Jonathon Fletcher / Mbed 2 deprecated MBEDZlib

Basic gzip/gunzip in memory buffer examples using zlib code.

Dependencies:   mbed-rtos mbed

There are small changes needed to the zconf.h file in the zlib distribution (I used 1.2.7). The zlib license applies to the zlib code - I have only imported a subset of the source.

The MBED has limited memory, so we need the following (near the top of zconf.h) to restrict memory allocation sizes:

#define    MAX_MEM_LEVEL    3
#define    MAX_WBITS        10

Because MAX_MEM_LEVEL and MAX_WBITS are so much lower than the default, there is a danger that the mbed cannot gunzip data compressed by a 'normal' zlib build. My use-case is to gzip on the mbed more than gunzip on the mbed so I have not given much time to this issue.

I also included this (also near the top of zconf.h) to prefix defines with Z_

#define    Z_PREFIX

In zconf.h, in the zlib distribution, the includes for <fcntl.h> and <sys/types.h> need commenting out when using the online compiler. No need when using GCC4MBED.

I also looked at miniz. I chose zlib because I needed the gzip headers and miniz does not implement them.

The sample main.cpp reads source data, compresses it, decompresses it, and finally compares the input data with the output data to confirm they are the same.

    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);
    }

zlib/inffixed.h@0:54f5be781526, 2012-10-21 (annotated)

Committer:
jonathonfletcher
Date:
Sun Oct 21 07:46:41 2012 +0000
Revision:
0:54f5be781526
initial checkin

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jonathonfletcher 0:54f5be781526 1 /* inffixed.h -- table for decoding fixed codes
jonathonfletcher 0:54f5be781526 2 * Generated automatically by makefixed().
jonathonfletcher 0:54f5be781526 3 */
jonathonfletcher 0:54f5be781526 4
jonathonfletcher 0:54f5be781526 5 /* WARNING: this file should *not* be used by applications.
jonathonfletcher 0:54f5be781526 6 It is part of the implementation of this library and is
jonathonfletcher 0:54f5be781526 7 subject to change. Applications should only use zlib.h.
jonathonfletcher 0:54f5be781526 8 */
jonathonfletcher 0:54f5be781526 9
jonathonfletcher 0:54f5be781526 10 static const code lenfix[512] = {
jonathonfletcher 0:54f5be781526 11 {96,7,0},{0,8,80},{0,8,16},{20,8,115},{18,7,31},{0,8,112},{0,8,48},
jonathonfletcher 0:54f5be781526 12 {0,9,192},{16,7,10},{0,8,96},{0,8,32},{0,9,160},{0,8,0},{0,8,128},
jonathonfletcher 0:54f5be781526 13 {0,8,64},{0,9,224},{16,7,6},{0,8,88},{0,8,24},{0,9,144},{19,7,59},
jonathonfletcher 0:54f5be781526 14 {0,8,120},{0,8,56},{0,9,208},{17,7,17},{0,8,104},{0,8,40},{0,9,176},
jonathonfletcher 0:54f5be781526 15 {0,8,8},{0,8,136},{0,8,72},{0,9,240},{16,7,4},{0,8,84},{0,8,20},
jonathonfletcher 0:54f5be781526 16 {21,8,227},{19,7,43},{0,8,116},{0,8,52},{0,9,200},{17,7,13},{0,8,100},
jonathonfletcher 0:54f5be781526 17 {0,8,36},{0,9,168},{0,8,4},{0,8,132},{0,8,68},{0,9,232},{16,7,8},
jonathonfletcher 0:54f5be781526 18 {0,8,92},{0,8,28},{0,9,152},{20,7,83},{0,8,124},{0,8,60},{0,9,216},
jonathonfletcher 0:54f5be781526 19 {18,7,23},{0,8,108},{0,8,44},{0,9,184},{0,8,12},{0,8,140},{0,8,76},
jonathonfletcher 0:54f5be781526 20 {0,9,248},{16,7,3},{0,8,82},{0,8,18},{21,8,163},{19,7,35},{0,8,114},
jonathonfletcher 0:54f5be781526 21 {0,8,50},{0,9,196},{17,7,11},{0,8,98},{0,8,34},{0,9,164},{0,8,2},
jonathonfletcher 0:54f5be781526 22 {0,8,130},{0,8,66},{0,9,228},{16,7,7},{0,8,90},{0,8,26},{0,9,148},
jonathonfletcher 0:54f5be781526 23 {20,7,67},{0,8,122},{0,8,58},{0,9,212},{18,7,19},{0,8,106},{0,8,42},
jonathonfletcher 0:54f5be781526 24 {0,9,180},{0,8,10},{0,8,138},{0,8,74},{0,9,244},{16,7,5},{0,8,86},
jonathonfletcher 0:54f5be781526 25 {0,8,22},{64,8,0},{19,7,51},{0,8,118},{0,8,54},{0,9,204},{17,7,15},
jonathonfletcher 0:54f5be781526 26 {0,8,102},{0,8,38},{0,9,172},{0,8,6},{0,8,134},{0,8,70},{0,9,236},
jonathonfletcher 0:54f5be781526 27 {16,7,9},{0,8,94},{0,8,30},{0,9,156},{20,7,99},{0,8,126},{0,8,62},
jonathonfletcher 0:54f5be781526 28 {0,9,220},{18,7,27},{0,8,110},{0,8,46},{0,9,188},{0,8,14},{0,8,142},
jonathonfletcher 0:54f5be781526 29 {0,8,78},{0,9,252},{96,7,0},{0,8,81},{0,8,17},{21,8,131},{18,7,31},
jonathonfletcher 0:54f5be781526 30 {0,8,113},{0,8,49},{0,9,194},{16,7,10},{0,8,97},{0,8,33},{0,9,162},
jonathonfletcher 0:54f5be781526 31 {0,8,1},{0,8,129},{0,8,65},{0,9,226},{16,7,6},{0,8,89},{0,8,25},
jonathonfletcher 0:54f5be781526 32 {0,9,146},{19,7,59},{0,8,121},{0,8,57},{0,9,210},{17,7,17},{0,8,105},
jonathonfletcher 0:54f5be781526 33 {0,8,41},{0,9,178},{0,8,9},{0,8,137},{0,8,73},{0,9,242},{16,7,4},
jonathonfletcher 0:54f5be781526 34 {0,8,85},{0,8,21},{16,8,258},{19,7,43},{0,8,117},{0,8,53},{0,9,202},
jonathonfletcher 0:54f5be781526 35 {17,7,13},{0,8,101},{0,8,37},{0,9,170},{0,8,5},{0,8,133},{0,8,69},
jonathonfletcher 0:54f5be781526 36 {0,9,234},{16,7,8},{0,8,93},{0,8,29},{0,9,154},{20,7,83},{0,8,125},
jonathonfletcher 0:54f5be781526 37 {0,8,61},{0,9,218},{18,7,23},{0,8,109},{0,8,45},{0,9,186},{0,8,13},
jonathonfletcher 0:54f5be781526 38 {0,8,141},{0,8,77},{0,9,250},{16,7,3},{0,8,83},{0,8,19},{21,8,195},
jonathonfletcher 0:54f5be781526 39 {19,7,35},{0,8,115},{0,8,51},{0,9,198},{17,7,11},{0,8,99},{0,8,35},
jonathonfletcher 0:54f5be781526 40 {0,9,166},{0,8,3},{0,8,131},{0,8,67},{0,9,230},{16,7,7},{0,8,91},
jonathonfletcher 0:54f5be781526 41 {0,8,27},{0,9,150},{20,7,67},{0,8,123},{0,8,59},{0,9,214},{18,7,19},
jonathonfletcher 0:54f5be781526 42 {0,8,107},{0,8,43},{0,9,182},{0,8,11},{0,8,139},{0,8,75},{0,9,246},
jonathonfletcher 0:54f5be781526 43 {16,7,5},{0,8,87},{0,8,23},{64,8,0},{19,7,51},{0,8,119},{0,8,55},
jonathonfletcher 0:54f5be781526 44 {0,9,206},{17,7,15},{0,8,103},{0,8,39},{0,9,174},{0,8,7},{0,8,135},
jonathonfletcher 0:54f5be781526 45 {0,8,71},{0,9,238},{16,7,9},{0,8,95},{0,8,31},{0,9,158},{20,7,99},
jonathonfletcher 0:54f5be781526 46 {0,8,127},{0,8,63},{0,9,222},{18,7,27},{0,8,111},{0,8,47},{0,9,190},
jonathonfletcher 0:54f5be781526 47 {0,8,15},{0,8,143},{0,8,79},{0,9,254},{96,7,0},{0,8,80},{0,8,16},
jonathonfletcher 0:54f5be781526 48 {20,8,115},{18,7,31},{0,8,112},{0,8,48},{0,9,193},{16,7,10},{0,8,96},
jonathonfletcher 0:54f5be781526 49 {0,8,32},{0,9,161},{0,8,0},{0,8,128},{0,8,64},{0,9,225},{16,7,6},
jonathonfletcher 0:54f5be781526 50 {0,8,88},{0,8,24},{0,9,145},{19,7,59},{0,8,120},{0,8,56},{0,9,209},
jonathonfletcher 0:54f5be781526 51 {17,7,17},{0,8,104},{0,8,40},{0,9,177},{0,8,8},{0,8,136},{0,8,72},
jonathonfletcher 0:54f5be781526 52 {0,9,241},{16,7,4},{0,8,84},{0,8,20},{21,8,227},{19,7,43},{0,8,116},
jonathonfletcher 0:54f5be781526 53 {0,8,52},{0,9,201},{17,7,13},{0,8,100},{0,8,36},{0,9,169},{0,8,4},
jonathonfletcher 0:54f5be781526 54 {0,8,132},{0,8,68},{0,9,233},{16,7,8},{0,8,92},{0,8,28},{0,9,153},
jonathonfletcher 0:54f5be781526 55 {20,7,83},{0,8,124},{0,8,60},{0,9,217},{18,7,23},{0,8,108},{0,8,44},
jonathonfletcher 0:54f5be781526 56 {0,9,185},{0,8,12},{0,8,140},{0,8,76},{0,9,249},{16,7,3},{0,8,82},
jonathonfletcher 0:54f5be781526 57 {0,8,18},{21,8,163},{19,7,35},{0,8,114},{0,8,50},{0,9,197},{17,7,11},
jonathonfletcher 0:54f5be781526 58 {0,8,98},{0,8,34},{0,9,165},{0,8,2},{0,8,130},{0,8,66},{0,9,229},
jonathonfletcher 0:54f5be781526 59 {16,7,7},{0,8,90},{0,8,26},{0,9,149},{20,7,67},{0,8,122},{0,8,58},
jonathonfletcher 0:54f5be781526 60 {0,9,213},{18,7,19},{0,8,106},{0,8,42},{0,9,181},{0,8,10},{0,8,138},
jonathonfletcher 0:54f5be781526 61 {0,8,74},{0,9,245},{16,7,5},{0,8,86},{0,8,22},{64,8,0},{19,7,51},
jonathonfletcher 0:54f5be781526 62 {0,8,118},{0,8,54},{0,9,205},{17,7,15},{0,8,102},{0,8,38},{0,9,173},
jonathonfletcher 0:54f5be781526 63 {0,8,6},{0,8,134},{0,8,70},{0,9,237},{16,7,9},{0,8,94},{0,8,30},
jonathonfletcher 0:54f5be781526 64 {0,9,157},{20,7,99},{0,8,126},{0,8,62},{0,9,221},{18,7,27},{0,8,110},
jonathonfletcher 0:54f5be781526 65 {0,8,46},{0,9,189},{0,8,14},{0,8,142},{0,8,78},{0,9,253},{96,7,0},
jonathonfletcher 0:54f5be781526 66 {0,8,81},{0,8,17},{21,8,131},{18,7,31},{0,8,113},{0,8,49},{0,9,195},
jonathonfletcher 0:54f5be781526 67 {16,7,10},{0,8,97},{0,8,33},{0,9,163},{0,8,1},{0,8,129},{0,8,65},
jonathonfletcher 0:54f5be781526 68 {0,9,227},{16,7,6},{0,8,89},{0,8,25},{0,9,147},{19,7,59},{0,8,121},
jonathonfletcher 0:54f5be781526 69 {0,8,57},{0,9,211},{17,7,17},{0,8,105},{0,8,41},{0,9,179},{0,8,9},
jonathonfletcher 0:54f5be781526 70 {0,8,137},{0,8,73},{0,9,243},{16,7,4},{0,8,85},{0,8,21},{16,8,258},
jonathonfletcher 0:54f5be781526 71 {19,7,43},{0,8,117},{0,8,53},{0,9,203},{17,7,13},{0,8,101},{0,8,37},
jonathonfletcher 0:54f5be781526 72 {0,9,171},{0,8,5},{0,8,133},{0,8,69},{0,9,235},{16,7,8},{0,8,93},
jonathonfletcher 0:54f5be781526 73 {0,8,29},{0,9,155},{20,7,83},{0,8,125},{0,8,61},{0,9,219},{18,7,23},
jonathonfletcher 0:54f5be781526 74 {0,8,109},{0,8,45},{0,9,187},{0,8,13},{0,8,141},{0,8,77},{0,9,251},
jonathonfletcher 0:54f5be781526 75 {16,7,3},{0,8,83},{0,8,19},{21,8,195},{19,7,35},{0,8,115},{0,8,51},
jonathonfletcher 0:54f5be781526 76 {0,9,199},{17,7,11},{0,8,99},{0,8,35},{0,9,167},{0,8,3},{0,8,131},
jonathonfletcher 0:54f5be781526 77 {0,8,67},{0,9,231},{16,7,7},{0,8,91},{0,8,27},{0,9,151},{20,7,67},
jonathonfletcher 0:54f5be781526 78 {0,8,123},{0,8,59},{0,9,215},{18,7,19},{0,8,107},{0,8,43},{0,9,183},
jonathonfletcher 0:54f5be781526 79 {0,8,11},{0,8,139},{0,8,75},{0,9,247},{16,7,5},{0,8,87},{0,8,23},
jonathonfletcher 0:54f5be781526 80 {64,8,0},{19,7,51},{0,8,119},{0,8,55},{0,9,207},{17,7,15},{0,8,103},
jonathonfletcher 0:54f5be781526 81 {0,8,39},{0,9,175},{0,8,7},{0,8,135},{0,8,71},{0,9,239},{16,7,9},
jonathonfletcher 0:54f5be781526 82 {0,8,95},{0,8,31},{0,9,159},{20,7,99},{0,8,127},{0,8,63},{0,9,223},
jonathonfletcher 0:54f5be781526 83 {18,7,27},{0,8,111},{0,8,47},{0,9,191},{0,8,15},{0,8,143},{0,8,79},
jonathonfletcher 0:54f5be781526 84 {0,9,255}
jonathonfletcher 0:54f5be781526 85 };
jonathonfletcher 0:54f5be781526 86
jonathonfletcher 0:54f5be781526 87 static const code distfix[32] = {
jonathonfletcher 0:54f5be781526 88 {16,5,1},{23,5,257},{19,5,17},{27,5,4097},{17,5,5},{25,5,1025},
jonathonfletcher 0:54f5be781526 89 {21,5,65},{29,5,16385},{16,5,3},{24,5,513},{20,5,33},{28,5,8193},
jonathonfletcher 0:54f5be781526 90 {18,5,9},{26,5,2049},{22,5,129},{64,5,0},{16,5,2},{23,5,385},
jonathonfletcher 0:54f5be781526 91 {19,5,25},{27,5,6145},{17,5,7},{25,5,1537},{21,5,97},{29,5,24577},
jonathonfletcher 0:54f5be781526 92 {16,5,4},{24,5,769},{20,5,49},{28,5,12289},{18,5,13},{26,5,3073},
jonathonfletcher 0:54f5be781526 93 {22,5,193},{64,5,0}
jonathonfletcher 0:54f5be781526 94 };