LCOV - code coverage report
Current view: top level - src/backend/utils/adt - misc.c (source / functions) Hit Total Coverage
Test: PostgreSQL 17devel Lines: 262 346 75.7 %
Date: 2023-12-10 05:11:07 Functions: 22 24 91.7 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * misc.c
       4             :  *
       5             :  *
       6             :  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/utils/adt/misc.c
      12             :  *
      13             :  *-------------------------------------------------------------------------
      14             :  */
      15             : #include "postgres.h"
      16             : 
      17             : #include <sys/file.h>
      18             : #include <sys/stat.h>
      19             : #include <dirent.h>
      20             : #include <fcntl.h>
      21             : #include <math.h>
      22             : #include <unistd.h>
      23             : 
      24             : #include "access/sysattr.h"
      25             : #include "access/table.h"
      26             : #include "catalog/catalog.h"
      27             : #include "catalog/pg_tablespace.h"
      28             : #include "catalog/pg_type.h"
      29             : #include "catalog/system_fk_info.h"
      30             : #include "commands/dbcommands.h"
      31             : #include "commands/tablespace.h"
      32             : #include "common/keywords.h"
      33             : #include "funcapi.h"
      34             : #include "miscadmin.h"
      35             : #include "nodes/miscnodes.h"
      36             : #include "parser/parse_type.h"
      37             : #include "parser/scansup.h"
      38             : #include "pgstat.h"
      39             : #include "postmaster/syslogger.h"
      40             : #include "rewrite/rewriteHandler.h"
      41             : #include "storage/fd.h"
      42             : #include "storage/latch.h"
      43             : #include "tcop/tcopprot.h"
      44             : #include "utils/builtins.h"
      45             : #include "utils/fmgroids.h"
      46             : #include "utils/lsyscache.h"
      47             : #include "utils/ruleutils.h"
      48             : #include "utils/timestamp.h"
      49             : 
      50             : 
      51             : /*
      52             :  * structure to cache metadata needed in pg_input_is_valid_common
      53             :  */
      54             : typedef struct ValidIOData
      55             : {
      56             :     Oid         typoid;
      57             :     int32       typmod;
      58             :     bool        typname_constant;
      59             :     Oid         typiofunc;
      60             :     Oid         typioparam;
      61             :     FmgrInfo    inputproc;
      62             : } ValidIOData;
      63             : 
      64             : static bool pg_input_is_valid_common(FunctionCallInfo fcinfo,
      65             :                                      text *txt, text *typname,
      66             :                                      ErrorSaveContext *escontext);
      67             : 
      68             : 
      69             : /*
      70             :  * Common subroutine for num_nulls() and num_nonnulls().
      71             :  * Returns true if successful, false if function should return NULL.
      72             :  * If successful, total argument count and number of nulls are
      73             :  * returned into *nargs and *nulls.
      74             :  */
      75             : static bool
      76         120 : count_nulls(FunctionCallInfo fcinfo,
      77             :             int32 *nargs, int32 *nulls)
      78             : {
      79         120 :     int32       count = 0;
      80             :     int         i;
      81             : 
      82             :     /* Did we get a VARIADIC array argument, or separate arguments? */
      83         120 :     if (get_fn_expr_variadic(fcinfo->flinfo))
      84             :     {
      85             :         ArrayType  *arr;
      86             :         int         ndims,
      87             :                     nitems,
      88             :                    *dims;
      89             :         bits8      *bitmap;
      90             : 
      91             :         Assert(PG_NARGS() == 1);
      92             : 
      93             :         /*
      94             :          * If we get a null as VARIADIC array argument, we can't say anything
      95             :          * useful about the number of elements, so return NULL.  This behavior
      96             :          * is consistent with other variadic functions - see concat_internal.
      97             :          */
      98          60 :         if (PG_ARGISNULL(0))
      99          12 :             return false;
     100             : 
     101             :         /*
     102             :          * Non-null argument had better be an array.  We assume that any call
     103             :          * context that could let get_fn_expr_variadic return true will have
     104             :          * checked that a VARIADIC-labeled parameter actually is an array.  So
     105             :          * it should be okay to just Assert that it's an array rather than
     106             :          * doing a full-fledged error check.
     107             :          */
     108             :         Assert(OidIsValid(get_base_element_type(get_fn_expr_argtype(fcinfo->flinfo, 0))));
     109             : 
     110             :         /* OK, safe to fetch the array value */
     111          48 :         arr = PG_GETARG_ARRAYTYPE_P(0);
     112             : 
     113             :         /* Count the array elements */
     114          48 :         ndims = ARR_NDIM(arr);
     115          48 :         dims = ARR_DIMS(arr);
     116          48 :         nitems = ArrayGetNItems(ndims, dims);
     117             : 
     118             :         /* Count those that are NULL */
     119          48 :         bitmap = ARR_NULLBITMAP(arr);
     120          48 :         if (bitmap)
     121             :         {
     122          24 :             int         bitmask = 1;
     123             : 
     124        1272 :             for (i = 0; i < nitems; i++)
     125             :             {
     126        1248 :                 if ((*bitmap & bitmask) == 0)
     127          24 :                     count++;
     128             : 
     129        1248 :                 bitmask <<= 1;
     130        1248 :                 if (bitmask == 0x100)
     131             :                 {
     132         144 :                     bitmap++;
     133         144 :                     bitmask = 1;
     134             :                 }
     135             :             }
     136             :         }
     137             : 
     138          48 :         *nargs = nitems;
     139          48 :         *nulls = count;
     140             :     }
     141             :     else
     142             :     {
     143             :         /* Separate arguments, so just count 'em */
     144         204 :         for (i = 0; i < PG_NARGS(); i++)
     145             :         {
     146         144 :             if (PG_ARGISNULL(i))
     147          84 :                 count++;
     148             :         }
     149             : 
     150          60 :         *nargs = PG_NARGS();
     151          60 :         *nulls = count;
     152             :     }
     153             : 
     154         108 :     return true;
     155             : }
     156             : 
     157             : /*
     158             :  * num_nulls()
     159             :  *  Count the number of NULL arguments
     160             :  */
     161             : Datum
     162          60 : pg_num_nulls(PG_FUNCTION_ARGS)
     163             : {
     164             :     int32       nargs,
     165             :                 nulls;
     166             : 
     167          60 :     if (!count_nulls(fcinfo, &nargs, &nulls))
     168           6 :         PG_RETURN_NULL();
     169             : 
     170          54 :     PG_RETURN_INT32(nulls);
     171             : }
     172             : 
     173             : /*
     174             :  * num_nonnulls()
     175             :  *  Count the number of non-NULL arguments
     176             :  */
     177             : Datum
     178          60 : pg_num_nonnulls(PG_FUNCTION_ARGS)
     179             : {
     180             :     int32       nargs,
     181             :                 nulls;
     182             : 
     183          60 :     if (!count_nulls(fcinfo, &nargs, &nulls))
     184           6 :         PG_RETURN_NULL();
     185             : 
     186          54 :     PG_RETURN_INT32(nargs - nulls);
     187             : }
     188             : 
     189             : 
     190             : /*
     191             :  * current_database()
     192             :  *  Expose the current database to the user
     193             :  */
     194             : Datum
     195        4070 : current_database(PG_FUNCTION_ARGS)
     196             : {
     197             :     Name        db;
     198             : 
     199        4070 :     db = (Name) palloc(NAMEDATALEN);
     200             : 
     201        4070 :     namestrcpy(db, get_database_name(MyDatabaseId));
     202        4070 :     PG_RETURN_NAME(db);
     203             : }
     204             : 
     205             : 
     206             : /*
     207             :  * current_query()
     208             :  *  Expose the current query to the user (useful in stored procedures)
     209             :  *  We might want to use ActivePortal->sourceText someday.
     210             :  */
     211             : Datum
     212           0 : current_query(PG_FUNCTION_ARGS)
     213             : {
     214             :     /* there is no easy way to access the more concise 'query_string' */
     215           0 :     if (debug_query_string)
     216           0 :         PG_RETURN_TEXT_P(cstring_to_text(debug_query_string));
     217             :     else
     218           0 :         PG_RETURN_NULL();
     219             : }
     220             : 
     221             : /* Function to find out which databases make use of a tablespace */
     222             : 
     223             : Datum
     224           6 : pg_tablespace_databases(PG_FUNCTION_ARGS)
     225             : {
     226           6 :     Oid         tablespaceOid = PG_GETARG_OID(0);
     227           6 :     ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
     228             :     char       *location;
     229             :     DIR        *dirdesc;
     230             :     struct dirent *de;
     231             : 
     232           6 :     InitMaterializedSRF(fcinfo, MAT_SRF_USE_EXPECTED_DESC);
     233             : 
     234           6 :     if (tablespaceOid == GLOBALTABLESPACE_OID)
     235             :     {
     236           0 :         ereport(WARNING,
     237             :                 (errmsg("global tablespace never has databases")));
     238             :         /* return empty tuplestore */
     239           0 :         return (Datum) 0;
     240             :     }
     241             : 
     242           6 :     if (tablespaceOid == DEFAULTTABLESPACE_OID)
     243           6 :         location = "base";
     244             :     else
     245           0 :         location = psprintf("pg_tblspc/%u/%s", tablespaceOid,
     246             :                             TABLESPACE_VERSION_DIRECTORY);
     247             : 
     248           6 :     dirdesc = AllocateDir(location);
     249             : 
     250           6 :     if (!dirdesc)
     251             :     {
     252             :         /* the only expected error is ENOENT */
     253           0 :         if (errno != ENOENT)
     254           0 :             ereport(ERROR,
     255             :                     (errcode_for_file_access(),
     256             :                      errmsg("could not open directory \"%s\": %m",
     257             :                             location)));
     258           0 :         ereport(WARNING,
     259             :                 (errmsg("%u is not a tablespace OID", tablespaceOid)));
     260             :         /* return empty tuplestore */
     261           0 :         return (Datum) 0;
     262             :     }
     263             : 
     264          54 :     while ((de = ReadDir(dirdesc, location)) != NULL)
     265             :     {
     266          48 :         Oid         datOid = atooid(de->d_name);
     267             :         char       *subdir;
     268             :         bool        isempty;
     269             :         Datum       values[1];
     270             :         bool        nulls[1];
     271             : 
     272             :         /* this test skips . and .., but is awfully weak */
     273          48 :         if (!datOid)
     274          18 :             continue;
     275             : 
     276             :         /* if database subdir is empty, don't report tablespace as used */
     277             : 
     278          30 :         subdir = psprintf("%s/%s", location, de->d_name);
     279          30 :         isempty = directory_is_empty(subdir);
     280          30 :         pfree(subdir);
     281             : 
     282          30 :         if (isempty)
     283           0 :             continue;           /* indeed, nothing in it */
     284             : 
     285          30 :         values[0] = ObjectIdGetDatum(datOid);
     286          30 :         nulls[0] = false;
     287             : 
     288          30 :         tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc,
     289             :                              values, nulls);
     290             :     }
     291             : 
     292           6 :     FreeDir(dirdesc);
     293           6 :     return (Datum) 0;
     294             : }
     295             : 
     296             : 
     297             : /*
     298             :  * pg_tablespace_location - get location for a tablespace
     299             :  */
     300             : Datum
     301         100 : pg_tablespace_location(PG_FUNCTION_ARGS)
     302             : {
     303         100 :     Oid         tablespaceOid = PG_GETARG_OID(0);
     304             :     char        sourcepath[MAXPGPATH];
     305             :     char        targetpath[MAXPGPATH];
     306             :     int         rllen;
     307             :     struct stat st;
     308             : 
     309             :     /*
     310             :      * It's useful to apply this function to pg_class.reltablespace, wherein
     311             :      * zero means "the database's default tablespace".  So, rather than
     312             :      * throwing an error for zero, we choose to assume that's what is meant.
     313             :      */
     314         100 :     if (tablespaceOid == InvalidOid)
     315           0 :         tablespaceOid = MyDatabaseTableSpace;
     316             : 
     317             :     /*
     318             :      * Return empty string for the cluster's default tablespaces
     319             :      */
     320         100 :     if (tablespaceOid == DEFAULTTABLESPACE_OID ||
     321             :         tablespaceOid == GLOBALTABLESPACE_OID)
     322          82 :         PG_RETURN_TEXT_P(cstring_to_text(""));
     323             : 
     324             :     /*
     325             :      * Find the location of the tablespace by reading the symbolic link that
     326             :      * is in pg_tblspc/<oid>.
     327             :      */
     328          18 :     snprintf(sourcepath, sizeof(sourcepath), "pg_tblspc/%u", tablespaceOid);
     329             : 
     330             :     /*
     331             :      * Before reading the link, check if the source path is a link or a
     332             :      * junction point.  Note that a directory is possible for a tablespace
     333             :      * created with allow_in_place_tablespaces enabled.  If a directory is
     334             :      * found, a relative path to the data directory is returned.
     335             :      */
     336          18 :     if (lstat(sourcepath, &st) < 0)
     337             :     {
     338           0 :         ereport(ERROR,
     339             :                 (errcode_for_file_access(),
     340             :                  errmsg("could not stat file \"%s\": %m",
     341             :                         sourcepath)));
     342             :     }
     343             : 
     344          18 :     if (!S_ISLNK(st.st_mode))
     345          18 :         PG_RETURN_TEXT_P(cstring_to_text(sourcepath));
     346             : 
     347             :     /*
     348             :      * In presence of a link or a junction point, return the path pointing to.
     349             :      */
     350           0 :     rllen = readlink(sourcepath, targetpath, sizeof(targetpath));
     351           0 :     if (rllen < 0)
     352           0 :         ereport(ERROR,
     353             :                 (errcode_for_file_access(),
     354             :                  errmsg("could not read symbolic link \"%s\": %m",
     355             :                         sourcepath)));
     356           0 :     if (rllen >= sizeof(targetpath))
     357           0 :         ereport(ERROR,
     358             :                 (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
     359             :                  errmsg("symbolic link \"%s\" target is too long",
     360             :                         sourcepath)));
     361           0 :     targetpath[rllen] = '\0';
     362             : 
     363           0 :     PG_RETURN_TEXT_P(cstring_to_text(targetpath));
     364             : }
     365             : 
     366             : /*
     367             :  * pg_sleep - delay for N seconds
     368             :  */
     369             : Datum
     370          64 : pg_sleep(PG_FUNCTION_ARGS)
     371             : {
     372          64 :     float8      secs = PG_GETARG_FLOAT8(0);
     373             :     float8      endtime;
     374             : 
     375             :     /*
     376             :      * We sleep using WaitLatch, to ensure that we'll wake up promptly if an
     377             :      * important signal (such as SIGALRM or SIGINT) arrives.  Because
     378             :      * WaitLatch's upper limit of delay is INT_MAX milliseconds, and the user
     379             :      * might ask for more than that, we sleep for at most 10 minutes and then
     380             :      * loop.
     381             :      *
     382             :      * By computing the intended stop time initially, we avoid accumulation of
     383             :      * extra delay across multiple sleeps.  This also ensures we won't delay
     384             :      * less than the specified time when WaitLatch is terminated early by a
     385             :      * non-query-canceling signal such as SIGHUP.
     386             :      */
     387             : #define GetNowFloat()   ((float8) GetCurrentTimestamp() / 1000000.0)
     388             : 
     389          64 :     endtime = GetNowFloat() + secs;
     390             : 
     391             :     for (;;)
     392          80 :     {
     393             :         float8      delay;
     394             :         long        delay_ms;
     395             : 
     396         144 :         CHECK_FOR_INTERRUPTS();
     397             : 
     398         142 :         delay = endtime - GetNowFloat();
     399         142 :         if (delay >= 600.0)
     400           0 :             delay_ms = 600000;
     401         142 :         else if (delay > 0.0)
     402          80 :             delay_ms = (long) ceil(delay * 1000.0);
     403             :         else
     404          62 :             break;
     405             : 
     406          80 :         (void) WaitLatch(MyLatch,
     407             :                          WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
     408             :                          delay_ms,
     409             :                          WAIT_EVENT_PG_SLEEP);
     410          80 :         ResetLatch(MyLatch);
     411             :     }
     412             : 
     413          62 :     PG_RETURN_VOID();
     414             : }
     415             : 
     416             : /* Function to return the list of grammar keywords */
     417             : Datum
     418           0 : pg_get_keywords(PG_FUNCTION_ARGS)
     419             : {
     420             :     FuncCallContext *funcctx;
     421             : 
     422           0 :     if (SRF_IS_FIRSTCALL())
     423             :     {
     424             :         MemoryContext oldcontext;
     425             :         TupleDesc   tupdesc;
     426             : 
     427           0 :         funcctx = SRF_FIRSTCALL_INIT();
     428           0 :         oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
     429             : 
     430           0 :         if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
     431           0 :             elog(ERROR, "return type must be a row type");
     432           0 :         funcctx->tuple_desc = tupdesc;
     433           0 :         funcctx->attinmeta = TupleDescGetAttInMetadata(tupdesc);
     434             : 
     435           0 :         MemoryContextSwitchTo(oldcontext);
     436             :     }
     437             : 
     438           0 :     funcctx = SRF_PERCALL_SETUP();
     439             : 
     440           0 :     if (funcctx->call_cntr < ScanKeywords.num_keywords)
     441             :     {
     442             :         char       *values[5];
     443             :         HeapTuple   tuple;
     444             : 
     445             :         /* cast-away-const is ugly but alternatives aren't much better */
     446           0 :         values[0] = unconstify(char *,
     447             :                                GetScanKeyword(funcctx->call_cntr,
     448             :                                               &ScanKeywords));
     449             : 
     450           0 :         switch (ScanKeywordCategories[funcctx->call_cntr])
     451             :         {
     452           0 :             case UNRESERVED_KEYWORD:
     453           0 :                 values[1] = "U";
     454           0 :                 values[3] = _("unreserved");
     455           0 :                 break;
     456           0 :             case COL_NAME_KEYWORD:
     457           0 :                 values[1] = "C";
     458           0 :                 values[3] = _("unreserved (cannot be function or type name)");
     459           0 :                 break;
     460           0 :             case TYPE_FUNC_NAME_KEYWORD:
     461           0 :                 values[1] = "T";
     462           0 :                 values[3] = _("reserved (can be function or type name)");
     463           0 :                 break;
     464           0 :             case RESERVED_KEYWORD:
     465           0 :                 values[1] = "R";
     466           0 :                 values[3] = _("reserved");
     467           0 :                 break;
     468           0 :             default:            /* shouldn't be possible */
     469           0 :                 values[1] = NULL;
     470           0 :                 values[3] = NULL;
     471           0 :                 break;
     472             :         }
     473             : 
     474           0 :         if (ScanKeywordBareLabel[funcctx->call_cntr])
     475             :         {
     476           0 :             values[2] = "true";
     477           0 :             values[4] = _("can be bare label");
     478             :         }
     479             :         else
     480             :         {
     481           0 :             values[2] = "false";
     482           0 :             values[4] = _("requires AS");
     483             :         }
     484             : 
     485           0 :         tuple = BuildTupleFromCStrings(funcctx->attinmeta, values);
     486             : 
     487           0 :         SRF_RETURN_NEXT(funcctx, HeapTupleGetDatum(tuple));
     488             :     }
     489             : 
     490           0 :     SRF_RETURN_DONE(funcctx);
     491             : }
     492             : 
     493             : 
     494             : /* Function to return the list of catalog foreign key relationships */
     495             : Datum
     496        1320 : pg_get_catalog_foreign_keys(PG_FUNCTION_ARGS)
     497             : {
     498             :     FuncCallContext *funcctx;
     499             :     FmgrInfo   *arrayinp;
     500             : 
     501        1320 :     if (SRF_IS_FIRSTCALL())
     502             :     {
     503             :         MemoryContext oldcontext;
     504             :         TupleDesc   tupdesc;
     505             : 
     506           6 :         funcctx = SRF_FIRSTCALL_INIT();
     507           6 :         oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
     508             : 
     509           6 :         if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
     510           0 :             elog(ERROR, "return type must be a row type");
     511           6 :         funcctx->tuple_desc = BlessTupleDesc(tupdesc);
     512             : 
     513             :         /*
     514             :          * We use array_in to convert the C strings in sys_fk_relationships[]
     515             :          * to text arrays.  But we cannot use DirectFunctionCallN to call
     516             :          * array_in, and it wouldn't be very efficient if we could.  Fill an
     517             :          * FmgrInfo to use for the call.
     518             :          */
     519           6 :         arrayinp = (FmgrInfo *) palloc(sizeof(FmgrInfo));
     520           6 :         fmgr_info(F_ARRAY_IN, arrayinp);
     521           6 :         funcctx->user_fctx = arrayinp;
     522             : 
     523           6 :         MemoryContextSwitchTo(oldcontext);
     524             :     }
     525             : 
     526        1320 :     funcctx = SRF_PERCALL_SETUP();
     527        1320 :     arrayinp = (FmgrInfo *) funcctx->user_fctx;
     528             : 
     529        1320 :     if (funcctx->call_cntr < lengthof(sys_fk_relationships))
     530             :     {
     531        1314 :         const SysFKRelationship *fkrel = &sys_fk_relationships[funcctx->call_cntr];
     532             :         Datum       values[6];
     533             :         bool        nulls[6];
     534             :         HeapTuple   tuple;
     535             : 
     536        1314 :         memset(nulls, false, sizeof(nulls));
     537             : 
     538        1314 :         values[0] = ObjectIdGetDatum(fkrel->fk_table);
     539        1314 :         values[1] = FunctionCall3(arrayinp,
     540             :                                   CStringGetDatum(fkrel->fk_columns),
     541             :                                   ObjectIdGetDatum(TEXTOID),
     542             :                                   Int32GetDatum(-1));
     543        1314 :         values[2] = ObjectIdGetDatum(fkrel->pk_table);
     544        1314 :         values[3] = FunctionCall3(arrayinp,
     545             :                                   CStringGetDatum(fkrel->pk_columns),
     546             :                                   ObjectIdGetDatum(TEXTOID),
     547             :                                   Int32GetDatum(-1));
     548        1314 :         values[4] = BoolGetDatum(fkrel->is_array);
     549        1314 :         values[5] = BoolGetDatum(fkrel->is_opt);
     550             : 
     551        1314 :         tuple = heap_form_tuple(funcctx->tuple_desc, values, nulls);
     552             : 
     553        1314 :         SRF_RETURN_NEXT(funcctx, HeapTupleGetDatum(tuple));
     554             :     }
     555             : 
     556           6 :     SRF_RETURN_DONE(funcctx);
     557             : }
     558             : 
     559             : 
     560             : /*
     561             :  * Return the type of the argument.
     562             :  */
     563             : Datum
     564        1534 : pg_typeof(PG_FUNCTION_ARGS)
     565             : {
     566        1534 :     PG_RETURN_OID(get_fn_expr_argtype(fcinfo->flinfo, 0));
     567             : }
     568             : 
     569             : 
     570             : /*
     571             :  * Implementation of the COLLATE FOR expression; returns the collation
     572             :  * of the argument.
     573             :  */
     574             : Datum
     575          30 : pg_collation_for(PG_FUNCTION_ARGS)
     576             : {
     577             :     Oid         typeid;
     578             :     Oid         collid;
     579             : 
     580          30 :     typeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
     581          30 :     if (!typeid)
     582           0 :         PG_RETURN_NULL();
     583          30 :     if (!type_is_collatable(typeid) && typeid != UNKNOWNOID)
     584           6 :         ereport(ERROR,
     585             :                 (errcode(ERRCODE_DATATYPE_MISMATCH),
     586             :                  errmsg("collations are not supported by type %s",
     587             :                         format_type_be(typeid))));
     588             : 
     589          24 :     collid = PG_GET_COLLATION();
     590          24 :     if (!collid)
     591           6 :         PG_RETURN_NULL();
     592          18 :     PG_RETURN_TEXT_P(cstring_to_text(generate_collation_name(collid)));
     593             : }
     594             : 
     595             : 
     596             : /*
     597             :  * pg_relation_is_updatable - determine which update events the specified
     598             :  * relation supports.
     599             :  *
     600             :  * This relies on relation_is_updatable() in rewriteHandler.c, which see
     601             :  * for additional information.
     602             :  */
     603             : Datum
     604         894 : pg_relation_is_updatable(PG_FUNCTION_ARGS)
     605             : {
     606         894 :     Oid         reloid = PG_GETARG_OID(0);
     607         894 :     bool        include_triggers = PG_GETARG_BOOL(1);
     608             : 
     609         894 :     PG_RETURN_INT32(relation_is_updatable(reloid, NIL, include_triggers, NULL));
     610             : }
     611             : 
     612             : /*
     613             :  * pg_column_is_updatable - determine whether a column is updatable
     614             :  *
     615             :  * This function encapsulates the decision about just what
     616             :  * information_schema.columns.is_updatable actually means.  It's not clear
     617             :  * whether deletability of the column's relation should be required, so
     618             :  * we want that decision in C code where we could change it without initdb.
     619             :  */
     620             : Datum
     621         570 : pg_column_is_updatable(PG_FUNCTION_ARGS)
     622             : {
     623         570 :     Oid         reloid = PG_GETARG_OID(0);
     624         570 :     AttrNumber  attnum = PG_GETARG_INT16(1);
     625         570 :     AttrNumber  col = attnum - FirstLowInvalidHeapAttributeNumber;
     626         570 :     bool        include_triggers = PG_GETARG_BOOL(2);
     627             :     int         events;
     628             : 
     629             :     /* System columns are never updatable */
     630         570 :     if (attnum <= 0)
     631           0 :         PG_RETURN_BOOL(false);
     632             : 
     633         570 :     events = relation_is_updatable(reloid, NIL, include_triggers,
     634             :                                    bms_make_singleton(col));
     635             : 
     636             :     /* We require both updatability and deletability of the relation */
     637             : #define REQ_EVENTS ((1 << CMD_UPDATE) | (1 << CMD_DELETE))
     638             : 
     639         570 :     PG_RETURN_BOOL((events & REQ_EVENTS) == REQ_EVENTS);
     640             : }
     641             : 
     642             : 
     643             : /*
     644             :  * pg_input_is_valid - test whether string is valid input for datatype.
     645             :  *
     646             :  * Returns true if OK, false if not.
     647             :  *
     648             :  * This will only work usefully if the datatype's input function has been
     649             :  * updated to return "soft" errors via errsave/ereturn.
     650             :  */
     651             : Datum
     652         884 : pg_input_is_valid(PG_FUNCTION_ARGS)
     653             : {
     654         884 :     text       *txt = PG_GETARG_TEXT_PP(0);
     655         884 :     text       *typname = PG_GETARG_TEXT_PP(1);
     656         884 :     ErrorSaveContext escontext = {T_ErrorSaveContext};
     657             : 
     658         884 :     PG_RETURN_BOOL(pg_input_is_valid_common(fcinfo, txt, typname,
     659             :                                             &escontext));
     660             : }
     661             : 
     662             : /*
     663             :  * pg_input_error_info - test whether string is valid input for datatype.
     664             :  *
     665             :  * Returns NULL if OK, else the primary message, detail message, hint message
     666             :  * and sql error code from the error.
     667             :  *
     668             :  * This will only work usefully if the datatype's input function has been
     669             :  * updated to return "soft" errors via errsave/ereturn.
     670             :  */
     671             : Datum
     672         766 : pg_input_error_info(PG_FUNCTION_ARGS)
     673             : {
     674         766 :     text       *txt = PG_GETARG_TEXT_PP(0);
     675         766 :     text       *typname = PG_GETARG_TEXT_PP(1);
     676         766 :     ErrorSaveContext escontext = {T_ErrorSaveContext};
     677             :     TupleDesc   tupdesc;
     678             :     Datum       values[4];
     679             :     bool        isnull[4];
     680             : 
     681         766 :     if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
     682           0 :         elog(ERROR, "return type must be a row type");
     683             : 
     684             :     /* Enable details_wanted */
     685         766 :     escontext.details_wanted = true;
     686             : 
     687         766 :     if (pg_input_is_valid_common(fcinfo, txt, typname,
     688             :                                  &escontext))
     689          22 :         memset(isnull, true, sizeof(isnull));
     690             :     else
     691             :     {
     692             :         char       *sqlstate;
     693             : 
     694             :         Assert(escontext.error_occurred);
     695             :         Assert(escontext.error_data != NULL);
     696             :         Assert(escontext.error_data->message != NULL);
     697             : 
     698         714 :         memset(isnull, false, sizeof(isnull));
     699             : 
     700         714 :         values[0] = CStringGetTextDatum(escontext.error_data->message);
     701             : 
     702         714 :         if (escontext.error_data->detail != NULL)
     703          66 :             values[1] = CStringGetTextDatum(escontext.error_data->detail);
     704             :         else
     705         648 :             isnull[1] = true;
     706             : 
     707         714 :         if (escontext.error_data->hint != NULL)
     708           0 :             values[2] = CStringGetTextDatum(escontext.error_data->hint);
     709             :         else
     710         714 :             isnull[2] = true;
     711             : 
     712         714 :         sqlstate = unpack_sql_state(escontext.error_data->sqlerrcode);
     713         714 :         values[3] = CStringGetTextDatum(sqlstate);
     714             :     }
     715             : 
     716         736 :     return HeapTupleGetDatum(heap_form_tuple(tupdesc, values, isnull));
     717             : }
     718             : 
     719             : /* Common subroutine for the above */
     720             : static bool
     721        1650 : pg_input_is_valid_common(FunctionCallInfo fcinfo,
     722             :                          text *txt, text *typname,
     723             :                          ErrorSaveContext *escontext)
     724             : {
     725        1650 :     char       *str = text_to_cstring(txt);
     726             :     ValidIOData *my_extra;
     727             :     Datum       converted;
     728             : 
     729             :     /*
     730             :      * We arrange to look up the needed I/O info just once per series of
     731             :      * calls, assuming the data type doesn't change underneath us.
     732             :      */
     733        1650 :     my_extra = (ValidIOData *) fcinfo->flinfo->fn_extra;
     734        1650 :     if (my_extra == NULL)
     735             :     {
     736        3076 :         fcinfo->flinfo->fn_extra =
     737        1538 :             MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
     738             :                                sizeof(ValidIOData));
     739        1538 :         my_extra = (ValidIOData *) fcinfo->flinfo->fn_extra;
     740        1538 :         my_extra->typoid = InvalidOid;
     741             :         /* Detect whether typname argument is constant. */
     742        1538 :         my_extra->typname_constant = get_fn_expr_arg_stable(fcinfo->flinfo, 1);
     743             :     }
     744             : 
     745             :     /*
     746             :      * If the typname argument is constant, we only need to parse it the first
     747             :      * time through.
     748             :      */
     749        1650 :     if (my_extra->typoid == InvalidOid || !my_extra->typname_constant)
     750             :     {
     751        1574 :         char       *typnamestr = text_to_cstring(typname);
     752             :         Oid         typoid;
     753             : 
     754             :         /* Parse type-name argument to obtain type OID and encoded typmod. */
     755        1574 :         (void) parseTypeString(typnamestr, &typoid, &my_extra->typmod, NULL);
     756             : 
     757             :         /* Update type-specific info if typoid changed. */
     758        1574 :         if (my_extra->typoid != typoid)
     759             :         {
     760        1554 :             getTypeInputInfo(typoid,
     761             :                              &my_extra->typiofunc,
     762             :                              &my_extra->typioparam);
     763        1554 :             fmgr_info_cxt(my_extra->typiofunc, &my_extra->inputproc,
     764        1554 :                           fcinfo->flinfo->fn_mcxt);
     765        1554 :             my_extra->typoid = typoid;
     766             :         }
     767             :     }
     768             : 
     769             :     /* Now we can try to perform the conversion. */
     770        1650 :     return InputFunctionCallSafe(&my_extra->inputproc,
     771             :                                  str,
     772             :                                  my_extra->typioparam,
     773             :                                  my_extra->typmod,
     774             :                                  (Node *) escontext,
     775             :                                  &converted);
     776             : }
     777             : 
     778             : 
     779             : /*
     780             :  * Is character a valid identifier start?
     781             :  * Must match scan.l's {ident_start} character class.
     782             :  */
     783             : static bool
     784        2202 : is_ident_start(unsigned char c)
     785             : {
     786             :     /* Underscores and ASCII letters are OK */
     787        2202 :     if (c == '_')
     788           0 :         return true;
     789        2202 :     if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
     790        2052 :         return true;
     791             :     /* Any high-bit-set character is OK (might be part of a multibyte char) */
     792         150 :     if (IS_HIGHBIT_SET(c))
     793           0 :         return true;
     794         150 :     return false;
     795             : }
     796             : 
     797             : /*
     798             :  * Is character a valid identifier continuation?
     799             :  * Must match scan.l's {ident_cont} character class.
     800             :  */
     801             : static bool
     802        2052 : is_ident_cont(unsigned char c)
     803             : {
     804             :     /* Can be digit or dollar sign ... */
     805        2052 :     if ((c >= '0' && c <= '9') || c == '$')
     806           0 :         return true;
     807             :     /* ... or an identifier start character */
     808        2052 :     return is_ident_start(c);
     809             : }
     810             : 
     811             : /*
     812             :  * parse_ident - parse a SQL qualified identifier into separate identifiers.
     813             :  * When strict mode is active (second parameter), then any chars after
     814             :  * the last identifier are disallowed.
     815             :  */
     816             : Datum
     817         114 : parse_ident(PG_FUNCTION_ARGS)
     818             : {
     819         114 :     text       *qualname = PG_GETARG_TEXT_PP(0);
     820         114 :     bool        strict = PG_GETARG_BOOL(1);
     821         114 :     char       *qualname_str = text_to_cstring(qualname);
     822         114 :     ArrayBuildState *astate = NULL;
     823             :     char       *nextp;
     824         114 :     bool        after_dot = false;
     825             : 
     826             :     /*
     827             :      * The code below scribbles on qualname_str in some cases, so we should
     828             :      * reconvert qualname if we need to show the original string in error
     829             :      * messages.
     830             :      */
     831         114 :     nextp = qualname_str;
     832             : 
     833             :     /* skip leading whitespace */
     834         144 :     while (scanner_isspace(*nextp))
     835          30 :         nextp++;
     836             : 
     837             :     for (;;)
     838          96 :     {
     839             :         char       *curname;
     840         210 :         bool        missing_ident = true;
     841             : 
     842         210 :         if (*nextp == '"')
     843             :         {
     844             :             char       *endp;
     845             : 
     846          60 :             curname = nextp + 1;
     847             :             for (;;)
     848             :             {
     849          60 :                 endp = strchr(nextp + 1, '"');
     850          60 :                 if (endp == NULL)
     851           0 :                     ereport(ERROR,
     852             :                             (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     853             :                              errmsg("string is not a valid identifier: \"%s\"",
     854             :                                     text_to_cstring(qualname)),
     855             :                              errdetail("String has unclosed double quotes.")));
     856          60 :                 if (endp[1] != '"')
     857          60 :                     break;
     858           0 :                 memmove(endp, endp + 1, strlen(endp));
     859           0 :                 nextp = endp;
     860             :             }
     861          60 :             nextp = endp + 1;
     862          60 :             *endp = '\0';
     863             : 
     864          60 :             if (endp - curname == 0)
     865           0 :                 ereport(ERROR,
     866             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     867             :                          errmsg("string is not a valid identifier: \"%s\"",
     868             :                                 text_to_cstring(qualname)),
     869             :                          errdetail("Quoted identifier must not be empty.")));
     870             : 
     871          60 :             astate = accumArrayResult(astate, CStringGetTextDatum(curname),
     872             :                                       false, TEXTOID, CurrentMemoryContext);
     873          60 :             missing_ident = false;
     874             :         }
     875         150 :         else if (is_ident_start((unsigned char) *nextp))
     876             :         {
     877             :             char       *downname;
     878             :             int         len;
     879             :             text       *part;
     880             : 
     881         102 :             curname = nextp++;
     882        2052 :             while (is_ident_cont((unsigned char) *nextp))
     883        1950 :                 nextp++;
     884             : 
     885         102 :             len = nextp - curname;
     886             : 
     887             :             /*
     888             :              * We don't implicitly truncate identifiers. This is useful for
     889             :              * allowing the user to check for specific parts of the identifier
     890             :              * being too long. It's easy enough for the user to get the
     891             :              * truncated names by casting our output to name[].
     892             :              */
     893         102 :             downname = downcase_identifier(curname, len, false, false);
     894         102 :             part = cstring_to_text_with_len(downname, len);
     895         102 :             astate = accumArrayResult(astate, PointerGetDatum(part), false,
     896             :                                       TEXTOID, CurrentMemoryContext);
     897         102 :             missing_ident = false;
     898             :         }
     899             : 
     900         210 :         if (missing_ident)
     901             :         {
     902             :             /* Different error messages based on where we failed. */
     903          48 :             if (*nextp == '.')
     904          18 :                 ereport(ERROR,
     905             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     906             :                          errmsg("string is not a valid identifier: \"%s\"",
     907             :                                 text_to_cstring(qualname)),
     908             :                          errdetail("No valid identifier before \".\".")));
     909          30 :             else if (after_dot)
     910          12 :                 ereport(ERROR,
     911             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     912             :                          errmsg("string is not a valid identifier: \"%s\"",
     913             :                                 text_to_cstring(qualname)),
     914             :                          errdetail("No valid identifier after \".\".")));
     915             :             else
     916          18 :                 ereport(ERROR,
     917             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     918             :                          errmsg("string is not a valid identifier: \"%s\"",
     919             :                                 text_to_cstring(qualname))));
     920             :         }
     921             : 
     922         204 :         while (scanner_isspace(*nextp))
     923          42 :             nextp++;
     924             : 
     925         162 :         if (*nextp == '.')
     926             :         {
     927          96 :             after_dot = true;
     928          96 :             nextp++;
     929         126 :             while (scanner_isspace(*nextp))
     930          30 :                 nextp++;
     931             :         }
     932          66 :         else if (*nextp == '\0')
     933             :         {
     934          36 :             break;
     935             :         }
     936             :         else
     937             :         {
     938          30 :             if (strict)
     939          24 :                 ereport(ERROR,
     940             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     941             :                          errmsg("string is not a valid identifier: \"%s\"",
     942             :                                 text_to_cstring(qualname))));
     943           6 :             break;
     944             :         }
     945             :     }
     946             : 
     947          42 :     PG_RETURN_DATUM(makeArrayResult(astate, CurrentMemoryContext));
     948             : }
     949             : 
     950             : /*
     951             :  * pg_current_logfile
     952             :  *
     953             :  * Report current log file used by log collector by scanning current_logfiles.
     954             :  */
     955             : Datum
     956          12 : pg_current_logfile(PG_FUNCTION_ARGS)
     957             : {
     958             :     FILE       *fd;
     959             :     char        lbuffer[MAXPGPATH];
     960             :     char       *logfmt;
     961             : 
     962             :     /* The log format parameter is optional */
     963          12 :     if (PG_NARGS() == 0 || PG_ARGISNULL(0))
     964           0 :         logfmt = NULL;
     965             :     else
     966             :     {
     967          12 :         logfmt = text_to_cstring(PG_GETARG_TEXT_PP(0));
     968             : 
     969          12 :         if (strcmp(logfmt, "stderr") != 0 &&
     970           8 :             strcmp(logfmt, "csvlog") != 0 &&
     971           4 :             strcmp(logfmt, "jsonlog") != 0)
     972           0 :             ereport(ERROR,
     973             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     974             :                      errmsg("log format \"%s\" is not supported", logfmt),
     975             :                      errhint("The supported log formats are \"stderr\", \"csvlog\", and \"jsonlog\".")));
     976             :     }
     977             : 
     978          12 :     fd = AllocateFile(LOG_METAINFO_DATAFILE, "r");
     979          12 :     if (fd == NULL)
     980             :     {
     981           0 :         if (errno != ENOENT)
     982           0 :             ereport(ERROR,
     983             :                     (errcode_for_file_access(),
     984             :                      errmsg("could not read file \"%s\": %m",
     985             :                             LOG_METAINFO_DATAFILE)));
     986           0 :         PG_RETURN_NULL();
     987             :     }
     988             : 
     989             : #ifdef WIN32
     990             :     /* syslogger.c writes CRLF line endings on Windows */
     991             :     _setmode(_fileno(fd), _O_TEXT);
     992             : #endif
     993             : 
     994             :     /*
     995             :      * Read the file to gather current log filename(s) registered by the
     996             :      * syslogger.
     997             :      */
     998          24 :     while (fgets(lbuffer, sizeof(lbuffer), fd) != NULL)
     999             :     {
    1000             :         char       *log_format;
    1001             :         char       *log_filepath;
    1002             :         char       *nlpos;
    1003             : 
    1004             :         /* Extract log format and log file path from the line. */
    1005          24 :         log_format = lbuffer;
    1006          24 :         log_filepath = strchr(lbuffer, ' ');
    1007          24 :         if (log_filepath == NULL)
    1008             :         {
    1009             :             /* Uh oh.  No space found, so file content is corrupted. */
    1010           0 :             elog(ERROR,
    1011             :                  "missing space character in \"%s\"", LOG_METAINFO_DATAFILE);
    1012             :             break;
    1013             :         }
    1014             : 
    1015          24 :         *log_filepath = '\0';
    1016          24 :         log_filepath++;
    1017          24 :         nlpos = strchr(log_filepath, '\n');
    1018          24 :         if (nlpos == NULL)
    1019             :         {
    1020             :             /* Uh oh.  No newline found, so file content is corrupted. */
    1021           0 :             elog(ERROR,
    1022             :                  "missing newline character in \"%s\"", LOG_METAINFO_DATAFILE);
    1023             :             break;
    1024             :         }
    1025          24 :         *nlpos = '\0';
    1026             : 
    1027          24 :         if (logfmt == NULL || strcmp(logfmt, log_format) == 0)
    1028             :         {
    1029          12 :             FreeFile(fd);
    1030          12 :             PG_RETURN_TEXT_P(cstring_to_text(log_filepath));
    1031             :         }
    1032             :     }
    1033             : 
    1034             :     /* Close the current log filename file. */
    1035           0 :     FreeFile(fd);
    1036             : 
    1037           0 :     PG_RETURN_NULL();
    1038             : }
    1039             : 
    1040             : /*
    1041             :  * Report current log file used by log collector (1 argument version)
    1042             :  *
    1043             :  * note: this wrapper is necessary to pass the sanity check in opr_sanity,
    1044             :  * which checks that all built-in functions that share the implementing C
    1045             :  * function take the same number of arguments
    1046             :  */
    1047             : Datum
    1048          12 : pg_current_logfile_1arg(PG_FUNCTION_ARGS)
    1049             : {
    1050          12 :     return pg_current_logfile(fcinfo);
    1051             : }
    1052             : 
    1053             : /*
    1054             :  * SQL wrapper around RelationGetReplicaIndex().
    1055             :  */
    1056             : Datum
    1057         658 : pg_get_replica_identity_index(PG_FUNCTION_ARGS)
    1058             : {
    1059         658 :     Oid         reloid = PG_GETARG_OID(0);
    1060             :     Oid         idxoid;
    1061             :     Relation    rel;
    1062             : 
    1063         658 :     rel = table_open(reloid, AccessShareLock);
    1064         658 :     idxoid = RelationGetReplicaIndex(rel);
    1065         658 :     table_close(rel, AccessShareLock);
    1066             : 
    1067         658 :     if (OidIsValid(idxoid))
    1068         376 :         PG_RETURN_OID(idxoid);
    1069             :     else
    1070         282 :         PG_RETURN_NULL();
    1071             : }
    1072             : 
    1073             : /*
    1074             :  * Transition function for the ANY_VALUE aggregate
    1075             :  */
    1076             : Datum
    1077          18 : any_value_transfn(PG_FUNCTION_ARGS)
    1078             : {
    1079          18 :     PG_RETURN_DATUM(PG_GETARG_DATUM(0));
    1080             : }

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