Cycle buffers

blosc/blosc2.c

@@ -907,6 +907,12 @@ static int blosc2_intialize_header_from_context(blosc2_context* context, blosc_h
   return 0;
 }
 
+void _cycle_buffers(void **src, void **dest, void **tmp) {
+  void *tmp2 = *src;
+  *src = *dest;
+  *dest = *tmp;
+  *tmp = tmp2;
+}
 
 uint8_t* pipeline_forward(struct thread_context* thread_context, const int32_t bsize,
                           const uint8_t* src, const int32_t offset,
@@ -948,10 +954,7 @@ uint8_t* pipeline_forward(struct thread_context* thread_context, const int32_t b
       // No more filters are required
       return _dest;
     }
-    // Cycle buffers
-    _src = _dest;
-    _dest = _tmp;
-    _tmp = _src;
+    _cycle_buffers(&_src, &_dest, &_tmp);
   }
 
   /* Process the filter pipeline */
@@ -964,9 +967,7 @@ uint8_t* pipeline_forward(struct thread_context* thread_context, const int32_t b
             shuffle(typesize, bsize, _src, _dest);
             // Cycle filters when required
             if (j < filters_meta[i]) {
-              _src = _dest;
-              _dest = _tmp;
-              _tmp = _src;
+              _cycle_buffers(&_src, &_dest, &_tmp);
             }
           }
           break;
@@ -1025,9 +1026,7 @@ uint8_t* pipeline_forward(struct thread_context* thread_context, const int32_t b
 
     // Cycle buffers when required
     if (filters[i] != BLOSC_NOFILTER) {
-      _src = _dest;
-      _dest = _tmp;
-      _tmp = _src;
+      _cycle_buffers(&_src, &_dest, &_tmp);
     }
   }
   return _src;
@@ -1344,9 +1343,7 @@ int pipeline_backward(struct thread_context* thread_context, const int32_t bsize
             unshuffle(typesize, bsize, _src, _dest);
             // Cycle filters when required
             if (j < filters_meta[i]) {
-              _src = _dest;
-              _dest = _tmp;
-              _tmp = _src;
+              _cycle_buffers(&_src, &_dest, &_tmp);
             }
             // Check whether we have to copy the intermediate _dest buffer to final destination
             if (last_copy_filter && (filters_meta[i] % 2) == 1 && j == filters_meta[i]) {
@@ -1424,9 +1421,7 @@ int pipeline_backward(struct thread_context* thread_context, const int32_t bsize
 
     // Cycle buffers when required
     if ((filters[i] != BLOSC_NOFILTER) && (filters[i] != BLOSC_TRUNC_PREC)) {
-      _src = _dest;
-      _dest = _tmp;
-      _tmp = _src;
+      _cycle_buffers(&_src, &_dest, &_tmp);
     }
     if (last_filter_index == i) {
       break;

tests/test_filters.c

@@ -0,0 +1,45 @@
+#include <stdio.h>
+#include <blosc2.h>
+#include <stdlib.h>
+
+#define NCHUNKS 1
+#define TYPESIZE 2
+#define LEN 39
+#define CHUNKSIZE (TYPESIZE * LEN)
+
+int main(void) {
+  blosc2_init();
+  srandom(0);
+  uint16_t *ref_data = (uint16_t *)malloc(CHUNKSIZE);
+  uint16_t *data_dest = (uint16_t *)malloc(CHUNKSIZE);
+  for (int i = 0; i < LEN; i++) {
+    ref_data[i] = random() % 118;
+  }
+  blosc2_cparams cparams = BLOSC2_CPARAMS_DEFAULTS;
+  cparams.compcode = BLOSC_ZSTD;
+  cparams.filters[BLOSC2_MAX_FILTERS - 2] = BLOSC_BITSHUFFLE;
+  cparams.filters[BLOSC2_MAX_FILTERS - 1] = BLOSC_SHUFFLE;
+
+  blosc2_dparams dparams = BLOSC2_DPARAMS_DEFAULTS;
+
+  cparams.typesize = TYPESIZE;
+  blosc2_storage storage = {.contiguous=false, .urlpath=NULL, .cparams=&cparams, .dparams=&dparams};
+
+  blosc2_schunk* schunk = blosc2_schunk_new(&storage);
+  blosc2_schunk_append_buffer(schunk, ref_data, CHUNKSIZE);
+
+  blosc2_schunk_decompress_chunk(schunk, 0, data_dest, CHUNKSIZE);
+  for (int i = 0; i < LEN; i++) {
+    if (data_dest[i] != ref_data[i]) {
+      printf("Decompressed data differs from original %d, %d, %d!\n",
+          i, ref_data[i], data_dest[i]);
+      return -1;
+    }
+  }
+
+  printf("Successful roundtrip data <-> schunk !\n");
+
+  blosc2_schunk_free(schunk);
+  blosc2_destroy();
+  return 0;
+}