C++ VARDATA函数代码示例

Datum
gin_leafpage_items(PG_FUNCTION_ARGS)
{
	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
	int			raw_page_size;
	FuncCallContext *fctx;
	gin_leafpage_items_state *inter_call_data;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use raw page functions"))));

	raw_page_size = VARSIZE(raw_page) - VARHDRSZ;

	if (SRF_IS_FIRSTCALL())
	{
		TupleDesc	tupdesc;
		MemoryContext mctx;
		Page		page;
		GinPageOpaque opaq;

		if (raw_page_size < BLCKSZ)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				  errmsg("input page too small (%d bytes)", raw_page_size)));
		page = VARDATA(raw_page);

		if (PageGetSpecialSize(page) != MAXALIGN(sizeof(GinPageOpaqueData)))
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
					 errmsg("input page is not a valid GIN data leaf page"),
					 errdetail("Special size %d, expected %d",
							   (int) PageGetSpecialSize(page),
							   (int) MAXALIGN(sizeof(GinPageOpaqueData)))));

		opaq = (GinPageOpaque) PageGetSpecialPointer(page);
		if (opaq->flags != (GIN_DATA | GIN_LEAF | GIN_COMPRESSED))
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("input page is not a compressed GIN data leaf page"),
					 errdetail("Flags %04X, expected %04X",
							   opaq->flags,
							   (GIN_DATA | GIN_LEAF | GIN_COMPRESSED))));

		fctx = SRF_FIRSTCALL_INIT();
		mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);

		inter_call_data = palloc(sizeof(gin_leafpage_items_state));

		/* Build a tuple descriptor for our result type */
		if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
			elog(ERROR, "return type must be a row type");

		inter_call_data->tupd = tupdesc;

		inter_call_data->seg = GinDataLeafPageGetPostingList(page);
		inter_call_data->lastseg = (GinPostingList *)
			(((char *) inter_call_data->seg) +
			 GinDataLeafPageGetPostingListSize(page));

		fctx->user_fctx = inter_call_data;

		MemoryContextSwitchTo(mctx);
	}

	fctx = SRF_PERCALL_SETUP();
	inter_call_data = fctx->user_fctx;

	if (inter_call_data->seg != inter_call_data->lastseg)
	{
		GinPostingList *cur = inter_call_data->seg;
		HeapTuple	resultTuple;
		Datum		result;
		Datum		values[3];
		bool		nulls[3];
		int			ndecoded,
					i;
		ItemPointer tids;
		Datum	   *tids_datum;

		memset(nulls, 0, sizeof(nulls));

		values[0] = ItemPointerGetDatum(&cur->first);
		values[1] = UInt16GetDatum(cur->nbytes);

		/* build an array of decoded item pointers */
		tids = ginPostingListDecode(cur, &ndecoded);
		tids_datum = (Datum *) palloc(ndecoded * sizeof(Datum));
		for (i = 0; i < ndecoded; i++)
			tids_datum[i] = ItemPointerGetDatum(&tids[i]);
		values[2] = PointerGetDatum(construct_array(tids_datum,
													ndecoded,
													TIDOID,
													sizeof(ItemPointerData),
													false, 's'));
		pfree(tids_datum);
		pfree(tids);

		/* Build and return the result tuple. */
//.........这里部分代码省略.........

/* ----------------
 *		printtup --- print a tuple in protocol 3.0
 * ----------------
 */
static bool
printtup(TupleTableSlot *slot, DestReceiver *self)
{
	TupleDesc	typeinfo = slot->tts_tupleDescriptor;
	DR_printtup *myState = (DR_printtup *) self;
	MemoryContext oldcontext;
	StringInfoData buf;
	int			natts = typeinfo->natts;
	int			i;

	/* Set or update my derived attribute info, if needed */
	if (myState->attrinfo != typeinfo || myState->nattrs != natts)
		printtup_prepare_info(myState, typeinfo, natts);

	/* Make sure the tuple is fully deconstructed */
	slot_getallattrs(slot);

	/* Switch into per-row context so we can recover memory below */
	oldcontext = MemoryContextSwitchTo(myState->tmpcontext);

	/*
	 * Prepare a DataRow message (note buffer is in per-row context)
	 */
	pq_beginmessage(&buf, 'D');

	pq_sendint(&buf, natts, 2);

	/*
	 * send the attributes of this tuple
	 */
	for (i = 0; i < natts; ++i)
	{
		PrinttupAttrInfo *thisState = myState->myinfo + i;
		Datum		attr = slot->tts_values[i];

		if (slot->tts_isnull[i])
		{
			pq_sendint(&buf, -1, 4);
			continue;
		}

		/*
		 * Here we catch undefined bytes in datums that are returned to the
		 * client without hitting disk; see comments at the related check in
		 * PageAddItem().  This test is most useful for uncompressed,
		 * non-external datums, but we're quite likely to see such here when
		 * testing new C functions.
		 */
		if (thisState->typisvarlena)
			VALGRIND_CHECK_MEM_IS_DEFINED(DatumGetPointer(attr),
										  VARSIZE_ANY(attr));

		if (thisState->format == 0)
		{
			/* Text output */
			char	   *outputstr;

			outputstr = OutputFunctionCall(&thisState->finfo, attr);
			pq_sendcountedtext(&buf, outputstr, strlen(outputstr), false);
		}
		else
		{
			/* Binary output */
			bytea	   *outputbytes;

			outputbytes = SendFunctionCall(&thisState->finfo, attr);
			pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
			pq_sendbytes(&buf, VARDATA(outputbytes),
						 VARSIZE(outputbytes) - VARHDRSZ);
		}
	}

	pq_endmessage(&buf);

	/* Return to caller's context, and flush row's temporary memory */
	MemoryContextSwitchTo(oldcontext);
	MemoryContextReset(myState->tmpcontext);

	return true;
}

static void *uri_char(HeapTupleHeader ud, bool hdr, bool term)
{
	TupleDesc td;
	HeapTupleData tuple;
	Datum d[URI_LEN];
	bool n[URI_LEN];
	text *scheme = NULL, *host = NULL, *path = NULL;
	int16 port;
	char portbuf[8];
	unsigned schemelen = 0, hostlen = 0, portlen = 0, pathlen = 0;
	unsigned len;
	void *out;
	char *p;

	td = lookup_rowtype_tupdesc(HeapTupleHeaderGetTypeId(ud), HeapTupleHeaderGetTypMod(ud));
	tuple.t_len = HeapTupleHeaderGetDatumLength(ud);
	ItemPointerSetInvalid(&(tuple.t_self));
	tuple.t_tableOid = InvalidOid;
	tuple.t_data = ud;
	heap_deform_tuple(&tuple, td, d, n);
	ReleaseTupleDesc(td);

	if (!n[URI_SCHEME])
	{
		scheme = DatumGetTextP(d[URI_SCHEME]);
		schemelen = VARSIZE_ANY_EXHDR(scheme);
	}
	if (!n[URI_HOST])
	{
		host = DatumGetTextP(d[URI_HOST]);
		hostlen = VARSIZE_ANY_EXHDR(host);
	}
	if (!n[URI_PORT])
	{
		port = DatumGetInt16(d[URI_PORT]);
		portlen = snprintf(portbuf, sizeof(portbuf)-1, ":%hu", port);
	}
	if (!n[URI_PATH])
	{
		path = DatumGetTextP(d[URI_PATH]);
		pathlen = VARSIZE_ANY_EXHDR(path);
	}

	len = (hdr ? VARHDRSZ : 0) + schemelen + (scheme ? 3 : 0) + hostlen + portlen + pathlen + term;
	out = palloc(len);
	if (hdr)
		SET_VARSIZE(out, len);
	p = hdr ? VARDATA(out) : out;

	if (scheme)
	{
		memcpy(p, VARDATA(scheme), schemelen);
		p += schemelen;
		*p++ = ':';
		*p++ = '/';
		*p++ = '/';
	}
	if (host)
	{
		domainname_flip(p, VARDATA(host), hostlen);
		p += hostlen;
	}
	memcpy(p, portbuf, portlen);
	p += portlen;
	if (path)
	{
		memcpy(p, VARDATA(path), pathlen);
		p += pathlen;
	}
	if (term)
		*p = '\0';

	return out;
}

Datum
spg_text_leaf_consistent(PG_FUNCTION_ARGS)
{
	spgLeafConsistentIn *in = (spgLeafConsistentIn *) PG_GETARG_POINTER(0);
	spgLeafConsistentOut *out = (spgLeafConsistentOut *) PG_GETARG_POINTER(1);
	int			level = in->level;
	text	   *leafValue,
			   *reconstrValue = NULL;
	char	   *fullValue;
	int			fullLen;
	bool		res;
	int			j;

	/* all tests are exact */
	out->recheck = false;

	leafValue = DatumGetTextPP(in->leafDatum);

	if (DatumGetPointer(in->reconstructedValue))
		reconstrValue = DatumGetTextP(in->reconstructedValue);

	Assert(level == 0 ? reconstrValue == NULL :
		   VARSIZE_ANY_EXHDR(reconstrValue) == level);

	/* Reconstruct the full string represented by this leaf tuple */
	fullLen = level + VARSIZE_ANY_EXHDR(leafValue);
	if (VARSIZE_ANY_EXHDR(leafValue) == 0 && level > 0)
	{
		fullValue = VARDATA(reconstrValue);
		out->leafValue = PointerGetDatum(reconstrValue);
	}
	else
	{
		text	   *fullText = palloc(VARHDRSZ + fullLen);

		SET_VARSIZE(fullText, VARHDRSZ + fullLen);
		fullValue = VARDATA(fullText);
		if (level)
			memcpy(fullValue, VARDATA(reconstrValue), level);
		if (VARSIZE_ANY_EXHDR(leafValue) > 0)
			memcpy(fullValue + level, VARDATA_ANY(leafValue),
				   VARSIZE_ANY_EXHDR(leafValue));
		out->leafValue = PointerGetDatum(fullText);
	}

	/* Perform the required comparison(s) */
	res = true;
	for (j = 0; j < in->nkeys; j++)
	{
		StrategyNumber strategy = in->scankeys[j].sk_strategy;
		text	   *query = DatumGetTextPP(in->scankeys[j].sk_argument);
		int			queryLen = VARSIZE_ANY_EXHDR(query);
		int			r;

		if (strategy > 10)
		{
			/* Collation-aware comparison */
			strategy -= 10;

			/* If asserts enabled, verify encoding of reconstructed string */
			Assert(pg_verifymbstr(fullValue, fullLen, false));

			r = varstr_cmp(fullValue, Min(queryLen, fullLen),
						   VARDATA_ANY(query), Min(queryLen, fullLen),
						   PG_GET_COLLATION());
		}
		else
		{
			/* Non-collation-aware comparison */
			r = memcmp(fullValue, VARDATA_ANY(query), Min(queryLen, fullLen));
		}

		if (r == 0)
		{
			if (queryLen > fullLen)
				r = -1;
			else if (queryLen < fullLen)
				r = 1;
		}

		switch (strategy)
		{
			case BTLessStrategyNumber:
				res = (r < 0);
				break;
			case BTLessEqualStrategyNumber:
				res = (r <= 0);
				break;
			case BTEqualStrategyNumber:
				res = (r == 0);
				break;
			case BTGreaterEqualStrategyNumber:
				res = (r >= 0);
				break;
			case BTGreaterStrategyNumber:
				res = (r > 0);
				break;
			default:
				elog(ERROR, "unrecognized strategy number: %d",
					 in->scankeys[j].sk_strategy);
//.........这里部分代码省略.........

Datum
gin_extract_query_trgm(PG_FUNCTION_ARGS)
{
	text	   *val = (text *) PG_GETARG_TEXT_P(0);
	int32	   *nentries = (int32 *) PG_GETARG_POINTER(1);
	StrategyNumber strategy = PG_GETARG_UINT16(2);

	/* bool   **pmatch = (bool **) PG_GETARG_POINTER(3); */
	Pointer   **extra_data = (Pointer **) PG_GETARG_POINTER(4);

	/* bool   **nullFlags = (bool **) PG_GETARG_POINTER(5); */
	int32	   *searchMode = (int32 *) PG_GETARG_POINTER(6);
	Datum	   *entries = NULL;
	TRGM	   *trg;
	int32		trglen;
	trgm	   *ptr;
	TrgmPackedGraph *graph;
	int32		i;

	switch (strategy)
	{
		case SimilarityStrategyNumber:
			trg = generate_trgm(VARDATA(val), VARSIZE(val) - VARHDRSZ);
			break;
		case ILikeStrategyNumber:
#ifndef IGNORECASE
			elog(ERROR, "cannot handle ~~* with case-sensitive trigrams");
#endif
			/* FALL THRU */
		case LikeStrategyNumber:

			/*
			 * For wildcard search we extract all the trigrams that every
			 * potentially-matching string must include.
			 */
			trg = generate_wildcard_trgm(VARDATA(val), VARSIZE(val) - VARHDRSZ);
			break;
		case RegExpICaseStrategyNumber:
#ifndef IGNORECASE
			elog(ERROR, "cannot handle ~* with case-sensitive trigrams");
#endif
			/* FALL THRU */
		case RegExpStrategyNumber:
			trg = createTrgmNFA(val, PG_GET_COLLATION(),
								&graph, CurrentMemoryContext);
			if (trg && ARRNELEM(trg) > 0)
			{
				/*
				 * Successful regex processing: store NFA-like graph as
				 * extra_data.  GIN API requires an array of nentries
				 * Pointers, but we just put the same value in each element.
				 */
				trglen = ARRNELEM(trg);
				*extra_data = (Pointer *) palloc(sizeof(Pointer) * trglen);
				for (i = 0; i < trglen; i++)
					(*extra_data)[i] = (Pointer) graph;
			}
			else
			{
				/* No result: have to do full index scan. */
				*nentries = 0;
				*searchMode = GIN_SEARCH_MODE_ALL;
				PG_RETURN_POINTER(entries);
			}
			break;
		default:
			elog(ERROR, "unrecognized strategy number: %d", strategy);
			trg = NULL;			/* keep compiler quiet */
			break;
	}

	trglen = ARRNELEM(trg);
	*nentries = trglen;

	if (trglen > 0)
	{
		entries = (Datum *) palloc(sizeof(Datum) * trglen);
		ptr = GETARR(trg);
		for (i = 0; i < trglen; i++)
		{
			int32		item = trgm2int(ptr);

			entries[i] = Int32GetDatum(item);
			ptr++;
		}
	}

	/*
	 * If no trigram was extracted then we have to scan all the index.
	 */
	if (trglen == 0)
		*searchMode = GIN_SEARCH_MODE_ALL;

	PG_RETURN_POINTER(entries);
}

/*
 * Deserialize a HeapTuple's data from a byte-array.
 *
 * This code is based on the binary input handling functions in copy.c.
 */
HeapTuple
DeserializeTuple(SerTupInfo *pSerInfo, StringInfo serialTup)
{
	MemoryContext oldCtxt;
	TupleDesc	tupdesc;
	HeapTuple	htup;
	int			natts;
	SerAttrInfo *attrInfo;
	int			i;

	AssertArg(pSerInfo != NULL);
	AssertArg(serialTup != NULL);

	tupdesc = pSerInfo->tupdesc;
	natts = tupdesc->natts;

	/*
	 * Flip to our tuple-serialization memory-context, to speed up memory
	 * reclamation operations.
	 */
	AssertState(s_tupSerMemCtxt != NULL);
	oldCtxt = MemoryContextSwitchTo(s_tupSerMemCtxt);

	/* Receive nulls character-array. */
	pq_copymsgbytes(serialTup, pSerInfo->nulls, natts);
	skipPadding(serialTup);

	/* Deserialize the non-NULL attributes of this tuple */
	for (i = 0; i < natts; ++i)
	{
		attrInfo = pSerInfo->myinfo + i;

		if (pSerInfo->nulls[i]) /* NULL field. */
		{
			pSerInfo->values[i] = (Datum) 0;
			continue;
		}

		if (attrInfo->typlen == -1)
		{
			int32		sz;
			struct varlena *p;

			/* Read length first */
			pq_copymsgbytes(serialTup, (char *) &sz, sizeof(int32));
			if (sz < 0)
				elog(ERROR, "invalid length received for a varlen Datum");

			p = palloc(sz + VARHDRSZ);

			pq_copymsgbytes(serialTup, VARDATA(p), sz);
			SET_VARSIZE(p, sz + VARHDRSZ);

			pSerInfo->values[i] = PointerGetDatum(p);
		}
		else if (attrInfo->typlen == -2)
		{
			int32		sz;
			char	   *p;

			/* CString, with terminating '\0' included */

			/* Read length first */
			pq_copymsgbytes(serialTup, (char *) &sz, sizeof(int32));
			if (sz < 0)
				elog(ERROR, "invalid length received for a CString");

			p = palloc(sz + VARHDRSZ);

			/* Then data */
			pq_copymsgbytes(serialTup, p, sz);

			pSerInfo->values[i] = CStringGetDatum(p);
		}
		else if (attrInfo->typbyval)
		{
			/* Read a whole Datum */

			pq_copymsgbytes(serialTup, (char *) &(pSerInfo->values[i]), sizeof(Datum));
		}
		else
		{
			/* fixed width, pass-by-ref */
			char	   *p = palloc(attrInfo->typlen);

			pq_copymsgbytes(serialTup, p, attrInfo->typlen);

			pSerInfo->values[i] = PointerGetDatum(p);
		}
	}

	/*
	 * Construct the tuple from the Datums and nulls values.  NOTE:  Switch
	 * out of our temporary context before we form the tuple!
	 */
//.........这里部分代码省略.........

//.........这里部分代码省略.........
			case 0:
			case 2:
				cs->plan_active_log = cs->plan_insert_log_1;
				break;

			case 1:
			case 3:
				cs->plan_active_log = cs->plan_insert_log_2;
				break;

			default:
				elog(ERROR, "Slony-I: illegal log status %d", log_status);
				break;
		}

		cs->currentXid = newXid;
	}

	/*
	 * Determine cmdtype and cmddata depending on the command type
	 */
	if (TRIGGER_FIRED_BY_INSERT(tg->tg_event))
	{
		HeapTuple	new_row = tg->tg_trigtuple;
		TupleDesc	tupdesc = tg->tg_relation->rd_att;
		char	   *col_ident;
		char	   *col_value;

		int			len_ident;
		int			len_value;
		int			i;
		int			need_comma = false;
		char	   *OldDateStyle;
		char	   *cp = VARDATA(cs->cmddata_buf);

		/*
		 * INSERT
		 *
		 * cmdtype = 'I' cmddata = ("col" [, ...]) values ('value' [, ...])
		 */
		cmdtype = cs->cmdtype_I;

		/*
		 * Specify all the columns
		 */
		*cp++ = '(';
		for (i = 0; i < tg->tg_relation->rd_att->natts; i++)
		{
			/*
			 * Skip dropped columns
			 */
			if (tupdesc->attrs[i]->attisdropped)
				continue;

			col_ident = (char *) slon_quote_identifier(SPI_fname(tupdesc, i + 1));
			cmddata_need = (cp - (char *) (cs->cmddata_buf)) + 16 +
				(len_ident = strlen(col_ident));
			if (cs->cmddata_size < cmddata_need)
			{
				int			have = (cp - (char *) (cs->cmddata_buf));

				while (cs->cmddata_size < cmddata_need)
					cs->cmddata_size *= 2;
				cs->cmddata_buf = realloc(cs->cmddata_buf, cs->cmddata_size);
				cp = (char *) (cs->cmddata_buf) + have;
			}

	/*
	 * If CREATE/SET, add new options to array; if RESET, just check that the
	 * user didn't say RESET (option=val).  (Must do this because the grammar
	 * doesn't enforce it.)
	 */
	foreach(cell, defList)
	{
		DefElem    *def = (DefElem *) lfirst(cell);

		if (isReset)
		{
			if (def->arg != NULL)
				ereport(ERROR,
						(errcode(ERRCODE_SYNTAX_ERROR),
					errmsg("RESET must not include values for parameters")));
		}
		else
		{
			text	   *t;
			const char *value;
			Size		len;

			/*
			 * Error out if the namespace is not valid.  A NULL namespace is
			 * always valid.
			 */
			if (def->defnamespace != NULL)
			{
				bool		valid = false;
				int			i;

				if (validnsps)
				{
					for (i = 0; validnsps[i]; i++)
					{
						if (pg_strcasecmp(def->defnamespace,
										  validnsps[i]) == 0)
						{
							valid = true;
							break;
						}
					}
				}

				if (!valid)
					ereport(ERROR,
							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
							 errmsg("unrecognized parameter namespace \"%s\"",
									def->defnamespace)));
			}

			if (ignoreOids && pg_strcasecmp(def->defname, "oids") == 0)
				continue;

			/* ignore if not in the same namespace */
			if (namspace == NULL)
			{
				if (def->defnamespace != NULL)
					continue;
			}
			else if (def->defnamespace == NULL)
				continue;
			else if (pg_strcasecmp(def->defnamespace, namspace) != 0)
				continue;

			/*
			 * Flatten the DefElem into a text string like "name=arg". If we
			 * have just "name", assume "name=true" is meant.  Note: the
			 * namespace is not output.
			 */
			if (def->arg != NULL)
				value = defGetString(def);
			else
				value = "true";
			len = VARHDRSZ + strlen(def->defname) + 1 + strlen(value);
			/* +1 leaves room for sprintf's trailing null */
			t = (text *) palloc(len + 1);
			SET_VARSIZE(t, len);
			sprintf(VARDATA(t), "%s=%s", def->defname, value);

			astate = accumArrayResult(astate, PointerGetDatum(t),
									  false, TEXTOID,
									  CurrentMemoryContext);
		}
	}

/* cash_words()
 * This converts a int4 as well but to a representation using words
 * Obviously way North American centric - sorry
 */
Datum
cash_words(PG_FUNCTION_ARGS)
{
	Cash		value = PG_GETARG_CASH(0);
	uint64		val;
	char		buf[256];
	char	   *p = buf;
	Cash		m0;
	Cash		m1;
	Cash		m2;
	Cash		m3;
	Cash		m4;
	Cash		m5;
	Cash		m6;
	text	   *result;

	/* work with positive numbers */
	if (value < 0)
	{
		value = -value;
		strcpy(buf, "minus ");
		p += 6;
	}
	else
		buf[0] = '\0';

	/* Now treat as unsigned, to avoid trouble at INT_MIN */
	val = (uint64) value;

	m0 = val % INT64CONST(100);							/* cents */
	m1 = (val / INT64CONST(100)) % 1000;				/* hundreds */
	m2 = (val / INT64CONST(100000)) % 1000;				/* thousands */
	m3 = (val / INT64CONST(100000000)) % 1000;			/* millions */
	m4 = (val / INT64CONST(100000000000)) % 1000;		/* billions */
	m5 = (val / INT64CONST(100000000000000)) % 1000;	/* trillions */
	m6 = (val / INT64CONST(100000000000000000)) % 1000;	/* quadrillions */

	if (m6)
	{
		strcat(buf, num_word(m6));
		strcat(buf, " quadrillion ");
	}

	if (m5)
	{
		strcat(buf, num_word(m5));
		strcat(buf, " trillion ");
	}

	if (m4)
	{
		strcat(buf, num_word(m4));
		strcat(buf, " billion ");
	}

	if (m3)
	{
		strcat(buf, num_word(m3));
		strcat(buf, " million ");
	}

	if (m2)
	{
		strcat(buf, num_word(m2));
		strcat(buf, " thousand ");
	}

	if (m1)
		strcat(buf, num_word(m1));

	if (!*p)
		strcat(buf, "zero");

	strcat(buf, (val / 100) == 1 ? " dollar and " : " dollars and ");
	strcat(buf, num_word(m0));
	strcat(buf, m0 == 1 ? " cent" : " cents");

	/* capitalize output */
	buf[0] = pg_toupper((unsigned char) buf[0]);

	/* make a text type for output */
	result = (text *) palloc(strlen(buf) + VARHDRSZ);
	SET_VARSIZE(result, strlen(buf) + VARHDRSZ);
	memcpy(VARDATA(result), buf, strlen(buf));

	PG_RETURN_TEXT_P(result);
}

/*
 * Converts a CHARACTER type to the specified size.
 *
 * maxlen is the typmod, ie, declared length plus VARHDRSZ bytes.
 * isExplicit is true if this is for an explicit cast to char(N).
 *
 * Truncation rules: for an explicit cast, silently truncate to the given
 * length; for an implicit cast, raise error unless extra characters are
 * all spaces.	(This is sort-of per SQL: the spec would actually have us
 * raise a "completion condition" for the explicit cast case, but Postgres
 * hasn't got such a concept.)
 */
Datum
bpchar(PG_FUNCTION_ARGS)
{
	BpChar	   *source = PG_GETARG_BPCHAR_P(0);
	int32		maxlen = PG_GETARG_INT32(1);
	bool		isExplicit = PG_GETARG_BOOL(2);
	BpChar	   *result;
	int32		len;
	char	   *r;
	char	   *s;
	int			i;
	int			charlen;		/* number of characters in the input string +
								 * VARHDRSZ */

	/* No work if typmod is invalid */
	if (maxlen < (int32) VARHDRSZ)
		PG_RETURN_BPCHAR_P(source);

	len = VARSIZE(source);

	charlen = pg_mbstrlen_with_len(VARDATA(source), len - VARHDRSZ) + VARHDRSZ;

	/* No work if supplied data matches typmod already */
	if (charlen == maxlen)
		PG_RETURN_BPCHAR_P(source);

	if (charlen > maxlen)
	{
		/* Verify that extra characters are spaces, and clip them off */
		size_t		maxmblen;

		maxmblen = pg_mbcharcliplen(VARDATA(source), len - VARHDRSZ,
									maxlen - VARHDRSZ) + VARHDRSZ;

		if (!isExplicit)
		{
			for (i = maxmblen - VARHDRSZ; i < len - VARHDRSZ; i++)
				if (*(VARDATA(source) + i) != ' ')
					ereport(ERROR,
							(errcode(ERRCODE_STRING_DATA_RIGHT_TRUNCATION),
							 errmsg("value too long for type character(%d)",
									maxlen - VARHDRSZ)));
		}

		len = maxmblen;

		/*
		 * XXX: at this point, maxlen is the necessary byte length+VARHDRSZ,
		 * not the number of CHARACTERS!
		 */
		maxlen = len;
	}
	else
	{
		/*
		 * XXX: at this point, maxlen is the necessary byte length+VARHDRSZ,
		 * not the number of CHARACTERS!
		 */
		maxlen = len + (maxlen - charlen);
	}

	s = VARDATA(source);

	result = palloc(maxlen);
	VARATT_SIZEP(result) = maxlen;
	r = VARDATA(result);

	memcpy(r, s, len - VARHDRSZ);

	/* blank pad the string if necessary */
	if (maxlen > len)
		memset(r + len - VARHDRSZ, ' ', maxlen - len);

	PG_RETURN_BPCHAR_P(result);
}

/*
 * bpchar_input -- common guts of bpcharin and bpcharrecv
 *
 * s is the input text of length len (may not be null-terminated)
 * atttypmod is the typmod value to apply
 *
 * Note that atttypmod is measured in characters, which
 * is not necessarily the same as the number of bytes.
 *
 * If the input string is too long, raise an error, unless the extra
 * characters are spaces, in which case they're truncated.  (per SQL)
 */
static BpChar *
bpchar_input(const char *s, size_t len, int32 atttypmod)
{
	BpChar	   *result;
	char	   *r;
	size_t		maxlen;

	/* verify encoding */
	pg_verifymbstr(s, len, false);

	/* If typmod is -1 (or invalid), use the actual string length */
	if (atttypmod < (int32) VARHDRSZ)
		maxlen = len;
	else
	{
		size_t		charlen;	/* number of CHARACTERS in the input */

		maxlen = atttypmod - VARHDRSZ;
		charlen = pg_mbstrlen_with_len(s, len);
		if (charlen > maxlen)
		{
			/* Verify that extra characters are spaces, and clip them off */
			size_t		mbmaxlen = pg_mbcharcliplen(s, len, maxlen);
			size_t		j;

			/*
			 * at this point, len is the actual BYTE length of the input
			 * string, maxlen is the max number of CHARACTERS allowed for this
			 * bpchar type, mbmaxlen is the length in BYTES of those chars.
			 */
			for (j = mbmaxlen; j < len; j++)
			{
				if (s[j] != ' ')
					ereport(ERROR,
							(errcode(ERRCODE_STRING_DATA_RIGHT_TRUNCATION),
							 errmsg("value too long for type character(%d)",
									(int) maxlen)));
			}

			/*
			 * Now we set maxlen to the necessary byte length, not the number
			 * of CHARACTERS!
			 */
			maxlen = len = mbmaxlen;
		}
		else
		{
			/*
			 * Now we set maxlen to the necessary byte length, not the number
			 * of CHARACTERS!
			 */
			maxlen = len + (maxlen - charlen);
		}
	}

	result = (BpChar *) palloc(maxlen + VARHDRSZ);
	VARATT_SIZEP(result) = maxlen + VARHDRSZ;
	r = VARDATA(result);
	memcpy(r, s, len);

	/* blank pad the string if necessary */
	if (maxlen > len)
		memset(r + len, ' ', maxlen - len);

	return result;
}

/* ----------------
 *		printtup_internal_20 --- print a binary tuple in protocol 2.0
 *
 * We use a different message type, i.e. 'B' instead of 'D' to
 * indicate a tuple in internal (binary) form.
 *
 * This is largely same as printtup_20, except we use binary formatting.
 * ----------------
 */
static void
printtup_internal_20(TupleTableSlot *slot, DestReceiver *self)
{
	TupleDesc	typeinfo = slot->tts_tupleDescriptor;
	DR_printtup *myState = (DR_printtup *) self;
	StringInfoData buf;
	int			natts = typeinfo->natts;
	int			i,
				j,
				k;

	/* Set or update my derived attribute info, if needed */
	if (myState->attrinfo != typeinfo || myState->nattrs != natts)
		printtup_prepare_info(myState, typeinfo, natts);

	/* Make sure the tuple is fully deconstructed */
	slot_getallattrs(slot);

	/*
	 * tell the frontend to expect new tuple data (in binary style)
	 */
	pq_beginmessage(&buf, 'B');

	/*
	 * send a bitmap of which attributes are not null
	 */
	j = 0;
	k = 1 << 7;
	for (i = 0; i < natts; ++i)
	{
		if (!slot->tts_isnull[i])
			j |= k;				/* set bit if not null */
		k >>= 1;
		if (k == 0)				/* end of byte? */
		{
			pq_sendint(&buf, j, 1);
			j = 0;
			k = 1 << 7;
		}
	}
	if (k != (1 << 7))			/* flush last partial byte */
		pq_sendint(&buf, j, 1);

	/*
	 * send the attributes of this tuple
	 */
	for (i = 0; i < natts; ++i)
	{
		PrinttupAttrInfo *thisState = myState->myinfo + i;
		Datum		origattr = slot->tts_values[i],
					attr;
		bytea	   *outputbytes;

		if (slot->tts_isnull[i])
			continue;

		Assert(thisState->format == 1);

		/*
		 * If we have a toasted datum, forcibly detoast it here to avoid
		 * memory leakage inside the type's output routine.
		 */
		if (thisState->typisvarlena)
			attr = PointerGetDatum(PG_DETOAST_DATUM(origattr));
		else
			attr = origattr;

		outputbytes = SendFunctionCall(&thisState->finfo, attr);
		/* We assume the result will not have been toasted */
		pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
		pq_sendbytes(&buf, VARDATA(outputbytes),
					 VARSIZE(outputbytes) - VARHDRSZ);
		pfree(outputbytes);

		/* Clean up detoasted copy, if any */
		if (DatumGetPointer(attr) != DatumGetPointer(origattr))
			pfree(DatumGetPointer(attr));
	}

	pq_endmessage(&buf);
}

/* ----------------
 *		printtup --- print a tuple in protocol 3.0
 * ----------------
 */
static void
printtup(TupleTableSlot *slot, DestReceiver *self)
{
	TupleDesc	typeinfo = slot->tts_tupleDescriptor;
	DR_printtup *myState = (DR_printtup *) self;
	StringInfoData buf;
	int			natts = typeinfo->natts;
	int			i;

#ifdef PGXC
	/*
	 * If we are having DataRow-based tuple we do not have to encode attribute
	 * values, just send over the DataRow message as we received it from the
	 * Datanode
	 */
	if (slot->tts_dataRow)
	{
		pq_putmessage('D', slot->tts_dataRow, slot->tts_dataLen);
		return;
	}
#endif

	/* Set or update my derived attribute info, if needed */
	if (myState->attrinfo != typeinfo || myState->nattrs != natts)
		printtup_prepare_info(myState, typeinfo, natts);

	/* Make sure the tuple is fully deconstructed */
	slot_getallattrs(slot);

	/*
	 * Prepare a DataRow message
	 */
	pq_beginmessage(&buf, 'D');

	pq_sendint(&buf, natts, 2);

	/*
	 * send the attributes of this tuple
	 */
	for (i = 0; i < natts; ++i)
	{
		PrinttupAttrInfo *thisState = myState->myinfo + i;
		Datum		origattr = slot->tts_values[i],
					attr;

		if (slot->tts_isnull[i])
		{
			pq_sendint(&buf, -1, 4);
			continue;
		}

		/*
		 * If we have a toasted datum, forcibly detoast it here to avoid
		 * memory leakage inside the type's output routine.
		 */
		if (thisState->typisvarlena)
			attr = PointerGetDatum(PG_DETOAST_DATUM(origattr));
		else
			attr = origattr;

		if (thisState->format == 0)
		{
			/* Text output */
			char	   *outputstr;

			outputstr = OutputFunctionCall(&thisState->finfo, attr);
			pq_sendcountedtext(&buf, outputstr, strlen(outputstr), false);
			pfree(outputstr);
		}
		else
		{
			/* Binary output */
			bytea	   *outputbytes;

			outputbytes = SendFunctionCall(&thisState->finfo, attr);
			pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
			pq_sendbytes(&buf, VARDATA(outputbytes),
						 VARSIZE(outputbytes) - VARHDRSZ);
			pfree(outputbytes);
		}

		/* Clean up detoasted copy, if any */
		if (DatumGetPointer(attr) != DatumGetPointer(origattr))
			pfree(DatumGetPointer(attr));
	}

	pq_endmessage(&buf);
}

Datum
gin_page_opaque_info(PG_FUNCTION_ARGS)
{
	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
	int			raw_page_size;
	TupleDesc	tupdesc;
	Page		page;
	GinPageOpaque opaq;
	HeapTuple	resultTuple;
	Datum		values[3];
	bool		nulls[10];
	Datum		flags[16];
	int			nflags = 0;
	uint16		flagbits;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use raw page functions"))));

	raw_page_size = VARSIZE(raw_page) - VARHDRSZ;
	if (raw_page_size < BLCKSZ)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("input page too small (%d bytes)", raw_page_size)));
	page = VARDATA(raw_page);

	opaq = (GinPageOpaque) PageGetSpecialPointer(page);

	/* Build a tuple descriptor for our result type */
	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
		elog(ERROR, "return type must be a row type");

	/* Convert the flags bitmask to an array of human-readable names */
	flagbits = opaq->flags;
	if (flagbits & GIN_DATA)
		flags[nflags++] = CStringGetTextDatum("data");
	if (flagbits & GIN_LEAF)
		flags[nflags++] = CStringGetTextDatum("leaf");
	if (flagbits & GIN_DELETED)
		flags[nflags++] = CStringGetTextDatum("deleted");
	if (flagbits & GIN_META)
		flags[nflags++] = CStringGetTextDatum("meta");
	if (flagbits & GIN_LIST)
		flags[nflags++] = CStringGetTextDatum("list");
	if (flagbits & GIN_LIST_FULLROW)
		flags[nflags++] = CStringGetTextDatum("list_fullrow");
	if (flagbits & GIN_INCOMPLETE_SPLIT)
		flags[nflags++] = CStringGetTextDatum("incomplete_split");
	if (flagbits & GIN_COMPRESSED)
		flags[nflags++] = CStringGetTextDatum("compressed");
	flagbits &= ~(GIN_DATA | GIN_LEAF | GIN_DELETED | GIN_META | GIN_LIST |
				  GIN_LIST_FULLROW | GIN_INCOMPLETE_SPLIT | GIN_COMPRESSED);
	if (flagbits)
	{
		/* any flags we don't recognize are printed in hex */
		flags[nflags++] = DirectFunctionCall1(to_hex32, Int32GetDatum(flagbits));
	}

	memset(nulls, 0, sizeof(nulls));

	values[0] = Int64GetDatum(opaq->rightlink);
	values[1] = Int64GetDatum(opaq->maxoff);
	values[2] = PointerGetDatum(
					construct_array(flags, nflags, TEXTOID, -1, false, 'i'));

	/* Build and return the result tuple. */
	resultTuple = heap_form_tuple(tupdesc, values, nulls);

	return HeapTupleGetDatum(resultTuple);
}

Datum
page_header(PG_FUNCTION_ARGS)
{
	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
	int			raw_page_size;

	TupleDesc	tupdesc;

	Datum		result;
	HeapTuple	tuple;
	Datum		values[9];
	bool		nulls[9];

	PageHeader	page;
	XLogRecPtr	lsn;
	char		lsnchar[64];

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use raw page functions"))));

	raw_page_size = VARSIZE(raw_page) - VARHDRSZ;

	/*
	 * Check that enough data was supplied, so that we don't try to access
	 * fields outside the supplied buffer.
	 */
	if (raw_page_size < sizeof(PageHeaderData))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("input page too small (%d bytes)", raw_page_size)));

	page = (PageHeader) VARDATA(raw_page);

	/* Build a tuple descriptor for our result type */
	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
		elog(ERROR, "return type must be a row type");

	/* Extract information from the page header */

	lsn = PageGetLSN(page);
	snprintf(lsnchar, sizeof(lsnchar), "%X/%X", lsn.xlogid, lsn.xrecoff);

	values[0] = CStringGetTextDatum(lsnchar);
	values[1] = UInt16GetDatum(PageGetTLI(page));
	values[2] = UInt16GetDatum(page->pd_flags);
	values[3] = UInt16GetDatum(page->pd_lower);
	values[4] = UInt16GetDatum(page->pd_upper);
	values[5] = UInt16GetDatum(page->pd_special);
	values[6] = UInt16GetDatum(PageGetPageSize(page));
	values[7] = UInt16GetDatum(PageGetPageLayoutVersion(page));
	values[8] = TransactionIdGetDatum(page->pd_prune_xid);

	/* Build and return the tuple. */

	memset(nulls, 0, sizeof(nulls));

	tuple = heap_form_tuple(tupdesc, values, nulls);
	result = HeapTupleGetDatum(tuple);

	PG_RETURN_DATUM(result);
}