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/*
Copyright (c) 2021 Blosc Development Team <blosc@blosc.org>
https://blosc.org
License: BSD 3-Clause (see LICENSE.txt)
Example program demonstrating the use of a Blosc from C code.
To compile this program:
$ gcc -O contexts.c -o contexts -lblosc2
To run:
$ ./contexts
Blosc version info: 2.0.0a2 ($Date:: 2016-01-08 #$)
Compression: 40000000 -> 999393 (40.0x)
Correctly extracted 5 elements from compressed chunk!
Decompression successful!
Successful roundtrip!
*/
#include <stdio.h>
#include "blosc2.h"
#define SIZE (100 * 1000)
#define NTHREADS 2
int main(void) {
blosc2_init();
static float data[SIZE];
static float data_out[SIZE];
static float data_dest[SIZE];
float data_subset[5];
float data_subset_ref[5] = {5, 6, 7, 8, 9};
int isize = SIZE * sizeof(float), osize = SIZE * sizeof(float);
int dsize = SIZE * sizeof(float), csize;
int i, ret;
blosc2_cparams cparams = BLOSC2_CPARAMS_DEFAULTS;
blosc2_dparams dparams = BLOSC2_DPARAMS_DEFAULTS;
blosc2_context *cctx, *dctx;
/* Initialize dataset */
for (i = 0; i < SIZE; i++) {
data[i] = (float)i;
}
printf("Blosc version info: %s (%s)\n",
BLOSC2_VERSION_STRING, BLOSC2_VERSION_DATE);
/* Create a context for compression */
cparams.typesize = sizeof(float);
cparams.compcode = BLOSC_BLOSCLZ;
cparams.filters[BLOSC2_MAX_FILTERS - 1] = BLOSC_SHUFFLE;
cparams.clevel = 5;
cparams.nthreads = NTHREADS;
cctx = blosc2_create_cctx(cparams);
/* Do the actual compression */
csize = blosc2_compress_ctx(cctx, data, isize, data_out, osize);
blosc2_free_ctx(cctx);
if (csize == 0) {
printf("Buffer is incompressible. Giving up.\n");
return 1;
}
else if (csize < 0) {
printf("Compression error. Error code: %d\n", csize);
return csize;
}
printf("Compression: %d -> %d (%.1fx)\n", isize, csize, (1. * isize) / csize);
/* Create a context for decompression */
dparams.nthreads = NTHREADS;
dctx = blosc2_create_dctx(dparams);
ret = blosc2_getitem_ctx(dctx, data_out, csize, 5, 5, data_subset, sizeof(data_subset));
if (ret < 0) {
printf("Error in blosc2_getitem_ctx(). Giving up.\n");
blosc2_free_ctx(dctx);
return 1;
}
for (i = 0; i < 5; i++) {
if (data_subset[i] != data_subset_ref[i]) {
printf("blosc2_getitem_ctx() fetched data differs from original!\n");
blosc2_free_ctx(dctx);
return -1;
}
}
printf("Correctly extracted 5 elements from compressed chunk!\n");
/* Decompress */
dsize = blosc2_decompress_ctx(dctx, data_out, csize, data_dest, dsize);
blosc2_free_ctx(dctx);
if (dsize < 0) {
printf("Decompression error. Error code: %d\n", dsize);
return dsize;
}
printf("Decompression successful!\n");
for (i = 0; i < SIZE; i++) {
if (data[i] != data_dest[i]) {
printf("Decompressed data differs from original!\n");
return -1;
}
}
printf("Successful roundtrip!\n");
blosc2_destroy();
return 0;
}
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