postgresql/contrib/vacuumlo/vacuumlo.c
Tom Lane f85f43dfb5 Backend support for autocommit removed, per recent discussions. The
only remnant of this failed experiment is that the server will take
SET AUTOCOMMIT TO ON.  Still TODO: provide some client-side autocommit
logic in libpq.
2003-05-14 03:26:03 +00:00

479 lines
10 KiB
C

/*-------------------------------------------------------------------------
*
* vacuumlo.c
* This removes orphaned large objects from a database.
*
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/contrib/vacuumlo/vacuumlo.c,v 1.20 2003/05/14 03:25:57 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres_fe.h"
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#ifdef HAVE_TERMIOS_H
#include <termios.h>
#endif
#include "libpq-fe.h"
#include "libpq/libpq-fs.h"
#define atooid(x) ((Oid) strtoul((x), NULL, 10))
#define BUFSIZE 1024
extern char *optarg;
extern int optind,
opterr,
optopt;
struct _param
{
char *pg_user;
int pg_prompt;
char *pg_port;
char *pg_host;
int verbose;
int dry_run;
};
int vacuumlo(char *, struct _param *);
char *simple_prompt(const char *prompt, int, int);
void usage(void);
/*
* simple_prompt
*
* Generalized function especially intended for reading in usernames and
* password interactively. Reads from /dev/tty or stdin/stderr.
*
* prompt: The prompt to print
* maxlen: How many characters to accept
* echo: Set to 0 if you want to hide what is entered (for passwords)
*
* Returns a malloc()'ed string with the input (w/o trailing newline).
*/
static int prompt_state = 0;
char *
simple_prompt(const char *prompt, int maxlen, int echo)
{
int length;
char *destination;
FILE *termin,
*termout;
#ifdef HAVE_TERMIOS_H
struct termios t_orig,
t;
#endif
destination = (char *) malloc(maxlen + 2);
if (!destination)
return NULL;
prompt_state = 1; /* disable SIGINT */
/*
* Do not try to collapse these into one "w+" mode file. Doesn't work
* on some platforms (eg, HPUX 10.20).
*/
termin = fopen("/dev/tty", "r");
termout = fopen("/dev/tty", "w");
if (!termin || !termout)
{
if (termin)
fclose(termin);
if (termout)
fclose(termout);
termin = stdin;
termout = stderr;
}
#ifdef HAVE_TERMIOS_H
if (!echo)
{
tcgetattr(fileno(termin), &t);
t_orig = t;
t.c_lflag &= ~ECHO;
tcsetattr(fileno(termin), TCSAFLUSH, &t);
}
#endif
if (prompt)
{
fputs(prompt, termout);
fflush(termout);
}
if (fgets(destination, maxlen, termin) == NULL)
destination[0] = '\0';
length = strlen(destination);
if (length > 0 && destination[length - 1] != '\n')
{
/* eat rest of the line */
char buf[128];
int buflen;
do
{
if (fgets(buf, sizeof(buf), termin) == NULL)
break;
buflen = strlen(buf);
} while (buflen > 0 && buf[buflen - 1] != '\n');
}
if (length > 0 && destination[length - 1] == '\n')
/* remove trailing newline */
destination[length - 1] = '\0';
#ifdef HAVE_TERMIOS_H
if (!echo)
{
tcsetattr(fileno(termin), TCSAFLUSH, &t_orig);
fputs("\n", termout);
fflush(termout);
}
#endif
if (termin != stdin)
{
fclose(termin);
fclose(termout);
}
prompt_state = 0; /* SIGINT okay again */
return destination;
}
/*
* This vacuums LOs of one database. It returns 0 on success, -1 on failure.
*/
int
vacuumlo(char *database, struct _param * param)
{
PGconn *conn;
PGresult *res,
*res2;
char buf[BUFSIZE];
int matched;
int deleted;
int i;
char *password = NULL;
if (param->pg_prompt)
{
password = simple_prompt("Password: ", 32, 0);
if (!password)
{
fprintf(stderr, "failed to get password\n");
exit(1);
}
}
conn = PQsetdbLogin(param->pg_host,
param->pg_port,
NULL,
NULL,
database,
param->pg_user,
password
);
/* check to see that the backend connection was successfully made */
if (PQstatus(conn) == CONNECTION_BAD)
{
fprintf(stderr, "Connection to database '%s' failed:\n", database);
fprintf(stderr, "%s", PQerrorMessage(conn));
PQfinish(conn);
return -1;
}
if (param->verbose)
{
fprintf(stdout, "Connected to %s\n", database);
if (param->dry_run)
fprintf(stdout, "Test run: no large objects will be removed!\n");
}
res = PQexec(conn, "SET search_path = public");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "Failed to set search_path on:\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return -1;
}
PQclear(res);
/*
* First we create and populate the LO temp table
*/
buf[0] = '\0';
strcat(buf, "SELECT DISTINCT loid AS lo ");
strcat(buf, "INTO TEMP TABLE vacuum_l ");
strcat(buf, "FROM pg_largeobject ");
res = PQexec(conn, buf);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "Failed to create temp table:\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return -1;
}
PQclear(res);
/*
* Vacuum the temp table so that planner will generate decent plans
* for the DELETEs below.
*/
buf[0] = '\0';
strcat(buf, "VACUUM ANALYZE vacuum_l ");
res = PQexec(conn, buf);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "Failed to vacuum temp table:\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return -1;
}
PQclear(res);
/*
* Now find any candidate tables who have columns of type oid.
*
* NOTE: the temp table formed above is ignored, because its real table
* name will be pg_something. Also, pg_largeobject will be ignored.
* If either of these were scanned, obviously we'd end up with nothing
* to delete...
*
* NOTE: the system oid column is ignored, as it has attnum < 1. This
* shouldn't matter for correctness, but it saves time.
*/
buf[0] = '\0';
strcat(buf, "SELECT c.relname, a.attname ");
strcat(buf, "FROM pg_class c, pg_attribute a, pg_type t ");
strcat(buf, "WHERE a.attnum > 0 ");
strcat(buf, " AND a.attrelid = c.oid ");
strcat(buf, " AND a.atttypid = t.oid ");
strcat(buf, " AND t.typname in ('oid', 'lo') ");
strcat(buf, " AND c.relkind = 'r'");
strcat(buf, " AND c.relname NOT LIKE 'pg_%'");
strcat(buf, " AND c.relname != 'vacuum_l'");
res = PQexec(conn, buf);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Failed to find OID columns:\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return -1;
}
for (i = 0; i < PQntuples(res); i++)
{
char *table,
*field;
table = PQgetvalue(res, i, 0);
field = PQgetvalue(res, i, 1);
if (param->verbose)
fprintf(stdout, "Checking %s in %s\n", field, table);
/*
* We use a DELETE with implicit join for efficiency. This is a
* Postgres-ism and not portable to other DBMSs, but then this
* whole program is a Postgres-ism.
*/
snprintf(buf, BUFSIZE, "DELETE FROM vacuum_l WHERE lo = \"%s\".\"%s\" ",
table, field);
res2 = PQexec(conn, buf);
if (PQresultStatus(res2) != PGRES_COMMAND_OK)
{
fprintf(stderr, "Failed to check %s in table %s:\n",
field, table);
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res2);
PQclear(res);
PQfinish(conn);
return -1;
}
PQclear(res2);
}
PQclear(res);
/*
* Run the actual deletes in a single transaction. Note that this
* would be a bad idea in pre-7.1 Postgres releases (since rolling
* back a table delete used to cause problems), but it should be safe
* now.
*/
res = PQexec(conn, "begin");
PQclear(res);
/*
* Finally, those entries remaining in vacuum_l are orphans.
*/
buf[0] = '\0';
strcat(buf, "SELECT lo ");
strcat(buf, "FROM vacuum_l");
res = PQexec(conn, buf);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
fprintf(stderr, "Failed to read temp table:\n");
fprintf(stderr, "%s", PQerrorMessage(conn));
PQclear(res);
PQfinish(conn);
return -1;
}
matched = PQntuples(res);
deleted = 0;
for (i = 0; i < matched; i++)
{
Oid lo = atooid(PQgetvalue(res, i, 0));
if (param->verbose)
{
fprintf(stdout, "\rRemoving lo %6u ", lo);
fflush(stdout);
}
if (param->dry_run == 0)
{
if (lo_unlink(conn, lo) < 0)
{
fprintf(stderr, "\nFailed to remove lo %u: ", lo);
fprintf(stderr, "%s", PQerrorMessage(conn));
}
else
deleted++;
}
else
deleted++;
}
PQclear(res);
/*
* That's all folks!
*/
res = PQexec(conn, "end");
PQclear(res);
PQfinish(conn);
if (param->verbose)
fprintf(stdout, "\r%s %d large objects from %s.\n",
(param->dry_run ? "Would remove" : "Removed"), deleted, database);
return 0;
}
void
usage(void)
{
fprintf(stdout, "vacuumlo removes unreferenced large objects from databases\n\n");
fprintf(stdout, "Usage:\n vacuumlo [options] dbname [dbnames...]\n\n");
fprintf(stdout, "Options:\n");
fprintf(stdout, " -v\t\tWrite a lot of output\n");
fprintf(stdout, " -n\t\tDon't remove any large object, just show what would be done\n");
fprintf(stdout, " -U username\tUsername to connect as\n");
fprintf(stdout, " -W\t\tPrompt for password\n");
fprintf(stdout, " -h hostname\tDatabase server host\n");
fprintf(stdout, " -p port\tDatabase server port\n\n");
}
int
main(int argc, char **argv)
{
int rc = 0;
struct _param param;
int c;
int port;
/* Parameter handling */
param.pg_user = NULL;
param.pg_prompt = 0;
param.pg_host = NULL;
param.pg_port = 0;
param.verbose = 0;
param.dry_run = 0;
while (1)
{
c = getopt(argc, argv, "?h:U:p:vnW");
if (c == -1)
break;
switch (c)
{
case '?':
if (optopt == '?')
{
usage();
exit(0);
}
exit(1);
case ':':
exit(1);
case 'v':
param.verbose = 1;
break;
case 'n':
param.dry_run = 1;
param.verbose = 1;
break;
case 'U':
param.pg_user = strdup(optarg);
break;
case 'W':
param.pg_prompt = 1;
break;
case 'p':
port = strtol(optarg, NULL, 10);
if ((port < 1) || (port > 65535))
{
fprintf(stderr, "[%s]: invalid port number '%s'\n", argv[0], optarg);
exit(1);
}
param.pg_port = strdup(optarg);
break;
case 'h':
param.pg_host = strdup(optarg);
break;
}
}
/* No database given? Show usage */
if (optind >= argc)
{
fprintf(stderr, "vacuumlo: missing required argument: database name\n");
fprintf(stderr, "Try 'vacuumlo -?' for help.\n");
exit(1);
}
for (c = optind; c < argc; c++)
{
/* Work on selected database */
rc += (vacuumlo(argv[c], &param) != 0);
}
return rc;
}