rdelaage
/
postgresql
mirror of https://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
postgresql/src/backend/tcop/fastpath.c

602 lines
15 KiB
C
Raw Blame History

/*-------------------------------------------------------------------------
*
* fastpath.c
* routines to handle function requests from the frontend
*
* Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/tcop/fastpath.c,v 1.75 2004/08/29 05:06:49 momjian Exp $
*
* NOTES
* This cruft is the server side of PQfn.
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <netinet/in.h>
#include <arpa/inet.h>
#include "catalog/pg_proc.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
#include "miscadmin.h"
#include "mb/pg_wchar.h"
#include "tcop/fastpath.h"
#include "utils/acl.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
#include "utils/tqual.h"
/*
* Formerly, this code attempted to cache the function and type info
* looked up by fetch_fp_info, but only for the duration of a single
* transaction command (since in theory the info could change between
* commands). This was utterly useless, because postgres.c executes
* each fastpath call as a separate transaction command, and so the
* cached data could never actually have been reused. If it had worked
* as intended, it would have had problems anyway with dangling references
* in the FmgrInfo struct. So, forget about caching and just repeat the
* syscache fetches on each usage. They're not *that* expensive.
*/
struct fp_info
{
Oid funcid;
FmgrInfo flinfo; /* function lookup info for funcid */
Oid namespace; /* other stuff from pg_proc */
Oid rettype;
Oid argtypes[FUNC_MAX_ARGS];
};
static int16 parse_fcall_arguments(StringInfo msgBuf, struct fp_info * fip,
FunctionCallInfo fcinfo);
static int16 parse_fcall_arguments_20(StringInfo msgBuf, struct fp_info * fip,
FunctionCallInfo fcinfo);
/* ----------------
* GetOldFunctionMessage
*
* In pre-3.0 protocol, there is no length word on the message, so we have
* to have code that understands the message layout to absorb the message
* into a buffer. We want to do this before we start execution, so that
* we do not lose sync with the frontend if there's an error.
*
* The caller should already have initialized buf to empty.
* ----------------
*/
static int
GetOldFunctionMessage(StringInfo buf)
{
int32 ibuf;
int nargs;
/* Dummy string argument */
if (pq_getstring(buf))
return EOF;
/* Function OID */
if (pq_getbytes((char *) &ibuf, 4))
return EOF;
appendBinaryStringInfo(buf, (char *) &ibuf, 4);
/* Number of arguments */
if (pq_getbytes((char *) &ibuf, 4))
return EOF;
appendBinaryStringInfo(buf, (char *) &ibuf, 4);
nargs = ntohl(ibuf);
/* For each argument ... */
while (nargs-- > 0)
{
int argsize;
/* argsize */
if (pq_getbytes((char *) &ibuf, 4))
return EOF;
appendBinaryStringInfo(buf, (char *) &ibuf, 4);
argsize = ntohl(ibuf);
if (argsize < -1)
{
/* FATAL here since no hope of regaining message sync */
ereport(FATAL,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid argument size %d in function call message",
argsize)));
}
/* and arg contents */
if (argsize > 0)
{
/* Allocate space for arg */
enlargeStringInfo(buf, argsize);
/* And grab it */
if (pq_getbytes(buf->data + buf->len, argsize))
return EOF;
buf->len += argsize;
/* Place a trailing null per StringInfo convention */
buf->data[buf->len] = '\0';
}
}
return 0;
}
/* ----------------
* SendFunctionResult
*
* Note: although this routine doesn't check, the format had better be 1
* (binary) when talking to a pre-3.0 client.
* ----------------
*/
static void
SendFunctionResult(Datum retval, bool isnull, Oid rettype, int16 format)
{
bool newstyle = (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3);
StringInfoData buf;
pq_beginmessage(&buf, 'V');
if (isnull)
{
if (newstyle)
pq_sendint(&buf, -1, 4);
}
else
{
if (!newstyle)
pq_sendbyte(&buf, 'G');
if (format == 0)
{
Oid typoutput,
typioparam;
bool typisvarlena;
char *outputstr;
getTypeOutputInfo(rettype, &typoutput, &typioparam, &typisvarlena);
outputstr = DatumGetCString(OidFunctionCall3(typoutput,
retval,
ObjectIdGetDatum(typioparam),
Int32GetDatum(-1)));
pq_sendcountedtext(&buf, outputstr, strlen(outputstr), false);
pfree(outputstr);
}
else if (format == 1)
{
Oid typsend,
typioparam;
bool typisvarlena;
bytea *outputbytes;
getTypeBinaryOutputInfo(rettype,
&typsend, &typioparam, &typisvarlena);
outputbytes = DatumGetByteaP(OidFunctionCall2(typsend,
retval,
ObjectIdGetDatum(typioparam)));
/* 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);
}
else
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unsupported format code: %d", format)));
}
if (!newstyle)
pq_sendbyte(&buf, '0');
pq_endmessage(&buf);
}
/*
* fetch_fp_info
*
* Performs catalog lookups to load a struct fp_info 'fip' for the
* function 'func_id'.
*/
static void
fetch_fp_info(Oid func_id, struct fp_info * fip)
{
HeapTuple func_htp;
Form_pg_proc pp;
Assert(OidIsValid(func_id));
Assert(fip != NULL);
/*
* Since the validity of this structure is determined by whether the
* funcid is OK, we clear the funcid here. It must not be set to the
* correct value until we are about to return with a good struct
* fp_info, since we can be interrupted (i.e., with an ereport(ERROR,
* ...)) at any time. [No longer really an issue since we don't save
* the struct fp_info across transactions anymore, but keep it
* anyway.]
*/
MemSet((char *) fip, 0, sizeof(struct fp_info));
fip->funcid = InvalidOid;
fmgr_info(func_id, &fip->flinfo);
func_htp = SearchSysCache(PROCOID,
ObjectIdGetDatum(func_id),
0, 0, 0);
if (!HeapTupleIsValid(func_htp))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("function with OID %u does not exist", func_id)));
pp = (Form_pg_proc) GETSTRUCT(func_htp);
fip->namespace = pp->pronamespace;
fip->rettype = pp->prorettype;
memcpy(fip->argtypes, pp->proargtypes, FUNC_MAX_ARGS * sizeof(Oid));
ReleaseSysCache(func_htp);
/*
* This must be last!
*/
fip->funcid = func_id;
}
/*
* HandleFunctionRequest
*
* Server side of PQfn (fastpath function calls from the frontend).
* This corresponds to the libpq protocol symbol "F".
*
* INPUT:
* In protocol version 3, postgres.c has already read the message body
* and will pass it in msgBuf.
* In old protocol, the passed msgBuf is empty and we must read the
* message here.
*
* RETURNS:
* 0 if successful completion, EOF if frontend connection lost.
*
* Note: All ordinary errors result in ereport(ERROR,...). However,
* if we lose the frontend connection there is no one to ereport to,
* and no use in proceeding...
*
* Note: palloc()s done here and in the called function do not need to be
* cleaned up explicitly. We are called from PostgresMain() in the
* MessageContext memory context, which will be automatically reset when
* control returns to PostgresMain.
*/
int
HandleFunctionRequest(StringInfo msgBuf)
{
Oid fid;
AclResult aclresult;
FunctionCallInfoData fcinfo;
int16 rformat;
Datum retval;
struct fp_info my_fp;
struct fp_info *fip;
bool callit;
/*
* Read message contents if not already done.
*/
if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
{
if (GetOldFunctionMessage(msgBuf))
{
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("unexpected EOF on client connection")));
return EOF;
}
}
/*
* Now that we've eaten the input message, check to see if we actually
* want to do the function call or not. It's now safe to ereport();
* we won't lose sync with the frontend.
*/
if (IsAbortedTransactionBlockState())
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block")));
/*
* Begin parsing the buffer contents.
*/
if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
(void) pq_getmsgstring(msgBuf); /* dummy string */
fid = (Oid) pq_getmsgint(msgBuf, 4); /* function oid */
/*
* There used to be a lame attempt at caching lookup info here. Now we
* just do the lookups on every call.
*/
fip = &my_fp;
fetch_fp_info(fid, fip);
/*
* Check permission to access and call function. Since we didn't go
* through a normal name lookup, we need to check schema usage too.
*/
aclresult = pg_namespace_aclcheck(fip->namespace, GetUserId(), ACL_USAGE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
get_namespace_name(fip->namespace));
aclresult = pg_proc_aclcheck(fid, GetUserId(), ACL_EXECUTE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_PROC,
get_func_name(fid));
/*
* Set up a query snapshot in case function needs one.
*/
SetQuerySnapshot();
/*
* Prepare function call info block and insert arguments.
*/
MemSet(&fcinfo, 0, sizeof(fcinfo));
fcinfo.flinfo = &fip->flinfo;
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
rformat = parse_fcall_arguments(msgBuf, fip, &fcinfo);
else
rformat = parse_fcall_arguments_20(msgBuf, fip, &fcinfo);
/* Verify we reached the end of the message where expected. */
pq_getmsgend(msgBuf);
/*
* If func is strict, must not call it for null args.
*/
callit = true;
if (fip->flinfo.fn_strict)
{
int i;
for (i = 0; i < fcinfo.nargs; i++)
{
if (fcinfo.argnull[i])
{
callit = false;
break;
}
}
}
if (callit)
{
/* Okay, do it ... */
retval = FunctionCallInvoke(&fcinfo);
}
else
{
fcinfo.isnull = true;
retval = (Datum) 0;
}
SendFunctionResult(retval, fcinfo.isnull, fip->rettype, rformat);
return 0;
}
/*
* Parse function arguments in a 3.0 protocol message
*
* Argument values are loaded into *fcinfo, and the desired result format
* is returned.
*/
static int16
parse_fcall_arguments(StringInfo msgBuf, struct fp_info * fip,
FunctionCallInfo fcinfo)
{
int nargs;
int i;
int numAFormats;
int16 *aformats = NULL;
StringInfoData abuf;
/* Get the argument format codes */
numAFormats = pq_getmsgint(msgBuf, 2);
if (numAFormats > 0)
{
aformats = (int16 *) palloc(numAFormats * sizeof(int16));
for (i = 0; i < numAFormats; i++)
aformats[i] = pq_getmsgint(msgBuf, 2);
}
nargs = pq_getmsgint(msgBuf, 2); /* # of arguments */
if (fip->flinfo.fn_nargs != nargs || nargs > FUNC_MAX_ARGS)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("function call message contains %d arguments but function requires %d",
nargs, fip->flinfo.fn_nargs)));
fcinfo->nargs = nargs;
if (numAFormats > 1 && numAFormats != nargs)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("function call message contains %d argument formats but %d arguments",
numAFormats, nargs)));
initStringInfo(&abuf);
/*
* Copy supplied arguments into arg vector.
*/
for (i = 0; i < nargs; ++i)
{
int argsize;
int16 aformat;
argsize = pq_getmsgint(msgBuf, 4);
if (argsize == -1)
{
fcinfo->argnull[i] = true;
continue;
}
if (argsize < 0)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid argument size %d in function call message",
argsize)));
/* Reset abuf to empty, and insert raw data into it */
abuf.len = 0;
abuf.data[0] = '\0';
abuf.cursor = 0;
appendBinaryStringInfo(&abuf,
pq_getmsgbytes(msgBuf, argsize),
argsize);
if (numAFormats > 1)
aformat = aformats[i];
else if (numAFormats > 0)
aformat = aformats[0];
else
aformat = 0; /* default = text */
if (aformat == 0)
{
Oid typinput;
Oid typioparam;
char *pstring;
getTypeInputInfo(fip->argtypes[i], &typinput, &typioparam);
/*
* Since stringinfo.c keeps a trailing null in place even for
* binary data, the contents of abuf are a valid C string. We
* have to do encoding conversion before calling the typinput
* routine, though.
*/
pstring = (char *)
pg_client_to_server((unsigned char *) abuf.data,
argsize);
fcinfo->arg[i] =
OidFunctionCall3(typinput,
CStringGetDatum(pstring),
ObjectIdGetDatum(typioparam),
Int32GetDatum(-1));
/* Free result of encoding conversion, if any */
if (pstring != abuf.data)
pfree(pstring);
}
else if (aformat == 1)
{
Oid typreceive;
Oid typioparam;
/* Call the argument type's binary input converter */
getTypeBinaryInputInfo(fip->argtypes[i], &typreceive, &typioparam);
fcinfo->arg[i] = OidFunctionCall2(typreceive,
PointerGetDatum(&abuf),
ObjectIdGetDatum(typioparam));
/* Trouble if it didn't eat the whole buffer */
if (abuf.cursor != abuf.len)
ereport(ERROR,
(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
errmsg("incorrect binary data format in function argument %d",
i + 1)));
}
else
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unsupported format code: %d", aformat)));
}
/* Return result format code */
return (int16) pq_getmsgint(msgBuf, 2);
}
/*
* Parse function arguments in a 2.0 protocol message
*
* Argument values are loaded into *fcinfo, and the desired result format
* is returned.
*/
static int16
parse_fcall_arguments_20(StringInfo msgBuf, struct fp_info * fip,
FunctionCallInfo fcinfo)
{
int nargs;
int i;
StringInfoData abuf;
nargs = pq_getmsgint(msgBuf, 4); /* # of arguments */
if (fip->flinfo.fn_nargs != nargs || nargs > FUNC_MAX_ARGS)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("function call message contains %d arguments but function requires %d",
nargs, fip->flinfo.fn_nargs)));
fcinfo->nargs = nargs;
initStringInfo(&abuf);
/*
* Copy supplied arguments into arg vector. In protocol 2.0 these are
* always assumed to be supplied in binary format.
*
* Note: although the original protocol 2.0 code did not have any way for
* the frontend to specify a NULL argument, we now choose to interpret
* length == -1 as meaning a NULL.
*/
for (i = 0; i < nargs; ++i)
{
int argsize;
Oid typreceive;
Oid typioparam;
argsize = pq_getmsgint(msgBuf, 4);
if (argsize == -1)
{
fcinfo->argnull[i] = true;
continue;
}
if (argsize < 0)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid argument size %d in function call message",
argsize)));
/* Reset abuf to empty, and insert raw data into it */
abuf.len = 0;
abuf.data[0] = '\0';
abuf.cursor = 0;
appendBinaryStringInfo(&abuf,
pq_getmsgbytes(msgBuf, argsize),
argsize);
/* Call the argument type's binary input converter */
getTypeBinaryInputInfo(fip->argtypes[i], &typreceive, &typioparam);
fcinfo->arg[i] = OidFunctionCall2(typreceive,
PointerGetDatum(&abuf),
ObjectIdGetDatum(typioparam));
/* Trouble if it didn't eat the whole buffer */
if (abuf.cursor != abuf.len)
ereport(ERROR,
(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
errmsg("incorrect binary data format in function argument %d",
i + 1)));
}
/* Desired result format is always binary in protocol 2.0 */
return 1;
}
Reference in New Issue View Git Blame Copy Permalink