blosc2-src 0.1.4

FFI bindings for c-blosc2
Documentation
/*
  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 frame_simple.c -o frame_simple -lblosc2

  To run:

  $ ./frame_simple
  Blosc version info: 2.0.0a6.dev ($Date:: 2018-05-18 #$)
  Compression ratio: 381.5 MB -> 9.5 MB (40.2x)
  Compression time: 0.705 s, 541.0 MB/s
  Time for schunk -> frame: 0.00796 s, 47905.3 MB/s
  Frame length in memory: 9940344 bytes
  Frame length on disk: 9940344 bytes
  Time for frame -> fileframe (frame_simple.b2frame): 0.0108 s, 35159.6 MB/s
  Time for fileframe (frame_simple.b2frame) -> frame : 0.000254 s, 1.5e+06 MB/s
  Time for frame -> schunk: 1.1e-05 s, 3.48e+07 MB/s
  Time for fileframe -> schunk: 1.25e-05 s, 3.05e+07 MB/s
  Successful roundtrip schunk <-> frame <-> fileframe !

 */

#include <stdio.h>
#include <blosc2.h>

#define KB  1024.

#define MB  (1024*KB)

#define GB  (1024*MB)


#define CHUNKSIZE (200 * 1000)

#define NCHUNKS 100

#define NTHREADS 4



int main(void) {

  blosc2_init();

  static int32_t data[CHUNKSIZE];
  static int32_t data_dest[CHUNKSIZE];
  static int32_t data_dest2[CHUNKSIZE];
  int32_t isize = CHUNKSIZE * sizeof(int32_t);
  int64_t nbytes, cbytes;
  int i, nchunk;
  int64_t nchunks;
  blosc_timestamp_t last, current;
  double ttotal;

  printf("Blosc version info: %s (%s)\n",
         BLOSC2_VERSION_STRING, BLOSC2_VERSION_DATE);

  /* Create a super-chunk container */
  blosc2_cparams cparams = BLOSC2_CPARAMS_DEFAULTS;
  cparams.typesize = sizeof(int32_t);
  cparams.compcode = BLOSC_LZ4;
  cparams.clevel = 9;
  cparams.nthreads = NTHREADS;
  blosc2_dparams dparams = BLOSC2_DPARAMS_DEFAULTS;
  dparams.nthreads = NTHREADS;
  blosc2_storage storage = {.cparams=&cparams, .dparams=&dparams};
  blosc2_schunk* schunk = blosc2_schunk_new(&storage);

  // Add some data
  blosc_set_timestamp(&last);
  for (nchunk = 0; nchunk < NCHUNKS; nchunk++) {
    for (i = 0; i < CHUNKSIZE; i++) {
      data[i] = i * nchunk;
    }
    nchunks = blosc2_schunk_append_buffer(schunk, data, isize);
    if (nchunks != nchunk + 1) {
      printf("blosc2_schunk_append_buffer is not working correctly");
      return BLOSC2_ERROR_FAILURE;
    }
  }

  // Add some vlmetalayers data
  int32_t content_len = 10;
  uint8_t *content = malloc(content_len);
  for (int32_t j = 0; j < content_len; ++j) {
    content[j] = (uint8_t) j;
  }
  int umlen = blosc2_vlmeta_add(schunk, "vlmetalayer", content, content_len, NULL);
  free(content);
  if (umlen < 0) {
    printf("Cannot write vlmetalayers chunk");
    return umlen;
  }

  /* Gather some info */
  nbytes = schunk->nbytes;
  cbytes = schunk->cbytes;
  blosc_set_timestamp(&current);
  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));
  uint8_t* vlmetalayer;

  blosc2_vlmeta_get(schunk, "vlmetalayer", &vlmetalayer, &content_len);
  printf("Variable-length metalayer length: %d\n", content_len);
  for (int j = 0; j < content_len; ++j) {
    printf("%3d", vlmetalayer[j]);
  }
  printf("\n");
  free(vlmetalayer);

  // Start different conversions between schunks, frames and fileframes

  // super-chunk -> cframe (contiguous frame, or buffer)
  blosc_set_timestamp(&last);
  uint8_t* cframe;
  bool cframe_needs_free;
  int64_t frame_len = blosc2_schunk_to_buffer(schunk, &cframe, &cframe_needs_free);
  if (frame_len < 0) {
    return (int)frame_len;
  }
  blosc_set_timestamp(&current);
  ttotal = blosc_elapsed_secs(last, current);
  printf("Time for schunk -> frame: %.3g s, %.1f MB/s\n",
         ttotal, (double)nbytes / (ttotal * MB));
  printf("Frame length in memory: %ld bytes\n", (long)frame_len);

  // super-chunk -> fileframe (contiguous frame, on-disk)
  remove("frame_simple.b2frame");
  blosc_set_timestamp(&last);
  frame_len = blosc2_schunk_to_file(schunk, "frame_simple.b2frame");
  if (frame_len < 0) {
    return (int)frame_len;
  }
  printf("Frame length on disk: %ld bytes\n", (long)frame_len);
  blosc_set_timestamp(&current);
  ttotal = blosc_elapsed_secs(last, current);
  printf("Time for frame -> fileframe (frame_simple.b2frame): %.3g s, %.1f GB/s\n",
         ttotal, (double)nbytes / (ttotal * GB));

  // fileframe (file) -> schunk2 (on-disk contiguous, super-chunk)
  blosc_set_timestamp(&last);
  blosc2_schunk* schunk2 = blosc2_schunk_open("file:///frame_simple.b2frame");
  blosc_set_timestamp(&current);
  ttotal = blosc_elapsed_secs(last, current);
  printf("Time for fileframe (%s) -> frame : %.3g s, %.1f GB/s\n",
         schunk2->storage->urlpath, ttotal, (double)nbytes / (ttotal * GB));

  // frame1 (in-memory) -> schunk
  blosc_set_timestamp(&last);
  // The next creates a schunk from the in-memory frame
  blosc2_schunk* schunk1 = blosc2_schunk_from_buffer(cframe, frame_len, false);
  if (schunk1 == NULL) {
    printf("Bad conversion frame1 -> schunk1!\n");
    return -1;
  }
  blosc_set_timestamp(&current);
  ttotal = blosc_elapsed_secs(last, current);
  printf("Time for frame -> schunk: %.3g s, %.1f GB/s\n",
         ttotal, (double)nbytes / (ttotal * GB));


  /* Retrieve and decompress the chunks from the super-chunks and compare values */
  for (nchunk = 0; nchunk < NCHUNKS; nchunk++) {
    int32_t dsize = blosc2_schunk_decompress_chunk(schunk1, nchunk, data_dest, isize);
    if (dsize < 0) {
      printf("Decompression error in schunk1.  Error code: %d\n", dsize);
      return dsize;
    }
    dsize = blosc2_schunk_decompress_chunk(schunk2, nchunk, data_dest2, isize);
    if (dsize < 0) {
      printf("Decompression error in schunk2.  Error code: %d\n", dsize);
      return dsize;
    }
    /* Check integrity of this chunk */
    for (i = 0; i < CHUNKSIZE; i++) {
      if ((data_dest[i] != i * nchunk) || (data_dest2[i] != i * nchunk)) {
        printf("data mismatch");
        return BLOSC2_ERROR_FAILURE;
      }
    }
  }
  printf("Successful roundtrip schunk <-> frame <-> fileframe !\n");

  blosc2_vlmeta_get(schunk1, "vlmetalayer", &vlmetalayer, &content_len);
  for (int j = 0; j < content_len; ++j) {
    printf("%3d", vlmetalayer[j]);
  }
  printf("\n");
  free(vlmetalayer);
  blosc2_vlmeta_get(schunk2, "vlmetalayer", &vlmetalayer, &content_len);
  for (int j = 0; j < content_len; ++j) {
    printf("%3d", vlmetalayer[j]);
  }
  printf("\n");
  free(vlmetalayer);

  /* Free resources */
  blosc2_schunk_free(schunk);
  blosc2_schunk_free(schunk1);
  blosc2_schunk_free(schunk2);
  if (cframe_needs_free) {
    free(cframe);
  }
  blosc2_destroy();

  return 0;
}