improved Cache_read()

src/cache.c

@@ -730,7 +730,7 @@ static void Seg_set(Cache *cf, off_t offset, int i)
 
 long Cache_read(Cache *cf, char *output_buf, off_t len, off_t offset)
 {
- long sent;
+ long send;
  /*
  * Quick fix for SIGFPE,
  * this shouldn't happen in the first place!
@@ -747,30 +747,34 @@ long Cache_read(Cache *cf, char *output_buf, off_t len, off_t offset)
  * The metadata shows the segment already exists. This part is easy,
  * as you don't have to worry about alignment
  */
- sent = Data_read(cf, (uint8_t *) output_buf, len, offset);
+ send = Data_read(cf, (uint8_t *) output_buf, len, offset);
  } else {
  /* Calculate the aligned offset */
  off_t dl_offset = offset / cf->blksz * cf->blksz;
  /* Download the segment */
  long recv = path_download(cf->path, (char *) RECV_BUF, cf->blksz,
  dl_offset);
- /* Send it off */
- memmove(output_buf, RECV_BUF + (offset - dl_offset), len);
- sent = len;
- /* Write it to the disk, check if we haven't received enough data*/
- if (recv == cf->blksz) {
- Data_write(cf, RECV_BUF, cf->blksz, dl_offset);
- Seg_set(cf, dl_offset, 1);
- } else if (dl_offset == (cf->content_length / cf->blksz * cf->blksz)) {
- /* Check if we are at the last block */
+ /*
+ * check if we have received enough data
+ * send it off, then write it to the disk
+ *
+ * Condition 1: received the exact amount as the segment size.
+ * Condition 2: offset is the last segment
+ */
+ if ( (recv == cf->blksz) ||
+ (dl_offset == (cf->content_length / cf->blksz * cf->blksz)) ) {
+ memmove(output_buf, RECV_BUF + (offset - dl_offset), len);
+ send = len;
  Data_write(cf, RECV_BUF, cf->blksz, dl_offset);
  Seg_set(cf, dl_offset, 1);
- } else {
+ } else {
+ memmove(output_buf, RECV_BUF + (offset - dl_offset), recv);
+ send = recv;
  fprintf(stderr,
  "Cache_read(): recv (%ld) < cf->blksz! Possible network error?\n",
  recv);
  }
  }
  pthread_mutex_unlock(&cf->rw_lock);
- return sent;
+ return send;
 }