On 04/13/14 14:22, Jan Wieck wrote:
On 04/13/14 08:27, Marko Kreen wrote:
I think you need to do SET_VARSIZE also here. Alternative is to
move SET_VARSIZE after sort_snapshot().
And it seems the drop-double-txid logic should be added also to
txid_snapshot_recv(). It seems weird to have it behave differently
from txid_snapshot_in().
Thanks,
yes on both issues. Will create another patch.
New patch attached.
New github commit is
https://github.com/wieck/postgres/commit/b8fd0d2eb78791e5171e34aecd233fd06218890d
Thanks again,
Jan
--
Jan Wieck
Senior Software Engineer
http://slony.info
diff --git a/src/backend/utils/adt/txid.c b/src/backend/utils/adt/txid.c
index a005e67..1023566 100644
*** a/src/backend/utils/adt/txid.c
--- b/src/backend/utils/adt/txid.c
*************** cmp_txid(const void *aa, const void *bb)
*** 131,146 ****
}
/*
! * sort a snapshot's txids, so we can use bsearch() later.
*
* For consistency of on-disk representation, we always sort even if bsearch
! * will not be used.
*/
static void
sort_snapshot(TxidSnapshot *snap)
{
if (snap->nxip > 1)
qsort(snap->xip, snap->nxip, sizeof(txid), cmp_txid);
}
/*
--- 131,161 ----
}
/*
! * unique sort a snapshot's txids, so we can use bsearch() later.
*
* For consistency of on-disk representation, we always sort even if bsearch
! * will not be used.
*/
static void
sort_snapshot(TxidSnapshot *snap)
{
+ txid last = 0;
+ int nxip, idx1, idx2;
+
if (snap->nxip > 1)
+ {
qsort(snap->xip, snap->nxip, sizeof(txid), cmp_txid);
+ nxip = snap->nxip;
+ idx1 = idx2 = 0;
+ while (idx1 < nxip)
+ {
+ if (snap->xip[idx1] != last)
+ last = snap->xip[idx2++] = snap->xip[idx1];
+ else
+ snap->nxip--;
+ idx1++;
+ }
+ }
}
/*
*************** parse_snapshot(const char *str)
*** 294,304 ****
val = str2txid(str, &endp);
str = endp;
! /* require the input to be in order */
! if (val < xmin || val >= xmax || val <= last_val)
goto bad_format;
! buf_add_txid(buf, val);
last_val = val;
if (*str == ',')
--- 309,320 ----
val = str2txid(str, &endp);
str = endp;
! /* require the input to be in order and skip duplicates */
! if (val < xmin || val >= xmax || val < last_val)
goto bad_format;
! if (val != last_val)
! buf_add_txid(buf, val);
last_val = val;
if (*str == ',')
*************** txid_current_snapshot(PG_FUNCTION_ARGS)
*** 361,368 ****
{
TxidSnapshot *snap;
uint32 nxip,
! i,
! size;
TxidEpoch state;
Snapshot cur;
--- 377,383 ----
{
TxidSnapshot *snap;
uint32 nxip,
! i;
TxidEpoch state;
Snapshot cur;
*************** txid_current_snapshot(PG_FUNCTION_ARGS)
*** 381,389 ****
/* allocate */
nxip = cur->xcnt;
! size = TXID_SNAPSHOT_SIZE(nxip);
! snap = palloc(size);
! SET_VARSIZE(snap, size);
/* fill */
snap->xmin = convert_xid(cur->xmin, &state);
--- 396,402 ----
/* allocate */
nxip = cur->xcnt;
! snap = palloc(TXID_SNAPSHOT_SIZE(nxip));
/* fill */
snap->xmin = convert_xid(cur->xmin, &state);
*************** txid_current_snapshot(PG_FUNCTION_ARGS)
*** 395,400 ****
--- 408,416 ----
/* we want them guaranteed to be in ascending order */
sort_snapshot(snap);
+ /* we set the size here because the sort may have removed duplicate
xips */
+ SET_VARSIZE(snap, TXID_SNAPSHOT_SIZE(snap->nxip));
+
PG_RETURN_POINTER(snap);
}
*************** txid_snapshot_recv(PG_FUNCTION_ARGS)
*** 472,489 ****
snap = palloc(TXID_SNAPSHOT_SIZE(nxip));
snap->xmin = xmin;
snap->xmax = xmax;
- snap->nxip = nxip;
- SET_VARSIZE(snap, TXID_SNAPSHOT_SIZE(nxip));
for (i = 0; i < nxip; i++)
{
txid cur = pq_getmsgint64(buf);
! if (cur <= last || cur < xmin || cur >= xmax)
goto bad_format;
snap->xip[i] = cur;
last = cur;
}
PG_RETURN_POINTER(snap);
bad_format:
--- 488,514 ----
snap = palloc(TXID_SNAPSHOT_SIZE(nxip));
snap->xmin = xmin;
snap->xmax = xmax;
for (i = 0; i < nxip; i++)
{
txid cur = pq_getmsgint64(buf);
! if (cur < last || cur < xmin || cur >= xmax)
goto bad_format;
+
+ /* skip duplicate xips */
+ if (cur == last)
+ {
+ i--;
+ nxip--;
+ continue;
+ }
+
snap->xip[i] = cur;
last = cur;
}
+ snap->nxip = nxip;
+ SET_VARSIZE(snap, TXID_SNAPSHOT_SIZE(nxip));
PG_RETURN_POINTER(snap);
bad_format:
diff --git a/src/test/regress/expected/txid.out
b/src/test/regress/expected/txid.out
index 930b86a..7750b7b 100644
*** a/src/test/regress/expected/txid.out
--- b/src/test/regress/expected/txid.out
*************** select '12:18:14,16'::txid_snapshot;
*** 12,17 ****
--- 12,23 ----
12:18:14,16
(1 row)
+ select '12:16:14,14'::txid_snapshot;
+ txid_snapshot
+ ---------------
+ 12:16:14
+ (1 row)
+
-- errors
select '31:12:'::txid_snapshot;
ERROR: invalid input for txid_snapshot: "31:12:"
*************** select '12:16:14,13'::txid_snapshot;
*** 29,38 ****
ERROR: invalid input for txid_snapshot: "12:16:14,13"
LINE 1: select '12:16:14,13'::txid_snapshot;
^
- select '12:16:14,14'::txid_snapshot;
- ERROR: invalid input for txid_snapshot: "12:16:14,14"
- LINE 1: select '12:16:14,14'::txid_snapshot;
- ^
create temp table snapshot_test (
nr integer,
snap txid_snapshot
--- 35,40 ----
diff --git a/src/test/regress/sql/txid.sql b/src/test/regress/sql/txid.sql
index ecae10e..b6650b9 100644
*** a/src/test/regress/sql/txid.sql
--- b/src/test/regress/sql/txid.sql
***************
*** 3,15 ****
-- i/o
select '12:13:'::txid_snapshot;
select '12:18:14,16'::txid_snapshot;
-- errors
select '31:12:'::txid_snapshot;
select '0:1:'::txid_snapshot;
select '12:13:0'::txid_snapshot;
select '12:16:14,13'::txid_snapshot;
- select '12:16:14,14'::txid_snapshot;
create temp table snapshot_test (
nr integer,
--- 3,15 ----
-- i/o
select '12:13:'::txid_snapshot;
select '12:18:14,16'::txid_snapshot;
+ select '12:16:14,14'::txid_snapshot;
-- errors
select '31:12:'::txid_snapshot;
select '0:1:'::txid_snapshot;
select '12:13:0'::txid_snapshot;
select '12:16:14,13'::txid_snapshot;
create temp table snapshot_test (
nr integer,
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
