When we stop reading, it is highly unlikely that we start up again.
In this manner we actually save time and diskaccess (and buffer cache).
Thanks to Dave Plonka for the Idea of using POSIX_FADV_RANDOM here. */
- if (0 != posix_fadvise(rrd_file->fd, 0, 0, POSIX_FADV_RANDOM)) {
- rrd_set_error("setting POSIX_FADV_RANDOM on '%s': %s", file_name,
- rrd_strerror(errno));
- goto out_close;
- }
+ posix_fadvise(rrd_file->fd, 0, 0, POSIX_FADV_RANDOM);
#endif
/*
}
-/* Close a reference to an rrd_file. */
+/* Print list of in-core pages of a the current rrd_file. */
static
void mincore_print(
rrd_file_t *rrd_file,
#endif
}
dontneed_start = active_block;
- /* do not relase 'hot' block if update for this RAA will occure within 10 minutes */
+ /* do not release 'hot' block if update for this RAA will occur
+ * within 10 minutes */
if (rrd->stat_head->pdp_step * rrd->rra_def[i].pdp_cnt -
rrd->live_head->last_up % (rrd->stat_head->pdp_step *
rrd->rra_def[i].pdp_cnt) < 10 * 60) {
int ret;
#ifdef HAVE_MMAP
+ ret = msync(rrd_file->file_start, rrd_file->file_len, MS_ASYNC);
+ if (ret != 0)
+ rrd_set_error("msync rrd_file: %s", rrd_strerror(errno));
ret = munmap(rrd_file->file_start, rrd_file->file_len);
if (ret != 0)
rrd_set_error("munmap rrd_file: %s", rrd_strerror(errno));
rrd_set_error("lseek: %s", rrd_strerror(errno));
rrd_file->pos = ret;
#endif
-//XXX: mimic fseek, which returns 0 upon success
- return ret == -1; //XXX: or just ret to mimic lseek
+ /* mimic fseek, which returns 0 upon success */
+ return ret < 0; //XXX: or just ret to mimic lseek
}
}
-/* read count bytes into buffer buf, starting at rrd_file->pos.
+/* Read count bytes into buffer buf, starting at rrd_file->pos.
* Returns the number of bytes read or <0 on error. */
inline ssize_t rrd_read(
size_t _cnt = count;
ssize_t _surplus;
- if (rrd_file->pos > rrd_file->file_len || _cnt == 0) /* EOF */
- return 0;
+ if (rrd_file->pos > rrd_file->file_len || _cnt == 0) /* EOF */
+ return 0;
if (buf == NULL)
- return -1; /* EINVAL */
+ return -1; /* EINVAL */
_surplus = rrd_file->pos + _cnt - rrd_file->file_len;
if (_surplus > 0) { /* short read */
_cnt -= _surplus;
}
-/* write count bytes from buffer buf to the current position
+/* Write count bytes from buffer buf to the current position
* rrd_file->pos of rrd_file->fd.
* Returns the number of bytes written or <0 on error. */
{
#ifdef HAVE_MMAP
if (count == 0)
- return 0;
+ return 0;
if (buf == NULL)
- return -1; /* EINVAL */
+ return -1; /* EINVAL */
memcpy(rrd_file->file_start + rrd_file->pos, buf, count);
rrd_file->pos += count;
return count; /* mimmic write() semantics */