1 /*-------------------------------------------------------------------------
4 * routines to handle function requests from the frontend
6 * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
11 * $PostgreSQL: pgsql/src/backend/tcop/fastpath.c,v 1.102 2010/01/02 16:57:52 momjian Exp $
14 * This cruft is the server side of PQfn.
16 *-------------------------------------------------------------------------
20 #include <netinet/in.h>
21 #include <arpa/inet.h>
23 #include "access/xact.h"
24 #include "catalog/pg_proc.h"
25 #include "libpq/libpq.h"
26 #include "libpq/pqformat.h"
27 #include "mb/pg_wchar.h"
28 #include "miscadmin.h"
29 #include "tcop/fastpath.h"
30 #include "tcop/tcopprot.h"
31 #include "utils/acl.h"
32 #include "utils/lsyscache.h"
33 #include "utils/snapmgr.h"
34 #include "utils/syscache.h"
38 * Formerly, this code attempted to cache the function and type info
39 * looked up by fetch_fp_info, but only for the duration of a single
40 * transaction command (since in theory the info could change between
41 * commands). This was utterly useless, because postgres.c executes
42 * each fastpath call as a separate transaction command, and so the
43 * cached data could never actually have been reused. If it had worked
44 * as intended, it would have had problems anyway with dangling references
45 * in the FmgrInfo struct. So, forget about caching and just repeat the
46 * syscache fetches on each usage. They're not *that* expensive.
51 FmgrInfo flinfo; /* function lookup info for funcid */
52 Oid namespace; /* other stuff from pg_proc */
54 Oid argtypes[FUNC_MAX_ARGS];
55 char fname[NAMEDATALEN]; /* function name for logging */
59 static int16 parse_fcall_arguments(StringInfo msgBuf, struct fp_info * fip,
60 FunctionCallInfo fcinfo);
61 static int16 parse_fcall_arguments_20(StringInfo msgBuf, struct fp_info * fip,
62 FunctionCallInfo fcinfo);
66 * GetOldFunctionMessage
68 * In pre-3.0 protocol, there is no length word on the message, so we have
69 * to have code that understands the message layout to absorb the message
70 * into a buffer. We want to do this before we start execution, so that
71 * we do not lose sync with the frontend if there's an error.
73 * The caller should already have initialized buf to empty.
77 GetOldFunctionMessage(StringInfo buf)
82 /* Dummy string argument */
83 if (pq_getstring(buf))
86 if (pq_getbytes((char *) &ibuf, 4))
88 appendBinaryStringInfo(buf, (char *) &ibuf, 4);
89 /* Number of arguments */
90 if (pq_getbytes((char *) &ibuf, 4))
92 appendBinaryStringInfo(buf, (char *) &ibuf, 4);
94 /* For each argument ... */
100 if (pq_getbytes((char *) &ibuf, 4))
102 appendBinaryStringInfo(buf, (char *) &ibuf, 4);
103 argsize = ntohl(ibuf);
106 /* FATAL here since no hope of regaining message sync */
108 (errcode(ERRCODE_PROTOCOL_VIOLATION),
109 errmsg("invalid argument size %d in function call message",
112 /* and arg contents */
115 /* Allocate space for arg */
116 enlargeStringInfo(buf, argsize);
118 if (pq_getbytes(buf->data + buf->len, argsize))
121 /* Place a trailing null per StringInfo convention */
122 buf->data[buf->len] = '\0';
131 * Note: although this routine doesn't check, the format had better be 1
132 * (binary) when talking to a pre-3.0 client.
136 SendFunctionResult(Datum retval, bool isnull, Oid rettype, int16 format)
138 bool newstyle = (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3);
141 pq_beginmessage(&buf, 'V');
146 pq_sendint(&buf, -1, 4);
151 pq_sendbyte(&buf, 'G');
159 getTypeOutputInfo(rettype, &typoutput, &typisvarlena);
160 outputstr = OidOutputFunctionCall(typoutput, retval);
161 pq_sendcountedtext(&buf, outputstr, strlen(outputstr), false);
164 else if (format == 1)
170 getTypeBinaryOutputInfo(rettype, &typsend, &typisvarlena);
171 outputbytes = OidSendFunctionCall(typsend, retval);
172 pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
173 pq_sendbytes(&buf, VARDATA(outputbytes),
174 VARSIZE(outputbytes) - VARHDRSZ);
179 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
180 errmsg("unsupported format code: %d", format)));
184 pq_sendbyte(&buf, '0');
192 * Performs catalog lookups to load a struct fp_info 'fip' for the
193 * function 'func_id'.
196 fetch_fp_info(Oid func_id, struct fp_info * fip)
201 Assert(OidIsValid(func_id));
205 * Since the validity of this structure is determined by whether the
206 * funcid is OK, we clear the funcid here. It must not be set to the
207 * correct value until we are about to return with a good struct fp_info,
208 * since we can be interrupted (i.e., with an ereport(ERROR, ...)) at any
209 * time. [No longer really an issue since we don't save the struct
210 * fp_info across transactions anymore, but keep it anyway.]
212 MemSet(fip, 0, sizeof(struct fp_info));
213 fip->funcid = InvalidOid;
215 fmgr_info(func_id, &fip->flinfo);
217 func_htp = SearchSysCache(PROCOID,
218 ObjectIdGetDatum(func_id),
220 if (!HeapTupleIsValid(func_htp))
222 (errcode(ERRCODE_UNDEFINED_FUNCTION),
223 errmsg("function with OID %u does not exist", func_id)));
224 pp = (Form_pg_proc) GETSTRUCT(func_htp);
226 /* watch out for catalog entries with more than FUNC_MAX_ARGS args */
227 if (pp->pronargs > FUNC_MAX_ARGS)
228 elog(ERROR, "function %s has more than %d arguments",
229 NameStr(pp->proname), FUNC_MAX_ARGS);
231 fip->namespace = pp->pronamespace;
232 fip->rettype = pp->prorettype;
233 memcpy(fip->argtypes, pp->proargtypes.values, pp->pronargs * sizeof(Oid));
234 strlcpy(fip->fname, NameStr(pp->proname), NAMEDATALEN);
236 ReleaseSysCache(func_htp);
241 fip->funcid = func_id;
246 * HandleFunctionRequest
248 * Server side of PQfn (fastpath function calls from the frontend).
249 * This corresponds to the libpq protocol symbol "F".
252 * In protocol version 3, postgres.c has already read the message body
253 * and will pass it in msgBuf.
254 * In old protocol, the passed msgBuf is empty and we must read the
258 * 0 if successful completion, EOF if frontend connection lost.
260 * Note: All ordinary errors result in ereport(ERROR,...). However,
261 * if we lose the frontend connection there is no one to ereport to,
262 * and no use in proceeding...
264 * Note: palloc()s done here and in the called function do not need to be
265 * cleaned up explicitly. We are called from PostgresMain() in the
266 * MessageContext memory context, which will be automatically reset when
267 * control returns to PostgresMain.
270 HandleFunctionRequest(StringInfo msgBuf)
274 FunctionCallInfoData fcinfo;
277 struct fp_info my_fp;
280 bool was_logged = false;
284 * Read message contents if not already done.
286 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
288 if (GetOldFunctionMessage(msgBuf))
291 (errcode(ERRCODE_PROTOCOL_VIOLATION),
292 errmsg("unexpected EOF on client connection")));
298 * Now that we've eaten the input message, check to see if we actually
299 * want to do the function call or not. It's now safe to ereport(); we
300 * won't lose sync with the frontend.
302 if (IsAbortedTransactionBlockState())
304 (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
305 errmsg("current transaction is aborted, "
306 "commands ignored until end of transaction block")));
309 * Now that we know we are in a valid transaction, set snapshot in case
310 * needed by function itself or one of the datatype I/O routines.
312 PushActiveSnapshot(GetTransactionSnapshot());
315 * Begin parsing the buffer contents.
317 if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
318 (void) pq_getmsgstring(msgBuf); /* dummy string */
320 fid = (Oid) pq_getmsgint(msgBuf, 4); /* function oid */
323 * There used to be a lame attempt at caching lookup info here. Now we
324 * just do the lookups on every call.
327 fetch_fp_info(fid, fip);
329 /* Log as soon as we have the function OID and name */
330 if (log_statement == LOGSTMT_ALL)
333 (errmsg("fastpath function call: \"%s\" (OID %u)",
339 * Check permission to access and call function. Since we didn't go
340 * through a normal name lookup, we need to check schema usage too.
342 aclresult = pg_namespace_aclcheck(fip->namespace, GetUserId(), ACL_USAGE);
343 if (aclresult != ACLCHECK_OK)
344 aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
345 get_namespace_name(fip->namespace));
347 aclresult = pg_proc_aclcheck(fid, GetUserId(), ACL_EXECUTE);
348 if (aclresult != ACLCHECK_OK)
349 aclcheck_error(aclresult, ACL_KIND_PROC,
353 * Prepare function call info block and insert arguments.
355 InitFunctionCallInfoData(fcinfo, &fip->flinfo, 0, NULL, NULL);
357 if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
358 rformat = parse_fcall_arguments(msgBuf, fip, &fcinfo);
360 rformat = parse_fcall_arguments_20(msgBuf, fip, &fcinfo);
362 /* Verify we reached the end of the message where expected. */
363 pq_getmsgend(msgBuf);
366 * If func is strict, must not call it for null args.
369 if (fip->flinfo.fn_strict)
373 for (i = 0; i < fcinfo.nargs; i++)
375 if (fcinfo.argnull[i])
385 /* Okay, do it ... */
386 retval = FunctionCallInvoke(&fcinfo);
390 fcinfo.isnull = true;
394 /* ensure we do at least one CHECK_FOR_INTERRUPTS per function call */
395 CHECK_FOR_INTERRUPTS();
397 SendFunctionResult(retval, fcinfo.isnull, fip->rettype, rformat);
399 /* We no longer need the snapshot */
403 * Emit duration logging if appropriate.
405 switch (check_log_duration(msec_str, was_logged))
409 (errmsg("duration: %s ms", msec_str)));
413 (errmsg("duration: %s ms fastpath function call: \"%s\" (OID %u)",
414 msec_str, fip->fname, fid)));
422 * Parse function arguments in a 3.0 protocol message
424 * Argument values are loaded into *fcinfo, and the desired result format
428 parse_fcall_arguments(StringInfo msgBuf, struct fp_info * fip,
429 FunctionCallInfo fcinfo)
434 int16 *aformats = NULL;
437 /* Get the argument format codes */
438 numAFormats = pq_getmsgint(msgBuf, 2);
441 aformats = (int16 *) palloc(numAFormats * sizeof(int16));
442 for (i = 0; i < numAFormats; i++)
443 aformats[i] = pq_getmsgint(msgBuf, 2);
446 nargs = pq_getmsgint(msgBuf, 2); /* # of arguments */
448 if (fip->flinfo.fn_nargs != nargs || nargs > FUNC_MAX_ARGS)
450 (errcode(ERRCODE_PROTOCOL_VIOLATION),
451 errmsg("function call message contains %d arguments but function requires %d",
452 nargs, fip->flinfo.fn_nargs)));
454 fcinfo->nargs = nargs;
456 if (numAFormats > 1 && numAFormats != nargs)
458 (errcode(ERRCODE_PROTOCOL_VIOLATION),
459 errmsg("function call message contains %d argument formats but %d arguments",
460 numAFormats, nargs)));
462 initStringInfo(&abuf);
465 * Copy supplied arguments into arg vector.
467 for (i = 0; i < nargs; ++i)
472 argsize = pq_getmsgint(msgBuf, 4);
475 fcinfo->argnull[i] = true;
479 fcinfo->argnull[i] = false;
482 (errcode(ERRCODE_PROTOCOL_VIOLATION),
483 errmsg("invalid argument size %d in function call message",
486 /* Reset abuf to empty, and insert raw data into it */
487 resetStringInfo(&abuf);
488 appendBinaryStringInfo(&abuf,
489 pq_getmsgbytes(msgBuf, argsize),
494 aformat = aformats[i];
495 else if (numAFormats > 0)
496 aformat = aformats[0];
498 aformat = 0; /* default = text */
506 getTypeInputInfo(fip->argtypes[i], &typinput, &typioparam);
509 * Since stringinfo.c keeps a trailing null in place even for
510 * binary data, the contents of abuf are a valid C string. We
511 * have to do encoding conversion before calling the typinput
517 pstring = pg_client_to_server(abuf.data, argsize);
519 fcinfo->arg[i] = OidInputFunctionCall(typinput, pstring,
521 /* Free result of encoding conversion, if any */
522 if (pstring && pstring != abuf.data)
525 else if (aformat == 1)
531 /* Call the argument type's binary input converter */
532 getTypeBinaryInputInfo(fip->argtypes[i], &typreceive, &typioparam);
539 fcinfo->arg[i] = OidReceiveFunctionCall(typreceive, bufptr,
542 /* Trouble if it didn't eat the whole buffer */
543 if (argsize != -1 && abuf.cursor != abuf.len)
545 (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
546 errmsg("incorrect binary data format in function argument %d",
551 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
552 errmsg("unsupported format code: %d", aformat)));
555 /* Return result format code */
556 return (int16) pq_getmsgint(msgBuf, 2);
560 * Parse function arguments in a 2.0 protocol message
562 * Argument values are loaded into *fcinfo, and the desired result format
566 parse_fcall_arguments_20(StringInfo msgBuf, struct fp_info * fip,
567 FunctionCallInfo fcinfo)
573 nargs = pq_getmsgint(msgBuf, 4); /* # of arguments */
575 if (fip->flinfo.fn_nargs != nargs || nargs > FUNC_MAX_ARGS)
577 (errcode(ERRCODE_PROTOCOL_VIOLATION),
578 errmsg("function call message contains %d arguments but function requires %d",
579 nargs, fip->flinfo.fn_nargs)));
581 fcinfo->nargs = nargs;
583 initStringInfo(&abuf);
586 * Copy supplied arguments into arg vector. In protocol 2.0 these are
587 * always assumed to be supplied in binary format.
589 * Note: although the original protocol 2.0 code did not have any way for
590 * the frontend to specify a NULL argument, we now choose to interpret
591 * length == -1 as meaning a NULL.
593 for (i = 0; i < nargs; ++i)
599 getTypeBinaryInputInfo(fip->argtypes[i], &typreceive, &typioparam);
601 argsize = pq_getmsgint(msgBuf, 4);
604 fcinfo->argnull[i] = true;
605 fcinfo->arg[i] = OidReceiveFunctionCall(typreceive, NULL,
609 fcinfo->argnull[i] = false;
612 (errcode(ERRCODE_PROTOCOL_VIOLATION),
613 errmsg("invalid argument size %d in function call message",
616 /* Reset abuf to empty, and insert raw data into it */
617 resetStringInfo(&abuf);
618 appendBinaryStringInfo(&abuf,
619 pq_getmsgbytes(msgBuf, argsize),
622 fcinfo->arg[i] = OidReceiveFunctionCall(typreceive, &abuf,
625 /* Trouble if it didn't eat the whole buffer */
626 if (abuf.cursor != abuf.len)
628 (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
629 errmsg("incorrect binary data format in function argument %d",
633 /* Desired result format is always binary in protocol 2.0 */