Edge Zlib

- return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY, version, stream_size);
+ return deflateInit2_(strm, level, Z_DEFLATED, -15, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY, version, stream_size);

- return inflateInit2_(strm, DEF_WBITS, version, stream_size);
+ return inflateInit2_(strm, -15, version, stream_size);

// Read header as BE bytes
let src_size: u16 = u16::from_be_bytes([data[i], data[i + 1]]);
let comp_size: u16 = u16::from_be_bytes([data[i + 2], data[i + 3]]);

#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <stdlib.h>
#include "zlib.h"
 
#define CHUNK 0x4000
 
 
int def(const unsigned char *source, size_t source_size, unsigned char **dest, size_t *dest_size, int level) {
    int ret, flush;
    unsigned have;
    z_stream strm;
    unsigned char in[CHUNK];
    unsigned char out[CHUNK];
 
    /* allocate deflate state */
    strm.zalloc = Z_NULL;
    strm.zfree = Z_NULL;
    strm.opaque = Z_NULL;
    ret = deflateInit(&strm, level);
    if (ret != Z_OK)
        return ret;
 
    size_t dest_offset = 0;
 
    /* compress until end of input */
    do {
        // Copy data from source buffer to input buffer
        size_t bytes_to_copy = (source_size < CHUNK) ? source_size : CHUNK;
        memcpy(in, source, bytes_to_copy);
        source += bytes_to_copy;
        source_size -= bytes_to_copy;
 
        strm.avail_in = bytes_to_copy;
        flush = (source_size == 0) ? Z_FINISH : Z_NO_FLUSH;
        strm.next_in = in;
 
        /* run deflate() on input until output buffer not full, finish
           compression if all of source has been processed */
        do {
            strm.avail_out = CHUNK;
            strm.next_out = out;
            ret = deflate(&strm, flush);    /* no bad return value */
            assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
            have = CHUNK - strm.avail_out;
 
            // Copy compressed data to the output buffer
            memcpy(*dest + dest_offset, out, have);
            dest_offset += have;
        } while (strm.avail_out == 0);
        assert(strm.avail_in == 0);
 
    } while (flush != Z_FINISH);
 
    // Set the actual size of the compressed data in dest_size
    if (dest_size) {
        *dest_size = dest_offset;
    }
 
    assert(ret == Z_STREAM_END);
 
    /* clean up and return */
    (void)deflateEnd(&strm);
    return Z_OK;
}
 
/* Decompress from file source to file dest until stream ends or EOF.
   inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
   allocated for processing, Z_DATA_ERROR if the deflate data is
   invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
   the version of the library linked dgo not match, or Z_ERRNO if there
   is an error reading or writing the files. */
int inf(unsigned char *source, size_t source_size, unsigned char **dest, size_t dest_size)
{
    int ret;
    unsigned have;
    z_stream strm;
    unsigned char in[CHUNK];
    unsigned char out[CHUNK];
 
    // Allocate memory for the destination buffer
    *dest = (unsigned char*)malloc(dest_size); // Allocate enough space for the decompressed data
    dest_size = 0;  // Initialize the output size
 
    /* allocate inflate state */
    strm.zalloc = Z_NULL;
    strm.zfree = Z_NULL;
    strm.opaque = Z_NULL;
    strm.avail_in = 0;
    strm.next_in = Z_NULL;
    ret = inflateInit(&strm);
    if (ret != Z_OK)
        return ret;
 
    /* decompress until deflate stream ends or end of file */
    strm.avail_in = source_size;
    strm.next_in = source;
 
    do {
        /* run inflate() on input until output buffer not full */
        do {
 
            strm.avail_out = CHUNK;
            strm.next_out = out;
            ret = inflate(&strm, Z_NO_FLUSH);
            assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
            switch (ret) {
            case Z_NEED_DICT:
                ret = Z_DATA_ERROR;     /* and fall through */
            case Z_DATA_ERROR:
            case Z_MEM_ERROR:
                (void)inflateEnd(&strm);
                return ret;
            }
            have = CHUNK - strm.avail_out;
            
            // Copy decompressed data to the output buffer
            memcpy(*dest + dest_size, out, have);
            dest_size += have;
 
 
        } while (strm.avail_out == 0);
 
        /* done when inflate() says it's done */
    } while (ret != Z_STREAM_END);
 
    /* clean up and return */
    (void)inflateEnd(&strm);
    return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}
 
/* report a zlib or i/o error */
void zerr(int ret)
{
    fputs("zpipe: ", stderr);
    switch (ret) {
    case Z_ERRNO:
        if (ferror(stdin))
            fputs("error reading stdin\n", stderr);
        if (ferror(stdout))
            fputs("error writing stdout\n", stderr);
        break;
    case Z_STREAM_ERROR:
        fputs("invalid compression level\n", stderr);
        break;
    case Z_DATA_ERROR:
        fputs("invalid or incomplete deflate data\n", stderr);
        break;
    case Z_MEM_ERROR:
        fputs("out of memory\n", stderr);
        break;
    case Z_VERSION_ERROR:
        fputs("zlib version mismatch!\n", stderr);
    }
}
 
// take input buffer and input buffer size
#if __cplusplus
extern "C" {
#endif
 
ZEXTERN int ZEXPORT inflate_noheader(unsigned char *source, size_t source_size, unsigned char **dest, size_t dest_size)
{
    return inf(source, source_size, dest, dest_size);
}
 
ZEXTERN int ZEXPORT deflate_noheader(const unsigned char *source, size_t source_size, unsigned char **dest, size_t *dest_size)
{
    return def(source, source_size, dest, dest_size, 9);
}
 
#if __cplusplus
}
#endif