fastpath.c File Reference

#include "postgres.h"
#include "access/htup_details.h"
#include "access/xact.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_proc.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "port/pg_bswap.h"
#include "tcop/fastpath.h"
#include "tcop/tcopprot.h"
#include "utils/acl.h"
#include "utils/lsyscache.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"

Include dependency graph for fastpath.c:

Go to the source code of this file.

Data Structures
struct	fp_info

Functions
static int16	parse_fcall_arguments (StringInfo msgBuf, struct fp_info *fip, FunctionCallInfo fcinfo)
static void	SendFunctionResult (Datum retval, bool isnull, Oid rettype, int16 format)
static void	fetch_fp_info (Oid func_id, struct fp_info *fip)
void	HandleFunctionRequest (StringInfo msgBuf)

Function Documentation

fetch_fp_info()

static void fetch_fp_info ( Oid  func_id, struct fp_info *  fip  )

static

Definition at line 119 of file fastpath.c.

References fp_info::argtypes, Assert, elog, ereport, errcode(), errmsg(), ERROR, fp_info::flinfo, fmgr_info(), fp_info::fname, FUNC_MAX_ARGS, fp_info::funcid, GETSTRUCT, HeapTupleIsValid, InvalidOid, MemSet, NAMEDATALEN, NameStr, ObjectIdGetDatum, PROCOID, ReleaseSysCache(), fp_info::rettype, SearchSysCache1(), and strlcpy().

Referenced by HandleFunctionRequest().

{
    HeapTuple   func_htp;
    Form_pg_proc pp;

    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(fip, 0, sizeof(struct fp_info));
    fip->funcid = InvalidOid;

    func_htp = SearchSysCache1(PROCOID, ObjectIdGetDatum(func_id));
    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);

    /* reject pg_proc entries that are unsafe to call via fastpath */
    if (pp->prokind != PROKIND_FUNCTION || pp->proretset)
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("cannot call function \"%s\" via fastpath interface",
                        NameStr(pp->proname))));

    /* watch out for catalog entries with more than FUNC_MAX_ARGS args */
    if (pp->pronargs > FUNC_MAX_ARGS)
        elog(ERROR, "function %s has more than %d arguments",
             NameStr(pp->proname), FUNC_MAX_ARGS);

    fip->namespace = pp->pronamespace;
    fip->rettype = pp->prorettype;
    memcpy(fip->argtypes, pp->proargtypes.values, pp->pronargs * sizeof(Oid));
    strlcpy(fip->fname, NameStr(pp->proname), NAMEDATALEN);

    ReleaseSysCache(func_htp);

    fmgr_info(func_id, &fip->flinfo);

    /*
     * This must be last!
     */
    fip->funcid = func_id;
}

HandleFunctionRequest()

void HandleFunctionRequest

(

StringInfo

msgBuf

)

Definition at line 188 of file fastpath.c.

References ACL_EXECUTE, ACL_USAGE, aclcheck_error(), ACLCHECK_OK, CHECK_FOR_INTERRUPTS, check_log_duration(), ereport, errcode(), errmsg(), ERROR, fetch_fp_info(), fp_info::flinfo, FmgrInfo::fn_strict, fp_info::fname, FUNC_MAX_ARGS, FunctionCallInvoke, get_func_name(), get_namespace_name(), GetTransactionSnapshot(), GetUserId(), i, InitFunctionCallInfoData, InvalidOid, InvokeFunctionExecuteHook, InvokeNamespaceSearchHook, IsAbortedTransactionBlockState(), LOCAL_FCINFO, LOG, log_statement, LOGSTMT_ALL, OBJECT_FUNCTION, OBJECT_SCHEMA, parse_fcall_arguments(), pg_namespace_aclcheck(), pg_proc_aclcheck(), PopActiveSnapshot(), pq_getmsgend(), pq_getmsgint(), PushActiveSnapshot(), fp_info::rettype, and SendFunctionResult().

Referenced by PostgresMain().

{
    LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
    Oid         fid;
    AclResult   aclresult;
    int16       rformat;
    Datum       retval;
    struct fp_info my_fp;
    struct fp_info *fip;
    bool        callit;
    bool        was_logged = false;
    char        msec_str[32];

    /*
     * We only accept COMMIT/ABORT if we are in an aborted transaction, and
     * COMMIT/ABORT cannot be executed through the fastpath interface.
     */
    if (IsAbortedTransactionBlockState())
        ereport(ERROR,
                (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
                 errmsg("current transaction is aborted, "
                        "commands ignored until end of transaction block")));

    /*
     * Now that we know we are in a valid transaction, set snapshot in case
     * needed by function itself or one of the datatype I/O routines.
     */
    PushActiveSnapshot(GetTransactionSnapshot());

    /*
     * Begin parsing the buffer contents.
     */
    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);

    /* Log as soon as we have the function OID and name */
    if (log_statement == LOGSTMT_ALL)
    {
        ereport(LOG,
                (errmsg("fastpath function call: \"%s\" (OID %u)",
                        fip->fname, fid)));
        was_logged = true;
    }

    /*
     * 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, OBJECT_SCHEMA,
                       get_namespace_name(fip->namespace));
    InvokeNamespaceSearchHook(fip->namespace, true);

    aclresult = pg_proc_aclcheck(fid, GetUserId(), ACL_EXECUTE);
    if (aclresult != ACLCHECK_OK)
        aclcheck_error(aclresult, OBJECT_FUNCTION,
                       get_func_name(fid));
    InvokeFunctionExecuteHook(fid);

    /*
     * Prepare function call info block and insert arguments.
     *
     * Note: for now we pass collation = InvalidOid, so collation-sensitive
     * functions can't be called this way.  Perhaps we should pass
     * DEFAULT_COLLATION_OID, instead?
     */
    InitFunctionCallInfoData(*fcinfo, &fip->flinfo, 0, InvalidOid, NULL, NULL);

    rformat = parse_fcall_arguments(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->args[i].isnull)
            {
                callit = false;
                break;
            }
        }
    }

    if (callit)
    {
        /* Okay, do it ... */
        retval = FunctionCallInvoke(fcinfo);
    }
    else
    {
        fcinfo->isnull = true;
        retval = (Datum) 0;
    }

    /* ensure we do at least one CHECK_FOR_INTERRUPTS per function call */
    CHECK_FOR_INTERRUPTS();

    SendFunctionResult(retval, fcinfo->isnull, fip->rettype, rformat);

    /* We no longer need the snapshot */
    PopActiveSnapshot();

    /*
     * Emit duration logging if appropriate.
     */
    switch (check_log_duration(msec_str, was_logged))
    {
        case 1:
            ereport(LOG,
                    (errmsg("duration: %s ms", msec_str)));
            break;
        case 2:
            ereport(LOG,
                    (errmsg("duration: %s ms  fastpath function call: \"%s\" (OID %u)",
                            msec_str, fip->fname, fid)));
            break;
    }
}

parse_fcall_arguments()

static int16 parse_fcall_arguments ( StringInfo  msgBuf, struct fp_info *  fip, FunctionCallInfo  fcinfo  )

static

Definition at line 329 of file fastpath.c.

References appendBinaryStringInfo(), FunctionCallInfoBaseData::args, fp_info::argtypes, StringInfoData::cursor, StringInfoData::data, ereport, errcode(), errmsg(), ERROR, fp_info::flinfo, FmgrInfo::fn_nargs, FUNC_MAX_ARGS, getTypeBinaryInputInfo(), getTypeInputInfo(), i, initStringInfo(), NullableDatum::isnull, StringInfoData::len, FunctionCallInfoBaseData::nargs, OidInputFunctionCall(), OidReceiveFunctionCall(), palloc(), pfree(), pg_client_to_server(), pq_getmsgbytes(), pq_getmsgint(), resetStringInfo(), and NullableDatum::value.

Referenced by HandleFunctionRequest().

{
    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->args[i].isnull = true;
        }
        else
        {
            fcinfo->args[i].isnull = false;
            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 */
            resetStringInfo(&abuf);
            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.
             */
            if (argsize == -1)
                pstring = NULL;
            else
                pstring = pg_client_to_server(abuf.data, argsize);

            fcinfo->args[i].value = OidInputFunctionCall(typinput, pstring,
                                                         typioparam, -1);
            /* Free result of encoding conversion, if any */
            if (pstring && pstring != abuf.data)
                pfree(pstring);
        }
        else if (aformat == 1)
        {
            Oid         typreceive;
            Oid         typioparam;
            StringInfo  bufptr;

            /* Call the argument type's binary input converter */
            getTypeBinaryInputInfo(fip->argtypes[i], &typreceive, &typioparam);

            if (argsize == -1)
                bufptr = NULL;
            else
                bufptr = &abuf;

            fcinfo->args[i].value = OidReceiveFunctionCall(typreceive, bufptr,
                                                           typioparam, -1);

            /* Trouble if it didn't eat the whole buffer */
            if (argsize != -1 && 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);
}

SendFunctionResult()

static void SendFunctionResult ( Datum  retval, bool  isnull, Oid  rettype, int16  format  )

static

Definition at line 67 of file fastpath.c.

References buf, ereport, errcode(), errmsg(), ERROR, getTypeBinaryOutputInfo(), getTypeOutputInfo(), OidOutputFunctionCall(), OidSendFunctionCall(), pfree(), pq_beginmessage(), pq_endmessage(), pq_sendbytes(), pq_sendcountedtext(), pq_sendint32(), VARDATA, VARHDRSZ, and VARSIZE.

Referenced by HandleFunctionRequest().

{
    StringInfoData buf;

    pq_beginmessage(&buf, 'V');

    if (isnull)
    {
        pq_sendint32(&buf, -1);
    }
    else
    {
        if (format == 0)
        {
            Oid         typoutput;
            bool        typisvarlena;
            char       *outputstr;

            getTypeOutputInfo(rettype, &typoutput, &typisvarlena);
            outputstr = OidOutputFunctionCall(typoutput, retval);
            pq_sendcountedtext(&buf, outputstr, strlen(outputstr), false);
            pfree(outputstr);
        }
        else if (format == 1)
        {
            Oid         typsend;
            bool        typisvarlena;
            bytea      *outputbytes;

            getTypeBinaryOutputInfo(rettype, &typsend, &typisvarlena);
            outputbytes = OidSendFunctionCall(typsend, retval);
            pq_sendint32(&buf, VARSIZE(outputbytes) - VARHDRSZ);
            pq_sendbytes(&buf, VARDATA(outputbytes),
                         VARSIZE(outputbytes) - VARHDRSZ);
            pfree(outputbytes);
        }
        else
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("unsupported format code: %d", format)));
    }

    pq_endmessage(&buf);
}