char *map_ptr(struct map_struct *map,OFF_T offset,int len)
{
- int nread = -2;
+ int nread;
- if (map->map)
- return map->map+offset;
+ if (map->map)
+ return map->map+offset;
- if (len == 0)
- return NULL;
+ if (len == 0)
+ return NULL;
- if (len > (map->size-offset))
- len = map->size-offset;
+ if (len > (map->size-offset))
+ len = map->size-offset;
- if (offset >= map->p_offset &&
- offset+len <= map->p_offset+map->p_len) {
- return (map->p + (offset - map->p_offset));
- }
+ if (offset >= map->p_offset &&
+ offset+len <= map->p_offset+map->p_len) {
+ return (map->p + (offset - map->p_offset));
+ }
- len = MAX(len,CHUNK_SIZE);
- if (len > (map->size-offset))
- len = map->size-offset;
+ len = MAX(len,CHUNK_SIZE);
+ if (len > (map->size-offset))
+ len = map->size-offset;
- if (len > map->p_size) {
- if (map->p) free(map->p);
- map->p = (char *)malloc(len);
- if (!map->p) out_of_memory("map_ptr");
- map->p_size = len;
- }
+ if (len > map->p_size) {
+ if (map->p) free(map->p);
+ map->p = (char *)malloc(len);
+ if (!map->p) out_of_memory("map_ptr");
+ map->p_size = len;
+ }
- if (do_lseek(map->fd,offset,SEEK_SET) != offset ||
- (nread=read(map->fd,map->p,len)) != len) {
- rprintf(FERROR,"EOF in map_ptr! (offset=%d len=%d nread=%d errno=%d)\n",
- (int)offset, len, nread, errno);
- exit_cleanup(1);
- }
+ map->p_offset = offset;
+ map->p_len = len;
- map->p_offset = offset;
- map->p_len = len;
+ if (do_lseek(map->fd,offset,SEEK_SET) != offset) {
+ rprintf(FERROR,"lseek failed in map_ptr\n");
+ exit_cleanup(1);
+ }
- return map->p;
+ if ((nread=read(map->fd,map->p,len)) != len) {
+ if (nread < 0) nread = 0;
+ /* the best we can do is zero the buffer - the file
+ has changed mid transfer! */
+ memset(map->p+nread, 0, len - nread);
+ }
+
+ return map->p;
}