QB64-PE/internal/c/parts/compression/compression.cpp

//----------------------------------------------------------------------------------------------------
//  QB64-PE Compression Library
//  Powered by miniz (https://github.com/richgel999/miniz)
//-----------------------------------------------------------------------------------------------------

#include "compression.h"
#include "../../libqb.h"
#include "miniz.h"

uint32_t func__adler32(qbs *text) {
    if (!text->len) return 1;
    return (uint32_t) adler32(1, text->chr, text->len);
}

uint32_t func__crc32(qbs *text) {
    if (!text->len) return 0;
    return (uint32_t) crc32(0, text->chr, text->len);
}

qbs *func__deflate(qbs *text) {
    uLongf filesize = (uint32_t)text->len; // length of the text
    uLongf compsize = compressBound(filesize);
    unsigned char *dest = (unsigned char *)malloc(compsize);
    int32_t result = compress(dest, &compsize, text->chr, filesize);
    qbs *ret = qbs_new(compsize, 1);
    memcpy(ret->chr, dest, compsize);
    free(dest);
    return ret;
}

qbs *func__inflate(qbs *text, int64_t originalsize, int32_t passed) {
    int32_t result = 0;
    if (passed == 1) {
        uLongf uncompsize = originalsize;
        unsigned char *dest = (unsigned char *)malloc(originalsize);
        int32_t result = uncompress(dest, &uncompsize, text->chr, text->len);
        qbs *ret = qbs_new(uncompsize, 1);
        memcpy(ret->chr, dest, uncompsize);
        free(dest);
        return ret;
    } else {
        uLongf uncompsize = 0;
        unsigned char *dest;
        do {
            uncompsize = uncompsize + 10000000; // 10 mb original buffer, resized by 10 mb each pass until it's large enough to hold the uncompressed data.
            dest = (unsigned char *)malloc(uncompsize);
            result = uncompress(dest, &uncompsize, text->chr, text->len);
            if (result == Z_BUF_ERROR)
                free(dest);              // if the buffer is too small, free the old buffer
        } while (result == Z_BUF_ERROR); // and try again with a larger buffer
        qbs *ret = qbs_new(uncompsize, 1);
        memcpy(ret->chr, dest, uncompsize);
        free(dest);
        return ret;
    }
}