = Z_NULL;
stream.opaque = Z_NULL;
stream.avail_in = (uint)self.length;
stream.next_in = (Bytef *)(void *)self.bytes;
stream.total_out = 0;
stream.avail_out = 0;
static const NSUInteger ChunkSize = 16384;
NSMutableData *output = nil;
int compression = (level < 0.0f) ? Z_DEFAULT_COMPRESSION : (int)(roundf(level * 9));
if (deflateInit2(&stream, compression, Z_DEFLATED, 31, 8, Z_DEFAULT_STRATEGY) == Z_OK) {
output = [NSMutableData dataWithLength:ChunkSize];
while (stream.avail_out == 0) {
if (stream.total_out >= output.length) {
output.length += ChunkSize;
}
stream.next_out = (uint8_t *)output.mutableBytes + stream.total_out;
stream.avail_out = (uInt)(output.length - stream.total_out);
deflate(&stream, Z_FINISH);
}
deflateEnd(&stream);
output.length = stream.total_out;
}
return output;
}
- (NSData *)gzippedData
{
return [self gzippedDataWithCompressionLevel:-1.0f];
}
- (BOOL)isGzippedData
{
const UInt8 *bytes = (const UInt8 *)self.bytes;
return (self.length >= 2 && bytes[0] == 0x1f && bytes[1] == 0x8b);
}
@end
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