-# $PostgreSQL: pgsql/contrib/Makefile,v 1.79 2007/10/07 23:32:19 wieck Exp $
+# $PostgreSQL: pgsql/contrib/Makefile,v 1.80 2007/10/13 22:59:43 tgl Exp $
subdir = contrib
top_builddir = ..
pgstattuple \
seg \
spi \
- txid \
tablefunc \
vacuumlo
+++ /dev/null
-# $PostgreSQL: pgsql/contrib/txid/Makefile,v 1.2 2007/10/11 19:54:17 tgl Exp $
-
-MODULES = txid
-DATA_built = txid.sql
-DATA = uninstall_txid.sql
-DOCS = README.txid
-REGRESS = txid
-
-ifdef USE_PGXS
-PG_CONFIG = pg_config
-PGXS := $(shell $(PG_CONFIG) --pgxs)
-include $(PGXS)
-else
-subdir = contrib/txid
-top_builddir = ../..
-include $(top_builddir)/src/Makefile.global
-include $(top_srcdir)/contrib/contrib-global.mk
-endif
+++ /dev/null
-txid - export transaction IDs to user level
-===========================================
-
-The goal is to make PostgreSQL's internal transaction ID and snapshot
-data usable externally. This allows very efficient queue
-implementation done inside database.
-
-[towrite: what snapshot means]
-
-The module defines type txid_snapshot and following functions:
-
-
-txid_current() returns int8
-
- Current transaction ID.
-
-txid_current_snapshot() returns txid_snapshot
-
- Current snapshot.
-
-txid_snapshot_xmin( snap ) returns int8
-
- Smallest TXID in snapshot. TXID's smaller than this
- are all visible in snapshot.
-
-txid_snapshot_xmax( snap ) returns int8
-
- Largest TXID in snapshot. TXID's starting from this one are
- all invisible in snapshot.
-
-txid_snapshot_xip( snap ) setof int8
-
- List of in-progress TXID's in snapshot, that are invisible.
- Values are between xmin (inclusive) and xmax (exclusive).
-
-txid_visible_in_snapshot(id, snap) returns bool
-
- Is TXID visible in snapshot?
-
-
-Fetching events
----------------
-
-Lets say there is following event table:
-
- CREATE TABLE events (
- ev_txid int8 not null default txid_current(),
- ev_data text
- );
- CREATE INDEX ev_txid_idx ON events (ev_txid);
-
-Then event between 2 snapshots snap1 and snap2 can be fetched
-with followign query:
-
- SELECT ev_data FROM events
- WHERE ev_txid >= txid_snapshot_xmin(:snap1)
- AND ev_txid < txid_snapshot_xmax(:snap2)
- AND NOT txid_visible_in_snapshot(ev_txid, :snap1)
- AND txid_visible_in_snapshot(ev_txid, :snap2);
-
-This is the simplest query but it has problem if there are long
-transactions running - the txid_snapshot_xmin(snap1) will stay low
-and the range will get very large.
-
-This can be fixed by fetching only snap1.xmax ... snap1.xmax by range and
-fetching possible txids below snap1.xmax explicitly:
-
- SELECT ev_data FROM events
- WHERE ((ev_txid >= txid_snapshot_xmax(:snap1) AND ev_txid < txid_snapshot_xmax(:snap2))
- OR
- (ev_txid IN (SELECT * FROM txid_snapshot_xip(:snap1))))
- AND NOT txid_visible_in_snapshot(ev_txid, :snap1)
- AND txid_visible_in_snapshot(ev_txid, :snap2);
-
-Note that although the above queries work, PostgreSQL fails to
-plan them efficiently. For actual usage the values for txid_snapshot_xmin,
-txid_snapshot_xmax and txid_snapshot_xip should be filled in directly,
-only then will they use index.
-
-There are few more optimizations possible, like:
-
-- Picking out only TXIDs that were actually committed between snap1 and snap2.
-
-- Lowering the range from txid_snapshot_xmax(snap1) to decrease the list if TXIDs to be fetched separately.
-
-To see example code for that it's best to see pgq.batch_event_sql() function in Skytools.
-
- http://pgfoundry.org/projects/skytools/
-
-
-Dumping and restoring data containing TXIDs.
---------------------------------------------
-
-When reloading TXID data you will typically want to be sure that the current
-XID counter is beyond the reloaded data. The easiest way to do this is to
-increase the XID epoch to beyond the largest one in the input data.
-
-You can look at current epoch with queries such as:
-
- SELECT MAX(txid) >> 32 as epoch FROM ...;
-
-Epoch can be changed with pg_resetxlog command:
-
- pg_resetxlog -e NEWEPOCH DATADIR
-
-Database needs to be shut down for that moment.
+++ /dev/null
--- init
-\set ECHO none
--- i/o
-select '12:13:'::txid_snapshot;
- txid_snapshot
----------------
- 12:13:
-(1 row)
-
-select '12:13:1,2'::txid_snapshot;
-ERROR: invalid input for txid_snapshot: "12:13:1,2"
--- errors
-select '31:12:'::txid_snapshot;
-ERROR: invalid input for txid_snapshot: "31:12:"
-select '0:1:'::txid_snapshot;
-ERROR: invalid input for txid_snapshot: "0:1:"
-select '12:13:0'::txid_snapshot;
-ERROR: invalid input for txid_snapshot: "12:13:0"
-select '12:16:14,13'::txid_snapshot;
-ERROR: invalid input for txid_snapshot: "12:16:14,13"
-select '12:16:14,14'::txid_snapshot;
-ERROR: invalid input for txid_snapshot: "12:16:14,14"
-create table snapshot_test (
- nr integer,
- snap txid_snapshot
-);
-insert into snapshot_test values (1, '12:13:');
-insert into snapshot_test values (2, '12:20:13,15,18');
-insert into snapshot_test values (3, '100001:100009:100005,100007,100008');
-insert into snapshot_test values (4, '100:150:101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131');
-select snap from snapshot_test order by nr;
- snap
--------------------------------------------------------------------------------------------------------------------------------------
- 12:13:
- 12:20:13,15,18
- 100001:100009:100005,100007,100008
- 100:150:101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131
-(4 rows)
-
-select txid_snapshot_xmin(snap),
- txid_snapshot_xmax(snap),
- txid_snapshot_xip(snap)
-from snapshot_test order by nr;
- txid_snapshot_xmin | txid_snapshot_xmax | txid_snapshot_xip
---------------------+--------------------+-------------------
- 12 | 20 | 13
- 12 | 20 | 15
- 12 | 20 | 18
- 100001 | 100009 | 100005
- 100001 | 100009 | 100007
- 100001 | 100009 | 100008
- 100 | 150 | 101
- 100 | 150 | 102
- 100 | 150 | 103
- 100 | 150 | 104
- 100 | 150 | 105
- 100 | 150 | 106
- 100 | 150 | 107
- 100 | 150 | 108
- 100 | 150 | 109
- 100 | 150 | 110
- 100 | 150 | 111
- 100 | 150 | 112
- 100 | 150 | 113
- 100 | 150 | 114
- 100 | 150 | 115
- 100 | 150 | 116
- 100 | 150 | 117
- 100 | 150 | 118
- 100 | 150 | 119
- 100 | 150 | 120
- 100 | 150 | 121
- 100 | 150 | 122
- 100 | 150 | 123
- 100 | 150 | 124
- 100 | 150 | 125
- 100 | 150 | 126
- 100 | 150 | 127
- 100 | 150 | 128
- 100 | 150 | 129
- 100 | 150 | 130
- 100 | 150 | 131
-(37 rows)
-
-select id, txid_visible_in_snapshot(id, snap)
-from snapshot_test, generate_series(11, 21) id
-where nr = 2;
- id | txid_visible_in_snapshot
-----+--------------------------
- 11 | t
- 12 | t
- 13 | f
- 14 | t
- 15 | f
- 16 | t
- 17 | t
- 18 | f
- 19 | t
- 20 | f
- 21 | f
-(11 rows)
-
--- test bsearch
-select id, txid_visible_in_snapshot(id, snap)
-from snapshot_test, generate_series(90, 160) id
-where nr = 4;
- id | txid_visible_in_snapshot
------+--------------------------
- 90 | t
- 91 | t
- 92 | t
- 93 | t
- 94 | t
- 95 | t
- 96 | t
- 97 | t
- 98 | t
- 99 | t
- 100 | t
- 101 | f
- 102 | f
- 103 | f
- 104 | f
- 105 | f
- 106 | f
- 107 | f
- 108 | f
- 109 | f
- 110 | f
- 111 | f
- 112 | f
- 113 | f
- 114 | f
- 115 | f
- 116 | f
- 117 | f
- 118 | f
- 119 | f
- 120 | f
- 121 | f
- 122 | f
- 123 | f
- 124 | f
- 125 | f
- 126 | f
- 127 | f
- 128 | f
- 129 | f
- 130 | f
- 131 | f
- 132 | t
- 133 | t
- 134 | t
- 135 | t
- 136 | t
- 137 | t
- 138 | t
- 139 | t
- 140 | t
- 141 | t
- 142 | t
- 143 | t
- 144 | t
- 145 | t
- 146 | t
- 147 | t
- 148 | t
- 149 | t
- 150 | f
- 151 | f
- 152 | f
- 153 | f
- 154 | f
- 155 | f
- 156 | f
- 157 | f
- 158 | f
- 159 | f
- 160 | f
-(71 rows)
-
--- test current values also
-select txid_current() >= txid_snapshot_xmin(txid_current_snapshot());
- ?column?
-----------
- t
-(1 row)
-
-/* due to lazy xid alloc in 8.3 those are different in 8.2 and 8.3
-select txid_current() < txid_snapshot_xmax(txid_current_snapshot());
-
-select txid_visible_in_snapshot(txid_current(), txid_current_snapshot());
-*/
--- test 64bitness
-select txid_snapshot '1000100010001000:1000100010001100:1000100010001012,1000100010001013';
- txid_snapshot
----------------------------------------------------------------------
- 1000100010001000:1000100010001100:1000100010001012,1000100010001013
-(1 row)
-
-select txid_visible_in_snapshot('1000100010001012', '1000100010001000:1000100010001100:1000100010001012,1000100010001013');
- txid_visible_in_snapshot
---------------------------
- f
-(1 row)
-
-select txid_visible_in_snapshot('1000100010001015', '1000100010001000:1000100010001100:1000100010001012,1000100010001013');
- txid_visible_in_snapshot
---------------------------
- t
-(1 row)
-
--- test 64bit overflow
-SELECT txid_snapshot '1:9223372036854775807:3';
- txid_snapshot
--------------------------
- 1:9223372036854775807:3
-(1 row)
-
-SELECT txid_snapshot '1:9223372036854775808:3';
-ERROR: invalid input for txid_snapshot: "1:9223372036854775808:3"
+++ /dev/null
--- init
-\set ECHO none
-set client_min_messages = 'warning';
-\i txid.sql
-set client_min_messages = 'notice';
-\set ECHO all
-
--- i/o
-select '12:13:'::txid_snapshot;
-select '12:13:1,2'::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 table snapshot_test (
- nr integer,
- snap txid_snapshot
-);
-
-insert into snapshot_test values (1, '12:13:');
-insert into snapshot_test values (2, '12:20:13,15,18');
-insert into snapshot_test values (3, '100001:100009:100005,100007,100008');
-insert into snapshot_test values (4, '100:150:101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131');
-select snap from snapshot_test order by nr;
-
-select txid_snapshot_xmin(snap),
- txid_snapshot_xmax(snap),
- txid_snapshot_xip(snap)
-from snapshot_test order by nr;
-
-select id, txid_visible_in_snapshot(id, snap)
-from snapshot_test, generate_series(11, 21) id
-where nr = 2;
-
--- test bsearch
-select id, txid_visible_in_snapshot(id, snap)
-from snapshot_test, generate_series(90, 160) id
-where nr = 4;
-
--- test current values also
-select txid_current() >= txid_snapshot_xmin(txid_current_snapshot());
-
-/* due to lazy xid alloc in 8.3 those are different in 8.2 and 8.3
-select txid_current() < txid_snapshot_xmax(txid_current_snapshot());
-
-select txid_visible_in_snapshot(txid_current(), txid_current_snapshot());
-*/
-
--- test 64bitness
-
-select txid_snapshot '1000100010001000:1000100010001100:1000100010001012,1000100010001013';
-select txid_visible_in_snapshot('1000100010001012', '1000100010001000:1000100010001100:1000100010001012,1000100010001013');
-select txid_visible_in_snapshot('1000100010001015', '1000100010001000:1000100010001100:1000100010001012,1000100010001013');
-
--- test 64bit overflow
-SELECT txid_snapshot '1:9223372036854775807:3';
-SELECT txid_snapshot '1:9223372036854775808:3';
+++ /dev/null
-/*-------------------------------------------------------------------------
- * txid.c
- *
- * Export internal transaction IDs to user level.
- *
- * Note that only top-level transaction IDs are ever converted to TXID.
- * This is important because TXIDs frequently persist beyond the global
- * xmin horizon, or may even be shipped to other machines, so we cannot
- * rely on being able to correlate subtransaction IDs with their parents
- * via functions such as SubTransGetTopmostTransaction().
- *
- *
- * Copyright (c) 2003-2007, PostgreSQL Global Development Group
- * Author: Jan Wieck, Afilias USA INC.
- * 64-bit txids: Marko Kreen, Skype Technologies
- *
- * $PostgreSQL: pgsql/contrib/txid/txid.c,v 1.4 2007/10/11 19:54:17 tgl Exp $
- *
- *-------------------------------------------------------------------------
- */
-
-#include "postgres.h"
-
-#include "access/transam.h"
-#include "access/xact.h"
-#include "funcapi.h"
-#include "libpq/pqformat.h"
-
-
-PG_MODULE_MAGIC;
-
-#ifdef INT64_IS_BUSTED
-#error txid needs working int64
-#endif
-
-/* txid will be signed int8 in database, so must limit to 63 bits */
-#define MAX_TXID UINT64CONST(0x7FFFFFFFFFFFFFFF)
-
-/* Use unsigned variant internally */
-typedef uint64 txid;
-
-/* sprintf format code for uint64 */
-#define TXID_FMT UINT64_FORMAT
-
-/*
- * If defined, use bsearch() function for searching for txids in snapshots
- * that have more than the specified number of values.
- */
-#define USE_BSEARCH_IF_NXIP_GREATER 30
-
-
-/*
- * Snapshot containing 8byte txids.
- */
-typedef struct
-{
- /*
- * 4-byte length hdr, should not be touched directly.
- *
- * Explicit embedding is ok as we want always correct
- * alignment anyway.
- */
- int32 __varsz;
-
- uint32 nxip; /* number of txids in xip array */
- txid xmin;
- txid xmax;
- txid xip[1]; /* in-progress txids, xmin <= xip[i] < xmax */
-} TxidSnapshot;
-
-#define TXID_SNAPSHOT_SIZE(nxip) \
- (offsetof(TxidSnapshot, xip) + sizeof(txid) * (nxip))
-
-/*
- * Epoch values from xact.c
- */
-typedef struct
-{
- TransactionId last_xid;
- uint32 epoch;
-} TxidEpoch;
-
-
-/* public functions */
-Datum txid_snapshot_in(PG_FUNCTION_ARGS);
-Datum txid_snapshot_out(PG_FUNCTION_ARGS);
-Datum txid_snapshot_recv(PG_FUNCTION_ARGS);
-Datum txid_snapshot_send(PG_FUNCTION_ARGS);
-Datum txid_current(PG_FUNCTION_ARGS);
-Datum txid_current_snapshot(PG_FUNCTION_ARGS);
-Datum txid_snapshot_xmin(PG_FUNCTION_ARGS);
-Datum txid_snapshot_xmax(PG_FUNCTION_ARGS);
-Datum txid_snapshot_xip(PG_FUNCTION_ARGS);
-Datum txid_visible_in_snapshot(PG_FUNCTION_ARGS);
-
-/* public function tags */
-PG_FUNCTION_INFO_V1(txid_snapshot_in);
-PG_FUNCTION_INFO_V1(txid_snapshot_out);
-PG_FUNCTION_INFO_V1(txid_snapshot_recv);
-PG_FUNCTION_INFO_V1(txid_snapshot_send);
-PG_FUNCTION_INFO_V1(txid_current);
-PG_FUNCTION_INFO_V1(txid_current_snapshot);
-PG_FUNCTION_INFO_V1(txid_snapshot_xmin);
-PG_FUNCTION_INFO_V1(txid_snapshot_xmax);
-PG_FUNCTION_INFO_V1(txid_snapshot_xip);
-PG_FUNCTION_INFO_V1(txid_visible_in_snapshot);
-
-
-/*
- * Fetch epoch data from xact.c.
- */
-static void
-load_xid_epoch(TxidEpoch *state)
-{
- GetNextXidAndEpoch(&state->last_xid, &state->epoch);
-}
-
-/*
- * do a TransactionId -> txid conversion for an XID near the given epoch
- */
-static txid
-convert_xid(TransactionId xid, const TxidEpoch *state)
-{
- uint64 epoch;
-
- /* return special xid's as-is */
- if (!TransactionIdIsNormal(xid))
- return (txid) xid;
-
- /* xid can be on either side when near wrap-around */
- epoch = (uint64) state->epoch;
- if (xid > state->last_xid &&
- TransactionIdPrecedes(xid, state->last_xid))
- epoch--;
- else if (xid < state->last_xid &&
- TransactionIdFollows(xid, state->last_xid))
- epoch++;
-
- return (epoch << 32) | xid;
-}
-
-/*
- * txid comparator for qsort/bsearch
- */
-static int
-cmp_txid(const void *aa, const void *bb)
-{
- txid a = *(const txid *) aa;
- txid b = *(const txid *) bb;
-
- if (a < b)
- return -1;
- if (a > b)
- return 1;
- return 0;
-}
-
-/*
- * 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);
-}
-
-/*
- * check txid visibility.
- */
-static bool
-is_visible_txid(txid value, const TxidSnapshot *snap)
-{
- if (value < snap->xmin)
- return true;
- else if (value >= snap->xmax)
- return false;
-#ifdef USE_BSEARCH_IF_NXIP_GREATER
- else if (snap->nxip > USE_BSEARCH_IF_NXIP_GREATER)
- {
- void *res;
-
- res = bsearch(&value, snap->xip, snap->nxip, sizeof(txid), cmp_txid);
- /* if found, transaction is still in progress */
- return (res) ? false : true;
- }
-#endif
- else
- {
- uint32 i;
-
- for (i = 0; i < snap->nxip; i++)
- {
- if (value == snap->xip[i])
- return false;
- }
- return true;
- }
-}
-
-/*
- * helper functions to use StringInfo for TxidSnapshot creation.
- */
-
-static StringInfo
-buf_init(txid xmin, txid xmax)
-{
- TxidSnapshot snap;
- StringInfo buf;
-
- snap.xmin = xmin;
- snap.xmax = xmax;
- snap.nxip = 0;
-
- buf = makeStringInfo();
- appendBinaryStringInfo(buf, (char *)&snap, TXID_SNAPSHOT_SIZE(0));
- return buf;
-}
-
-static void
-buf_add_txid(StringInfo buf, txid xid)
-{
- TxidSnapshot *snap = (TxidSnapshot *)buf->data;
-
- /* do this before possible realloc */
- snap->nxip++;
-
- appendBinaryStringInfo(buf, (char *)&xid, sizeof(xid));
-}
-
-static TxidSnapshot *
-buf_finalize(StringInfo buf)
-{
- TxidSnapshot *snap = (TxidSnapshot *)buf->data;
-
- SET_VARSIZE(snap, buf->len);
-
- /* buf is not needed anymore */
- buf->data = NULL;
- pfree(buf);
-
- return snap;
-}
-
-/*
- * simple number parser.
- *
- * We return 0 on error, which is invalid value for txid.
- */
-static txid
-str2txid(const char *s, const char **endp)
-{
- txid val = 0;
- txid cutoff = MAX_TXID / 10;
- txid cutlim = MAX_TXID % 10;
-
- for (; *s; s++)
- {
- unsigned d;
-
- if (*s < '0' || *s > '9')
- break;
- d = *s - '0';
-
- /*
- * check for overflow
- */
- if (val > cutoff || (val == cutoff && d > cutlim))
- {
- val = 0;
- break;
- }
-
- val = val * 10 + d;
- }
- if (endp)
- *endp = s;
- return val;
-}
-
-/*
- * parse snapshot from cstring
- */
-static TxidSnapshot *
-parse_snapshot(const char *str)
-{
- txid xmin;
- txid xmax;
- txid last_val = 0, val;
- const char *str_start = str;
- const char *endp;
- StringInfo buf;
-
- xmin = str2txid(str, &endp);
- if (*endp != ':')
- goto bad_format;
- str = endp + 1;
-
- xmax = str2txid(str, &endp);
- if (*endp != ':')
- goto bad_format;
- str = endp + 1;
-
- /* it should look sane */
- if (xmin == 0 || xmax == 0 || xmin > xmax)
- goto bad_format;
-
- /* allocate buffer */
- buf = buf_init(xmin, xmax);
-
- /* loop over values */
- while (*str != '\0')
- {
- /* read next value */
- 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 == ',')
- str++;
- else if (*str != '\0')
- goto bad_format;
- }
-
- return buf_finalize(buf);
-
-bad_format:
- elog(ERROR, "invalid input for txid_snapshot: \"%s\"", str_start);
- return NULL;
-}
-
-/*
- * Public functions.
- *
- * txid_current() and txid_current_snapshot() are the only ones that
- * communicate with core xid machinery. All the others work on data
- * returned by them.
- */
-
-/*
- * txid_current() returns int8
- *
- * Return the current toplevel transaction ID as TXID
- */
-Datum
-txid_current(PG_FUNCTION_ARGS)
-{
- txid val;
- TxidEpoch state;
-
- load_xid_epoch(&state);
-
- val = convert_xid(GetTopTransactionId(), &state);
-
- PG_RETURN_INT64(val);
-}
-
-/*
- * txid_current_snapshot() returns txid_snapshot
- *
- * Return current snapshot in TXID format
- *
- * Note that only top-transaction XIDs are included in the snapshot.
- */
-Datum
-txid_current_snapshot(PG_FUNCTION_ARGS)
-{
- TxidSnapshot *snap;
- uint32 nxip, i, size;
- TxidEpoch state;
- Snapshot cur;
-
- cur = ActiveSnapshot;
- if (cur == NULL)
- elog(ERROR, "txid_current_snapshot: ActiveSnapshot == NULL");
-
- load_xid_epoch(&state);
-
- /* allocate */
- nxip = cur->xcnt;
- size = TXID_SNAPSHOT_SIZE(nxip);
- snap = palloc(size);
- SET_VARSIZE(snap, size);
-
- /* fill */
- snap->xmin = convert_xid(cur->xmin, &state);
- snap->xmax = convert_xid(cur->xmax, &state);
- snap->nxip = nxip;
- for (i = 0; i < nxip; i++)
- snap->xip[i] = convert_xid(cur->xip[i], &state);
-
- /* we want them guaranteed to be in ascending order */
- sort_snapshot(snap);
-
- PG_RETURN_POINTER(snap);
-}
-
-/*
- * txid_snapshot_in(cstring) returns txid_snapshot
- *
- * input function for type txid_snapshot
- */
-Datum
-txid_snapshot_in(PG_FUNCTION_ARGS)
-{
- char *str = PG_GETARG_CSTRING(0);
- TxidSnapshot *snap;
-
- snap = parse_snapshot(str);
-
- PG_RETURN_POINTER(snap);
-}
-
-/*
- * txid_snapshot_out(txid_snapshot) returns cstring
- *
- * output function for type txid_snapshot
- */
-Datum
-txid_snapshot_out(PG_FUNCTION_ARGS)
-{
- TxidSnapshot *snap = (TxidSnapshot *) PG_GETARG_VARLENA_P(0);
- StringInfoData str;
- uint32 i;
-
- initStringInfo(&str);
-
- appendStringInfo(&str, TXID_FMT ":", snap->xmin);
- appendStringInfo(&str, TXID_FMT ":", snap->xmax);
-
- for (i = 0; i < snap->nxip; i++)
- {
- if (i > 0)
- appendStringInfoChar(&str, ',');
- appendStringInfo(&str, TXID_FMT, snap->xip[i]);
- }
-
- PG_RETURN_CSTRING(str.data);
-}
-
-/*
- * txid_snapshot_recv(internal) returns txid_snapshot
- *
- * binary input function for type txid_snapshot
- *
- * format: int4 nxip, int8 xmin, int8 xmax, int8 xip
- */
-Datum
-txid_snapshot_recv(PG_FUNCTION_ARGS)
-{
- StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
- TxidSnapshot *snap;
- txid last = 0;
- int nxip;
- int i;
- int avail;
- int expect;
- txid xmin, xmax;
-
- /*
- * load nxip and check for nonsense.
- *
- * (nxip > avail) check is against int overflows in 'expect'.
- */
- nxip = pq_getmsgint(buf, 4);
- avail = buf->len - buf->cursor;
- expect = 8 + 8 + nxip * 8;
- if (nxip < 0 || nxip > avail || expect > avail)
- goto bad_format;
-
- xmin = pq_getmsgint64(buf);
- xmax = pq_getmsgint64(buf);
- if (xmin == 0 || xmax == 0 || xmin > xmax || xmax > MAX_TXID)
- goto bad_format;
-
- 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:
- elog(ERROR, "invalid snapshot data");
- return (Datum)NULL;
-}
-
-/*
- * txid_snapshot_send(txid_snapshot) returns bytea
- *
- * binary output function for type txid_snapshot
- *
- * format: int4 nxip, int8 xmin, int8 xmax, int8 xip
- */
-Datum
-txid_snapshot_send(PG_FUNCTION_ARGS)
-{
- TxidSnapshot *snap = (TxidSnapshot *)PG_GETARG_VARLENA_P(0);
- StringInfoData buf;
- uint32 i;
-
- pq_begintypsend(&buf);
- pq_sendint(&buf, snap->nxip, 4);
- pq_sendint64(&buf, snap->xmin);
- pq_sendint64(&buf, snap->xmax);
- for (i = 0; i < snap->nxip; i++)
- pq_sendint64(&buf, snap->xip[i]);
- PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
-}
-
-/*
- * txid_visible_in_snapshot(int8, txid_snapshot) returns bool
- *
- * is txid visible in snapshot ?
- */
-Datum
-txid_visible_in_snapshot(PG_FUNCTION_ARGS)
-{
- txid value = PG_GETARG_INT64(0);
- TxidSnapshot *snap = (TxidSnapshot *) PG_GETARG_VARLENA_P(1);
-
- PG_RETURN_BOOL(is_visible_txid(value, snap));
-}
-
-/*
- * txid_snapshot_xmin(txid_snapshot) returns int8
- *
- * return snapshot's xmin
- */
-Datum
-txid_snapshot_xmin(PG_FUNCTION_ARGS)
-{
- TxidSnapshot *snap = (TxidSnapshot *) PG_GETARG_VARLENA_P(0);
-
- PG_RETURN_INT64(snap->xmin);
-}
-
-/*
- * txid_snapshot_xmax(txid_snapshot) returns int8
- *
- * return snapshot's xmax
- */
-Datum
-txid_snapshot_xmax(PG_FUNCTION_ARGS)
-{
- TxidSnapshot *snap = (TxidSnapshot *) PG_GETARG_VARLENA_P(0);
-
- PG_RETURN_INT64(snap->xmax);
-}
-
-/*
- * txid_snapshot_xip(txid_snapshot) returns setof int8
- *
- * return in-progress TXIDs in snapshot.
- */
-Datum
-txid_snapshot_xip(PG_FUNCTION_ARGS)
-{
- FuncCallContext *fctx;
- TxidSnapshot *snap;
- txid value;
-
- /* on first call initialize snap_state and get copy of snapshot */
- if (SRF_IS_FIRSTCALL()) {
- TxidSnapshot *arg = (TxidSnapshot *) PG_GETARG_VARLENA_P(0);
-
- fctx = SRF_FIRSTCALL_INIT();
-
- /* make a copy of user snapshot */
- snap = MemoryContextAlloc(fctx->multi_call_memory_ctx, VARSIZE(arg));
- memcpy(snap, arg, VARSIZE(arg));
-
- fctx->user_fctx = snap;
- }
-
- /* return values one-by-one */
- fctx = SRF_PERCALL_SETUP();
- snap = fctx->user_fctx;
- if (fctx->call_cntr < snap->nxip) {
- value = snap->xip[fctx->call_cntr];
- SRF_RETURN_NEXT(fctx, Int64GetDatum(value));
- } else {
- SRF_RETURN_DONE(fctx);
- }
-}
+++ /dev/null
--- ----------
--- txid.sql
---
--- SQL script for loading the transaction ID compatible datatype
---
--- Copyright (c) 2003-2007, PostgreSQL Global Development Group
--- Author: Jan Wieck, Afilias USA INC.
--- 64-bit txids: Marko Kreen, Skype Technologies
---
--- $PostgreSQL: pgsql/contrib/txid/txid.sql.in,v 1.2 2007/10/11 19:54:17 tgl Exp $
---
--- ----------
-
--- Adjust this setting to control where the objects get created.
-SET search_path = public;
-
-BEGIN;
-
---
--- A special transaction snapshot data type for faster visibility checks
---
-CREATE TYPE txid_snapshot;
-
-CREATE FUNCTION txid_snapshot_in(cstring)
- RETURNS txid_snapshot
- AS 'MODULE_PATHNAME' LANGUAGE C
- IMMUTABLE STRICT;
-CREATE FUNCTION txid_snapshot_out(txid_snapshot)
- RETURNS cstring
- AS 'MODULE_PATHNAME' LANGUAGE C
- IMMUTABLE STRICT;
-CREATE FUNCTION txid_snapshot_recv(internal)
- RETURNS txid_snapshot
- AS 'MODULE_PATHNAME' LANGUAGE C
- IMMUTABLE STRICT;
-CREATE FUNCTION txid_snapshot_send(txid_snapshot)
- RETURNS bytea
- AS 'MODULE_PATHNAME' LANGUAGE C
- IMMUTABLE STRICT;
-
---
--- The data type itself
---
-CREATE TYPE txid_snapshot (
- INPUT = txid_snapshot_in,
- OUTPUT = txid_snapshot_out,
- RECEIVE = txid_snapshot_recv,
- SEND = txid_snapshot_send,
- INTERNALLENGTH = variable,
- STORAGE = extended,
- ALIGNMENT = double
-);
-
---
--- Functions for txid
---
-CREATE FUNCTION txid_current()
- RETURNS bigint
- AS 'MODULE_PATHNAME', 'txid_current' LANGUAGE C
- STABLE;
-
-CREATE FUNCTION txid_current_snapshot()
- RETURNS txid_snapshot
- AS 'MODULE_PATHNAME', 'txid_current_snapshot' LANGUAGE C
- STABLE;
-
-CREATE FUNCTION txid_snapshot_xmin(txid_snapshot)
- RETURNS bigint
- AS 'MODULE_PATHNAME', 'txid_snapshot_xmin' LANGUAGE C
- IMMUTABLE STRICT;
-
-CREATE FUNCTION txid_snapshot_xmax(txid_snapshot)
- RETURNS bigint
- AS 'MODULE_PATHNAME', 'txid_snapshot_xmax' LANGUAGE C
- IMMUTABLE STRICT;
-
-CREATE FUNCTION txid_snapshot_xip(txid_snapshot)
- RETURNS setof bigint
- AS 'MODULE_PATHNAME', 'txid_snapshot_xip' LANGUAGE C
- IMMUTABLE STRICT;
-
-CREATE FUNCTION txid_visible_in_snapshot(bigint, txid_snapshot)
- RETURNS boolean
- AS 'MODULE_PATHNAME', 'txid_visible_in_snapshot' LANGUAGE C
- IMMUTABLE STRICT;
-
-COMMIT;
+++ /dev/null
-SET search_path = public;
-
-DROP FUNCTION txid_current();
-DROP FUNCTION txid_current_snapshot();
-DROP FUNCTION txid_snapshot_xmin(txid_snapshot);
-DROP FUNCTION txid_snapshot_xmax(txid_snapshot);
-DROP FUNCTION txid_snapshot_xip(txid_snapshot);
-DROP FUNCTION txid_visible_in_snapshot(bigint, txid_snapshot);
-
-DROP TYPE txid_snapshot CASCADE;
--- need cascade to drop the I/O functions
projects / postgresql / commitdiff