mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-09-09 02:59:28 +02:00
nullvalue, nonvalue. A long time ago, these were used to implement the SQL constructs IS TRUE, etc.
374 lines
8.4 KiB
C
374 lines
8.4 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* misc.c
|
|
*
|
|
*
|
|
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
*
|
|
* IDENTIFICATION
|
|
* $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.64 2008/10/05 17:33:16 petere Exp $
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#include "postgres.h"
|
|
|
|
#include <sys/file.h>
|
|
#include <signal.h>
|
|
#include <dirent.h>
|
|
#include <math.h>
|
|
|
|
#include "access/xact.h"
|
|
#include "catalog/pg_type.h"
|
|
#include "catalog/pg_tablespace.h"
|
|
#include "commands/dbcommands.h"
|
|
#include "funcapi.h"
|
|
#include "miscadmin.h"
|
|
#include "parser/keywords.h"
|
|
#include "postmaster/syslogger.h"
|
|
#include "storage/fd.h"
|
|
#include "storage/pmsignal.h"
|
|
#include "storage/procarray.h"
|
|
#include "utils/builtins.h"
|
|
#include "tcop/tcopprot.h"
|
|
|
|
#define atooid(x) ((Oid) strtoul((x), NULL, 10))
|
|
|
|
|
|
/*
|
|
* current_database()
|
|
* Expose the current database to the user
|
|
*/
|
|
Datum
|
|
current_database(PG_FUNCTION_ARGS)
|
|
{
|
|
Name db;
|
|
|
|
db = (Name) palloc(NAMEDATALEN);
|
|
|
|
namestrcpy(db, get_database_name(MyDatabaseId));
|
|
PG_RETURN_NAME(db);
|
|
}
|
|
|
|
|
|
/*
|
|
* current_query()
|
|
* Expose the current query to the user (useful in stored procedures)
|
|
*/
|
|
Datum
|
|
current_query(PG_FUNCTION_ARGS)
|
|
{
|
|
if (debug_query_string)
|
|
PG_RETURN_TEXT_P(cstring_to_text(debug_query_string));
|
|
else
|
|
PG_RETURN_NULL();
|
|
}
|
|
|
|
/*
|
|
* Functions to send signals to other backends.
|
|
*/
|
|
static bool
|
|
pg_signal_backend(int pid, int sig)
|
|
{
|
|
if (!superuser())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("must be superuser to signal other server processes"))));
|
|
|
|
if (!IsBackendPid(pid))
|
|
{
|
|
/*
|
|
* This is just a warning so a loop-through-resultset will not abort
|
|
* if one backend terminated on it's own during the run
|
|
*/
|
|
ereport(WARNING,
|
|
(errmsg("PID %d is not a PostgreSQL server process", pid)));
|
|
return false;
|
|
}
|
|
|
|
/* If we have setsid(), signal the backend's whole process group */
|
|
#ifdef HAVE_SETSID
|
|
if (kill(-pid, sig))
|
|
#else
|
|
if (kill(pid, sig))
|
|
#endif
|
|
{
|
|
/* Again, just a warning to allow loops */
|
|
ereport(WARNING,
|
|
(errmsg("could not send signal to process %d: %m", pid)));
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
Datum
|
|
pg_cancel_backend(PG_FUNCTION_ARGS)
|
|
{
|
|
PG_RETURN_BOOL(pg_signal_backend(PG_GETARG_INT32(0), SIGINT));
|
|
}
|
|
|
|
Datum
|
|
pg_terminate_backend(PG_FUNCTION_ARGS)
|
|
{
|
|
PG_RETURN_BOOL(pg_signal_backend(PG_GETARG_INT32(0), SIGTERM));
|
|
}
|
|
|
|
Datum
|
|
pg_reload_conf(PG_FUNCTION_ARGS)
|
|
{
|
|
if (!superuser())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("must be superuser to signal the postmaster"))));
|
|
|
|
if (kill(PostmasterPid, SIGHUP))
|
|
{
|
|
ereport(WARNING,
|
|
(errmsg("failed to send signal to postmaster: %m")));
|
|
PG_RETURN_BOOL(false);
|
|
}
|
|
|
|
PG_RETURN_BOOL(true);
|
|
}
|
|
|
|
|
|
/*
|
|
* Rotate log file
|
|
*/
|
|
Datum
|
|
pg_rotate_logfile(PG_FUNCTION_ARGS)
|
|
{
|
|
if (!superuser())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("must be superuser to rotate log files"))));
|
|
|
|
if (!Logging_collector)
|
|
{
|
|
ereport(WARNING,
|
|
(errmsg("rotation not possible because log collection not active")));
|
|
PG_RETURN_BOOL(false);
|
|
}
|
|
|
|
SendPostmasterSignal(PMSIGNAL_ROTATE_LOGFILE);
|
|
PG_RETURN_BOOL(true);
|
|
}
|
|
|
|
/* Function to find out which databases make use of a tablespace */
|
|
|
|
typedef struct
|
|
{
|
|
char *location;
|
|
DIR *dirdesc;
|
|
} ts_db_fctx;
|
|
|
|
Datum
|
|
pg_tablespace_databases(PG_FUNCTION_ARGS)
|
|
{
|
|
FuncCallContext *funcctx;
|
|
struct dirent *de;
|
|
ts_db_fctx *fctx;
|
|
|
|
if (SRF_IS_FIRSTCALL())
|
|
{
|
|
MemoryContext oldcontext;
|
|
Oid tablespaceOid = PG_GETARG_OID(0);
|
|
|
|
funcctx = SRF_FIRSTCALL_INIT();
|
|
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
|
|
|
|
fctx = palloc(sizeof(ts_db_fctx));
|
|
|
|
/*
|
|
* size = tablespace dirname length + dir sep char + oid + terminator
|
|
*/
|
|
fctx->location = (char *) palloc(10 + 10 + 1);
|
|
if (tablespaceOid == GLOBALTABLESPACE_OID)
|
|
{
|
|
fctx->dirdesc = NULL;
|
|
ereport(WARNING,
|
|
(errmsg("global tablespace never has databases")));
|
|
}
|
|
else
|
|
{
|
|
if (tablespaceOid == DEFAULTTABLESPACE_OID)
|
|
sprintf(fctx->location, "base");
|
|
else
|
|
sprintf(fctx->location, "pg_tblspc/%u", tablespaceOid);
|
|
|
|
fctx->dirdesc = AllocateDir(fctx->location);
|
|
|
|
if (!fctx->dirdesc)
|
|
{
|
|
/* the only expected error is ENOENT */
|
|
if (errno != ENOENT)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open directory \"%s\": %m",
|
|
fctx->location)));
|
|
ereport(WARNING,
|
|
(errmsg("%u is not a tablespace OID", tablespaceOid)));
|
|
}
|
|
}
|
|
funcctx->user_fctx = fctx;
|
|
MemoryContextSwitchTo(oldcontext);
|
|
}
|
|
|
|
funcctx = SRF_PERCALL_SETUP();
|
|
fctx = (ts_db_fctx *) funcctx->user_fctx;
|
|
|
|
if (!fctx->dirdesc) /* not a tablespace */
|
|
SRF_RETURN_DONE(funcctx);
|
|
|
|
while ((de = ReadDir(fctx->dirdesc, fctx->location)) != NULL)
|
|
{
|
|
char *subdir;
|
|
DIR *dirdesc;
|
|
Oid datOid = atooid(de->d_name);
|
|
|
|
/* this test skips . and .., but is awfully weak */
|
|
if (!datOid)
|
|
continue;
|
|
|
|
/* if database subdir is empty, don't report tablespace as used */
|
|
|
|
/* size = path length + dir sep char + file name + terminator */
|
|
subdir = palloc(strlen(fctx->location) + 1 + strlen(de->d_name) + 1);
|
|
sprintf(subdir, "%s/%s", fctx->location, de->d_name);
|
|
dirdesc = AllocateDir(subdir);
|
|
while ((de = ReadDir(dirdesc, subdir)) != NULL)
|
|
{
|
|
if (strcmp(de->d_name, ".") != 0 && strcmp(de->d_name, "..") != 0)
|
|
break;
|
|
}
|
|
FreeDir(dirdesc);
|
|
pfree(subdir);
|
|
|
|
if (!de)
|
|
continue; /* indeed, nothing in it */
|
|
|
|
SRF_RETURN_NEXT(funcctx, ObjectIdGetDatum(datOid));
|
|
}
|
|
|
|
FreeDir(fctx->dirdesc);
|
|
SRF_RETURN_DONE(funcctx);
|
|
}
|
|
|
|
|
|
/*
|
|
* pg_sleep - delay for N seconds
|
|
*/
|
|
Datum
|
|
pg_sleep(PG_FUNCTION_ARGS)
|
|
{
|
|
float8 secs = PG_GETARG_FLOAT8(0);
|
|
float8 endtime;
|
|
|
|
/*
|
|
* We break the requested sleep into segments of no more than 1 second, to
|
|
* put an upper bound on how long it will take us to respond to a cancel
|
|
* or die interrupt. (Note that pg_usleep is interruptible by signals on
|
|
* some platforms but not others.) Also, this method avoids exposing
|
|
* pg_usleep's upper bound on allowed delays.
|
|
*
|
|
* By computing the intended stop time initially, we avoid accumulation of
|
|
* extra delay across multiple sleeps. This also ensures we won't delay
|
|
* less than the specified time if pg_usleep is interrupted by other
|
|
* signals such as SIGHUP.
|
|
*/
|
|
|
|
#ifdef HAVE_INT64_TIMESTAMP
|
|
#define GetNowFloat() ((float8) GetCurrentTimestamp() / 1000000.0)
|
|
#else
|
|
#define GetNowFloat() GetCurrentTimestamp()
|
|
#endif
|
|
|
|
endtime = GetNowFloat() + secs;
|
|
|
|
for (;;)
|
|
{
|
|
float8 delay;
|
|
|
|
CHECK_FOR_INTERRUPTS();
|
|
delay = endtime - GetNowFloat();
|
|
if (delay >= 1.0)
|
|
pg_usleep(1000000L);
|
|
else if (delay > 0.0)
|
|
pg_usleep((long) ceil(delay * 1000000.0));
|
|
else
|
|
break;
|
|
}
|
|
|
|
PG_RETURN_VOID();
|
|
}
|
|
|
|
/* Function to return the list of grammar keywords */
|
|
Datum
|
|
pg_get_keywords(PG_FUNCTION_ARGS)
|
|
{
|
|
FuncCallContext *funcctx;
|
|
|
|
if (SRF_IS_FIRSTCALL())
|
|
{
|
|
MemoryContext oldcontext;
|
|
TupleDesc tupdesc;
|
|
|
|
funcctx = SRF_FIRSTCALL_INIT();
|
|
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
|
|
|
|
tupdesc = CreateTemplateTupleDesc(3, false);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "word",
|
|
TEXTOID, -1, 0);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 2, "catcode",
|
|
CHAROID, -1, 0);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 3, "catdesc",
|
|
TEXTOID, -1, 0);
|
|
|
|
funcctx->attinmeta = TupleDescGetAttInMetadata(tupdesc);
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
}
|
|
|
|
funcctx = SRF_PERCALL_SETUP();
|
|
|
|
if (&ScanKeywords[funcctx->call_cntr] < LastScanKeyword)
|
|
{
|
|
char *values[3];
|
|
HeapTuple tuple;
|
|
|
|
/* cast-away-const is ugly but alternatives aren't much better */
|
|
values[0] = (char *) ScanKeywords[funcctx->call_cntr].name;
|
|
|
|
switch (ScanKeywords[funcctx->call_cntr].category)
|
|
{
|
|
case UNRESERVED_KEYWORD:
|
|
values[1] = "U";
|
|
values[2] = _("Unreserved");
|
|
break;
|
|
case COL_NAME_KEYWORD:
|
|
values[1] = "C";
|
|
values[2] = _("Column name");
|
|
break;
|
|
case TYPE_FUNC_NAME_KEYWORD:
|
|
values[1] = "T";
|
|
values[2] = _("Type or function name");
|
|
break;
|
|
case RESERVED_KEYWORD:
|
|
values[1] = "R";
|
|
values[2] = _("Reserved");
|
|
break;
|
|
default: /* shouldn't be possible */
|
|
values[1] = NULL;
|
|
values[2] = NULL;
|
|
break;
|
|
}
|
|
|
|
tuple = BuildTupleFromCStrings(funcctx->attinmeta, values);
|
|
|
|
SRF_RETURN_NEXT(funcctx, HeapTupleGetDatum(tuple));
|
|
}
|
|
|
|
SRF_RETURN_DONE(funcctx);
|
|
}
|