File content as of revision 0:54f5be781526:

#include "mbed.h"
#include "rtos.h"

#include "zlib.h"


static const char *newline = "\r\n";


BusOut leds(LED1, LED2, LED3, LED4);
LocalFileSystem fs("local");



/** GUNZIP a from src buffer to dst buffer
 @param dst : destination buffer
 @param dst_length : pointer to destination buffer length
 @param src : source buffer
 @param src_length : source buffer length
 @return Z_OK on success, zlib error (<0) on failure
 */
int gunzip(unsigned char *dst, unsigned long *dst_length, unsigned char *src, unsigned long src_length)
{
    z_stream stream;
    memset(&stream, 0, sizeof(stream));

    stream.next_in = src;
    stream.avail_in = src_length;

    stream.next_out = dst;
    stream.avail_out = *dst_length;

    int rv = inflateInit2(&stream, 15 + 16);
    if (Z_OK == rv) {
        rv = inflate(&stream, Z_NO_FLUSH);
        if (Z_STREAM_END == rv) {
            inflateEnd(&stream);
            rv = Z_OK;
        }
    }

    if (Z_OK == rv) {
        *dst_length = stream.total_out;
    } else {
        *dst_length = 0;
    }

    return rv;
}

/** GUNZIP a from src buffer to dst buffer
 @param dst : destination buffer
 @param dst_length : pointer to destination buffer length
 @param src : source buffer
 @param src_length : source buffer length
 @return Z_OK on success, zlib error (<0) on failure
 */
int gzip(unsigned char *dst, unsigned long *dst_length, unsigned char *src, unsigned long src_length)
{
    z_stream        stream;
    memset(&stream, 0, sizeof(stream));

    stream.next_in = src;
    stream.avail_in = src_length;

    stream.next_out = Z_NULL;
    stream.avail_out = 0;

    /* add 16 to MAX_WBITS to specify gzip format - it gets taken off again in defaultInit2 */
    int rv = deflateInit2(&stream, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 16 + MAX_WBITS, MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
    if (Z_OK == rv) {
        unsigned long dst_bound = deflateBound(&stream, stream.avail_in) + 12; /* 12 bytes for the gzip header */
        if (dst_bound > *dst_length) {
            rv = Z_MEM_ERROR;
        } else {
            stream.next_out   = dst;
            stream.avail_out = dst_bound;
        }
    }

    if (Z_OK == rv) {
        gz_header        header;
        memset(&header, 0, sizeof(header));
        rv = deflateSetHeader(&stream, &header);
    }

    if (Z_OK == rv) {
        rv = deflate(&stream, Z_FINISH);
        if (Z_STREAM_END == rv) {
            rv = deflateEnd(&stream);
        }
    }

    if (Z_OK == rv) {
        *dst_length = stream.total_out;
    } else {
        *dst_length = 0;
    }

    return rv;
}


int main(int argc, char**argv)
{

    unsigned char input_data[2048];
    unsigned long input_data_length = 0;
    FILE *ifp = fopen("/local/src.txt", "r");
    if (ifp) {
        int br = fread(input_data, 1, sizeof(input_data), ifp);
        fclose(ifp);
        input_data_length = br;
    }
    printf("%s:%d: input_data_length:%lu%s", __FILE__, __LINE__, input_data_length, newline);


    unsigned char gzip_data[2048];
    unsigned long gzip_data_length = 0;
    if (input_data_length > 0) {
        gzip_data_length = sizeof(gzip_data);
        int rv = gzip(gzip_data, &gzip_data_length, input_data, input_data_length);
        if (Z_OK == rv) {
            FILE *ofp = fopen("/local/dst.gz", "w");
            if (ofp) {
                int bw = fwrite(gzip_data, 1, gzip_data_length, ofp);
                fclose(ofp);
            }
        } else {
            printf("%s:%d: %d%s", __FILE__, __LINE__, rv, newline);
        }
    }
    printf("%s:%d: gzip_data_length:%lu%s", __FILE__, __LINE__, gzip_data_length, newline);


    unsigned char output_data[2048];
    unsigned long output_data_length = 0;
    if (gzip_data_length > 0) {
        output_data_length = sizeof(output_data);
        int rv = gunzip(output_data, &output_data_length, gzip_data, gzip_data_length);
        if (Z_OK != rv) {
            printf("%s:%d: %d%s", __FILE__, __LINE__, rv, newline);
        }
    }
    printf("%s:%d: output_data_length:%lu%s", __FILE__, __LINE__, output_data_length, newline);


    if (input_data_length > 0 and input_data_length > 0) {
        bool input_matches_output = false;
        if (input_data_length == output_data_length) {
            input_matches_output = true;
            for ( size_t i = 0 ; input_matches_output && i < input_data_length ; i++ ) {
                if (input_data[i] != output_data[i]) {
                    input_matches_output = false;
                }
            }
        }
        printf("%s:%d: input (%lu bytes) %s output (%lu bytes)%s", __FILE__, __LINE__, input_data_length, input_matches_output?"matches":"does not match", output_data_length, newline);
    } else {
        printf("%s:%d: input and/or output length is 0%s", __FILE__, __LINE__, newline);
    }

    while (true) {
        leds = (leds ^ 1);
        Thread::wait(1000);
    }
}