C++ palloc函数代码示例

/*
 * EnumValuesCreate
 *		Create an entry in pg_enum for each of the supplied enum values.
 *
 * vals is a list of Value strings.
 */
void
EnumValuesCreate(Oid enumTypeOid, List *vals)
{
	Relation	pg_enum;
	NameData	enumlabel;
	Oid		   *oids;
	int			elemno,
				num_elems;
	Datum		values[Natts_pg_enum];
	bool		nulls[Natts_pg_enum];
	ListCell   *lc;
	HeapTuple	tup;

	num_elems = list_length(vals);

	/*
	 * We do not bother to check the list of values for duplicates --- if
	 * you have any, you'll get a less-than-friendly unique-index violation.
	 * It is probably not worth trying harder.
	 */

	pg_enum = heap_open(EnumRelationId, RowExclusiveLock);

	/*
	 * Allocate OIDs for the enum's members.
	 *
	 * While this method does not absolutely guarantee that we generate no
	 * duplicate OIDs (since we haven't entered each oid into the table
	 * before allocating the next), trouble could only occur if the OID
	 * counter wraps all the way around before we finish. Which seems
	 * unlikely.
	 */
	oids = (Oid *) palloc(num_elems * sizeof(Oid));

	for (elemno = 0; elemno < num_elems; elemno++)
	{
		/*
		 * We assign even-numbered OIDs to all the new enum labels.  This
		 * tells the comparison functions the OIDs are in the correct sort
		 * order and can be compared directly.
		 */
		Oid		new_oid;

		do {
			new_oid = GetNewOid(pg_enum);
		} while (new_oid & 1);
		oids[elemno] = new_oid;
	}

	/* sort them, just in case OID counter wrapped from high to low */
	qsort(oids, num_elems, sizeof(Oid), oid_cmp);

	/* and make the entries */
	memset(nulls, false, sizeof(nulls));

	elemno = 0;
	foreach(lc, vals)
	{
		char	   *lab = strVal(lfirst(lc));

		/*
		 * labels are stored in a name field, for easier syscache lookup, so
		 * check the length to make sure it's within range.
		 */
		if (strlen(lab) > (NAMEDATALEN - 1))
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_NAME),
					 errmsg("invalid enum label \"%s\"", lab),
					 errdetail("Labels must be %d characters or less.",
							   NAMEDATALEN - 1)));

		values[Anum_pg_enum_enumtypid - 1] = ObjectIdGetDatum(enumTypeOid);
		values[Anum_pg_enum_enumsortorder - 1] = Float4GetDatum(elemno + 1);
		namestrcpy(&enumlabel, lab);
		values[Anum_pg_enum_enumlabel - 1] = NameGetDatum(&enumlabel);

		tup = heap_form_tuple(RelationGetDescr(pg_enum), values, nulls);
		HeapTupleSetOid(tup, oids[elemno]);

		simple_heap_insert(pg_enum, tup);
		CatalogUpdateIndexes(pg_enum, tup);
		heap_freetuple(tup);

		elemno++;
	}

void
worker_spi_main(Datum main_arg)
{
	int			index = DatumGetInt32(main_arg);
	worktable  *table;
	StringInfoData buf;
	char		name[20];

	table = palloc(sizeof(worktable));
	sprintf(name, "schema%d", index);
	table->schema = pstrdup(name);
	table->name = pstrdup("counted");

	/* Establish signal handlers before unblocking signals. */
	pqsignal(SIGHUP, worker_spi_sighup);
	pqsignal(SIGTERM, worker_spi_sigterm);

	/* We're now ready to receive signals */
	BackgroundWorkerUnblockSignals();

	/* Connect to our database */
	BackgroundWorkerInitializeConnection("postgres", NULL);

	elog(LOG, "%s initialized with %s.%s",
		 MyBgworkerEntry->bgw_name, table->schema, table->name);
	initialize_worker_spi(table);

	/*
	 * Quote identifiers passed to us.  Note that this must be done after
	 * initialize_worker_spi, because that routine assumes the names are not
	 * quoted.
	 *
	 * Note some memory might be leaked here.
	 */
	table->schema = quote_identifier(table->schema);
	table->name = quote_identifier(table->name);

	initStringInfo(&buf);
	appendStringInfo(&buf,
					 "WITH deleted AS (DELETE "
					 "FROM %s.%s "
					 "WHERE type = 'delta' RETURNING value), "
					 "total AS (SELECT coalesce(sum(value), 0) as sum "
					 "FROM deleted) "
					 "UPDATE %s.%s "
					 "SET value = %s.value + total.sum "
					 "FROM total WHERE type = 'total' "
					 "RETURNING %s.value",
					 table->schema, table->name,
					 table->schema, table->name,
					 table->name,
					 table->name);

	/*
	 * Main loop: do this until the SIGTERM handler tells us to terminate
	 */
	while (!got_sigterm)
	{
		int			ret;
		int			rc;

		/*
		 * Background workers mustn't call usleep() or any direct equivalent:
		 * instead, they may wait on their process latch, which sleeps as
		 * necessary, but is awakened if postmaster dies.  That way the
		 * background process goes away immediately in an emergency.
		 */
		rc = WaitLatch(&MyProc->procLatch,
					   WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
					   worker_spi_naptime * 1000L);
		ResetLatch(&MyProc->procLatch);

		/* emergency bailout if postmaster has died */
		if (rc & WL_POSTMASTER_DEATH)
			proc_exit(1);

		/*
		 * In case of a SIGHUP, just reload the configuration.
		 */
		if (got_sighup)
		{
			got_sighup = false;
			ProcessConfigFile(PGC_SIGHUP);
		}

		/*
		 * Start a transaction on which we can run queries.  Note that each
		 * StartTransactionCommand() call should be preceded by a
		 * SetCurrentStatementStartTimestamp() call, which sets both the time
		 * for the statement we're about the run, and also the transaction
		 * start time.  Also, each other query sent to SPI should probably be
		 * preceded by SetCurrentStatementStartTimestamp(), so that statement
		 * start time is always up to date.
		 *
		 * The SPI_connect() call lets us run queries through the SPI manager,
		 * and the PushActiveSnapshot() call creates an "active" snapshot
		 * which is necessary for queries to have MVCC data to work on.
		 *
		 * The pgstat_report_activity() call makes our activity visible
		 * through the pgstat views.
//.........这里部分代码省略.........

Datum
palloc_bench(PG_FUNCTION_ARGS)
{

	/* info for anyelement */
	int i = 0;
	int32	ncontexts   = PG_GETARG_INT32(0);
	int32	niterations = PG_GETARG_INT32(1);
	int32	allocsize   = PG_GETARG_INT32(2);

	struct timeval start_time, end_time;

	/* memory contexts */
	MemoryContext initctx = CurrentMemoryContext;
	MemoryContext ctx = initctx;

	/* switch to the per-group hash-table memory context */

	for (i = 0; i < ncontexts; i++) {
		
		char name[256];
		sprintf(name, "test context %d", i);

#ifdef TRACKING_FLAG
		ctx = AllocSetContextCreateTracked(ctx,
										   name,
										   ALLOCSET_DEFAULT_MINSIZE,
										   ALLOCSET_DEFAULT_INITSIZE,
										   ALLOCSET_DEFAULT_MAXSIZE,
										   true);
#else
		ctx = AllocSetContextCreate(ctx,
									name,
									ALLOCSET_DEFAULT_MINSIZE,
									ALLOCSET_DEFAULT_INITSIZE,
									ALLOCSET_DEFAULT_MAXSIZE);
#endif
	}

	MemoryContextSwitchTo(ctx);

	gettimeofday(&start_time, NULL);
	
	for (i = 0; i < niterations; i++) {

		char * p = palloc(allocsize);
		
		if (p != NULL)
			pfree(p);

	}

	gettimeofday(&end_time, NULL);
	
	MemoryContextSwitchTo(initctx);

	elog(WARNING, "duration = %.2f ms", (end_time.tv_sec - start_time.tv_sec) * 1000 + (end_time.tv_usec - start_time.tv_usec) / 1000.0);

    PG_RETURN_VOID();

}

//.........这里部分代码省略.........
	/*
	 * Create the tuplestore - work_mem is the max in-memory size before a
	 * file is created on disk to hold it.
	 */
	tupstore =
		tuplestore_begin_heap(rsinfo->allowedModes & SFRM_Materialize_Random,
							  false, work_mem);

	MemoryContextSwitchTo(oldcontext);

	/* get the requested return tuple description */
	ret_tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);

	/* must have at least one output column (for the pkey) */
	if (ret_tupdesc->natts < 1)
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("xpath_table must have at least one output column")));

	/*
	 * At the moment we assume that the returned attributes make sense for the
	 * XPath specififed (i.e. we trust the caller). It's not fatal if they get
	 * it wrong - the input function for the column type will raise an error
	 * if the path result can't be converted into the correct binary
	 * representation.
	 */

	attinmeta = TupleDescGetAttInMetadata(ret_tupdesc);

	/* Set return mode and allocate value space. */
	rsinfo->returnMode = SFRM_Materialize;
	rsinfo->setDesc = ret_tupdesc;

	values = (char **) palloc(ret_tupdesc->natts * sizeof(char *));
	xpaths = (xmlChar **) palloc(ret_tupdesc->natts * sizeof(xmlChar *));

	/*
	 * Split XPaths. xpathset is a writable CString.
	 *
	 * Note that we stop splitting once we've done all needed for tupdesc
	 */
	numpaths = 0;
	pos = xpathset;
	while (numpaths < (ret_tupdesc->natts - 1))
	{
		xpaths[numpaths++] = (xmlChar *) pos;
		pos = strstr(pos, pathsep);
		if (pos != NULL)
		{
			*pos = '\0';
			pos++;
		}
		else
			break;
	}

	/* Now build query */
	initStringInfo(&query_buf);

	/* Build initial sql statement */
	appendStringInfo(&query_buf, "SELECT %s, %s FROM %s WHERE %s",
					 pkeyfield,
					 xmlfield,
					 relname,
					 condition);

static ArrayType *
enum_range_internal(Oid enumtypoid, Oid lower, Oid upper)
{
	ArrayType  *result;
	Relation	enum_rel;
	Relation	enum_idx;
	SysScanDesc enum_scan;
	HeapTuple	enum_tuple;
	ScanKeyData skey;
	Datum	   *elems;
	int			max,
				cnt;
	bool		left_found;

	/*
	 * Scan the enum members in order using pg_enum_typid_sortorder_index.
	 * Note we must not use the syscache, and must use an MVCC snapshot here.
	 * See comments for RenumberEnumType in catalog/pg_enum.c for more info.
	 */
	ScanKeyInit(&skey,
				Anum_pg_enum_enumtypid,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(enumtypoid));

	enum_rel = heap_open(EnumRelationId, AccessShareLock);
	enum_idx = index_open(EnumTypIdSortOrderIndexId, AccessShareLock);
	enum_scan = systable_beginscan_ordered(enum_rel, enum_idx,
										   GetTransactionSnapshot(),
										   1, &skey);

	max = 64;
	elems = (Datum *) palloc(max * sizeof(Datum));
	cnt = 0;
	left_found = !OidIsValid(lower);

	while (HeapTupleIsValid(enum_tuple = systable_getnext_ordered(enum_scan, ForwardScanDirection)))
	{
		Oid			enum_oid = HeapTupleGetOid(enum_tuple);

		if (!left_found && lower == enum_oid)
			left_found = true;

		if (left_found)
		{
			if (cnt >= max)
			{
				max *= 2;
				elems = (Datum *) repalloc(elems, max * sizeof(Datum));
			}

			elems[cnt++] = ObjectIdGetDatum(enum_oid);
		}

		if (OidIsValid(upper) && upper == enum_oid)
			break;
	}

	systable_endscan_ordered(enum_scan);
	index_close(enum_idx, AccessShareLock);
	heap_close(enum_rel, AccessShareLock);

	/* and build the result array */
	/* note this hardwires some details about the representation of Oid */
	result = construct_array(elems, cnt, enumtypoid, sizeof(Oid), true, 'i');

	pfree(elems);

	return result;
}

//.........这里部分代码省略.........
	if (slot_idx > STATISTIC_NUM_SLOTS - 2)
		elog(ERROR, "insufficient pg_statistic slots for array stats");

	/* We can only compute real stats if we found some non-null values. */
	if (analyzed_rows > 0)
	{
		int			nonnull_cnt = analyzed_rows;
		int			count_items_count;
		int			i;
		TrackItem **sort_table;
		int			track_len;
		int64		cutoff_freq;
		int64		minfreq,
					maxfreq;

		/*
		 * We assume the standard stats code already took care of setting
		 * stats_valid, stanullfrac, stawidth, stadistinct.  We'd have to
		 * re-compute those values if we wanted to not store the standard
		 * stats.
		 */

		/*
		 * Construct an array of the interesting hashtable items, that is,
		 * those meeting the cutoff frequency (s - epsilon)*N.  Also identify
		 * the minimum and maximum frequencies among these items.
		 *
		 * Since epsilon = s/10 and bucket_width = 1/epsilon, the cutoff
		 * frequency is 9*N / bucket_width.
		 */
		cutoff_freq = 9 * element_no / bucket_width;

		i = hash_get_num_entries(elements_tab); /* surely enough space */
		sort_table = (TrackItem **) palloc(sizeof(TrackItem *) * i);

		hash_seq_init(&scan_status, elements_tab);
		track_len = 0;
		minfreq = element_no;
		maxfreq = 0;
		while ((item = (TrackItem *) hash_seq_search(&scan_status)) != NULL)
		{
			if (item->frequency > cutoff_freq)
			{
				sort_table[track_len++] = item;
				minfreq = Min(minfreq, item->frequency);
				maxfreq = Max(maxfreq, item->frequency);
			}
		}
		Assert(track_len <= i);

		/* emit some statistics for debug purposes */
		elog(DEBUG3, "compute_array_stats: target # mces = %d, "
			 "bucket width = %d, "
			 "# elements = " INT64_FORMAT ", hashtable size = %d, "
			 "usable entries = %d",
			 num_mcelem, bucket_width, element_no, i, track_len);

		/*
		 * If we obtained more elements than we really want, get rid of those
		 * with least frequencies.  The easiest way is to qsort the array into
		 * descending frequency order and truncate the array.
		 */
		if (num_mcelem < track_len)
		{
			qsort(sort_table, track_len, sizeof(TrackItem *),
				  trackitem_compare_frequencies_desc);

/*
 * CreateConstraintEntry
 *	Create a constraint table entry.
 *
 * Subsidiary records (such as triggers or indexes to implement the
 * constraint) are *not* created here.	But we do make dependency links
 * from the constraint to the things it depends on.
 */
Oid
CreateConstraintEntry(const char *constraintName,
					  Oid constraintNamespace,
					  char constraintType,
					  bool isDeferrable,
					  bool isDeferred,
					  Oid relId,
					  const int16 *constraintKey,
					  int constraintNKeys,
					  Oid domainId,
					  Oid indexRelId,
					  Oid foreignRelId,
					  const int16 *foreignKey,
					  const Oid *pfEqOp,
					  const Oid *ppEqOp,
					  const Oid *ffEqOp,
					  int foreignNKeys,
					  char foreignUpdateType,
					  char foreignDeleteType,
					  char foreignMatchType,
					  const Oid *exclOp,
					  Node *conExpr,
					  const char *conBin,
					  const char *conSrc,
					  bool conIsLocal,
					  int conInhCount)
{
	Relation	conDesc;
	Oid			conOid;
	HeapTuple	tup;
	bool		nulls[Natts_pg_constraint];
	Datum		values[Natts_pg_constraint];
	ArrayType  *conkeyArray;
	ArrayType  *confkeyArray;
	ArrayType  *conpfeqopArray;
	ArrayType  *conppeqopArray;
	ArrayType  *conffeqopArray;
	ArrayType  *conexclopArray;
	NameData	cname;
	int			i;
	ObjectAddress conobject;

	conDesc = heap_open(ConstraintRelationId, RowExclusiveLock);

	Assert(constraintName);
	namestrcpy(&cname, constraintName);

	/*
	 * Convert C arrays into Postgres arrays.
	 */
	if (constraintNKeys > 0)
	{
		Datum	   *conkey;

		conkey = (Datum *) palloc(constraintNKeys * sizeof(Datum));
		for (i = 0; i < constraintNKeys; i++)
			conkey[i] = Int16GetDatum(constraintKey[i]);
		conkeyArray = construct_array(conkey, constraintNKeys,
									  INT2OID, 2, true, 's');
	}
	else
		conkeyArray = NULL;

	if (foreignNKeys > 0)
	{
		Datum	   *fkdatums;

		fkdatums = (Datum *) palloc(foreignNKeys * sizeof(Datum));
		for (i = 0; i < foreignNKeys; i++)
			fkdatums[i] = Int16GetDatum(foreignKey[i]);
		confkeyArray = construct_array(fkdatums, foreignNKeys,
									   INT2OID, 2, true, 's');
		for (i = 0; i < foreignNKeys; i++)
			fkdatums[i] = ObjectIdGetDatum(pfEqOp[i]);
		conpfeqopArray = construct_array(fkdatums, foreignNKeys,
										 OIDOID, sizeof(Oid), true, 'i');
		for (i = 0; i < foreignNKeys; i++)
			fkdatums[i] = ObjectIdGetDatum(ppEqOp[i]);
		conppeqopArray = construct_array(fkdatums, foreignNKeys,
										 OIDOID, sizeof(Oid), true, 'i');
		for (i = 0; i < foreignNKeys; i++)
			fkdatums[i] = ObjectIdGetDatum(ffEqOp[i]);
		conffeqopArray = construct_array(fkdatums, foreignNKeys,
										 OIDOID, sizeof(Oid), true, 'i');
	}
	else
	{
		confkeyArray = NULL;
		conpfeqopArray = NULL;
		conppeqopArray = NULL;
		conffeqopArray = NULL;
	}
//.........这里部分代码省略.........

//.........这里部分代码省略.........
						if (token[0] == ')')
							break;
						val = (int) strtol(token, &endptr, 10);
						if (endptr != token + tok_len)
							elog(ERROR, "unrecognized integer: \"%.*s\"",
								 tok_len, token);
						l = lappend_int(l, val);
					}
				}
				else if (tok_len == 1 && token[0] == 'o')
				{
					/* List of OIDs */
					for (;;)
					{
						Oid			val;
						char	   *endptr;

						token = pg_strtok(&tok_len);
						if (token == NULL)
							elog(ERROR, "unterminated List structure");
						if (token[0] == ')')
							break;
						val = (Oid) strtoul(token, &endptr, 10);
						if (endptr != token + tok_len)
							elog(ERROR, "unrecognized OID: \"%.*s\"",
								 tok_len, token);
						l = lappend_oid(l, val);
					}
				}
				else
				{
					/* List of other node types */
					for (;;)
					{
						/* We have already scanned next token... */
						if (token[0] == ')')
							break;
						l = lappend(l, nodeRead(token, tok_len));
						token = pg_strtok(&tok_len);
						if (token == NULL)
							elog(ERROR, "unterminated List structure");
					}
				}
				result = (Node *) l;
				break;
			}
		case RIGHT_PAREN:
			elog(ERROR, "unexpected right parenthesis");
			result = NULL;		/* keep compiler happy */
			break;
		case OTHER_TOKEN:
			if (tok_len == 0)
			{
				/* must be "<>" --- represents a null pointer */
				result = NULL;
			}
			else
			{
				elog(ERROR, "unrecognized token: \"%.*s\"", tok_len, token);
				result = NULL;	/* keep compiler happy */
			}
			break;
		case T_Integer:

			/*
			 * we know that the token terminates on a char atol will stop at
			 */
			result = (Node *) makeInteger(atol(token));
			break;
		case T_Float:
			{
				char	   *fval = (char *) palloc(tok_len + 1);

				memcpy(fval, token, tok_len);
				fval[tok_len] = '\0';
				result = (Node *) makeFloat(fval);
			}
			break;
		case T_String:
			/* need to remove leading and trailing quotes, and backslashes */
			result = (Node *) makeString(debackslash(token + 1, tok_len - 2));
			break;
		case T_BitString:
			{
				char	   *val = palloc(tok_len);

				/* skip leading 'b' */
				memcpy(val, token + 1, tok_len - 1);
				val[tok_len - 1] = '\0';
				result = (Node *) makeBitString(val);
				break;
			}
		default:
			elog(ERROR, "unrecognized node type: %d", (int) type);
			result = NULL;		/* keep compiler happy */
			break;
	}

	return (void *) result;
}

/*
 * lowerstr_with_len --- fold string to lower case
 *
 * Input string need not be null-terminated.
 *
 * Returned string is palloc'd
 */
char *
lowerstr_with_len(const char *str, int len)
{
	char	   *out;

	if (len == 0)
		return pstrdup("");

#ifdef USE_WIDE_UPPER_LOWER

	/*
	 * Use wide char code only when max encoding length > 1 and ctype != C.
	 * Some operating systems fail with multi-byte encodings and a C locale.
	 * Also, for a C locale there is no need to process as multibyte. From
	 * backend/utils/adt/oracle_compat.c Teodor
	 */
	if (pg_database_encoding_max_length() > 1 && !lc_ctype_is_c())
	{
		wchar_t    *wstr,
				   *wptr;
		int			wlen;

		/*
		 * alloc number of wchar_t for worst case, len contains number of
		 * bytes >= number of characters and alloc 1 wchar_t for 0, because
		 * wchar2char wants zero-terminated string
		 */
		wptr = wstr = (wchar_t *) palloc(sizeof(wchar_t) * (len + 1));

		wlen = char2wchar(wstr, len + 1, str, len);
		Assert(wlen <= len);

		while (*wptr)
		{
			*wptr = towlower((wint_t) *wptr);
			wptr++;
		}

		/*
		 * Alloc result string for worst case + '\0'
		 */
		len = pg_database_encoding_max_length() * wlen + 1;
		out = (char *) palloc(len);

		wlen = wchar2char(out, wstr, len);

		pfree(wstr);

		if (wlen < 0)
			ereport(ERROR,
					(errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
			errmsg("conversion from wchar_t to server encoding failed: %m")));
		Assert(wlen < len);
	}
	else
#endif   /* USE_WIDE_UPPER_LOWER */
	{
		const char *ptr = str;
		char	   *outptr;

		outptr = out = (char *) palloc(sizeof(char) * (len + 1));
		while ((ptr - str) < len && *ptr)
		{
			*outptr++ = tolower(TOUCHAR(ptr));
			ptr++;
		}
		*outptr = '\0';
	}

	return out;
}

/*
 * create and populate the crosstab tuplestore using the provided source query
 */
static Tuplestorestate *
get_crosstab_tuplestore(char *sql,
						HTAB *crosstab_hash,
						TupleDesc tupdesc,
						MemoryContext per_query_ctx,
						bool randomAccess)
{
	Tuplestorestate *tupstore;
	int			num_categories = hash_get_num_entries(crosstab_hash);
	AttInMetadata *attinmeta = TupleDescGetAttInMetadata(tupdesc);
	char	  **values;
	HeapTuple	tuple;
	int			ret;
	int			proc;

	/* initialize our tuplestore (while still in query context!) */
	tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);

	/* Connect to SPI manager */
	if ((ret = SPI_connect()) < 0)
		/* internal error */
		elog(ERROR, "get_crosstab_tuplestore: SPI_connect returned %d", ret);

	/* Now retrieve the crosstab source rows */
	ret = SPI_execute(sql, true, 0);
	proc = SPI_processed;

	/* Check for qualifying tuples */
	if ((ret == SPI_OK_SELECT) && (proc > 0))
	{
		SPITupleTable *spi_tuptable = SPI_tuptable;
		TupleDesc	spi_tupdesc = spi_tuptable->tupdesc;
		int			ncols = spi_tupdesc->natts;
		char	   *rowid;
		char	   *lastrowid = NULL;
		bool		firstpass = true;
		int			i,
					j;
		int			result_ncols;

		if (num_categories == 0)
		{
			/* no qualifying category tuples */
			ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
					 errmsg("provided \"categories\" SQL must " \
							"return 1 column of at least one row")));
		}

		/*
		 * The provided SQL query must always return at least three columns:
		 *
		 * 1. rowname	the label for each row - column 1 in the final result
		 * 2. category	the label for each value-column in the final result 3.
		 * value	 the values used to populate the value-columns
		 *
		 * If there are more than three columns, the last two are taken as
		 * "category" and "values". The first column is taken as "rowname".
		 * Additional columns (2 thru N-2) are assumed the same for the same
		 * "rowname", and are copied into the result tuple from the first time
		 * we encounter a particular rowname.
		 */
		if (ncols < 3)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
					 errmsg("invalid source data SQL statement"),
					 errdetail("The provided SQL must return 3 " \
							   " columns; rowid, category, and values.")));

		result_ncols = (ncols - 2) + num_categories;

		/* Recheck to make sure we tuple descriptor still looks reasonable */
		if (tupdesc->natts != result_ncols)
			ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
					 errmsg("invalid return type"),
					 errdetail("Query-specified return " \
							   "tuple has %d columns but crosstab " \
							   "returns %d.", tupdesc->natts, result_ncols)));

		/* allocate space */
		values = (char **) palloc(result_ncols * sizeof(char *));

		/* and make sure it's clear */
		memset(values, '\0', result_ncols * sizeof(char *));

		for (i = 0; i < proc; i++)
		{
			HeapTuple	spi_tuple;
			crosstab_cat_desc *catdesc;
			char	   *catname;

			/* get the next sql result tuple */
			spi_tuple = spi_tuptable->vals[i];

			/* get the rowid from the current sql result tuple */
			rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
//.........这里部分代码省略.........

Datum
gtsvector_compress(PG_FUNCTION_ARGS)
{
	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
	GISTENTRY  *retval = entry;

	if (entry->leafkey)
	{							/* tsvector */
		SignTSVector *res;
		TSVector	val = DatumGetTSVector(entry->key);
		int32		len;
		int32	   *arr;
		WordEntry  *ptr = ARRPTR(val);
		char	   *words = STRPTR(val);

		len = CALCGTSIZE(ARRKEY, val->size);
		res = (SignTSVector *) palloc(len);
		SET_VARSIZE(res, len);
		res->flag = ARRKEY;
		arr = GETARR(res);
		len = val->size;
		while (len--)
		{
			pg_crc32	c;

			INIT_LEGACY_CRC32(c);
			COMP_LEGACY_CRC32(c, words + ptr->pos, ptr->len);
			FIN_LEGACY_CRC32(c);

			*arr = *(int32 *) &c;
			arr++;
			ptr++;
		}

		len = uniqueint(GETARR(res), val->size);
		if (len != val->size)
		{
			/*
			 * there is a collision of hash-function; len is always less than
			 * val->size
			 */
			len = CALCGTSIZE(ARRKEY, len);
			res = (SignTSVector *) repalloc((void *) res, len);
			SET_VARSIZE(res, len);
		}

		/* make signature, if array is too long */
		if (VARSIZE(res) > TOAST_INDEX_TARGET)
		{
			SignTSVector *ressign;

			len = CALCGTSIZE(SIGNKEY, 0);
			ressign = (SignTSVector *) palloc(len);
			SET_VARSIZE(ressign, len);
			ressign->flag = SIGNKEY;
			makesign(GETSIGN(ressign), res);
			res = ressign;
		}

		retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
		gistentryinit(*retval, PointerGetDatum(res),
					  entry->rel, entry->page,
					  entry->offset, FALSE);
	}
	else if (ISSIGNKEY(DatumGetPointer(entry->key)) &&
			 !ISALLTRUE(DatumGetPointer(entry->key)))
	{
		int32		i,
					len;
		SignTSVector *res;
		BITVECP		sign = GETSIGN(DatumGetPointer(entry->key));

		LOOPBYTE
		{
			if ((sign[i] & 0xff) != 0xff)
				PG_RETURN_POINTER(retval);
		}

		len = CALCGTSIZE(SIGNKEY | ALLISTRUE, 0);
		res = (SignTSVector *) palloc(len);
		SET_VARSIZE(res, len);
		res->flag = SIGNKEY | ALLISTRUE;

		retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
		gistentryinit(*retval, PointerGetDatum(res),
					  entry->rel, entry->page,
					  entry->offset, FALSE);
	}

/*
 * load up the categories hash table
 */
static HTAB *
load_categories_hash(char *cats_sql, MemoryContext per_query_ctx)
{
	HTAB	   *crosstab_hash;
	HASHCTL		ctl;
	int			ret;
	int			proc;
	MemoryContext SPIcontext;

	/* initialize the category hash table */
	MemSet(&ctl, 0, sizeof(ctl));
	ctl.keysize = MAX_CATNAME_LEN;
	ctl.entrysize = sizeof(crosstab_HashEnt);
	ctl.hcxt = per_query_ctx;

	/*
	 * use INIT_CATS, defined above as a guess of how many hash table entries
	 * to create, initially
	 */
	crosstab_hash = hash_create("crosstab hash",
								INIT_CATS,
								&ctl,
								HASH_ELEM | HASH_CONTEXT);

	/* Connect to SPI manager */
	if ((ret = SPI_connect()) < 0)
		/* internal error */
		elog(ERROR, "load_categories_hash: SPI_connect returned %d", ret);

	/* Retrieve the category name rows */
	ret = SPI_execute(cats_sql, true, 0);
	proc = SPI_processed;

	/* Check for qualifying tuples */
	if ((ret == SPI_OK_SELECT) && (proc > 0))
	{
		SPITupleTable *spi_tuptable = SPI_tuptable;
		TupleDesc	spi_tupdesc = spi_tuptable->tupdesc;
		int			i;

		/*
		 * The provided categories SQL query must always return one column:
		 * category - the label or identifier for each column
		 */
		if (spi_tupdesc->natts != 1)
			ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
					 errmsg("provided \"categories\" SQL must " \
							"return 1 column of at least one row")));

		for (i = 0; i < proc; i++)
		{
			crosstab_cat_desc *catdesc;
			char	   *catname;
			HeapTuple	spi_tuple;

			/* get the next sql result tuple */
			spi_tuple = spi_tuptable->vals[i];

			/* get the category from the current sql result tuple */
			catname = SPI_getvalue(spi_tuple, spi_tupdesc, 1);

			SPIcontext = MemoryContextSwitchTo(per_query_ctx);

			catdesc = (crosstab_cat_desc *) palloc(sizeof(crosstab_cat_desc));
			catdesc->catname = catname;
			catdesc->attidx = i;

			/* Add the proc description block to the hashtable */
			crosstab_HashTableInsert(crosstab_hash, catdesc);

			MemoryContextSwitchTo(SPIcontext);
		}
	}

	if (SPI_finish() != SPI_OK_FINISH)
		/* internal error */
		elog(ERROR, "load_categories_hash: SPI_finish() failed");

	return crosstab_hash;
}

Datum
normal_rand(PG_FUNCTION_ARGS)
{
	FuncCallContext *funcctx;
	int			call_cntr;
	int			max_calls;
	normal_rand_fctx *fctx;
	float8		mean;
	float8		stddev;
	float8		carry_val;
	bool		use_carry;
	MemoryContext oldcontext;

	/* stuff done only on the first call of the function */
	if (SRF_IS_FIRSTCALL())
	{
		/* create a function context for cross-call persistence */
		funcctx = SRF_FIRSTCALL_INIT();

		/*
		 * switch to memory context appropriate for multiple function calls
		 */
		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

		/* total number of tuples to be returned */
		funcctx->max_calls = PG_GETARG_UINT32(0);

		/* allocate memory for user context */
		fctx = (normal_rand_fctx *) palloc(sizeof(normal_rand_fctx));

		/*
		 * Use fctx to keep track of upper and lower bounds from call to call.
		 * It will also be used to carry over the spare value we get from the
		 * Box-Muller algorithm so that we only actually calculate a new value
		 * every other call.
		 */
		fctx->mean = PG_GETARG_FLOAT8(1);
		fctx->stddev = PG_GETARG_FLOAT8(2);
		fctx->carry_val = 0;
		fctx->use_carry = false;

		funcctx->user_fctx = fctx;

		MemoryContextSwitchTo(oldcontext);
	}

	/* stuff done on every call of the function */
	funcctx = SRF_PERCALL_SETUP();

	call_cntr = funcctx->call_cntr;
	max_calls = funcctx->max_calls;
	fctx = funcctx->user_fctx;
	mean = fctx->mean;
	stddev = fctx->stddev;
	carry_val = fctx->carry_val;
	use_carry = fctx->use_carry;

	if (call_cntr < max_calls)	/* do when there is more left to send */
	{
		float8		result;

		if (use_carry)
		{
			/*
			 * reset use_carry and use second value obtained on last pass
			 */
			fctx->use_carry = false;
			result = carry_val;
		}
		else
		{
			float8		normval_1;
			float8		normval_2;

			/* Get the next two normal values */
			get_normal_pair(&normval_1, &normval_2);

			/* use the first */
			result = mean + (stddev * normval_1);

			/* and save the second */
			fctx->carry_val = mean + (stddev * normval_2);
			fctx->use_carry = true;
		}

		/* send the result */
		SRF_RETURN_NEXT(funcctx, Float8GetDatum(result));
	}
	else
		/* do when there is no more left */
		SRF_RETURN_DONE(funcctx);
}

static Tuplestorestate *
build_tuplestore_recursively(char *key_fld,
							 char *parent_key_fld,
							 char *relname,
							 char *orderby_fld,
							 char *branch_delim,
							 char *start_with,
							 char *branch,
							 int level,
							 int *serial,
							 int max_depth,
							 bool show_branch,
							 bool show_serial,
							 MemoryContext per_query_ctx,
							 AttInMetadata *attinmeta,
							 Tuplestorestate *tupstore)
{
	TupleDesc	tupdesc = attinmeta->tupdesc;
	int			ret;
	int			proc;
	int			serial_column;
	StringInfoData sql;
	char	  **values;
	char	   *current_key;
	char	   *current_key_parent;
	char		current_level[INT32_STRLEN];
	char		serial_str[INT32_STRLEN];
	char	   *current_branch;
	HeapTuple	tuple;

	if (max_depth > 0 && level > max_depth)
		return tupstore;

	initStringInfo(&sql);

	/* Build initial sql statement */
	if (!show_serial)
	{
		appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s",
						 key_fld,
						 parent_key_fld,
						 relname,
						 parent_key_fld,
						 quote_literal_cstr(start_with),
						 key_fld, key_fld, parent_key_fld);
		serial_column = 0;
	}
	else
	{
		appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s ORDER BY %s",
						 key_fld,
						 parent_key_fld,
						 relname,
						 parent_key_fld,
						 quote_literal_cstr(start_with),
						 key_fld, key_fld, parent_key_fld,
						 orderby_fld);
		serial_column = 1;
	}

	if (show_branch)
		values = (char **) palloc((CONNECTBY_NCOLS + serial_column) * sizeof(char *));
	else
		values = (char **) palloc((CONNECTBY_NCOLS_NOBRANCH + serial_column) * sizeof(char *));

	/* First time through, do a little setup */
	if (level == 0)
	{
		/* root value is the one we initially start with */
		values[0] = start_with;

		/* root value has no parent */
		values[1] = NULL;

		/* root level is 0 */
		sprintf(current_level, "%d", level);
		values[2] = current_level;

		/* root branch is just starting root value */
		if (show_branch)
			values[3] = start_with;

		/* root starts the serial with 1 */
		if (show_serial)
		{
			sprintf(serial_str, "%d", (*serial)++);
			if (show_branch)
				values[4] = serial_str;
			else
				values[3] = serial_str;
		}

		/* construct the tuple */
		tuple = BuildTupleFromCStrings(attinmeta, values);

		/* now store it */
		tuplestore_puttuple(tupstore, tuple);

		/* increment level */
		level++;
//.........这里部分代码省略.........

/*
** The GiST PickSplit method for _intments
** We use Guttman's poly time split algorithm
*/
Datum
g_int_picksplit(PG_FUNCTION_ARGS)
{
	bytea	   *entryvec = (bytea *) PG_GETARG_POINTER(0);
	GIST_SPLITVEC *v = (GIST_SPLITVEC *) PG_GETARG_POINTER(1);
	OffsetNumber i,
				j;
	ArrayType  *datum_alpha,
			   *datum_beta;
	ArrayType  *datum_l,
			   *datum_r;
	ArrayType  *union_d,
			   *union_dl,
			   *union_dr;
	ArrayType  *inter_d;
	bool		firsttime;
	float		size_alpha,
				size_beta,
				size_union,
				size_inter;
	float		size_waste,
				waste;
	float		size_l,
				size_r;
	int			nbytes;
	OffsetNumber seed_1 = 0,
				seed_2 = 0;
	OffsetNumber *left,
			   *right;
	OffsetNumber maxoff;
	SPLITCOST  *costvector;

#ifdef GIST_DEBUG
	elog(DEBUG3, "--------picksplit %d", (VARSIZE(entryvec) - VARHDRSZ) / sizeof(GISTENTRY));
#endif

	maxoff = ((VARSIZE(entryvec) - VARHDRSZ) / sizeof(GISTENTRY)) - 2;
	nbytes = (maxoff + 2) * sizeof(OffsetNumber);
	v->spl_left = (OffsetNumber *) palloc(nbytes);
	v->spl_right = (OffsetNumber *) palloc(nbytes);

	firsttime = true;
	waste = 0.0;
	for (i = FirstOffsetNumber; i < maxoff; i = OffsetNumberNext(i))
	{
		datum_alpha = (ArrayType *) DatumGetPointer(((GISTENTRY *) VARDATA(entryvec))[i].key);
		for (j = OffsetNumberNext(i); j <= maxoff; j = OffsetNumberNext(j))
		{
			datum_beta = (ArrayType *) DatumGetPointer(((GISTENTRY *) VARDATA(entryvec))[j].key);

			/* compute the wasted space by unioning these guys */
			/* size_waste = size_union - size_inter; */
			union_d = inner_int_union(datum_alpha, datum_beta);
			rt__int_size(union_d, &size_union);
			inter_d = inner_int_inter(datum_alpha, datum_beta);
			rt__int_size(inter_d, &size_inter);
			size_waste = size_union - size_inter;

			pfree(union_d);

			if (inter_d != (ArrayType *) NULL)
				pfree(inter_d);

			/*
			 * are these a more promising split that what we've already
			 * seen?
			 */

			if (size_waste > waste || firsttime)
			{
				waste = size_waste;
				seed_1 = i;
				seed_2 = j;
				firsttime = false;
			}
		}
	}

	left = v->spl_left;
	v->spl_nleft = 0;
	right = v->spl_right;
	v->spl_nright = 0;
	if (seed_1 == 0 || seed_2 == 0)
	{
		seed_1 = 1;
		seed_2 = 2;
	}

	datum_alpha = (ArrayType *) DatumGetPointer(((GISTENTRY *) VARDATA(entryvec))[seed_1].key);
	datum_l = copy_intArrayType(datum_alpha);
	rt__int_size(datum_l, &size_l);
	datum_beta = (ArrayType *) DatumGetPointer(((GISTENTRY *) VARDATA(entryvec))[seed_2].key);
	datum_r = copy_intArrayType(datum_beta);
	rt__int_size(datum_r, &size_r);

	maxoff = OffsetNumberNext(maxoff);
//.........这里部分代码省略.........