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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 use of the Blosc filter from C code.
To compile this program:
$ gcc urcodecs.c -o urcodecs -lblosc2
To run:
$ ./urcodecs
*/
#include <stdio.h>
#include <blosc2.h>
#define KB 1024.
#define MB (1024*KB)
#define GB (1024*MB)
#define CHUNKSIZE (1000 * 1000)
#define NCHUNKS 100
#define NTHREADS 4
int codec_encoder(const uint8_t* input, int32_t input_len,
uint8_t* output, int32_t output_len,
uint8_t meta,
blosc2_cparams* cparams, const void* chunk) {
BLOSC_UNUSED_PARAM(meta);
BLOSC_UNUSED_PARAM(chunk);
if (cparams->schunk == NULL) {
return -1;
}
if (cparams->typesize != 4) {
fprintf(stderr, "Itemsize %d != 4", cparams->typesize);
return BLOSC2_ERROR_FAILURE;
}
int32_t nelem = input_len / 4;
int32_t *in_ = ((int32_t *) input);
int32_t *out_ = ((int32_t *) output);
// Check that is an arange
int32_t start = in_[0];
int32_t step = in_[1] - start;
for (int i = 1; i < nelem - 1; ++i) {
if (in_[i + 1] - in_[i] != step) {
fprintf(stderr, "Buffer is not an arange");
return BLOSC2_ERROR_FAILURE;
}
}
if (8 > output_len) {
return BLOSC2_ERROR_WRITE_BUFFER;
}
out_[0] = start;
out_[1] = step;
return 8;
}
int codec_decoder(const uint8_t* input, int32_t input_len,
uint8_t* output, int32_t output_len,
uint8_t meta,
blosc2_dparams *dparams, const void* chunk) {
BLOSC_UNUSED_PARAM(meta);
BLOSC_UNUSED_PARAM(chunk);
if (dparams->schunk == NULL) {
return -1;
}
int32_t nelem = output_len / 4;
int32_t *in_ = ((int32_t *) input);
int32_t *out_ = ((int32_t *) output);
if (8 > input_len) {
return BLOSC2_ERROR_WRITE_BUFFER;
}
int32_t start = in_[0];
int32_t step = in_[1];
for (int i = 0; i < nelem; ++i) {
out_[i] = start + i * step;
}
return output_len;
}
int main(void) {
blosc2_init();
static int32_t data[CHUNKSIZE];
static int32_t data_dest[CHUNKSIZE];
int32_t isize = CHUNKSIZE * sizeof(int32_t);
int dsize;
int64_t nbytes, cbytes;
blosc2_codec udcodec;
udcodec.compcode = 244;
udcodec.version = 1;
udcodec.complib = 1;
udcodec.compname = "udcodec";
udcodec.encoder = codec_encoder;
udcodec.decoder = codec_decoder;
int rc = blosc2_register_codec(&udcodec);
if (rc < 0) {
printf("Cannot register codec!");
return -1;
}
blosc2_cparams cparams = BLOSC2_CPARAMS_DEFAULTS;
cparams.compcode = 244;
for (int i = 0; i < BLOSC2_MAX_FILTERS; ++i) {
cparams.filters[i] = 0;
}
blosc2_dparams dparams = BLOSC2_DPARAMS_DEFAULTS;
blosc2_schunk* schunk;
int i, nchunk;
blosc_timestamp_t last, current;
double ttotal;
printf("Blosc version info: %s (%s)\n", blosc2_get_version_string(), BLOSC2_VERSION_DATE);
/* Create a super-chunk container */
cparams.typesize = sizeof(int32_t);
cparams.clevel = 9;
blosc2_storage storage = {.cparams=&cparams, .dparams=&dparams};
schunk = blosc2_schunk_new(&storage);
blosc_set_timestamp(&last);
for (nchunk = 0; nchunk < NCHUNKS; nchunk++) {
for (i = 0; i < CHUNKSIZE; i++) {
data[i] = i * nchunk;
}
int64_t nchunks = blosc2_schunk_append_buffer(schunk, data, isize);
if (nchunks != nchunk + 1) {
printf("Unexpected nchunks!");
return -1;
}
}
/* Gather some info */
nbytes = schunk->nbytes;
cbytes = schunk->cbytes;
blosc_set_timestamp(¤t);
ttotal = blosc_elapsed_secs(last, current);
printf("Compression ratio: %.1f MB -> %.1f MB (%.1fx)\n",
(double)nbytes / MB, (double)cbytes / MB, (1. * (double)nbytes) / (double)cbytes);
printf("Compression time: %.3g s, %.1f MB/s\n",
ttotal, (double)nbytes / (ttotal * MB));
/* Retrieve and decompress the chunks (0-based count) */
blosc_set_timestamp(&last);
for (nchunk = NCHUNKS-1; nchunk >= 0; nchunk--) {
dsize = blosc2_schunk_decompress_chunk(schunk, nchunk, data_dest, isize);
if (dsize < 0) {
printf("Decompression error. Error code: %d\n", dsize);
return dsize;
}
}
blosc_set_timestamp(¤t);
ttotal = blosc_elapsed_secs(last, current);
printf("Decompression time: %.3g s, %.1f MB/s\n",
ttotal, (double)nbytes / (ttotal * MB));
/* Check integrity of the second chunk (made of non-zeros) */
blosc2_schunk_decompress_chunk(schunk, 1, data_dest, isize);
for (i = 0; i < CHUNKSIZE; i++) {
if (data_dest[i] != i) {
printf("Decompressed data differs from original %d, %d!\n",
i, data_dest[i]);
return -1;
}
}
printf("Successful roundtrip data <-> schunk !\n");
/* Free resources */
/* Destroy the super-chunk */
blosc2_schunk_free(schunk);
blosc2_destroy();
return 0;
}
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