Initial PNG CC Implementation
Signed-off-by: Pin <wf6DJd8a3xSSCZbn@protonmail.com>
This commit is contained in:
Pin
132
src/compress_util.c
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132
src/compress_util.c
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#include <stdio.h>
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#include <stdlib.h>
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#include <assert.h>
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#include <errno.h>
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#include "compress_util.h"
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#define CHUNK 1024
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/*
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* Built from exmaple provided in: https://zlib.net/zlib_how.html
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*/
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void zlib_decompress_data(unsigned char *data_chunk, size_t file_length, unsigned char **buff, size_t *sz) {
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int ret;
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unsigned int have;
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z_stream strm;
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// Adding one to zero here
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unsigned char out[CHUNK];
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unsigned char in[CHUNK];
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errno=0;
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FILE *data_stream = fmemopen(data_chunk, file_length, "r");
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FILE *of = open_memstream((char**)buff, sz);
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if(data_stream == NULL) {
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perror("F MEM OPEN");
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}
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strm.zalloc = Z_NULL;
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strm.zfree = Z_NULL;
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strm.opaque = Z_NULL;
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strm.avail_in = 0;
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strm.next_in = Z_NULL;
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ret = inflateInit(&strm);
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if(ret != Z_OK) {
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return;
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}
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do {
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strm.avail_in = fread(in, 1, CHUNK, data_stream);
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if(ferror(data_stream)) {
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(void)inflateEnd(&strm);
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return;
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}
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if(strm.avail_in == 0) {
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break;
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}
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strm.next_in = in;
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do {
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strm.avail_out = CHUNK;
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strm.next_out = out;
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ret = inflate(&strm, Z_NO_FLUSH);
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assert(ret != Z_STREAM_ERROR);
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switch(ret) {
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case Z_NEED_DICT:
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ret = Z_DATA_ERROR;
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case Z_DATA_ERROR:
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case Z_MEM_ERROR:
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(void)inflateEnd(&strm);
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printf("Error: %d\n", ret);
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printf("MSG: %s\n", (char*)strm.msg);
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return;
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}
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have = CHUNK - strm.avail_out;
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fwrite(out, 1, have, of);
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} while(strm.avail_out == 0);
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} while(ret != Z_STREAM_END);
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(void)inflateEnd(&strm);
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fclose(data_stream);
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fclose(of);
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}
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/*
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* Built from exmaple provided in: https://zlib.net/zlib_how.html
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*/
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void zlib_compress_data(unsigned char *data_chunk, size_t file_length, unsigned char **buff, size_t *sz) {
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int ret, flush;
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unsigned int have;
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z_stream strm;
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unsigned char in[CHUNK];
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unsigned char out[CHUNK];
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int level = 9;
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int method = Z_DEFLATED;
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int windowBits = 10;
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int memLevel = 9;
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//int strategy = Z_DEFAULT_STRATEGY;
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int strategy = Z_FILTERED;
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FILE *data_stream = fmemopen(data_chunk, file_length, "r");
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FILE *out_data_stream = NULL;
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out_data_stream = open_memstream((char**)buff, sz);
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strm.zalloc = Z_NULL;
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strm.zfree = Z_NULL;
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strm.opaque = Z_NULL;
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ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
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if (ret != Z_OK) {
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return;
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}
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do {
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strm.avail_in = fread(in, 1, CHUNK, data_stream);
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if (ferror(data_stream)) {
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(void)deflateEnd(&strm);
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return;
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}
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flush = feof(data_stream) ? Z_FINISH : Z_NO_FLUSH;
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strm.next_in = in;
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do {
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strm.avail_out = CHUNK;
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strm.next_out = out;
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ret = deflate(&strm, flush);
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assert(ret != Z_STREAM_ERROR);
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have = CHUNK - strm.avail_out;
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if(fwrite(out, 1, have, out_data_stream) != have || ferror(out_data_stream)) {
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(void)deflateEnd(&strm);
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return;
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}
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} while(strm.avail_out == 0);
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assert(strm.avail_in == 0);
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} while(flush != Z_FINISH);
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assert(ret == Z_STREAM_END);
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fclose(data_stream);
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fclose(out_data_stream);
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(void)deflateEnd(&strm);
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}
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92
src/crc_util.c
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92
src/crc_util.c
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@@ -0,0 +1,92 @@
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#include <stdio.h>
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#include <stdlib.h>
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#include "crc_util.h"
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const long png_signature[8] = { 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a };
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int check_header_length(unsigned char *addr, long offset) {
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unsigned int res = 0;
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for( int i = 0; i < 4; i++ ) {
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res |= addr[offset+i];
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if (i < 3) {
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res <<= 8;
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}
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}
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return res;
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}
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int check_file_header(char *addr) {
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int signature_match = 0;
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for( int i = 0; i < 8; i++ ) {
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if (addr[i] != png_signature[i]) {
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signature_match = 1;
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}
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}
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printf("Sig Match: %d\n", signature_match);
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return signature_match;
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}
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void populate_idat_png(unsigned char *addr, struct PNG_IDAT_FILE_STRUCT *png_data, unsigned long offset) {
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unsigned long cur_idat_length = 0;
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for(int i = 0; i < 4; i++){
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png_data->idat_length[i] = addr[i+offset];
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}
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for(int i = 0; i < 4; i++){
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cur_idat_length += (png_data->idat_length[i] << (24-(8*i)));
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}
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for(int i = 0; i < 4; i++){
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png_data->idat_header[i] = addr[i+offset+4];
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}
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}
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void populate_start_png(unsigned char *addr, struct PNG_START_FILE_STRUCT *png_data) {
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union{
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unsigned char *data;
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struct PNG_START_FILE_STRUCT *png_data;
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}png;
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png.png_data = png_data;
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for(int i = 0; i < sizeof(struct PNG_START_FILE_STRUCT); i++) {
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png.data[i] = addr[i];
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}
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}
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int create_cc_file(unsigned char *addr, unsigned long file_length) {
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FILE *fp;
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fp = fopen("png2.png", "w");
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if(fp == NULL) {
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return EXIT_FAILURE;
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}
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for(int i = 0; i < file_length; i++){
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fputc(addr[i], fp);
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}
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fclose(fp);
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return 0;
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}
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unsigned char* file_to_char_array(FILE *in_file, size_t* size) {
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unsigned int c;
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unsigned long file_data_cap = 8;
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unsigned char* file_data = calloc(file_data_cap, sizeof(unsigned char));
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for(size_t i = 0;(c = fgetc(in_file)) != EOF; i++) {
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if(i == file_data_cap) {
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file_data_cap *= 2;
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file_data = reallocarray(file_data, file_data_cap, sizeof(unsigned char));
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if(file_data == NULL) {
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perror("FAILED ARRAY RESIZE");
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return NULL;
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}
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}
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file_data[i] = c;
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*size += 1;
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}
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return file_data;
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}
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