filter.c: Error handling, code simplification.

diff --git a/filter.c b/filter.c
index be53768d629f939e2062880cfc4274df33029d03..d51471b285e2841dc34223702839e328767c445f 100644 (file)
--- a/filter.c
+++ b/filter.c
@@ -29,39 +29,41 @@
  */
 int filter_probes(int in_unitsize, int out_unitsize, int *probelist,
                  char *data_in, uint64_t length_in, char **data_out,
-                 uint64_t * length_out)
+                 uint64_t *length_out)
 {
        unsigned int in_offset, out_offset;
        int num_enabled_probes, out_bit, i;
        uint64_t sample_in, sample_out;
 
-       *data_out = malloc(length_in);
+       if (!(*data_out = malloc(length_in)))
+               return SIGROK_ERR_MALLOC;
+
        num_enabled_probes = 0;
        for (i = 0; probelist[i]; i++)
                num_enabled_probes++;
 
-       if (num_enabled_probes != in_unitsize * 8) {
-               in_offset = out_offset = 0;
-               while (in_offset <= length_in - in_unitsize) {
-                       memcpy(&sample_in, data_in + in_offset, in_unitsize);
-                       sample_out = 0;
-                       out_bit = 0;
-                       for (i = 0; probelist[i]; i++) {
-                               if (sample_in & (1 << (probelist[i] - 1)))
-                                       sample_out |= 1 << out_bit;
-                               out_bit++;
-                       }
-                       memcpy((*data_out) + out_offset, &sample_out,
-                              out_unitsize);
-                       in_offset += in_unitsize;
-                       out_offset += out_unitsize;
-               }
-               *length_out = out_offset;
-       } else {
+       if (num_enabled_probes == in_unitsize * 8) {
                /* All probes are used -- no need to compress anything. */
                memcpy(*data_out, data_in, length_in);
                *length_out = length_in;
+               return SIGROK_OK;
+       }
+
+       /* If we reached this point, not all probes are used, so "compress". */
+       in_offset = out_offset = 0;
+       while (in_offset <= length_in - in_unitsize) {
+               memcpy(&sample_in, data_in + in_offset, in_unitsize);
+               sample_out = out_bit = 0;
+               for (i = 0; probelist[i]; i++) {
+                       if (sample_in & (1 << (probelist[i] - 1)))
+                               sample_out |= (1 << out_bit);
+                       out_bit++;
+               }
+               memcpy((*data_out) + out_offset, &sample_out, out_unitsize);
+               in_offset += in_unitsize;
+               out_offset += out_unitsize;
        }
+       *length_out = out_offset;
 
        return SIGROK_OK;
 }