}
}
if (r1 <= 0) {
- if (ret > 0) return ret;
+ if (ret > 0)
+ return ret;
return r1;
}
len -= r1;
}
-/* this provides functionality somewhat similar to mmap() but using
- read(). It gives sliding window access to a file. mmap() is not
- used because of the possibility of another program (such as a
- mailer) truncating the file thus giving us a SIGBUS */
-struct map_struct *map_file(int fd,OFF_T len)
+/* This provides functionality somewhat similar to mmap() but using read().
+ * It gives sliding window access to a file. mmap() is not used because of
+ * the possibility of another program (such as a mailer) truncating the
+ * file thus giving us a SIGBUS. */
+struct map_struct *map_file(int fd, OFF_T len, int32 read_size,
+ int32 blk_size)
{
struct map_struct *map;
if (!(map = new(struct map_struct)))
out_of_memory("map_file");
+ if (blk_size && (read_size % blk_size))
+ read_size += blk_size - (read_size % blk_size);
+
memset(map, 0, sizeof map[0]);
map->fd = fd;
map->file_size = len;
+ map->def_window_size = read_size;
return map;
}
/* slide the read window in the file */
-char *map_ptr(struct map_struct *map,OFF_T offset,int len)
+char *map_ptr(struct map_struct *map, OFF_T offset, int32 len)
{
- int nread;
+ int32 nread;
OFF_T window_start, read_start;
- int window_size, read_size, read_offset;
+ int32 window_size, read_size, read_offset;
- if (len == 0) {
+ if (len == 0)
return NULL;
- }
-
- /* can't go beyond the end of file */
- if (len > (map->file_size - offset)) {
- len = map->file_size - offset;
+ if (len < 0) {
+ rprintf(FERROR, "invalid len passed to map_ptr: %ld\n",
+ (long)len);
+ exit_cleanup(RERR_FILEIO);
}
/* in most cases the region will already be available */
- 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);
/* nope, we are going to have to do a read. Work out our desired window */
- if (offset > 2*CHUNK_SIZE) {
- window_start = offset - 2*CHUNK_SIZE;
- window_start &= ~((OFF_T)(CHUNK_SIZE-1)); /* assumes power of 2 */
- } else {
- window_start = 0;
- }
- window_size = MAX_MAP_SIZE;
- if (window_start + window_size > map->file_size) {
+ window_start = offset;
+ window_size = map->def_window_size;
+ if (window_start + window_size > map->file_size)
window_size = map->file_size - window_start;
- }
- if (offset + len > window_start + window_size) {
- window_size = (offset+len) - window_start;
- }
+ if (len > window_size)
+ window_size = len;
/* make sure we have allocated enough memory for the window */
if (window_size > map->p_size) {
map->p = realloc_array(map->p, char, window_size);
- if (!map->p) out_of_memory("map_ptr");
+ if (!map->p)
+ out_of_memory("map_ptr");
map->p_size = window_size;
}
- /* now try to avoid re-reading any bytes by reusing any bytes from the previous
- buffer. */
+ /* Now try to avoid re-reading any bytes by reusing any bytes
+ * from the previous buffer. */
if (window_start >= map->p_offset &&
window_start < map->p_offset + map->p_len &&
window_start + window_size >= map->p_offset + map->p_len) {
}
if (read_size <= 0) {
- rprintf(FINFO,"Warning: unexpected read size of %d in map_ptr\n", read_size);
+ rprintf(FERROR, "invalid read_size of %ld in map_ptr\n",
+ (long)read_size);
+ exit_cleanup(RERR_FILEIO);
} else {
if (map->p_fd_offset != read_start) {
if (do_lseek(map->fd,read_start,SEEK_SET) != read_start) {
map->p_offset = window_start;
map->p_len = window_size;
- return map->p + (offset - map->p_offset);
+ return map->p;
}