From 140ddb78fe62bf60a9ebba9cddf020b1f9920e5f Mon Sep 17 00:00:00 2001
From: Jan Wieck <JanWieck@Yahoo.com>
Date: Fri, 22 Jun 2001 19:18:36 +0000
Subject: [PATCH] The new files for statistical system views.
Jan
---
src/backend/postmaster/pgstat.c | 2809 +++++++++++++++++++++++++++
src/backend/utils/adt/pgstatfuncs.c | 376 ++++
src/include/pgstat.h | 380 ++++
3 files changed, 3565 insertions(+)
create mode 100644 src/backend/postmaster/pgstat.c
create mode 100644 src/backend/utils/adt/pgstatfuncs.c
create mode 100644 src/include/pgstat.h
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
new file mode 100644
index 00000000000..5420a121da4
--- /dev/null
+++ b/src/backend/postmaster/pgstat.c
@@ -0,0 +1,2809 @@
+/* ----------
+ * pgstat.c
+ *
+ * All the statistics collector stuff hacked up in one big, ugly file.
+ *
+ * TODO: - Separate collector, postmaster and backend stuff
+ * into different files.
+ *
+ * - Add some automatic call for pgstat vacuuming.
+ *
+ * - Add a pgstat config column to pg_database, so this
+ * entire thing can be enabled/disabled on a per db base.
+ * Not to be done before 7.2 - requires catalog change and
+ * thus an initdb and we might want to provide this as a
+ * patch for 7.1.
+ *
+ * - Make the functions from contrib/pgstat_tmp builtin
+ * and create the views on initdb.
+ *
+ * Copyright (c) 2001, PostgreSQL Global Development Group
+ *
+ * $Id: pgstat.c,v 1.1 2001/06/22 19:18:35 wieck Exp $
+ * ----------
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <errno.h>
+#include <signal.h>
+
+#include "postgres.h"
+
+#include "miscadmin.h"
+#include "utils/memutils.h"
+#include "storage/backendid.h"
+#include "utils/rel.h"
+#include "utils/hsearch.h"
+#include "utils/syscache.h"
+#include "access/xact.h"
+#include "access/heapam.h"
+#include "catalog/catname.h"
+#include "catalog/pg_shadow.h"
+#include "catalog/pg_database.h"
+
+#include "pgstat.h"
+
+
+/* ----------
+ * Global data
+ * ----------
+ */
+
+
+/* ----------
+ * Local data
+ * ----------
+ */
+static int pgStatSock = -1;
+static int pgStatPipe[2];
+static struct sockaddr_in pgStatAddr;
+static int pgStatPmPipe[2];
+
+static int pgStatRunning = 0;
+static int pgStatPid;
+
+static long pgStatNumMessages = 0;
+
+static bool pgStatRunningInCollector = FALSE;
+static int pgStatTabstatAlloc = 0;
+static int pgStatTabstatUsed = 0;
+static PgStat_MsgTabstat **pgStatTabstatMessages = NULL;
+static int pgStatXactCommit = 0;
+static int pgStatXactRollback = 0;
+
+
+static TransactionId pgStatDBHashXact = InvalidTransactionId;
+static HTAB *pgStatDBHash = NULL;
+static HTAB *pgStatBeDead = NULL;
+static PgStat_StatBeEntry *pgStatBeTable = NULL;
+static int pgStatNumBackends = 0;
+
+static char pgStat_tmpfname[PATH_MAX];
+static char pgStat_fname[PATH_MAX];
+
+
+/* ----------
+ * Local function forward declarations
+ * ----------
+ */
+static void pgstat_main(void);
+static void pgstat_recvbuffer(void);
+
+static int pgstat_add_backend(PgStat_MsgHdr *msg);
+static void pgstat_sub_backend(int procpid);
+static void pgstat_drop_database(Oid databaseid);
+static void pgstat_write_statsfile(void);
+static void pgstat_read_statsfile(HTAB **dbhash, Oid onlydb,
+ PgStat_StatBeEntry **betab,
+ int *numbackends);
+
+static void pgstat_setheader(PgStat_MsgHdr *hdr, int mtype);
+static void pgstat_send(void *msg, int len);
+
+static void pgstat_recv_bestart(PgStat_MsgBestart *msg, int len);
+static void pgstat_recv_beterm(PgStat_MsgBeterm *msg, int len);
+static void pgstat_recv_activity(PgStat_MsgActivity *msg, int len);
+static void pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len);
+static void pgstat_recv_tabpurge(PgStat_MsgTabpurge *msg, int len);
+static void pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len);
+static void pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len);
+
+
+/* ------------------------------------------------------------
+ * Public functions called from postmaster follow
+ * ------------------------------------------------------------
+ */
+
+
+/* ----------
+ * pgstat_init() -
+ *
+ * Called from postmaster at startup. Create the resources required
+ * by the statistics collector process.
+ * ----------
+ */
+int
+pgstat_init(void)
+{
+ int alen;
+
+ /*
+ * Initialize the filenames for the status reports.
+ */
+ snprintf(pgStat_tmpfname, PATH_MAX - 1,
+ PGSTAT_STAT_TMPFILE, DataDir, getpid());
+ snprintf(pgStat_fname, PATH_MAX - 1,
+ PGSTAT_STAT_FILENAME, DataDir);
+
+ /*
+ * Create the UDP socket for receiving statistic messages
+ */
+ if ((pgStatSock = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
+ {
+ perror("PGSTAT: socket(2)");
+ return -1;
+ }
+
+ /*
+ * Bind it to a kernel assigned port on localhost and
+ * get the assigned port via getsockname().
+ */
+ pgStatAddr.sin_family = AF_INET;
+ pgStatAddr.sin_port = htons(0);
+ inet_aton("127.0.0.1", &(pgStatAddr.sin_addr));
+ alen = sizeof(pgStatAddr);
+ if (bind(pgStatSock, (struct sockaddr *)&pgStatAddr, alen) < 0)
+ {
+ perror("PGSTAT: bind(2)");
+ close(pgStatSock);
+ pgStatSock = -1;
+ return -1;
+ }
+ if (getsockname(pgStatSock, (struct sockaddr *)&pgStatAddr, &alen) < 0)
+ {
+ perror("PGSTAT: getsockname(2)");
+ close(pgStatSock);
+ pgStatSock = -1;
+ return -1;
+ }
+
+ /*
+ * Set the socket to non-blocking IO
+ */
+ if (fcntl(pgStatSock, F_SETFL, O_NONBLOCK) < 0)
+ {
+ perror("PGSTAT: fcntl(2)");
+ close(pgStatSock);
+ pgStatSock = -1;
+ return -1;
+ }
+
+ /*
+ * Create the pipe that controls the statistics collector shutdown
+ */
+ if (pipe(pgStatPmPipe) < 0)
+ {
+ perror("PGSTAT: pipe(2)");
+ close(pgStatSock);
+ pgStatSock = -1;
+ return -1;
+ }
+
+ return 0;
+}
+
+
+/* ----------
+ * pgstat_start() -
+ *
+ * Called from postmaster at startup or after an existing collector
+ * died. Fire up a fresh statistics collector.
+ * ----------
+ */
+int
+pgstat_start(void)
+{
+ /*
+ * Check that the socket at least is there
+ */
+ if (pgStatSock < 0)
+ {
+ fprintf(stderr,
+ "PGSTAT: suppress collector startup due to missing socket\n");
+ return 0;
+ }
+
+ /*
+ * Then fork off the collector.
+ */
+ switch(pgStatPid = (int)fork())
+ {
+ case -1:
+ perror("PGSTAT: fork(2)");
+ pgStatRunning = 0;
+ return -1;
+
+ case 0:
+ break;
+
+ default:
+ pgStatRunning = 1;
+ return 0;
+ }
+
+ pgstat_main();
+ exit(0);
+}
+
+
+/* ----------
+ * pgstat_ispgstat() -
+ *
+ * Called from postmaster to check if a terminated child process
+ * was the statistics collector.
+ * ----------
+ */
+int
+pgstat_ispgstat(int pid)
+{
+ if (pgStatRunning == 0)
+ return 0;
+
+ if (pgStatPid != pid)
+ return 0;
+
+ return 1;
+}
+
+
+/* ----------
+ * pgstat_beterm() -
+ *
+ * Called from postmaster to tell collector a backend terminated.
+ * ----------
+ */
+void
+pgstat_beterm(int pid)
+{
+ PgStat_MsgBeterm msg;
+
+ msg.m_hdr.m_type = PGSTAT_MTYPE_BETERM;
+ msg.m_hdr.m_backendid = 0;
+ msg.m_hdr.m_procpid = pid;
+ msg.m_hdr.m_databaseid = 0;
+
+ pgstat_send(&msg, sizeof(msg));
+}
+
+
+/* ------------------------------------------------------------
+ * Public functions used by backends follow
+ *------------------------------------------------------------
+ */
+
+
+/* ----------
+ * pgstat_bestart() -
+ *
+ * Tell the collector that this new backend is soon ready to process
+ * queries. Called from tcop/postgres.c before entering the mainloop.
+ * ----------
+ */
+void
+pgstat_bestart(void)
+{
+ PgStat_MsgBestart msg;
+
+ if (pgStatSock < 0)
+ return;
+
+ pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_BESTART);
+ pgstat_send(&msg, sizeof(msg));
+}
+
+
+/* ----------
+ * pgstat_report_activity() -
+ *
+ * Called in tcop/postgres.c to tell the collector what the backend
+ * is actually doing (usually "<IDLE>" or the start of the query to
+ * be executed).
+ * ----------
+ */
+void
+pgstat_report_activity(char *what)
+{
+ PgStat_MsgActivity msg;
+ int len;
+
+ if (pgStatSock < 0)
+ return;
+
+ len = strlen(what);
+ if (len >= PGSTAT_ACTIVITY_SIZE)
+ len = PGSTAT_ACTIVITY_SIZE - 1;
+
+ memcpy(msg.m_what, what, len);
+ msg.m_what[len] = '\0';
+ len += offsetof(PgStat_MsgActivity, m_what) + 1;
+
+ pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_ACTIVITY);
+ pgstat_send(&msg, len);
+}
+
+
+/* ----------
+ * pgstat_report_tabstat() -
+ *
+ * Called from tcop/postgres.c to send the so far collected
+ * per table access statistics to the collector.
+ * ----------
+ */
+void
+pgstat_report_tabstat(void)
+{
+ int i;
+ int n;
+ int len;
+
+ if (pgStatSock < 0)
+ return;
+
+ /*
+ * For each message buffer used during the last query
+ * set the header fields and send it out.
+ */
+ for (i = 0; i < pgStatTabstatUsed; i++)
+ {
+ n = pgStatTabstatMessages[i]->m_nentries;
+ len = offsetof(PgStat_MsgTabstat, m_entry[n]);
+
+ pgStatTabstatMessages[i]->m_xact_commit = pgStatXactCommit;
+ pgStatTabstatMessages[i]->m_xact_rollback = pgStatXactRollback;
+ pgStatXactCommit = 0;
+ pgStatXactRollback = 0;
+
+ pgstat_setheader(&pgStatTabstatMessages[i]->m_hdr,
+ PGSTAT_MTYPE_TABSTAT);
+ pgstat_send(pgStatTabstatMessages[i], len);
+ }
+
+ pgStatTabstatUsed = 0;
+}
+
+
+/* ----------
+ * pgstat_vacuum_tabstat() -
+ *
+ * Will tell the collector about objects he can get rid of.
+ * ----------
+ */
+int
+pgstat_vacuum_tabstat(void)
+{
+ Relation dbrel;
+ HeapScanDesc dbscan;
+ HeapTuple dbtup;
+ Oid *dbidlist;
+ int dbidalloc;
+ int dbidused;
+ HASH_SEQ_STATUS hstat;
+ long *hentry;
+ PgStat_StatDBEntry *dbentry;
+ PgStat_StatTabEntry *tabentry;
+ HeapTuple reltup;
+ bool found;
+ int nobjects = 0;
+ PgStat_MsgTabpurge msg;
+ int len;
+ int i;
+
+ if (pgStatSock < 0)
+ return 0;
+
+ /*
+ * We don't vacuum inside of transaction blocks, because
+ * a possible later rollback might reactivate objects we
+ * didn't find because of earlier destruction in the xact.
+ */
+ if (IsTransactionBlock())
+ return 0;
+
+ /*
+ * If not done for this transaction, read the statistics collector
+ * stats file into some hash tables.
+ */
+ if (pgStatDBHashXact != GetCurrentTransactionId())
+ {
+ pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId,
+ &pgStatBeTable, &pgStatNumBackends);
+ pgStatDBHashXact = GetCurrentTransactionId();
+ }
+
+ /*
+ * Lookup our own database entry
+ */
+ dbentry = (PgStat_StatDBEntry *)hash_search(pgStatDBHash,
+ (char *)&MyDatabaseId, HASH_FIND, &found);
+ if (!found || dbentry == NULL)
+ return -1;
+
+ if (dbentry->tables == NULL)
+ return 0;
+
+ /*
+ * Initialize our messages table counter to zero
+ */
+ msg.m_nentries = 0;
+
+ /*
+ * Check for all tables if they still exist.
+ */
+ hash_seq_init(&hstat, dbentry->tables);
+ while((hentry = hash_seq_search(&hstat)) != (long *)TRUE)
+ {
+ if (hentry == NULL)
+ return -1;
+
+ /*
+ * Check if this relation is still alive by
+ * looking up it's pg_class tuple in the
+ * system catalog cache.
+ */
+ tabentry = (PgStat_StatTabEntry *)hentry;
+ reltup = SearchSysCache(RELOID,
+ ObjectIdGetDatum(tabentry->tableid),
+ 0, 0, 0);
+ if (HeapTupleIsValid(reltup))
+ {
+ ReleaseSysCache(reltup);
+ continue;
+ }
+
+ /*
+ * Add this tables Oid to the message
+ */
+ msg.m_tableid[msg.m_nentries++] = tabentry->tableid;
+ nobjects++;
+
+ /*
+ * If the message is full, send it out and reinitialize ot zero
+ */
+ if (msg.m_nentries >= PGSTAT_NUM_TABPURGE)
+ {
+ len = offsetof(PgStat_MsgTabpurge, m_tableid[msg.m_nentries]);
+
+ pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TABPURGE);
+ pgstat_send(&msg, len);
+
+ msg.m_nentries = 0;
+ }
+ }
+
+ /*
+ * Send the rest
+ */
+ if (msg.m_nentries > 0)
+ {
+ len = offsetof(PgStat_MsgTabpurge, m_tableid[msg.m_nentries]);
+
+ pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TABPURGE);
+ pgstat_send(&msg, len);
+ }
+
+ /*
+ * Read pg_database and remember the Oid's of all existing databases
+ */
+ dbidalloc = 256;
+ dbidused = 0;
+ dbidlist = (Oid *)palloc(sizeof(Oid) * dbidalloc);
+
+ dbrel = heap_openr(DatabaseRelationName, AccessShareLock);
+ dbscan = heap_beginscan(dbrel, 0, SnapshotNow, 0, NULL);
+ while (HeapTupleIsValid(dbtup = heap_getnext(dbscan, FALSE)))
+ {
+ if (dbidused >= dbidalloc)
+ {
+ dbidalloc *= 2;
+ dbidlist = (Oid *)repalloc((char *)dbidlist,
+ sizeof(Oid) * dbidalloc);
+ }
+ dbidlist[dbidused++] = dbtup->t_data->t_oid;
+ }
+ heap_endscan(dbscan);
+ heap_close(dbrel, AccessShareLock);
+
+ /*
+ * Search the database hash table for dead databases and
+ * tell the collector to drop them as well.
+ */
+ hash_seq_init(&hstat, pgStatDBHash);
+ while((hentry = hash_seq_search(&hstat)) != (long *)TRUE)
+ {
+ Oid dbid;
+
+ if (hentry == NULL)
+ break;
+
+ dbentry = (PgStat_StatDBEntry *)hentry;
+ dbid = dbentry->databaseid;
+
+ for (i = 0; i < dbidused; i++)
+ {
+ if (dbidlist[i] == dbid)
+ {
+ dbid = InvalidOid;
+ break;
+ }
+ }
+
+ if (dbid != InvalidOid)
+ {
+ nobjects++;
+ pgstat_drop_database(dbid);
+ }
+ }
+
+ /*
+ * Free the dbid list.
+ */
+ pfree((char *)dbidlist);
+
+ /*
+ * Tell the caller how many removeable objects we found
+ */
+ return nobjects;
+}
+
+
+/* ----------
+ * pgstat_drop_database() -
+ *
+ * Tell the collector that we just dropped a database.
+ * This is the only message that shouldn't get lost in space. Otherwise
+ * the collector will keep the statistics for the dead DB until his
+ * stats file got removed while the postmaster is down.
+ * ----------
+ */
+static void
+pgstat_drop_database(Oid databaseid)
+{
+ PgStat_MsgDropdb msg;
+
+ if (pgStatSock < 0)
+ return;
+
+ msg.m_databaseid = databaseid;
+
+ pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DROPDB);
+ pgstat_send(&msg, sizeof(msg));
+}
+
+
+/* ----------
+ * pgstat_reset_counters() -
+ *
+ * Tell the statistics collector to reset counters for our database.
+ * ----------
+ */
+void
+pgstat_reset_counters(void)
+{
+ PgStat_MsgResetcounter msg;
+
+ if (pgStatSock < 0)
+ return;
+
+ if (!superuser())
+ elog(ERROR, "Only database superusers can reset statistic counters");
+
+ pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETCOUNTER);
+ pgstat_send(&msg, sizeof(msg));
+}
+
+
+/* ----------
+ * pgstat_ping() -
+ *
+ * Send some junk data to the collector to increase traffic.
+ * ----------
+ */
+void
+pgstat_ping(void)
+{
+ PgStat_MsgDummy msg;
+
+ if (pgStatSock < 0)
+ return;
+
+ pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DUMMY);
+ pgstat_send(&msg, sizeof(msg));
+}
+
+
+/* ----------
+ * pgstat_initstats() -
+ *
+ * Called from various places usually dealing with initialization
+ * of Relation or Scan structures. The data placed into these
+ * structures from here tell where later to count for buffer reads,
+ * scans and tuples fetched.
+ * ----------
+ */
+void
+pgstat_initstats(PgStat_Info *stats, Relation rel)
+{
+ PgStat_TableEntry *useent = NULL;
+ Oid rel_id = rel->rd_id;
+ int mb;
+ int i;
+
+ /*
+ * Initialize data not to count at all.
+ */
+ stats->tabentry = NULL;
+ stats->no_stats = FALSE;
+ stats->heap_scan_counted = FALSE;
+ stats->index_scan_counted = FALSE;
+
+ if (pgStatSock < 0)
+ {
+ stats->no_stats = TRUE;
+ return;
+ }
+
+ /*
+ * On the first of all calls initialize the message buffers.
+ */
+ if (pgStatTabstatAlloc == 0)
+ {
+ pgStatTabstatAlloc = 4;
+ pgStatTabstatMessages = (PgStat_MsgTabstat **)
+ malloc(sizeof(PgStat_MsgTabstat *) * pgStatTabstatAlloc);
+ if (pgStatTabstatMessages == NULL)
+ {
+ perror("PGSTATBE: malloc(2)");
+ return;
+ }
+ for (i = 0; i < pgStatTabstatAlloc; i++)
+ {
+ pgStatTabstatMessages[i] = (PgStat_MsgTabstat *)
+ malloc(sizeof(PgStat_MsgTabstat));
+ if (pgStatTabstatMessages[i] == NULL)
+ {
+ perror("PGSTATBE: malloc(2)");
+ return;
+ }
+ }
+ }
+
+ /*
+ * Lookup the so far used table slots for this relation.
+ */
+ for (mb = 0; mb < pgStatTabstatUsed; mb++)
+ {
+ for (i = 0; i < pgStatTabstatMessages[mb]->m_nentries; i++)
+ {
+ if (pgStatTabstatMessages[mb]->m_entry[i].t_id == rel_id)
+ {
+ stats->tabentry = (void *)&(pgStatTabstatMessages[mb]->m_entry[i]);
+ return;
+ }
+ }
+
+ if (pgStatTabstatMessages[mb]->m_nentries >= PGSTAT_NUM_TABENTRIES)
+ continue;
+
+ /*
+ * Not found, but found a message buffer with an empty slot
+ * instead. Fine, let's use this one.
+ */
+ i = pgStatTabstatMessages[mb]->m_nentries++;
+ useent = &pgStatTabstatMessages[mb]->m_entry[i];
+ memset(useent, 0, sizeof(PgStat_TableEntry));
+ useent->t_id = rel_id;
+ stats->tabentry = (void *)useent;
+ return;
+ }
+
+ /*
+ * If we ran out of message buffers, we just allocate more.
+ */
+ if (pgStatTabstatUsed >= pgStatTabstatAlloc)
+ {
+ pgStatTabstatAlloc += 4;
+ pgStatTabstatMessages = (PgStat_MsgTabstat **)
+ realloc(pgStatTabstatMessages,
+ sizeof(PgStat_MsgTabstat *) * pgStatTabstatAlloc);
+ if (pgStatTabstatMessages == NULL)
+ {
+ pgStatTabstatAlloc -= 4;
+ perror("PGSTATBE: malloc(2)");
+ return;
+ }
+ for (i = pgStatTabstatUsed; i < pgStatTabstatAlloc; i++)
+ {
+ pgStatTabstatMessages[i] = (PgStat_MsgTabstat *)
+ malloc(sizeof(PgStat_MsgTabstat));
+ if (pgStatTabstatMessages[i] == NULL)
+ {
+ pgStatTabstatAlloc -= 4;
+ perror("PGSTATBE: malloc(2)");
+ return;
+ }
+ }
+ }
+
+ /*
+ * Use the first entry of the next message buffer.
+ */
+ mb = pgStatTabstatUsed++;
+ pgStatTabstatMessages[mb]->m_nentries = 1;
+ useent = &pgStatTabstatMessages[mb]->m_entry[0];
+ memset(useent, 0, sizeof(PgStat_TableEntry));
+ useent->t_id = rel_id;
+ stats->tabentry = (void *)useent;
+ return;
+}
+
+
+/* ----------
+ * pgstat_reset_heap_scan() -
+ *
+ * Called from heap_rescan() to reset the heap_scan_counted flag.
+ * Since the optimizer usually does a beginscan()/endscan() without
+ * really doing a scan, we cannot count those calls. We have to wait
+ * if after a beginscan() or rescan() really a call to the getnext()
+ * function happens.
+ * ----------
+ */
+void
+pgstat_reset_heap_scan(PgStat_Info *stats)
+{
+ if (stats->tabentry == NULL)
+ return;
+
+ stats->heap_scan_counted = FALSE;
+}
+
+
+/* ----------
+ * pgstat_count_heap_scan() -
+ *
+ * Called from heap_getnext() to tell us that now the relation
+ * really is scanned.
+ * ----------
+ */
+void
+pgstat_count_heap_scan(PgStat_Info *stats)
+{
+ if (stats->tabentry == NULL)
+ return;
+
+ if (!stats->heap_scan_counted)
+ {
+ ((PgStat_TableEntry *)(stats->tabentry))->t_numscans++;
+ stats->heap_scan_counted = TRUE;
+ }
+}
+
+
+/* ----------
+ * pgstat_count_heap_getnext() -
+ *
+ * Called from heap_getnext() whenever a valid tuple is returned
+ * from a sequential scan. The above cannot get combined into this,
+ * because if a heap scan didn't return any tuples, the scan itself
+ * would be missing in the stats.
+ * ----------
+ */
+void
+pgstat_count_heap_getnext(PgStat_Info *stats)
+{
+ if (stats->tabentry == NULL)
+ return;
+
+ ((PgStat_TableEntry *)(stats->tabentry))->t_tuples_returned++;
+}
+
+
+/* ----------
+ * pgstat_count_heap_fetch() -
+ *
+ * Called from heap_fetch() if this is caused by a heap lookup
+ * for an actually done index scan.
+ * ----------
+ */
+void
+pgstat_count_heap_fetch(PgStat_Info *stats)
+{
+ if (stats->tabentry == NULL)
+ return;
+
+ ((PgStat_TableEntry *)(stats->tabentry))->t_tuples_fetched++;
+}
+
+
+/* ----------
+ * pgstat_count_heap_insert() -
+ *
+ * Called from heap_insert().
+ * ----------
+ */
+void
+pgstat_count_heap_insert(PgStat_Info *stats)
+{
+ if (stats->tabentry == NULL)
+ return;
+
+ ((PgStat_TableEntry *)(stats->tabentry))->t_tuples_inserted++;
+}
+
+
+/* ----------
+ * pgstat_count_heap_update() -
+ *
+ * Called from heap_update().
+ * ----------
+ */
+void
+pgstat_count_heap_update(PgStat_Info *stats)
+{
+ if (stats->tabentry == NULL)
+ return;
+
+ ((PgStat_TableEntry *)(stats->tabentry))->t_tuples_updated++;
+}
+
+
+/* ----------
+ * pgstat_count_heap_delete() -
+ *
+ * Called from heap_delete().
+ * ----------
+ */
+void
+pgstat_count_heap_delete(PgStat_Info *stats)
+{
+ if (stats->tabentry == NULL)
+ return;
+
+ ((PgStat_TableEntry *)(stats->tabentry))->t_tuples_deleted++;
+}
+
+
+/* ----------
+ * pgstat_reset_index_scan() -
+ *
+ * See pgstat_reset_heap_scan().
+ * ----------
+ */
+void
+pgstat_reset_index_scan(PgStat_Info *stats)
+{
+ if (stats->tabentry == NULL)
+ return;
+
+ stats->index_scan_counted = FALSE;
+}
+
+
+/* ----------
+ * pgstat_count_index_scan() -
+ *
+ * See pgstat_count_heap_scan().
+ * ----------
+ */
+void
+pgstat_count_index_scan(PgStat_Info *stats)
+{
+ if (stats->tabentry == NULL)
+ return;
+
+ if (!stats->index_scan_counted)
+ {
+ ((PgStat_TableEntry *)(stats->tabentry))->t_numscans++;
+ stats->index_scan_counted = TRUE;
+ }
+}
+
+
+/* ----------
+ * pgstat_reset_index_getnext() -
+ *
+ * See pgstat_count_heap_getnext().
+ * ----------
+ */
+void
+pgstat_count_index_getnext(PgStat_Info *stats)
+{
+ if (stats->tabentry == NULL)
+ return;
+
+ ((PgStat_TableEntry *)(stats->tabentry))->t_tuples_returned++;
+}
+
+
+/* ----------
+ * pgstat_count_buffer_read() -
+ *
+ * Called from bufmgr.c when a buffer is looked up in the shared buffer
+ * cache. The real number of buffers read from the disk (or at least the
+ * OSs or drives cache) is this minus buffer_hit_count below.
+ * ----------
+ */
+void
+pgstat_count_buffer_read(PgStat_Info *stats, Relation rel)
+{
+ if (stats->tabentry == NULL)
+ {
+ if (stats->no_stats)
+ return;
+ pgstat_initstats(stats, rel);
+ if (stats->tabentry == NULL)
+ return;
+ }
+
+ ((PgStat_TableEntry *)(stats->tabentry))->t_blocks_fetched++;
+}
+
+
+/* ----------
+ * pgstat_count_buffer_hit() -
+ *
+ * Counts how many buffer per relation (or index) have been found
+ * in the buffer cache.
+ * ----------
+ */
+void
+pgstat_count_buffer_hit(PgStat_Info *stats, Relation rel)
+{
+ if (stats->tabentry == NULL)
+ {
+ if (stats->no_stats)
+ return;
+ pgstat_initstats(stats, rel);
+ if (stats->tabentry == NULL)
+ return;
+ }
+
+ ((PgStat_TableEntry *)(stats->tabentry))->t_blocks_hit++;
+}
+
+
+/* ----------
+ * pgstat_count_xact_commit() -
+ *
+ * Called from access/transam/xact.c to count transaction commits.
+ * ----------
+ */
+void
+pgstat_count_xact_commit(void)
+{
+ pgStatXactCommit++;
+
+ /*
+ * If there was no relation activity yet, just make
+ * one existing message buffer used without slots,
+ * causing the next report to tell new xact-counters.
+ */
+ if (pgStatTabstatAlloc > 0)
+ {
+ if (pgStatTabstatUsed == 0)
+ {
+ pgStatTabstatUsed++;
+ pgStatTabstatMessages[0]->m_nentries = 0;
+ }
+ }
+}
+
+
+/* ----------
+ * pgstat_count_xact_rollback() -
+ *
+ * Called from access/transam/xact.c to count transaction rollbacks.
+ * ----------
+ */
+void
+pgstat_count_xact_rollback(void)
+{
+ pgStatXactRollback++;
+
+ /*
+ * If there was no relation activity yet, just make
+ * one existing message buffer used without slots,
+ * causing the next report to tell new xact-counters.
+ */
+ if (pgStatTabstatAlloc > 0)
+ {
+ if (pgStatTabstatUsed == 0)
+ {
+ pgStatTabstatUsed++;
+ pgStatTabstatMessages[0]->m_nentries = 0;
+ }
+ }
+}
+
+
+/* ----------
+ * pgstat_fetch_stat_dbentry() -
+ *
+ * Support function for the SQL-callable pgstat* functions. Returns
+ * the collected statistics for one database or NULL. NULL doesn't mean
+ * that the database doesn't exist, it is just not yet known by the
+ * collector, so the caller is better off to report ZERO instead.
+ * ----------
+ */
+PgStat_StatDBEntry *
+pgstat_fetch_stat_dbentry(Oid dbid)
+{
+ PgStat_StatDBEntry *dbentry;
+ bool found;
+
+ /*
+ * If not done for this transaction, read the statistics collector
+ * stats file into some hash tables. Be careful with the read_statsfile()
+ * call below!
+ */
+ if (pgStatDBHashXact != GetCurrentTransactionId())
+ {
+ pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId,
+ &pgStatBeTable, &pgStatNumBackends);
+ pgStatDBHashXact = GetCurrentTransactionId();
+ }
+
+ /*
+ * Lookup the requested database
+ */
+ dbentry = (PgStat_StatDBEntry *)hash_search(pgStatDBHash,
+ (char *)&dbid, HASH_FIND, &found);
+ if (!found || dbentry == NULL)
+ return NULL;
+
+ return dbentry;
+}
+
+
+/* ----------
+ * pgstat_fetch_stat_tabentry() -
+ *
+ * Support function for the SQL-callable pgstat* functions. Returns
+ * the collected statistics for one table or NULL. NULL doesn't mean
+ * that the table doesn't exist, it is just not yet known by the
+ * collector, so the caller is better off to report ZERO instead.
+ * ----------
+ */
+PgStat_StatTabEntry *
+pgstat_fetch_stat_tabentry(Oid relid)
+{
+ PgStat_StatDBEntry *dbentry;
+ PgStat_StatTabEntry *tabentry;
+ bool found;
+
+ /*
+ * If not done for this transaction, read the statistics collector
+ * stats file into some hash tables. Be careful with the read_statsfile()
+ * call below!
+ */
+ if (pgStatDBHashXact != GetCurrentTransactionId())
+ {
+ pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId,
+ &pgStatBeTable, &pgStatNumBackends);
+ pgStatDBHashXact = GetCurrentTransactionId();
+ }
+
+ /*
+ * Lookup our database.
+ */
+ dbentry = (PgStat_StatDBEntry *)hash_search(pgStatDBHash,
+ (char *)&MyDatabaseId, HASH_FIND, &found);
+ if (!found || dbentry == NULL)
+ return NULL;
+
+ /*
+ * Now inside the DB's table hash table lookup the requested one.
+ */
+ if (dbentry->tables == NULL)
+ return NULL;
+ tabentry = (PgStat_StatTabEntry *)hash_search(dbentry->tables,
+ (char *)&relid, HASH_FIND, &found);
+ if (!found || tabentry == NULL)
+ return NULL;
+
+ return tabentry;
+}
+
+
+/* ----------
+ * pgstat_fetch_stat_beentry() -
+ *
+ * Support function for the SQL-callable pgstat* functions. Returns
+ * the actual activity slot of one active backend. The caller is
+ * responsible for a check if the actual user is permitted to see
+ * that info (especially the querystring).
+ * ----------
+ */
+PgStat_StatBeEntry *
+pgstat_fetch_stat_beentry(int beid)
+{
+ if (pgStatDBHashXact != GetCurrentTransactionId())
+ {
+ pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId,
+ &pgStatBeTable, &pgStatNumBackends);
+ pgStatDBHashXact = GetCurrentTransactionId();
+ }
+
+ if (beid < 1 || beid > pgStatNumBackends)
+ return NULL;
+
+ return &pgStatBeTable[beid - 1];
+}
+
+
+/* ----------
+ * pgstat_fetch_stat_numbackends() -
+ *
+ * Support function for the SQL-callable pgstat* functions. Returns
+ * the maximum current backend id.
+ * ----------
+ */
+int
+pgstat_fetch_stat_numbackends(void)
+{
+ if (pgStatDBHashXact != GetCurrentTransactionId())
+ {
+ pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId,
+ &pgStatBeTable, &pgStatNumBackends);
+ pgStatDBHashXact = GetCurrentTransactionId();
+ }
+
+ return pgStatNumBackends;
+}
+
+
+
+
+
+
+
+
+
+
+
+
+/* ------------------------------------------------------------
+ * Local support functions follow
+ * ------------------------------------------------------------
+ */
+
+
+/* ----------
+ * pgstat_setheader() -
+ *
+ * Set common header fields in a statistics message
+ * ----------
+ */
+static void
+pgstat_setheader(PgStat_MsgHdr *hdr, int mtype)
+{
+ hdr->m_type = mtype;
+ hdr->m_backendid = MyBackendId;
+ hdr->m_procpid = MyProcPid;
+ hdr->m_databaseid = MyDatabaseId;
+ hdr->m_userid = GetSessionUserId();
+}
+
+
+/* ----------
+ * pgstat_send() -
+ *
+ * Send out one statistics message to the collector
+ * ----------
+ */
+static void
+pgstat_send(void *msg, int len)
+{
+ if (pgStatSock < 0)
+ return;
+
+ ((PgStat_MsgHdr *)msg)->m_size = len;
+
+ sendto(pgStatSock, msg, len, 0,
+ (struct sockaddr *)&pgStatAddr, sizeof(pgStatAddr));
+}
+
+
+/* ------------------------------------------------------------
+ * Local functions implementing the statistics collector itself follow
+ *------------------------------------------------------------
+ */
+
+
+/* ----------
+ * pgstat_main() -
+ *
+ * The statistics collector itself.
+ * ----------
+ */
+static void
+pgstat_main(void)
+{
+ PgStat_Msg msg;
+ fd_set rfds;
+ int maxfd;
+ int nready;
+ int len;
+ int dlen;
+ struct timeval timeout;
+ struct timeval next_statwrite;
+ bool need_statwrite;
+ HASHCTL hash_ctl;
+
+ /*
+ * Close the writing end of the postmaster pipe, so we'll see
+ * it closing when the postmaster terminates and can terminate
+ * as well.
+ */
+ close(pgStatPmPipe[1]);
+
+ /*
+ * Ignore all signals usually bound to some action in the postmaster
+ */
+ signal(SIGHUP, SIG_IGN);
+ signal(SIGINT, SIG_IGN);
+ signal(SIGQUIT, SIG_IGN);
+ signal(SIGTERM, SIG_IGN);
+ signal(SIGALRM, SIG_IGN);
+ signal(SIGPIPE, SIG_IGN);
+ signal(SIGUSR1, SIG_IGN);
+ signal(SIGUSR2, SIG_IGN);
+ signal(SIGCHLD, SIG_IGN);
+ signal(SIGTTIN, SIG_IGN);
+ signal(SIGTTOU, SIG_IGN);
+ signal(SIGWINCH, SIG_IGN);
+
+ /*
+ * Write the initial status file right at startup
+ */
+ gettimeofday(&next_statwrite, NULL);
+ need_statwrite = TRUE;
+
+ /*
+ * Now we start the buffer process to read from the socket, so
+ * we have a little more time to process incoming messages.
+ */
+ if (pipe(pgStatPipe) < 0)
+ {
+ perror("PGSTAT: pipe(2)");
+ exit(1);
+ }
+
+ switch(fork())
+ {
+ case -1: perror("PGSTAT: fork(2)");
+ exit(1);
+
+ case 0: close(pgStatPipe[0]);
+ signal(SIGPIPE, SIG_DFL);
+ pgstat_recvbuffer();
+ exit(2);
+
+ default: close(pgStatPipe[1]);
+ close(pgStatSock);
+ break;
+ }
+
+ /*
+ * Read in an existing statistics stats file or initialize the
+ * stats to zero.
+ */
+ pgStatRunningInCollector = TRUE;
+ pgstat_read_statsfile(&pgStatDBHash, InvalidOid, NULL, NULL);
+
+ /*
+ * Create the dead backend hashtable
+ */
+ memset(&hash_ctl, 0, sizeof(hash_ctl));
+ hash_ctl.keysize = sizeof(int);
+ hash_ctl.datasize = sizeof(PgStat_StatBeDead);
+ hash_ctl.hash = tag_hash;
+ pgStatBeDead = hash_create(PGSTAT_BE_HASH_SIZE, &hash_ctl,
+ HASH_ELEM | HASH_FUNCTION);
+ if (pgStatBeDead == NULL)
+ {
+ fprintf(stderr,
+ "PGSTAT: Creation of dead backend hash table failed\n");
+ exit(1);
+ }
+
+ /*
+ * Create the known backends table
+ */
+ pgStatBeTable = (PgStat_StatBeEntry *)malloc(
+ sizeof(PgStat_StatBeEntry) * MaxBackends);
+ if (pgStatBeTable == NULL)
+ {
+ perror("PGSTAT: Allocation of backend table failed");
+ exit(1);
+ }
+ memset(pgStatBeTable, 0, sizeof(PgStat_StatBeEntry) * MaxBackends);
+
+ /*
+ * Process incoming messages and handle all the reporting stuff
+ * until the postmaster waves us good bye.
+ */
+ for (;;)
+ {
+ /*
+ * If we need to write the status file again (there have
+ * been changes in the statistics since we wrote it last)
+ * calculate the timeout until we have to do so.
+ */
+ if (need_statwrite)
+ {
+ gettimeofday(&timeout, NULL);
+ timeout.tv_usec = next_statwrite.tv_usec - timeout.tv_usec;
+ timeout.tv_sec = next_statwrite.tv_sec - timeout.tv_sec;
+ if (timeout.tv_usec < 0)
+ {
+ timeout.tv_sec -= 1;
+ timeout.tv_usec += 1000000;
+ }
+ if (timeout.tv_sec < 0)
+ {
+ timeout.tv_sec = 0;
+ timeout.tv_usec = 0;
+ }
+ }
+
+ /*
+ * Setup the descriptor set for select(2)
+ */
+ FD_ZERO(&rfds);
+ FD_SET(pgStatPipe[0], &rfds);
+ FD_SET(pgStatPmPipe[0], &rfds);
+
+ if (pgStatPipe[0] > pgStatPmPipe[0])
+ maxfd = pgStatPipe[0];
+ else
+ maxfd = pgStatPmPipe[0];
+
+ /*
+ * Now wait for something to do.
+ */
+ nready = select(maxfd + 1, &rfds, NULL, NULL,
+ (need_statwrite) ? &timeout : NULL);
+ if (nready < 0)
+ {
+ perror("PGSTAT: select(2)");
+ exit(1);
+ }
+
+ /*
+ * If there are no descriptors ready, our timeout for writing
+ * the stats file happened.
+ */
+ if (nready == 0)
+ {
+ pgstat_write_statsfile();
+ need_statwrite = FALSE;
+
+ continue;
+ }
+
+ /*
+ * Check if there is a new statistics message to collect.
+ */
+ if (FD_ISSET(pgStatPipe[0], &rfds))
+ {
+ /*
+ * If this is the first message after we wrote the stats
+ * file the last time, setup the timeout that it'd be
+ * written.
+ */
+ if (!need_statwrite)
+ {
+ gettimeofday(&next_statwrite, NULL);
+ next_statwrite.tv_usec += ((PGSTAT_STAT_INTERVAL) * 1000);
+ next_statwrite.tv_sec += (next_statwrite.tv_usec / 1000000);
+ next_statwrite.tv_usec %= 1000000;
+ need_statwrite = TRUE;
+ }
+
+ /*
+ * Read the header.
+ */
+ len = read(pgStatPipe[0], &msg, sizeof(PgStat_MsgHdr));
+ if (len < 0)
+ {
+ perror("PGSTAT: read(2)");
+ exit(1);
+ }
+ if (len == 0)
+ {
+ return;
+ }
+ if (len != sizeof(PgStat_MsgHdr))
+ {
+ fprintf(stderr, "PGSTAT: short read(2)");
+ exit(1);
+ }
+
+ /*
+ * And the body. We need to do it in two steps because
+ * we don't know the length.
+ */
+ dlen = msg.msg_hdr.m_size - sizeof(PgStat_MsgHdr);
+ if (dlen > 0)
+ {
+ len = read(pgStatPipe[0],
+ ((char *)&msg) + sizeof(PgStat_MsgHdr), dlen);
+ if (len < 0)
+ {
+ perror("PGSTAT: read(2)");
+ exit(1);
+ }
+ if (len == 0)
+ {
+ return;
+ }
+ if (len != dlen)
+ {
+ fprintf(stderr, "PGSTAT: short read(2)");
+ exit(1);
+ }
+ }
+
+ /*
+ * Distribute the message to the specific function
+ * handling it.
+ */
+ len += sizeof(PgStat_MsgHdr);
+ switch (msg.msg_hdr.m_type)
+ {
+ case PGSTAT_MTYPE_DUMMY:
+ break;
+
+ case PGSTAT_MTYPE_BESTART:
+ pgstat_recv_bestart((PgStat_MsgBestart *)&msg, len);
+ break;
+
+ case PGSTAT_MTYPE_BETERM:
+ pgstat_recv_beterm((PgStat_MsgBeterm *)&msg, len);
+ break;
+
+ case PGSTAT_MTYPE_TABSTAT:
+ pgstat_recv_tabstat((PgStat_MsgTabstat *)&msg, len);
+ break;
+
+ case PGSTAT_MTYPE_TABPURGE:
+ pgstat_recv_tabpurge((PgStat_MsgTabpurge *)&msg, len);
+ break;
+
+ case PGSTAT_MTYPE_ACTIVITY:
+ pgstat_recv_activity((PgStat_MsgActivity *)&msg, len);
+ break;
+
+ case PGSTAT_MTYPE_DROPDB:
+ pgstat_recv_dropdb((PgStat_MsgDropdb *)&msg, len);
+ break;
+
+ case PGSTAT_MTYPE_RESETCOUNTER:
+ pgstat_recv_resetcounter((PgStat_MsgResetcounter *)&msg,
+ len);
+ break;
+
+ default:
+ break;
+ }
+
+ /*
+ * Globally count messages and start over.
+ */
+ pgStatNumMessages++;
+ continue;
+ }
+
+ /*
+ * If the postmaster pipe is ready for reading this means that
+ * the kernel must have closed it because of the termination
+ * of the postmaster (he never really writes to it). Give up
+ * then, but save the final stats in case we want to reuse
+ * them at startup in the future.
+ */
+ if (FD_ISSET(pgStatPmPipe[0], &rfds))
+ {
+ pgstat_write_statsfile();
+ return;
+ }
+ }
+}
+
+
+/* ----------
+ * pgstat_recvbuffer() -
+ *
+ * This is a special receive buffer started by the statistics
+ * collector itself and running in a separate process. It's only
+ * purpose is to receive messages from the UDP socket as fast as
+ * possible and forward them over a pipe into the collector
+ * itself.
+ * ----------
+ */
+static void
+pgstat_recvbuffer(void)
+{
+ fd_set rfds;
+ fd_set wfds;
+ int maxfd;
+ int nready;
+ int len;
+ PgStat_Msg *msgbuffer = NULL;
+ int msg_recv = 0;
+ int msg_send = 0;
+ int msg_have = 0;
+ struct sockaddr_in fromaddr;
+ int fromlen;
+ int overflow = 0;
+
+ /*
+ * Allocate the message buffer
+ */
+ msgbuffer = (PgStat_Msg *)malloc(sizeof(PgStat_Msg) *
+ PGSTAT_RECVBUFFERSZ);
+ if (msgbuffer == NULL)
+ {
+ perror("PGSTATBUFF: malloc()");
+ exit(1);
+ }
+
+ /*
+ * Loop forever
+ */
+ for (;;)
+ {
+ FD_ZERO(&rfds);
+ FD_ZERO(&wfds);
+ maxfd = -1;
+
+ /*
+ * As long as we have buffer space we add the socket
+ * to the read descriptor set.
+ */
+ if (msg_have < PGSTAT_RECVBUFFERSZ)
+ {
+ FD_SET(pgStatSock, &rfds);
+ maxfd = pgStatSock;
+ overflow = 0;
+ }
+ else
+ {
+ if (overflow == 0)
+ {
+ fprintf(stderr, "PGSTAT: Warning - receive buffer full\n");
+ overflow = 1;
+ }
+ }
+
+
+ /*
+ * If we have messages to write out, we add the pipe
+ * to the write descriptor set. Otherwise, we check if
+ * the postmaster might have terminated.
+ */
+ if (msg_have > 0)
+ {
+ FD_SET(pgStatPipe[1], &wfds);
+ if (pgStatPipe[1] > maxfd)
+ maxfd = pgStatPipe[1];
+ }
+ else
+ {
+ FD_SET(pgStatPmPipe[0], &rfds);
+ if (pgStatPmPipe[0] > maxfd)
+ maxfd = pgStatPmPipe[0];
+ }
+
+
+ /*
+ * Wait for some work to do.
+ */
+ nready = select(maxfd + 1, &rfds, &wfds, NULL, NULL);
+ if (nready < 0)
+ {
+ perror("PGSTATBUFF: select(2)");
+ exit(1);
+ }
+
+ /*
+ * If there is a message on the socket, read it and check for
+ * validity.
+ */
+ if (FD_ISSET(pgStatSock, &rfds))
+ {
+ fromlen = sizeof(fromaddr);
+ len = recvfrom(pgStatSock,
+ &msgbuffer[msg_recv], sizeof(PgStat_Msg), 0,
+ (struct sockaddr *)&fromaddr, &fromlen);
+ if (len < 0)
+ {
+ perror("PGSTATBUFF: recvfrom(2)");
+ exit(1);
+ }
+
+ /*
+ * We ignore messages that are smaller than our common header
+ */
+ if (len < sizeof(PgStat_MsgHdr))
+ continue;
+
+ /*
+ * The received length must match the length in the header
+ */
+ if (msgbuffer[msg_recv].msg_hdr.m_size != len)
+ continue;
+
+ /*
+ * The source address of the packet must be our own socket.
+ * This ensures that only real hackers or our own backends
+ * tell us something.
+ */
+ if (fromaddr.sin_addr.s_addr != pgStatAddr.sin_addr.s_addr)
+ continue;
+ if (fromaddr.sin_port != pgStatAddr.sin_port)
+ continue;
+
+ /*
+ * O.K. - we accept this message.
+ */
+ msg_have++;
+ msg_recv++;
+ if (msg_recv == PGSTAT_RECVBUFFERSZ)
+ msg_recv = 0;
+ }
+
+ /*
+ * If the collector is ready to receive, write a buffered
+ * message into his pipe.
+ */
+ if (FD_ISSET(pgStatPipe[1], &wfds))
+ {
+ len = write(pgStatPipe[1], &msgbuffer[msg_send],
+ msgbuffer[msg_send].msg_hdr.m_size);
+ if (len < 0)
+ {
+ perror("PGSTATBUFF: write(2)");
+ exit(1);
+ }
+ if (len != msgbuffer[msg_send].msg_hdr.m_size)
+ {
+ fprintf(stderr, "PGSTATBUFF: short write(2)");
+ exit(1);
+ }
+
+ msg_have--;
+ msg_send++;
+ if (msg_send == PGSTAT_RECVBUFFERSZ)
+ msg_send = 0;
+ }
+
+ /*
+ * Make sure we forwarded all messages before we check for
+ * Postmaster termination.
+ */
+ if (FD_ISSET(pgStatSock, &rfds) || FD_ISSET(pgStatPipe[1], &wfds))
+ continue;
+
+ /*
+ * If the pipe from the postmaster is ready for reading,
+ * the kernel must have closed it on exit() (the postmaster
+ * never really writes to it). So we've done our job.
+ */
+ if (FD_ISSET(pgStatPmPipe[0], &rfds))
+ exit(0);
+ }
+}
+
+
+/* ----------
+ * pgstat_add_backend() -
+ *
+ * Support function to keep our backen list up to date.
+ * ----------
+ */
+static int
+pgstat_add_backend(PgStat_MsgHdr *msg)
+{
+ PgStat_StatDBEntry *dbentry;
+ PgStat_StatBeEntry *beentry;
+ PgStat_StatBeDead *deadbe;
+ bool found;
+
+ /*
+ * Check that the backend ID is valid
+ */
+ if (msg->m_backendid < 1 || msg->m_backendid > MaxBackends)
+ {
+ fprintf(stderr, "PGSTAT: Invalid backend ID %d\n", msg->m_backendid);
+ return -1;
+ }
+
+ /*
+ * Get the slot for this backendid.
+ */
+ beentry = &pgStatBeTable[msg->m_backendid - 1];
+ if (beentry->databaseid != InvalidOid)
+ {
+ /*
+ * If the slot contains the PID of this backend,
+ * everything is fine and we got nothing to do.
+ */
+ if (beentry->procpid == msg->m_procpid)
+ return 0;
+ }
+
+ /*
+ * Lookup if this backend is known to be dead. This can be caused
+ * due to messages arriving in the wrong order - i.e. Postmaster's
+ * BETERM message might have arrived before we received all the
+ * backends stats messages, or even a new backend with the same
+ * backendid was faster in sending his BESTART.
+ *
+ * If the backend is known to be dead, we ignore this add.
+ */
+ deadbe = (PgStat_StatBeDead *)hash_search(pgStatBeDead,
+ (char *)&(msg->m_procpid), HASH_FIND, &found);
+ if (deadbe == NULL)
+ {
+ fprintf(stderr, "PGSTAT: Dead backend table corrupted - abort\n");
+ exit(1);
+ }
+ if (found)
+ return 1;
+
+ /*
+ * Backend isn't known to be dead. If it's slot is currently used,
+ * we have to kick out the old backend.
+ */
+ if (beentry->databaseid != InvalidOid)
+ pgstat_sub_backend(beentry->procpid);
+
+ /*
+ * Put this new backend into the slot.
+ */
+ beentry->databaseid = msg->m_databaseid;
+ beentry->procpid = msg->m_procpid;
+ beentry->userid = msg->m_userid;
+
+ /*
+ * Lookup or create the database entry for this backends DB.
+ */
+ dbentry = (PgStat_StatDBEntry *)hash_search(pgStatDBHash,
+ (char *)&(msg->m_databaseid), HASH_ENTER,
+ &found);
+ if (dbentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: DB hash table corrupted - abort\n");
+ exit(1);
+ }
+
+ /*
+ * If not found, initialize the new one.
+ */
+ if (!found)
+ {
+ HASHCTL hash_ctl;
+
+ dbentry->tables = NULL;
+ dbentry->n_xact_commit = 0;
+ dbentry->n_xact_rollback = 0;
+ dbentry->n_blocks_fetched = 0;
+ dbentry->n_blocks_hit = 0;
+ dbentry->n_connects = 0;
+ dbentry->destroy = 0;
+
+ memset(&hash_ctl, 0, sizeof(hash_ctl));
+ hash_ctl.keysize = sizeof(Oid);
+ hash_ctl.datasize = sizeof(PgStat_StatTabEntry);
+ hash_ctl.hash = tag_hash;
+ dbentry->tables = hash_create(PGSTAT_TAB_HASH_SIZE, &hash_ctl,
+ HASH_ELEM | HASH_FUNCTION);
+ if (dbentry->tables == NULL)
+ {
+ fprintf(stderr, "PGSTAT: failed to initialize hash table for "
+ "new database entry\n");
+ exit(1);
+ }
+ }
+
+ /*
+ * Count number of connects to the database
+ */
+ dbentry->n_connects++;
+
+ return 0;
+}
+
+
+/* ----------
+ * pgstat_sub_backend() -
+ *
+ * Remove a backend from the actual backends list.
+ * ----------
+ */
+static void
+pgstat_sub_backend(int procpid)
+{
+ int i;
+ PgStat_StatBeDead *deadbe;
+ bool found;
+
+ /*
+ * Search in the known-backends table for the slot containing
+ * this PID.
+ */
+ for (i = 0; i < MaxBackends; i++)
+ {
+ if (pgStatBeTable[i].databaseid != InvalidOid &&
+ pgStatBeTable[i].procpid == procpid)
+ {
+ /*
+ * That's him. Add an entry to the known to be dead backends.
+ * Due to possible misorder in the arrival of UDP packets
+ * it's possible that even if we know the backend is dead,
+ * there could still be messages queued that arrive later.
+ * Those messages must not cause our number of backends
+ * statistics to get screwed up, so we remember for a couple
+ * of seconds that this PID is dead and ignore them (only
+ * the counting of backends, not the table access stats they
+ * sent).
+ */
+ deadbe = (PgStat_StatBeDead *)hash_search(pgStatBeDead,
+ (char *)&procpid, HASH_ENTER, &found);
+ if (deadbe == NULL)
+ {
+ fprintf(stderr, "PGSTAT: dead backend hash table corrupted "
+ "- abort\n");
+ exit(1);
+ }
+ if (!found)
+ {
+ deadbe->backendid = i + 1;
+ deadbe->destroy = PGSTAT_DESTROY_COUNT;
+ }
+
+ /*
+ * Declare the backend slot empty.
+ */
+ pgStatBeTable[i].databaseid = InvalidOid;
+ return;
+ }
+ }
+
+ /*
+ * No big problem if not found. This can happen if UDP messages
+ * arrive out of order here.
+ */
+}
+
+
+/* ----------
+ * pgstat_write_statsfile() -
+ *
+ * Tell the news.
+ * ----------
+ */
+static void
+pgstat_write_statsfile(void)
+{
+ HASH_SEQ_STATUS hstat;
+ HASH_SEQ_STATUS tstat;
+ PgStat_StatDBEntry *dbentry;
+ PgStat_StatTabEntry *tabentry;
+ PgStat_StatBeDead *deadbe;
+ FILE *fpout;
+ long *hentry;
+ bool found;
+ int i;
+
+ /*
+ * Open the statistics temp file to write out
+ * the current values.
+ */
+ fpout = fopen(pgStat_tmpfname, "w");
+ if (fpout == NULL)
+ {
+ fprintf(stderr, "PGSTAT: cannot open temp stats file\nPGSTAT: ");
+ perror(pgStat_tmpfname);
+ fflush(stderr);
+ return;
+ }
+
+ /*
+ * Walk through the database table.
+ */
+ hash_seq_init(&hstat, pgStatDBHash);
+ while ((hentry = hash_seq_search(&hstat)) != (long *)TRUE)
+ {
+ if (hentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: database hash table corrupted "
+ "- abort\n");
+ exit(1);
+ }
+ dbentry = (PgStat_StatDBEntry *)hentry;
+
+ /*
+ * If this database is marked destroyed, count down and do
+ * so if it reaches 0.
+ */
+ if (dbentry->destroy > 0)
+ {
+ if (--(dbentry->destroy) == 0)
+ {
+ if (dbentry->tables != NULL)
+ hash_destroy(dbentry->tables);
+
+ hentry = hash_search(pgStatDBHash,
+ (char *)&(dbentry->databaseid),
+ HASH_REMOVE, &found);
+ if (hentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: database hash table corrupted "
+ "during cleanup - abort\n");
+ exit(1);
+ }
+ }
+ /*
+ * Don't include statistics for it.
+ */
+ continue;
+ }
+
+ /*
+ * Write out the DB line including the number of life backends.
+ */
+ fputc('D', fpout);
+ fwrite(dbentry, sizeof(PgStat_StatDBEntry), 1, fpout);
+
+ /*
+ * Walk through the databases access stats per table.
+ */
+ hash_seq_init(&tstat, dbentry->tables);
+ while((hentry = hash_seq_search(&tstat)) != (long *)TRUE)
+ {
+ if (hentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: tables hash table for database "
+ "%d corrupted - abort\n",
+ dbentry->databaseid);
+ exit(1);
+ }
+ tabentry = (PgStat_StatTabEntry *)hentry;
+
+ /*
+ * If table entry marked for destruction, same as above
+ * for the database entry.
+ */
+ if (tabentry->destroy > 0)
+ {
+ if (--(tabentry->destroy) == 0)
+ {
+ hentry = hash_search(dbentry->tables,
+ (char *)&(tabentry->tableid),
+ HASH_REMOVE, &found);
+ if (hentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: tables hash table for "
+ "database %d corrupted during "
+ "cleanup - abort\n",
+ dbentry->databaseid);
+ exit(1);
+ }
+ }
+ continue;
+ }
+
+ /*
+ * At least we think this is still a life table. Print
+ * it's access stats.
+ */
+ fputc('T', fpout);
+ fwrite(tabentry, sizeof(PgStat_StatTabEntry), 1, fpout);
+ }
+
+ /*
+ * Mark the end of this DB
+ */
+ fputc('d', fpout);
+ }
+
+ /*
+ * Write out the known running backends to the stats file.
+ */
+ i = MaxBackends;
+ fputc('M', fpout);
+ fwrite(&i, sizeof(i), 1, fpout);
+
+ for (i = 0; i < MaxBackends; i++)
+ {
+ if (pgStatBeTable[i].databaseid != InvalidOid)
+ {
+ fputc('B', fpout);
+ fwrite(&pgStatBeTable[i], sizeof(PgStat_StatBeEntry), 1, fpout);
+ }
+ }
+
+ /*
+ * No more output to be done. Close the temp file and
+ * replace the old pgstat.stat with it's content.
+ */
+ fputc('E', fpout);
+ if (fclose(fpout) < 0)
+ {
+ fprintf(stderr, "PGSTAT: Error closing temp stats file\nPGSTAT: ");
+ perror(pgStat_tmpfname);
+ fprintf(stderr, "PGSTAT: Abort\n");
+ fflush(stderr);
+ exit(1);
+ }
+ else
+ {
+ if (rename(pgStat_tmpfname, pgStat_fname) < 0)
+ {
+ fprintf(stderr, "PGSTAT: Cannot rename temp stats file\n"
+ "PGSTAT: ");
+ perror(pgStat_fname);
+ fflush(stderr);
+ }
+ }
+
+ /*
+ * Clear out the dead backends table
+ */
+ hash_seq_init(&hstat, pgStatBeDead);
+ while ((hentry = hash_seq_search(&hstat)) != (long *)TRUE)
+ {
+ if (hentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: dead backend hash table corrupted "
+ "during cleanup - abort\n");
+ exit(1);
+ }
+ deadbe = (PgStat_StatBeDead *)hentry;
+
+ /*
+ * Count down the destroy delay and remove entries where
+ * it reaches 0.
+ */
+ if (--(deadbe->destroy) <= 0)
+ {
+ hentry = hash_search(pgStatBeDead, (char *)&(deadbe->procpid),
+ HASH_REMOVE, &found);
+ if (hentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: dead backend hash table corrupted "
+ "during cleanup - abort\n");
+ exit(1);
+ }
+ }
+ }
+}
+
+
+/* ----------
+ * pgstat_read_statsfile() -
+ *
+ * Reads in an existing statistics collector and initializes the
+ * databases hash table (who's entries point to the tables hash tables)
+ * and the current backend table.
+ * ----------
+ */
+static void
+pgstat_read_statsfile(HTAB **dbhash, Oid onlydb,
+ PgStat_StatBeEntry **betab, int *numbackends)
+{
+ PgStat_StatDBEntry *dbentry;
+ PgStat_StatDBEntry dbbuf;
+ PgStat_StatTabEntry *tabentry;
+ PgStat_StatTabEntry tabbuf;
+ HASHCTL hash_ctl;
+ HTAB *tabhash = NULL;
+ FILE *fpin;
+ int maxbackends = 0;
+ int havebackends = 0;
+ bool found;
+ MemoryContext use_mcxt;
+ int mcxt_flags;
+
+ /*
+ * If running in the collector we use the DynaHashCxt
+ * memory context. If running in a backend, we use the
+ * TopTransactionContext instead, so the caller must only know the
+ * last XactId when this call happened to know if his tables are
+ * still valid or already gone!
+ */
+ if (pgStatRunningInCollector)
+ {
+ use_mcxt = NULL;
+ mcxt_flags = 0;
+ }
+ else
+ {
+ use_mcxt = TopTransactionContext;
+ mcxt_flags = HASH_CONTEXT;
+ }
+
+ /*
+ * Create the DB hashtable
+ */
+ memset(&hash_ctl, 0, sizeof(hash_ctl));
+ hash_ctl.keysize = sizeof(Oid);
+ hash_ctl.datasize = sizeof(PgStat_StatDBEntry);
+ hash_ctl.hash = tag_hash;
+ hash_ctl.hcxt = use_mcxt;
+ *dbhash = hash_create(PGSTAT_DB_HASH_SIZE, &hash_ctl,
+ HASH_ELEM | HASH_FUNCTION | mcxt_flags);
+ if (pgStatDBHash == NULL)
+ {
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr, "PGSTAT: Creation of DB hash table failed\n");
+ exit(1);
+ }
+ elog(ERROR, "PGSTAT: Creation of DB hash table failed");
+ }
+
+ /*
+ * Initialize the number of known backends to zero, just in case we
+ * do a silent error return below.
+ */
+ if (numbackends != NULL)
+ *numbackends = 0;
+ if (betab != NULL)
+ *betab = NULL;
+
+ /*
+ * Try to open the status file. If it doesn't exist, the backends
+ * simply return zero for anything and the collector simply
+ * starts from scratch with empty counters.
+ */
+ if ((fpin = fopen(pgStat_fname, "r")) == NULL)
+ return;
+
+ /*
+ * We found an existing collector stats file. Read it and put
+ * all the hashtable entries into place.
+ */
+ for (;;)
+ {
+ switch (fgetc(fpin))
+ {
+ /*
+ * 'D' A PgStat_StatDBEntry struct describing a database
+ * follows. Subsequently, zero to many 'T' entries will
+ * follow until a 'd' is encountered.
+ */
+ case 'D':
+ if (fread(&dbbuf, 1, sizeof(dbbuf), fpin) != sizeof(dbbuf))
+ {
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr,
+ "PGSTAT: corrupted pgstat.stat file\n");
+ fclose(fpin);
+ return;
+ }
+ else
+ {
+ elog(NOTICE,
+ "PGSTAT: corrupted pgstat.stat file");
+ fclose(fpin);
+ return;
+ }
+ }
+
+ /*
+ * Add to the DB hash
+ */
+ dbentry = (PgStat_StatDBEntry *)hash_search(*dbhash,
+ (char *)&dbbuf.databaseid,
+ HASH_ENTER, &found);
+ if (dbentry == NULL)
+ {
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr, "PGSTAT: DB hash table corrupted\n");
+ exit(1);
+ }
+ else
+ {
+ fclose(fpin);
+ elog(ERROR, "PGSTAT: DB hash table corrupted");
+ }
+ }
+ if (found)
+ {
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr,
+ "PGSTAT: corrupted pgstat.stat file\n");
+ fclose(fpin);
+ return;
+ }
+ else
+ {
+ elog(NOTICE,
+ "PGSTAT: corrupted pgstat.stat file");
+ fclose(fpin);
+ return;
+ }
+ }
+
+ memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry));
+ dbentry->tables = NULL;
+ dbentry->destroy = 0;
+ dbentry->n_backends = 0;
+
+ /*
+ * Don't collect tables if not the requested DB
+ */
+ if (onlydb != InvalidOid && onlydb != dbbuf.databaseid)
+ break;
+
+
+ memset(&hash_ctl, 0, sizeof(hash_ctl));
+ hash_ctl.keysize = sizeof(Oid);
+ hash_ctl.datasize = sizeof(PgStat_StatTabEntry);
+ hash_ctl.hash = tag_hash;
+ hash_ctl.hcxt = use_mcxt;
+ dbentry->tables = hash_create(PGSTAT_TAB_HASH_SIZE, &hash_ctl,
+ HASH_ELEM | HASH_FUNCTION | mcxt_flags);
+ if (dbentry->tables == NULL)
+ {
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr, "PGSTAT: failed to initialize "
+ "hash table for new database entry\n");
+ exit(1);
+ }
+ else
+ {
+ fclose(fpin);
+ elog(ERROR, "PGSTAT: failed to initialize "
+ "hash table for new database entry\n");
+ }
+ }
+
+ /*
+ * Arrange that following 'T's add entries to this
+ * databases tables hash table.
+ */
+ tabhash = dbentry->tables;
+ break;
+
+ /*
+ * 'd' End of this database.
+ */
+ case 'd':
+ tabhash = NULL;
+ break;
+
+ /*
+ * 'T' A PgStat_StatTabEntry follows.
+ */
+ case 'T':
+ if (fread(&tabbuf, 1, sizeof(tabbuf), fpin) != sizeof(tabbuf))
+ {
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr,
+ "PGSTAT: corrupted pgstat.stat file\n");
+ fclose(fpin);
+ return;
+ }
+ else
+ {
+ elog(NOTICE,
+ "PGSTAT: corrupted pgstat.stat file");
+ fclose(fpin);
+ return;
+ }
+ }
+
+ /*
+ * Skip if table belongs to a not requested database.
+ */
+ if (tabhash == NULL)
+ break;
+
+ tabentry = (PgStat_StatTabEntry *)hash_search(tabhash,
+ (char *)&tabbuf.tableid,
+ HASH_ENTER, &found);
+ if (tabentry == NULL)
+ {
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr, "PGSTAT: Tab hash table corrupted\n");
+ exit(1);
+ }
+ else
+ {
+ fclose(fpin);
+ elog(ERROR, "PGSTAT: Tab hash table corrupted");
+ }
+ }
+
+ if (found)
+ {
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr,
+ "PGSTAT: corrupted pgstat.stat file\n");
+ fclose(fpin);
+ return;
+ }
+ else
+ {
+ elog(NOTICE,
+ "PGSTAT: corrupted pgstat.stat file");
+ fclose(fpin);
+ return;
+ }
+ }
+
+ memcpy(tabentry, &tabbuf, sizeof(tabbuf));
+ break;
+
+ /*
+ * 'M' The maximum number of backends to expect follows.
+ */
+ case 'M':
+ if (betab == NULL || numbackends == NULL)
+ {
+ fclose(fpin);
+ return;
+ }
+ if (fread(&maxbackends, 1, sizeof(maxbackends), fpin) !=
+ sizeof(maxbackends))
+ {
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr,
+ "PGSTAT: corrupted pgstat.stat file\n");
+ fclose(fpin);
+ return;
+ }
+ else
+ {
+ elog(NOTICE,
+ "PGSTAT: corrupted pgstat.stat file");
+ fclose(fpin);
+ return;
+ }
+ }
+ if (maxbackends == 0)
+ {
+ fclose(fpin);
+ return;
+ }
+
+ /*
+ * Allocate space (in TopTransactionContext too) for
+ * the backend table.
+ */
+ if (use_mcxt == NULL)
+ *betab = (PgStat_StatBeEntry *)malloc(
+ sizeof(PgStat_StatBeEntry) * maxbackends);
+ else
+ *betab = (PgStat_StatBeEntry *)MemoryContextAlloc(
+ use_mcxt,
+ sizeof(PgStat_StatBeEntry) * maxbackends);
+ break;
+
+ /*
+ * 'B' A PgStat_StatBeEntry follows.
+ */
+ case 'B':
+ if (betab == NULL || numbackends == NULL)
+ {
+ fclose(fpin);
+ return;
+ }
+ if (*betab == NULL)
+ {
+ fclose(fpin);
+ return;
+ }
+ /*
+ * Read it directly into the table.
+ */
+ if (fread(&(*betab)[havebackends], 1,
+ sizeof(PgStat_StatBeEntry), fpin) !=
+ sizeof(PgStat_StatBeEntry))
+ {
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr,
+ "PGSTAT: corrupted pgstat.stat file\n");
+ fclose(fpin);
+ return;
+ }
+ else
+ {
+ elog(NOTICE,
+ "PGSTAT: corrupted pgstat.stat file");
+ fclose(fpin);
+ return;
+ }
+ }
+
+ /*
+ * Count backends per database here.
+ */
+ dbentry = (PgStat_StatDBEntry *)hash_search(*dbhash,
+ (char *)&((*betab)[havebackends].databaseid),
+ HASH_FIND, &found);
+ if (found)
+ dbentry->n_backends++;
+
+ havebackends++;
+ if (numbackends != 0)
+ *numbackends = havebackends;
+ if (havebackends >= maxbackends)
+ {
+ fclose(fpin);
+ return;
+ }
+ break;
+
+ /*
+ * 'E' The EOF marker of a complete stats file.
+ */
+ case 'E':
+ fclose(fpin);
+ return;
+
+ default:
+ if (pgStatRunningInCollector)
+ {
+ fprintf(stderr, "PGSTAT: corrupted pgstat.stat file\n");
+ fclose(fpin);
+ return;
+ }
+ else
+ {
+ elog(NOTICE, "PGSTAT: corrupted pgstat.stat file");
+ fclose(fpin);
+ return;
+ }
+ }
+ }
+
+ fclose(fpin);
+}
+
+
+/* ----------
+ * pgstat_recv_bestart() -
+ *
+ * Process a backend starup message.
+ * ----------
+ */
+static void
+pgstat_recv_bestart(PgStat_MsgBestart *msg, int len)
+{
+ pgstat_add_backend(&msg->m_hdr);
+}
+
+
+/* ----------
+ * pgstat_recv_beterm() -
+ *
+ * Process a backend termination message.
+ * ----------
+ */
+static void
+pgstat_recv_beterm(PgStat_MsgBeterm *msg, int len)
+{
+ pgstat_sub_backend(msg->m_hdr.m_procpid);
+}
+
+
+/* ----------
+ * pgstat_recv_activity() -
+ *
+ * Remember what the backend is doing.
+ * ----------
+ */
+static void
+pgstat_recv_activity(PgStat_MsgActivity *msg, int len)
+{
+ /*
+ * Here we check explicitly for 0 return, since we don't
+ * want to mangle the activity of an active backend by
+ * a delayed packed from a dead one.
+ */
+ if (pgstat_add_backend(&msg->m_hdr) != 0)
+ return;
+
+ strncpy(pgStatBeTable[msg->m_hdr.m_backendid - 1].activity,
+ msg->m_what, PGSTAT_ACTIVITY_SIZE);
+}
+
+
+/* ----------
+ * pgstat_recv_tabstat() -
+ *
+ * Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len)
+{
+ PgStat_TableEntry *tabmsg = &(msg->m_entry[0]);
+ PgStat_StatDBEntry *dbentry;
+ PgStat_StatTabEntry *tabentry;
+ int i;
+ bool found;
+
+ /*
+ * Make sure the backend is counted for.
+ */
+ if (pgstat_add_backend(&msg->m_hdr) < 0)
+ return;
+
+ /*
+ * Lookup the database in the hashtable.
+ */
+ dbentry = (PgStat_StatDBEntry *)hash_search(pgStatDBHash,
+ (char *)&(msg->m_hdr.m_databaseid),
+ HASH_FIND, &found);
+ if (dbentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: database hash table corrupted - abort\n");
+ exit(1);
+ }
+ if (!found)
+ return;
+
+ /*
+ * If the database is marked for destroy, this is a delayed
+ * UDP packet and not worth beeing counted.
+ */
+ if (dbentry->destroy > 0)
+ return;
+
+ dbentry->n_xact_commit += (PgStat_Counter)(msg->m_xact_commit);
+ dbentry->n_xact_rollback += (PgStat_Counter)(msg->m_xact_rollback);
+
+ /*
+ * Process all table entries in the message.
+ */
+ for (i = 0; i < msg->m_nentries; i++)
+ {
+ tabentry = (PgStat_StatTabEntry *)hash_search(dbentry->tables,
+ (char *)&(tabmsg[i].t_id),
+ HASH_ENTER, &found);
+ if (tabentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: tables hash table corrupted for "
+ "database %d - abort\n", dbentry->databaseid);
+ exit(1);
+ }
+
+ if (!found)
+ {
+ /*
+ * If it's a new table entry, initialize counters
+ * to the values we just got.
+ */
+ tabentry->numscans = tabmsg[i].t_numscans;
+ tabentry->tuples_returned = tabmsg[i].t_tuples_returned;
+ tabentry->tuples_fetched = tabmsg[i].t_tuples_fetched;
+ tabentry->tuples_inserted = tabmsg[i].t_tuples_inserted;
+ tabentry->tuples_updated = tabmsg[i].t_tuples_updated;
+ tabentry->tuples_deleted = tabmsg[i].t_tuples_deleted;
+ tabentry->blocks_fetched = tabmsg[i].t_blocks_fetched;
+ tabentry->blocks_hit = tabmsg[i].t_blocks_hit;
+
+ tabentry->destroy = 0;
+ }
+ else
+ {
+ /*
+ * Otherwise add the values to the existing entry.
+ */
+ tabentry->numscans += tabmsg[i].t_numscans;
+ tabentry->tuples_returned += tabmsg[i].t_tuples_returned;
+ tabentry->tuples_fetched += tabmsg[i].t_tuples_fetched;
+ tabentry->tuples_inserted += tabmsg[i].t_tuples_inserted;
+ tabentry->tuples_updated += tabmsg[i].t_tuples_updated;
+ tabentry->tuples_deleted += tabmsg[i].t_tuples_deleted;
+ tabentry->blocks_fetched += tabmsg[i].t_blocks_fetched;
+ tabentry->blocks_hit += tabmsg[i].t_blocks_hit;
+ }
+
+ /*
+ * And add the block IO to the database entry.
+ */
+ dbentry->n_blocks_fetched += tabmsg[i].t_blocks_fetched;
+ dbentry->n_blocks_hit += tabmsg[i].t_blocks_hit;
+ }
+}
+
+
+/* ----------
+ * pgstat_recv_tabpurge() -
+ *
+ * Arrange for dead table removal.
+ * ----------
+ */
+static void
+pgstat_recv_tabpurge(PgStat_MsgTabpurge *msg, int len)
+{
+ PgStat_StatDBEntry *dbentry;
+ PgStat_StatTabEntry *tabentry;
+ int i;
+ bool found;
+
+ /*
+ * Make sure the backend is counted for.
+ */
+ if (pgstat_add_backend(&msg->m_hdr) < 0)
+ return;
+
+ /*
+ * Lookup the database in the hashtable.
+ */
+ dbentry = (PgStat_StatDBEntry *)hash_search(pgStatDBHash,
+ (char *)&(msg->m_hdr.m_databaseid),
+ HASH_FIND, &found);
+ if (dbentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: database hash table corrupted - abort\n");
+ exit(1);
+ }
+ if (!found)
+ return;
+
+ /*
+ * If the database is marked for destroy, this is a delayed
+ * UDP packet and the tables will go away at DB destruction.
+ */
+ if (dbentry->destroy > 0)
+ return;
+
+ /*
+ * Process all table entries in the message.
+ */
+ for (i = 0; i < msg->m_nentries; i++)
+ {
+ tabentry = (PgStat_StatTabEntry *)hash_search(dbentry->tables,
+ (char *)&(msg->m_tableid[i]),
+ HASH_FIND, &found);
+ if (tabentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: tables hash table corrupted for "
+ "database %d - abort\n", dbentry->databaseid);
+ exit(1);
+ }
+
+ if (found)
+ tabentry->destroy = PGSTAT_DESTROY_COUNT;
+ }
+}
+
+
+/* ----------
+ * pgstat_recv_dropdb() -
+ *
+ * Arrange for dead database removal
+ * ----------
+ */
+static void
+pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
+{
+ PgStat_StatDBEntry *dbentry;
+ bool found;
+
+ /*
+ * Make sure the backend is counted for.
+ */
+ if (pgstat_add_backend(&msg->m_hdr) < 0)
+ return;
+
+ /*
+ * Lookup the database in the hashtable.
+ */
+ dbentry = (PgStat_StatDBEntry *)hash_search(pgStatDBHash,
+ (char *)&(msg->m_databaseid),
+ HASH_FIND, &found);
+ if (dbentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: database hash table corrupted - abort\n");
+ exit(1);
+ }
+ if (!found)
+ return;
+
+ /*
+ * Mark the database for destruction.
+ */
+ dbentry->destroy = PGSTAT_DESTROY_COUNT;
+}
+
+
+/* ----------
+ * pgstat_recv_dropdb() -
+ *
+ * Arrange for dead database removal
+ * ----------
+ */
+static void
+pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
+{
+ HASHCTL hash_ctl;
+ PgStat_StatDBEntry *dbentry;
+ bool found;
+
+ /*
+ * Make sure the backend is counted for.
+ */
+ if (pgstat_add_backend(&msg->m_hdr) < 0)
+ return;
+
+ /*
+ * Lookup the database in the hashtable.
+ */
+ dbentry = (PgStat_StatDBEntry *)hash_search(pgStatDBHash,
+ (char *)&(msg->m_hdr.m_databaseid),
+ HASH_FIND, &found);
+ if (dbentry == NULL)
+ {
+ fprintf(stderr, "PGSTAT: database hash table corrupted - abort\n");
+ exit(1);
+ }
+ if (!found)
+ return;
+
+ /*
+ * We simply throw away all the databases table entries by recreating
+ * a new hash table for them.
+ */
+ if (dbentry->tables != NULL)
+ hash_destroy(dbentry->tables);
+
+ dbentry->tables = NULL;
+ dbentry->n_xact_commit = 0;
+ dbentry->n_xact_rollback = 0;
+ dbentry->n_blocks_fetched = 0;
+ dbentry->n_blocks_hit = 0;
+ dbentry->n_connects = 0;
+ dbentry->destroy = 0;
+
+ memset(&hash_ctl, 0, sizeof(hash_ctl));
+ hash_ctl.keysize = sizeof(Oid);
+ hash_ctl.datasize = sizeof(PgStat_StatTabEntry);
+ hash_ctl.hash = tag_hash;
+ dbentry->tables = hash_create(PGSTAT_TAB_HASH_SIZE, &hash_ctl,
+ HASH_ELEM | HASH_FUNCTION);
+ if (dbentry->tables == NULL)
+ {
+ fprintf(stderr, "PGSTAT: failed to reinitialize hash table for "
+ "database entry\n");
+ exit(1);
+ }
+}
+
+
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
new file mode 100644
index 00000000000..a629ea0ed1e
--- /dev/null
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -0,0 +1,376 @@
+#include "postgres.h"
+#include "fmgr.h"
+
+#include "utils/hsearch.h"
+#include "access/xact.h"
+#include "catalog/pg_shadow.h"
+#include "nodes/execnodes.h"
+
+#include "pgstat.h"
+
+extern Datum pg_stat_get_numscans(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_tuples_returned(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_tuples_fetched(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_tuples_inserted(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_tuples_updated(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_tuples_deleted(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_blocks_fetched(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_blocks_hit(PG_FUNCTION_ARGS);
+
+extern Datum pg_stat_get_backend_idset(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_backend_pid(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_backend_dbid(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_backend_userid(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_backend_activity(PG_FUNCTION_ARGS);
+
+extern Datum pg_stat_get_db_numbackends(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_db_xact_commit(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_db_xact_rollback(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_db_blocks_fetched(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_db_blocks_hit(PG_FUNCTION_ARGS);
+
+
+Datum
+pg_stat_get_numscans(PG_FUNCTION_ARGS)
+{
+ PgStat_StatTabEntry *tabentry;
+ Oid relid;
+ int64 result;
+
+ relid = PG_GETARG_OID(0);
+
+ if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(tabentry->numscans);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_tuples_returned(PG_FUNCTION_ARGS)
+{
+ PgStat_StatTabEntry *tabentry;
+ Oid relid;
+ int64 result;
+
+ relid = PG_GETARG_OID(0);
+
+ if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(tabentry->tuples_returned);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_tuples_fetched(PG_FUNCTION_ARGS)
+{
+ PgStat_StatTabEntry *tabentry;
+ Oid relid;
+ int64 result;
+
+ relid = PG_GETARG_OID(0);
+
+ if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(tabentry->tuples_fetched);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_tuples_inserted(PG_FUNCTION_ARGS)
+{
+ PgStat_StatTabEntry *tabentry;
+ Oid relid;
+ int64 result;
+
+ relid = PG_GETARG_OID(0);
+
+ if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(tabentry->tuples_inserted);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_tuples_updated(PG_FUNCTION_ARGS)
+{
+ PgStat_StatTabEntry *tabentry;
+ Oid relid;
+ int64 result;
+
+ relid = PG_GETARG_OID(0);
+
+ if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(tabentry->tuples_updated);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_tuples_deleted(PG_FUNCTION_ARGS)
+{
+ PgStat_StatTabEntry *tabentry;
+ Oid relid;
+ int64 result;
+
+ relid = PG_GETARG_OID(0);
+
+ if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(tabentry->tuples_deleted);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_blocks_fetched(PG_FUNCTION_ARGS)
+{
+ PgStat_StatTabEntry *tabentry;
+ Oid relid;
+ int64 result;
+
+ relid = PG_GETARG_OID(0);
+
+ if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(tabentry->blocks_fetched);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_blocks_hit(PG_FUNCTION_ARGS)
+{
+ PgStat_StatTabEntry *tabentry;
+ Oid relid;
+ int64 result;
+
+ relid = PG_GETARG_OID(0);
+
+ if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(tabentry->blocks_hit);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
+{
+ FmgrInfo *fmgr_info = fcinfo->flinfo;
+ MemoryContext oldcxt;
+ int32 result;
+
+ if (fcinfo->resultinfo == NULL)
+ elog(ERROR, "called in context that does not accept a set result (1)");
+ if (!IsA(fcinfo->resultinfo, ReturnSetInfo))
+ elog(ERROR, "called in context that does not accept a set result (2)");
+
+ if (fmgr_info->fn_extra == NULL)
+ {
+ if (fmgr_info->fn_mcxt == NULL)
+ elog(ERROR, "No function memory context in set-function");
+
+ oldcxt = MemoryContextSwitchTo(fmgr_info->fn_mcxt);
+ fmgr_info->fn_extra = palloc(sizeof(int32) * 2);
+ ((int32 *)(fmgr_info->fn_extra))[0] = 0;
+ ((int32 *)(fmgr_info->fn_extra))[1] =
+ (int32)pgstat_fetch_stat_numbackends();
+ MemoryContextSwitchTo(oldcxt);
+ }
+
+ ((int32 *)(fmgr_info->fn_extra))[0] += 1;
+ result = ((int32 *)(fmgr_info->fn_extra))[0];
+
+
+ if (result > ((int32 *)(fmgr_info->fn_extra))[1])
+ {
+ ((ReturnSetInfo *)(fcinfo->resultinfo))->isDone = ExprEndResult;
+ PG_RETURN_NULL();
+ }
+
+ ((ReturnSetInfo *)(fcinfo->resultinfo))->isDone = ExprMultipleResult;
+ PG_RETURN_INT32(result);
+}
+
+
+Datum
+pg_stat_get_backend_pid(PG_FUNCTION_ARGS)
+{
+ PgStat_StatBeEntry *beentry;
+ int32 beid;
+
+ beid = PG_GETARG_INT32(0);
+
+ if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+ PG_RETURN_NULL();
+
+ PG_RETURN_INT32(beentry->procpid);
+}
+
+
+Datum
+pg_stat_get_backend_dbid(PG_FUNCTION_ARGS)
+{
+ PgStat_StatBeEntry *beentry;
+ int32 beid;
+
+ beid = PG_GETARG_INT32(0);
+
+ if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+ PG_RETURN_NULL();
+
+ PG_RETURN_OID(beentry->databaseid);
+}
+
+
+Datum
+pg_stat_get_backend_userid(PG_FUNCTION_ARGS)
+{
+ PgStat_StatBeEntry *beentry;
+ int32 beid;
+
+ beid = PG_GETARG_INT32(0);
+
+ if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+ PG_RETURN_NULL();
+
+ PG_RETURN_OID(beentry->userid);
+}
+
+
+Datum
+pg_stat_get_backend_activity(PG_FUNCTION_ARGS)
+{
+ PgStat_StatBeEntry *beentry;
+ int32 beid;
+ int len;
+ text *result;
+
+ if (!superuser())
+ PG_RETURN_NULL();
+
+ beid = PG_GETARG_INT32(0);
+
+ if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+ PG_RETURN_NULL();
+
+ len = strlen(beentry->activity);
+ result = palloc(VARHDRSZ + len);
+ VARATT_SIZEP(result) = VARHDRSZ + len;
+ memcpy(VARDATA(result), beentry->activity, len);
+
+ PG_RETURN_TEXT_P(result);
+}
+
+
+Datum
+pg_stat_get_db_numbackends(PG_FUNCTION_ARGS)
+{
+ PgStat_StatDBEntry *dbentry;
+ Oid dbid;
+ int32 result;
+
+ dbid = PG_GETARG_OID(0);
+
+ if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+ result = 0;
+ else
+ result = (int32)(dbentry->n_backends);
+
+ PG_RETURN_INT32(result);
+}
+
+
+Datum
+pg_stat_get_db_xact_commit(PG_FUNCTION_ARGS)
+{
+ PgStat_StatDBEntry *dbentry;
+ Oid dbid;
+ int64 result;
+
+ dbid = PG_GETARG_OID(0);
+
+ if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(dbentry->n_xact_commit);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_db_xact_rollback(PG_FUNCTION_ARGS)
+{
+ PgStat_StatDBEntry *dbentry;
+ Oid dbid;
+ int64 result;
+
+ dbid = PG_GETARG_OID(0);
+
+ if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(dbentry->n_xact_rollback);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_db_blocks_fetched(PG_FUNCTION_ARGS)
+{
+ PgStat_StatDBEntry *dbentry;
+ Oid dbid;
+ int64 result;
+
+ dbid = PG_GETARG_OID(0);
+
+ if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(dbentry->n_blocks_fetched);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_db_blocks_hit(PG_FUNCTION_ARGS)
+{
+ PgStat_StatDBEntry *dbentry;
+ Oid dbid;
+ int64 result;
+
+ dbid = PG_GETARG_OID(0);
+
+ if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+ result = 0;
+ else
+ result = (int64)(dbentry->n_blocks_hit);
+
+ PG_RETURN_INT64(result);
+}
+
+
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
new file mode 100644
index 00000000000..952d7bad853
--- /dev/null
+++ b/src/include/pgstat.h
@@ -0,0 +1,380 @@
+/* ----------
+ * pgstat.h
+ *
+ * Definitions for the PostgreSQL statistics collector daemon.
+ *
+ * Copyright (c) 2001, PostgreSQL Global Development Group
+ *
+ * $Id: pgstat.h,v 1.1 2001/06/22 19:18:36 wieck Exp $
+ * ----------
+ */
+#ifndef PGSTAT_H
+#define PGSTAT_H
+
+/* ----------
+ * Paths for the statistics files. The %s is replaced with the
+ * installations $PGDATA.
+ * ----------
+ */
+#define PGSTAT_STAT_FILENAME "%s/pgstat.stat"
+#define PGSTAT_STAT_TMPFILE "%s/pgstat.tmp.%d"
+
+/* ----------
+ * Timer definitions.
+ * ----------
+ */
+#define PGSTAT_STAT_INTERVAL 500 /* How often to write the status */
+ /* file in milliseconds. */
+
+#define PGSTAT_DESTROY_DELAY 10000 /* How long to keep destroyed */
+ /* objects known to give delayed */
+ /* UDP packets time to arrive */
+ /* in milliseconds. */
+
+#define PGSTAT_DESTROY_COUNT (PGSTAT_DESTROY_DELAY \
+ / PGSTAT_STAT_INTERVAL)
+
+
+/* ----------
+ * How much of the actual query to send to the collector.
+ * ----------
+ */
+#define PGSTAT_ACTIVITY_SIZE 256
+
+
+/* ----------
+ * The types of backend/postmaster -> collector messages
+ * ----------
+ */
+#define PGSTAT_MTYPE_DUMMY 0
+#define PGSTAT_MTYPE_BESTART 1
+#define PGSTAT_MTYPE_BETERM 2
+#define PGSTAT_MTYPE_ACTIVITY 3
+#define PGSTAT_MTYPE_TABSTAT 4
+#define PGSTAT_MTYPE_TABPURGE 5
+#define PGSTAT_MTYPE_DROPDB 6
+#define PGSTAT_MTYPE_RESETCOUNTER 7
+
+/* ----------
+ * TODO
+ * For simplicity now, the number of messages buffered in
+ * pgstat_recvbuffer(). Should be an amount of bytes used
+ * for a gapless wraparound buffer.
+ * ----------
+ */
+#define PGSTAT_RECVBUFFERSZ 1024
+
+
+/* ----------
+ * The initial size hints for the hash tables used in the
+ * collector.
+ * ----------
+ */
+#define PGSTAT_DB_HASH_SIZE 16
+#define PGSTAT_BE_HASH_SIZE 512
+#define PGSTAT_TAB_HASH_SIZE 512
+
+
+/* ----------
+ * The data type used for counters.
+ * ----------
+ */
+typedef int64 PgStat_Counter;
+
+
+/* ------------------------------------------------------------
+ * Statistic collector data structures follow
+ * ------------------------------------------------------------
+ */
+/* ----------
+ * PgStat_StatDBEntry The collectors data per database
+ * ----------
+ */
+typedef struct PgStat_StatDBEntry
+{
+ Oid databaseid;
+ HTAB *tables;
+ int n_backends;
+ PgStat_Counter n_connects;
+ PgStat_Counter n_xact_commit;
+ PgStat_Counter n_xact_rollback;
+ PgStat_Counter n_blocks_fetched;
+ PgStat_Counter n_blocks_hit;
+ int destroy;
+} PgStat_StatDBEntry;
+
+
+/* ----------
+ * PgStat_StatBeEntry The collectors data per backend
+ * ----------
+ */
+typedef struct PgStat_StatBeEntry
+{
+ Oid databaseid;
+ Oid userid;
+ int procpid;
+ char activity[PGSTAT_ACTIVITY_SIZE];
+} PgStat_StatBeEntry;
+
+
+/* ----------
+ * PgStat_StatBeDead Because UDP packets can arrive out of
+ * order, we need to keep some information
+ * about backends that are known to be
+ * dead for some seconds. This info is held
+ * in a hash table of these structs.
+ * ----------
+ */
+typedef struct PgStat_StatBeDead
+{
+ int procpid;
+ int backendid;
+ int destroy;
+} PgStat_StatBeDead;
+
+
+/* ----------
+ * PgStat_StatTabEntry The collectors data table data
+ * ----------
+ */
+typedef struct PgStat_StatTabEntry
+{
+ Oid tableid;
+
+ PgStat_Counter numscans;
+
+ PgStat_Counter tuples_returned;
+ PgStat_Counter tuples_fetched;
+ PgStat_Counter tuples_inserted;
+ PgStat_Counter tuples_updated;
+ PgStat_Counter tuples_deleted;
+
+ PgStat_Counter blocks_fetched;
+ PgStat_Counter blocks_hit;
+
+ int destroy;
+} PgStat_StatTabEntry;
+
+
+/* ------------------------------------------------------------
+ * Message formats follow
+ * ------------------------------------------------------------
+ */
+
+
+/* ----------
+ * PgStat_MsgHdr The common message header
+ * ----------
+ */
+typedef struct PgStat_MsgHdr
+{
+ int m_type;
+ int m_size;
+ int m_backendid;
+ int m_procpid;
+ Oid m_databaseid;
+ Oid m_userid;
+} PgStat_MsgHdr;
+
+/* ----------
+ * PgStat_TabEntry A table slot in a MsgTabstat
+ * ----------
+ */
+typedef struct PgStat_TableEntry
+{
+ Oid t_id;
+
+ PgStat_Counter t_numscans;
+
+ PgStat_Counter t_tuples_returned;
+ PgStat_Counter t_tuples_fetched;
+ PgStat_Counter t_tuples_inserted;
+ PgStat_Counter t_tuples_updated;
+ PgStat_Counter t_tuples_deleted;
+
+ PgStat_Counter t_blocks_fetched;
+ PgStat_Counter t_blocks_hit;
+} PgStat_TableEntry;
+
+
+/* ----------
+ * PgStat_MsgDummy A dummy message, ignored by the collector
+ * ----------
+ */
+typedef struct PgStat_MsgDummy
+{
+ PgStat_MsgHdr m_hdr;
+ char m_dummy[512];
+} PgStat_MsgDummy;
+
+/* ----------
+ * PgStat_MsgBestart Sent by the backend on startup
+ * ----------
+ */
+typedef struct PgStat_MsgBestart
+{
+ PgStat_MsgHdr m_hdr;
+} PgStat_MsgBestart;
+
+/* ----------
+ * PgStat_MsgBeterm Sent by the postmaster after backend exit
+ * ----------
+ */
+typedef struct PgStat_MsgBeterm
+{
+ PgStat_MsgHdr m_hdr;
+} PgStat_MsgBeterm;
+
+/* ----------
+ * PgStat_MsgActivity Sent by the backends when they start
+ * to parse a query.
+ * ----------
+ */
+typedef struct PgStat_MsgActivity
+{
+ PgStat_MsgHdr m_hdr;
+ char m_what[PGSTAT_ACTIVITY_SIZE];
+} PgStat_MsgActivity;
+
+/* ----------
+ * How many table entries fit into a MsgTabstat. Actually,
+ * this will keep the UDP packets below 1K, what should fit
+ * unfragmented into the MTU of the lo interface on most
+ * platforms. Does anybody care for platforms where it doesn't?
+ * ----------
+ */
+#define PGSTAT_NUM_TABENTRIES ((1000 - sizeof(PgStat_MsgHdr)) \
+ / sizeof(PgStat_TableEntry))
+
+/* ----------
+ * PgStat_MsgTabstat Sent by the backend to report table
+ * and buffer access statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgTabstat
+{
+ PgStat_MsgHdr m_hdr;
+ int m_nentries;
+ int m_xact_commit;
+ int m_xact_rollback;
+ PgStat_TableEntry m_entry[PGSTAT_NUM_TABENTRIES];
+} PgStat_MsgTabstat;
+
+
+/* ----------
+ * How many Oid entries fit into a MsgTabpurge.
+ * ----------
+ */
+#define PGSTAT_NUM_TABPURGE ((1000 - sizeof(PgStat_MsgHdr)) \
+ / sizeof(PgStat_TableEntry))
+
+/* ----------
+ * PgStat_MsgTabpurge Sent by the backend to tell the collector
+ * about dead tables.
+ * ----------
+ */
+typedef struct PgStat_MsgTabpurge
+{
+ PgStat_MsgHdr m_hdr;
+ int m_nentries;
+ Oid m_tableid[PGSTAT_NUM_TABPURGE];
+} PgStat_MsgTabpurge;
+
+
+/* ----------
+ * PgStat_MsgDropdb Sent by the backend to tell the collector
+ * about dropped database
+ * ----------
+ */
+typedef struct PgStat_MsgDropdb
+{
+ PgStat_MsgHdr m_hdr;
+ Oid m_databaseid;
+} PgStat_MsgDropdb;
+
+
+/* ----------
+ * PgStat_MsgResetcounter Sent by the backend to tell the collector
+ * to reset counters
+ * ----------
+ */
+typedef struct PgStat_MsgResetcounter
+{
+ PgStat_MsgHdr m_hdr;
+} PgStat_MsgResetcounter;
+
+
+/* ----------
+ * PgStat_Msg Union over all possible messages.
+ * ----------
+ */
+typedef union PgStat_Msg
+{
+ PgStat_MsgHdr msg_hdr;
+ PgStat_MsgDummy msg_dummy;
+ PgStat_MsgBestart msg_bestart;
+ PgStat_MsgActivity msg_activity;
+ PgStat_MsgTabstat msg_tabstat;
+ PgStat_MsgTabpurge msg_tabpurge;
+ PgStat_MsgDropdb msg_dropdb;
+ PgStat_MsgResetcounter msg_resetcounter;
+} PgStat_Msg;
+
+
+
+
+/* ----------
+ * Functions called from postmaster
+ * ----------
+ */
+extern int pgstat_init(void);
+extern int pgstat_start(void);
+extern int pgstat_ispgstat(int pid);
+extern void pgstat_beterm(int pid);
+
+/* ----------
+ * Functions called from backends
+ * ----------
+ */
+extern void pgstat_bestart(void);
+
+extern void pgstat_ping(void);
+extern void pgstat_report_activity(char *what);
+extern void pgstat_report_tabstat(void);
+extern int pgstat_vacuum_tabstat(void);
+
+extern void pgstat_reset_counters(void);
+
+extern void pgstat_initstats(PgStat_Info *stats, Relation rel);
+
+extern void pgstat_reset_heap_scan(PgStat_Info *stats);
+extern void pgstat_count_heap_scan(PgStat_Info *stats);
+extern void pgstat_count_heap_getnext(PgStat_Info *stats);
+extern void pgstat_count_heap_fetch(PgStat_Info *stats);
+extern void pgstat_count_heap_insert(PgStat_Info *stats);
+extern void pgstat_count_heap_update(PgStat_Info *stats);
+extern void pgstat_count_heap_delete(PgStat_Info *stats);
+
+extern void pgstat_reset_index_scan(PgStat_Info *stats);
+extern void pgstat_count_index_scan(PgStat_Info *stats);
+extern void pgstat_count_index_getnext(PgStat_Info *stats);
+
+extern void pgstat_count_buffer_read(PgStat_Info *stats,
+ Relation rel);
+extern void pgstat_count_buffer_hit(PgStat_Info *stats,
+ Relation rel);
+extern void pgstat_count_xact_commit(void);
+extern void pgstat_count_xact_rollback(void);
+
+/* ----------
+ * Support functions for the SQL-callable functions to
+ * generate the pgstat* views.
+ * ----------
+ */
+extern PgStat_StatDBEntry *pgstat_fetch_stat_dbentry(Oid dbid);
+extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
+extern PgStat_StatBeEntry *pgstat_fetch_stat_beentry(int beid);
+extern int pgstat_fetch_stat_numbackends(void);
+
+
+#endif /* PGSTAT_H */
--
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