Merge remote branch 'refs/remotes/fml/master'

[paraslash.git] / fecdec_filter.c

diff --git a/fecdec_filter.c b/fecdec_filter.c
index 10f1c642034c9457af12e6c23a1450bbf5eb3245..939f7e3d06b5061e70275244ddcc3e112b7ce1ea 100644 (file)
--- a/fecdec_filter.c
+++ b/fecdec_filter.c
@@ -61,6 +61,8 @@ struct fecdec_group {
        struct fec_header h;
        /** How many slices received so far. */
        int num_received_slices;
+       /** Bitmap of received slices. */
+       uint8_t received_slices[32];
        /** The size of the \a idx and the \a data arrays below. */
        int num_slices;
        /** Array of indices of the received slices. */
@@ -102,18 +104,11 @@ static void clear_group(struct fecdec_group *fg)
 {
        int i;
 
-       for (i = 0; i < fg->num_slices; i++) {
+       for (i = 0; i < fg->num_slices; i++)
                free(fg->data[i]);
-               fg->data[i] = NULL;
-               fg->idx[i] = -1;
-       }
        free(fg->data);
-       fg->data = NULL;
        free(fg->idx);
-       fg->idx = NULL;
-       fg->num_slices = 0;
-       memset(&fg->h, 0, sizeof(struct fec_header));
-       fg->num_received_slices = 0;
+       memset(fg, 0, sizeof(*fg));
 }
 
 static int find_group(struct fec_header *h,
@@ -213,29 +208,40 @@ success:
        return ret;
 }
 
+static bool test_and_set_slice_bit(struct fecdec_group *fg, uint8_t slice_num)
+{
+       uint8_t *p = fg->received_slices + slice_num / 8, old = *p;
+
+       *p |= 1 << (slice_num % 8);
+       return old == *p;
+}
+
 /*
  * returns 1 if slice was added, zero otherwise (because the group was already
- * complete). In any case the number of received slices is being increased by
- * one.
+ * complete or a slice has been received twice).
  */
 static int add_slice(char *buf, struct fecdec_group *fg)
 {
-       int r, slice_num;
+       int r;
+       uint8_t slice_num = fg->h.slice_num;
 
        if (group_complete(fg)) {
                PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
-                       fg->h.group_num, fg->h.slice_num);
-               fg->num_received_slices++;
+                       fg->h.group_num, slice_num);
                return 0;
        }
-       slice_num = fg->h.slice_num;
        if (fg->num_slices == 0) {
                fg->num_slices = fg->h.slices_per_group;
                fg->idx = para_malloc(fg->num_slices * sizeof(int));
-               fg->data = para_malloc(fg->num_slices * sizeof(unsigned char *));
-               memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
+               fg->data = para_calloc(fg->num_slices * sizeof(unsigned char *));
        }
        r = fg->num_received_slices;
+       /* Check if we already have this slice. */
+       if (test_and_set_slice_bit(fg, slice_num)) {
+               PARA_INFO_LOG("ignoring duplicate slice %d:%d\n", fg->h.group_num,
+                       slice_num);
+               return 0;
+       }
        fg->idx[r] = slice_num;
        fg->data[r] = para_malloc(fg->h.slice_bytes);
        memcpy(fg->data[r], buf, fg->h.slice_bytes);