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/*-------------------------------------------------------------------------
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* routines to handle function requests from the frontend
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* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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* This cruft is the server side of PQfn.
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*-------------------------------------------------------------------------
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include "access/xact.h"
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#include "catalog/pg_proc.h"
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#include "libpq/libpq.h"
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#include "libpq/pqformat.h"
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#include "mb/pg_wchar.h"
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#include "miscadmin.h"
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#include "tcop/fastpath.h"
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#include "tcop/tcopprot.h"
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#include "utils/acl.h"
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#include "utils/lsyscache.h"
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#include "utils/snapmgr.h"
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#include "utils/syscache.h"
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* Formerly, this code attempted to cache the function and type info
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* looked up by fetch_fp_info, but only for the duration of a single
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* transaction command (since in theory the info could change between
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* commands). This was utterly useless, because postgres.c executes
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* each fastpath call as a separate transaction command, and so the
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* cached data could never actually have been reused. If it had worked
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* as intended, it would have had problems anyway with dangling references
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* in the FmgrInfo struct. So, forget about caching and just repeat the
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* syscache fetches on each usage. They're not *that* expensive.
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FmgrInfo flinfo; /* function lookup info for funcid */
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Oid namespace; /* other stuff from pg_proc */
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Oid argtypes[FUNC_MAX_ARGS];
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char fname[NAMEDATALEN]; /* function name for logging */
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static int16 parse_fcall_arguments(StringInfo msgBuf, struct fp_info * fip,
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FunctionCallInfo fcinfo);
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static int16 parse_fcall_arguments_20(StringInfo msgBuf, struct fp_info * fip,
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FunctionCallInfo fcinfo);
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* GetOldFunctionMessage
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* In pre-3.0 protocol, there is no length word on the message, so we have
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* to have code that understands the message layout to absorb the message
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* into a buffer. We want to do this before we start execution, so that
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* we do not lose sync with the frontend if there's an error.
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* The caller should already have initialized buf to empty.
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GetOldFunctionMessage(StringInfo buf)
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/* Dummy string argument */
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if (pq_getstring(buf))
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if (pq_getbytes((char *) &ibuf, 4))
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appendBinaryStringInfo(buf, (char *) &ibuf, 4);
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/* Number of arguments */
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if (pq_getbytes((char *) &ibuf, 4))
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appendBinaryStringInfo(buf, (char *) &ibuf, 4);
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/* For each argument ... */
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if (pq_getbytes((char *) &ibuf, 4))
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appendBinaryStringInfo(buf, (char *) &ibuf, 4);
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argsize = ntohl(ibuf);
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/* FATAL here since no hope of regaining message sync */
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("invalid argument size %d in function call message",
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/* and arg contents */
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/* Allocate space for arg */
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enlargeStringInfo(buf, argsize);
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if (pq_getbytes(buf->data + buf->len, argsize))
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/* Place a trailing null per StringInfo convention */
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buf->data[buf->len] = '\0';
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* Note: although this routine doesn't check, the format had better be 1
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* (binary) when talking to a pre-3.0 client.
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SendFunctionResult(Datum retval, bool isnull, Oid rettype, int16 format)
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bool newstyle = (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3);
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pq_beginmessage(&buf, 'V');
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pq_sendint(&buf, -1, 4);
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pq_sendbyte(&buf, 'G');
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getTypeOutputInfo(rettype, &typoutput, &typisvarlena);
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outputstr = OidOutputFunctionCall(typoutput, retval);
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pq_sendcountedtext(&buf, outputstr, strlen(outputstr), false);
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else if (format == 1)
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getTypeBinaryOutputInfo(rettype, &typsend, &typisvarlena);
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outputbytes = OidSendFunctionCall(typsend, retval);
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pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
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pq_sendbytes(&buf, VARDATA(outputbytes),
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VARSIZE(outputbytes) - VARHDRSZ);
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(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
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errmsg("unsupported format code: %d", format)));
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pq_sendbyte(&buf, '0');
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* Performs catalog lookups to load a struct fp_info 'fip' for the
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* function 'func_id'.
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fetch_fp_info(Oid func_id, struct fp_info * fip)
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Assert(OidIsValid(func_id));
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* Since the validity of this structure is determined by whether the
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* funcid is OK, we clear the funcid here. It must not be set to the
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* correct value until we are about to return with a good struct fp_info,
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* since we can be interrupted (i.e., with an ereport(ERROR, ...)) at any
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* time. [No longer really an issue since we don't save the struct
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* fp_info across transactions anymore, but keep it anyway.]
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MemSet(fip, 0, sizeof(struct fp_info));
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fip->funcid = InvalidOid;
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fmgr_info(func_id, &fip->flinfo);
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func_htp = SearchSysCache(PROCOID,
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ObjectIdGetDatum(func_id),
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if (!HeapTupleIsValid(func_htp))
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(errcode(ERRCODE_UNDEFINED_FUNCTION),
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errmsg("function with OID %u does not exist", func_id)));
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pp = (Form_pg_proc) GETSTRUCT(func_htp);
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/* watch out for catalog entries with more than FUNC_MAX_ARGS args */
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if (pp->pronargs > FUNC_MAX_ARGS)
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elog(ERROR, "function %s has more than %d arguments",
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NameStr(pp->proname), FUNC_MAX_ARGS);
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fip->namespace = pp->pronamespace;
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fip->rettype = pp->prorettype;
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memcpy(fip->argtypes, pp->proargtypes.values, pp->pronargs * sizeof(Oid));
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strlcpy(fip->fname, NameStr(pp->proname), NAMEDATALEN);
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ReleaseSysCache(func_htp);
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fip->funcid = func_id;
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* HandleFunctionRequest
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* Server side of PQfn (fastpath function calls from the frontend).
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* This corresponds to the libpq protocol symbol "F".
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* In protocol version 3, postgres.c has already read the message body
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* and will pass it in msgBuf.
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* In old protocol, the passed msgBuf is empty and we must read the
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* 0 if successful completion, EOF if frontend connection lost.
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* Note: All ordinary errors result in ereport(ERROR,...). However,
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* if we lose the frontend connection there is no one to ereport to,
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* and no use in proceeding...
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* Note: palloc()s done here and in the called function do not need to be
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* cleaned up explicitly. We are called from PostgresMain() in the
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* MessageContext memory context, which will be automatically reset when
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* control returns to PostgresMain.
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HandleFunctionRequest(StringInfo msgBuf)
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FunctionCallInfoData fcinfo;
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struct fp_info my_fp;
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bool was_logged = false;
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* Read message contents if not already done.
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if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
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if (GetOldFunctionMessage(msgBuf))
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("unexpected EOF on client connection")));
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* Now that we've eaten the input message, check to see if we actually
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* want to do the function call or not. It's now safe to ereport(); we
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* won't lose sync with the frontend.
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if (IsAbortedTransactionBlockState())
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(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
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errmsg("current transaction is aborted, "
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"commands ignored until end of transaction block")));
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* Now that we know we are in a valid transaction, set snapshot in case
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* needed by function itself or one of the datatype I/O routines.
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PushActiveSnapshot(GetTransactionSnapshot());
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* Begin parsing the buffer contents.
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if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
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(void) pq_getmsgstring(msgBuf); /* dummy string */
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fid = (Oid) pq_getmsgint(msgBuf, 4); /* function oid */
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* There used to be a lame attempt at caching lookup info here. Now we
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* just do the lookups on every call.
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fetch_fp_info(fid, fip);
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/* Log as soon as we have the function OID and name */
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if (log_statement == LOGSTMT_ALL)
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(errmsg("fastpath function call: \"%s\" (OID %u)",
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* Check permission to access and call function. Since we didn't go
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* through a normal name lookup, we need to check schema usage too.
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aclresult = pg_namespace_aclcheck(fip->namespace, GetUserId(), ACL_USAGE);
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if (aclresult != ACLCHECK_OK)
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aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
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get_namespace_name(fip->namespace));
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aclresult = pg_proc_aclcheck(fid, GetUserId(), ACL_EXECUTE);
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if (aclresult != ACLCHECK_OK)
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aclcheck_error(aclresult, ACL_KIND_PROC,
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* Prepare function call info block and insert arguments.
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InitFunctionCallInfoData(fcinfo, &fip->flinfo, 0, NULL, NULL);
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if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
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rformat = parse_fcall_arguments(msgBuf, fip, &fcinfo);
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rformat = parse_fcall_arguments_20(msgBuf, fip, &fcinfo);
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/* Verify we reached the end of the message where expected. */
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pq_getmsgend(msgBuf);
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* If func is strict, must not call it for null args.
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if (fip->flinfo.fn_strict)
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for (i = 0; i < fcinfo.nargs; i++)
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if (fcinfo.argnull[i])
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/* Okay, do it ... */
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retval = FunctionCallInvoke(&fcinfo);
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fcinfo.isnull = true;
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/* ensure we do at least one CHECK_FOR_INTERRUPTS per function call */
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CHECK_FOR_INTERRUPTS();
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SendFunctionResult(retval, fcinfo.isnull, fip->rettype, rformat);
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/* We no longer need the snapshot */
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* Emit duration logging if appropriate.
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switch (check_log_duration(msec_str, was_logged))
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(errmsg("duration: %s ms", msec_str)));
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(errmsg("duration: %s ms fastpath function call: \"%s\" (OID %u)",
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msec_str, fip->fname, fid)));
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* Parse function arguments in a 3.0 protocol message
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* Argument values are loaded into *fcinfo, and the desired result format
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parse_fcall_arguments(StringInfo msgBuf, struct fp_info * fip,
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FunctionCallInfo fcinfo)
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int16 *aformats = NULL;
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/* Get the argument format codes */
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numAFormats = pq_getmsgint(msgBuf, 2);
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aformats = (int16 *) palloc(numAFormats * sizeof(int16));
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for (i = 0; i < numAFormats; i++)
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aformats[i] = pq_getmsgint(msgBuf, 2);
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nargs = pq_getmsgint(msgBuf, 2); /* # of arguments */
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if (fip->flinfo.fn_nargs != nargs || nargs > FUNC_MAX_ARGS)
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("function call message contains %d arguments but function requires %d",
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nargs, fip->flinfo.fn_nargs)));
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fcinfo->nargs = nargs;
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if (numAFormats > 1 && numAFormats != nargs)
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("function call message contains %d argument formats but %d arguments",
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numAFormats, nargs)));
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initStringInfo(&abuf);
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* Copy supplied arguments into arg vector.
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for (i = 0; i < nargs; ++i)
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argsize = pq_getmsgint(msgBuf, 4);
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fcinfo->argnull[i] = true;
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fcinfo->argnull[i] = false;
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("invalid argument size %d in function call message",
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/* Reset abuf to empty, and insert raw data into it */
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resetStringInfo(&abuf);
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appendBinaryStringInfo(&abuf,
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pq_getmsgbytes(msgBuf, argsize),
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aformat = aformats[i];
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else if (numAFormats > 0)
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aformat = aformats[0];
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aformat = 0; /* default = text */
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getTypeInputInfo(fip->argtypes[i], &typinput, &typioparam);
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* Since stringinfo.c keeps a trailing null in place even for
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* binary data, the contents of abuf are a valid C string. We
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* have to do encoding conversion before calling the typinput
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pstring = pg_client_to_server(abuf.data, argsize);
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fcinfo->arg[i] = OidInputFunctionCall(typinput, pstring,
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/* Free result of encoding conversion, if any */
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if (pstring && pstring != abuf.data)
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else if (aformat == 1)
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/* Call the argument type's binary input converter */
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getTypeBinaryInputInfo(fip->argtypes[i], &typreceive, &typioparam);
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fcinfo->arg[i] = OidReceiveFunctionCall(typreceive, bufptr,
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/* Trouble if it didn't eat the whole buffer */
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if (argsize != -1 && abuf.cursor != abuf.len)
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(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
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errmsg("incorrect binary data format in function argument %d",
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(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
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errmsg("unsupported format code: %d", aformat)));
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/* Return result format code */
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return (int16) pq_getmsgint(msgBuf, 2);
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* Parse function arguments in a 2.0 protocol message
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* Argument values are loaded into *fcinfo, and the desired result format
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parse_fcall_arguments_20(StringInfo msgBuf, struct fp_info * fip,
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FunctionCallInfo fcinfo)
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nargs = pq_getmsgint(msgBuf, 4); /* # of arguments */
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if (fip->flinfo.fn_nargs != nargs || nargs > FUNC_MAX_ARGS)
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("function call message contains %d arguments but function requires %d",
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nargs, fip->flinfo.fn_nargs)));
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fcinfo->nargs = nargs;
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initStringInfo(&abuf);
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* Copy supplied arguments into arg vector. In protocol 2.0 these are
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* always assumed to be supplied in binary format.
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* Note: although the original protocol 2.0 code did not have any way for
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* the frontend to specify a NULL argument, we now choose to interpret
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* length == -1 as meaning a NULL.
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for (i = 0; i < nargs; ++i)
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getTypeBinaryInputInfo(fip->argtypes[i], &typreceive, &typioparam);
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argsize = pq_getmsgint(msgBuf, 4);
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fcinfo->argnull[i] = true;
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fcinfo->arg[i] = OidReceiveFunctionCall(typreceive, NULL,
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fcinfo->argnull[i] = false;
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("invalid argument size %d in function call message",
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/* Reset abuf to empty, and insert raw data into it */
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resetStringInfo(&abuf);
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appendBinaryStringInfo(&abuf,
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pq_getmsgbytes(msgBuf, argsize),
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fcinfo->arg[i] = OidReceiveFunctionCall(typreceive, &abuf,
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/* Trouble if it didn't eat the whole buffer */
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if (abuf.cursor != abuf.len)
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(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
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errmsg("incorrect binary data format in function argument %d",
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/* Desired result format is always binary in protocol 2.0 */