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Diffstat (limited to 'src/include/fmgr.h')
| -rw-r--r-- | src/include/fmgr.h | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/src/include/fmgr.h b/src/include/fmgr.h new file mode 100644 index 00000000000..18b01f7fad1 --- /dev/null +++ b/src/include/fmgr.h @@ -0,0 +1,301 @@ +/*------------------------------------------------------------------------- + * + * fmgr.h + * Definitions for the Postgres function manager and function-call + * interface. + * + * This file must be included by all Postgres modules that either define + * or call fmgr-callable functions. + * + * + * Portions Copyright (c) 1996-2000, PostgreSQL, Inc + * Portions Copyright (c) 1994, Regents of the University of California + * + * $Id: fmgr.h,v 1.1 2000/05/28 17:56:12 tgl Exp $ + * + *------------------------------------------------------------------------- + */ +#ifndef FMGR_H +#define FMGR_H + + +/* + * All functions that can be called directly by fmgr must have this signature. + * (Other functions can be called by using a handler that does have this + * signature.) + */ + +typedef struct FunctionCallInfoData *FunctionCallInfo; + +typedef Datum (*PGFunction) (FunctionCallInfo fcinfo); + +/* + * This struct holds the system-catalog information that must be looked up + * before a function can be called through fmgr. If the same function is + * to be called multiple times, the lookup need be done only once and the + * info struct saved for re-use. + */ +typedef struct +{ + PGFunction fn_addr; /* pointer to function or handler to be called */ + Oid fn_oid; /* OID of function (NOT of handler, if any) */ + short fn_nargs; /* 0..FUNC_MAX_ARGS, or -1 if variable arg count */ + bool fn_strict; /* function is "strict" (NULL in => NULL out) */ + void *fn_extra; /* extra space for use by handler */ +} FmgrInfo; + +/* + * This struct is the data actually passed to an fmgr-called function. + */ +typedef struct FunctionCallInfoData +{ + FmgrInfo *flinfo; /* ptr to lookup info used for this call */ + struct Node *context; /* pass info about context of call */ + struct Node *resultinfo; /* pass or return extra info about result */ + bool isnull; /* function must set true if result is NULL */ + short nargs; /* # arguments actually passed */ + Datum arg[FUNC_MAX_ARGS]; /* Arguments passed to function */ + bool argnull[FUNC_MAX_ARGS]; /* T if arg[i] is actually NULL */ +} FunctionCallInfoData; + +/* + * This routine fills a FmgrInfo struct, given the OID + * of the function to be called. + */ +extern void fmgr_info(Oid functionId, FmgrInfo *finfo); + +/* + * This macro invokes a function given a filled-in FunctionCallInfoData + * struct. The macro result is the returned Datum --- but note that + * caller must still check fcinfo->isnull! Also, if function is strict, + * it is caller's responsibility to verify that no null arguments are present + * before calling. + */ +#define FunctionCallInvoke(fcinfo) ((* (fcinfo)->flinfo->fn_addr) (fcinfo)) + + +/*------------------------------------------------------------------------- + * Support macros to ease writing fmgr-compatible functions + * + * A C-coded fmgr-compatible function should be declared as + * + * Datum + * function_name(PG_FUNCTION_ARGS) + * { + * ... + * } + * + * It should access its arguments using appropriate PG_GETARG_xxx macros + * and should return its result using PG_RETURN_xxx. + * + *------------------------------------------------------------------------- + */ + +/* Standard parameter list for fmgr-compatible functions */ +#define PG_FUNCTION_ARGS FunctionCallInfo fcinfo + +/* If function is not marked "proisstrict" in pg_proc, it must check for + * null arguments using this macro. Do not try to GETARG a null argument! + */ +#define PG_ARGISNULL(n) (fcinfo->argnull[n]) + +/* Macros for fetching arguments of standard types */ + +#define PG_GETARG_INT32(n) DatumGetInt32(fcinfo->arg[n]) +#define PG_GETARG_INT16(n) DatumGetInt16(fcinfo->arg[n]) +#define PG_GETARG_CHAR(n) DatumGetChar(fcinfo->arg[n]) +#define PG_GETARG_BOOL(n) DatumGetBool(fcinfo->arg[n]) +#define PG_GETARG_OID(n) DatumGetObjectId(fcinfo->arg[n]) +#define PG_GETARG_POINTER(n) DatumGetPointer(fcinfo->arg[n]) +/* these macros hide the pass-by-reference-ness of the datatype: */ +#define PG_GETARG_FLOAT4(n) DatumGetFloat4(fcinfo->arg[n]) +#define PG_GETARG_FLOAT8(n) DatumGetFloat8(fcinfo->arg[n]) +#define PG_GETARG_INT64(n) DatumGetInt64(fcinfo->arg[n]) +/* use this if you want the raw, possibly-toasted input datum: */ +#define PG_GETARG_RAW_VARLENA_P(n) ((struct varlena *) PG_GETARG_POINTER(n)) +/* use this if you want the input datum de-toasted: */ +#define PG_GETARG_VARLENA_P(n) \ + (VARATT_IS_EXTENDED(PG_GETARG_RAW_VARLENA_P(n)) ? \ + (struct varlena *) heap_tuple_untoast_attr((varattrib *) PG_GETARG_RAW_VARLENA_P(n)) : \ + PG_GETARG_RAW_VARLENA_P(n)) +/* GETARG macros for varlena types will typically look like this: */ +#define PG_GETARG_TEXT_P(n) ((text *) PG_GETARG_VARLENA_P(n)) + +/* To return a NULL do this: */ +#define PG_RETURN_NULL() \ + do { fcinfo->isnull = true; return (Datum) 0; } while (0) + +/* Macros for returning results of standard types */ + +#define PG_RETURN_INT32(x) return Int32GetDatum(x) +#define PG_RETURN_INT16(x) return Int16GetDatum(x) +#define PG_RETURN_CHAR(x) return CharGetDatum(x) +#define PG_RETURN_BOOL(x) return BoolGetDatum(x) +#define PG_RETURN_OID(x) return ObjectIdGetDatum(x) +#define PG_RETURN_POINTER(x) return PointerGetDatum(x) +/* these macros hide the pass-by-reference-ness of the datatype: */ +#define PG_RETURN_FLOAT4(x) return Float4GetDatum(x) +#define PG_RETURN_FLOAT8(x) return Float8GetDatum(x) +#define PG_RETURN_INT64(x) return Int64GetDatum(x) +/* RETURN macros for other pass-by-ref types will typically look like this: */ +#define PG_RETURN_TEXT_P(x) PG_RETURN_POINTER(x) + + +/*------------------------------------------------------------------------- + * Support routines and macros for callers of fmgr-compatible functions + *------------------------------------------------------------------------- + */ + +/* These are for invocation of a specifically named function with a + * directly-computed parameter list. Note that neither arguments nor result + * are allowed to be NULL. + */ +extern Datum DirectFunctionCall1(PGFunction func, Datum arg1); +extern Datum DirectFunctionCall2(PGFunction func, Datum arg1, Datum arg2); +extern Datum DirectFunctionCall3(PGFunction func, Datum arg1, Datum arg2, + Datum arg3); +extern Datum DirectFunctionCall4(PGFunction func, Datum arg1, Datum arg2, + Datum arg3, Datum arg4); +extern Datum DirectFunctionCall5(PGFunction func, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5); +extern Datum DirectFunctionCall6(PGFunction func, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6); +extern Datum DirectFunctionCall7(PGFunction func, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6, Datum arg7); +extern Datum DirectFunctionCall8(PGFunction func, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6, Datum arg7, Datum arg8); +extern Datum DirectFunctionCall9(PGFunction func, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6, Datum arg7, Datum arg8, + Datum arg9); + +/* These are for invocation of a previously-looked-up function with a + * directly-computed parameter list. Note that neither arguments nor result + * are allowed to be NULL. + */ +extern Datum FunctionCall1(FmgrInfo *flinfo, Datum arg1); +extern Datum FunctionCall2(FmgrInfo *flinfo, Datum arg1, Datum arg2); +extern Datum FunctionCall3(FmgrInfo *flinfo, Datum arg1, Datum arg2, + Datum arg3); +extern Datum FunctionCall4(FmgrInfo *flinfo, Datum arg1, Datum arg2, + Datum arg3, Datum arg4); +extern Datum FunctionCall5(FmgrInfo *flinfo, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5); +extern Datum FunctionCall6(FmgrInfo *flinfo, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6); +extern Datum FunctionCall7(FmgrInfo *flinfo, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6, Datum arg7); +extern Datum FunctionCall8(FmgrInfo *flinfo, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6, Datum arg7, Datum arg8); +extern Datum FunctionCall9(FmgrInfo *flinfo, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6, Datum arg7, Datum arg8, + Datum arg9); + +/* These are for invocation of a function identified by OID with a + * directly-computed parameter list. Note that neither arguments nor result + * are allowed to be NULL. These are essentially FunctionLookup() followed + * by FunctionCallN(). If the same function is to be invoked repeatedly, + * do the FunctionLookup() once and then use FunctionCallN(). + */ +extern Datum OidFunctionCall1(Oid functionId, Datum arg1); +extern Datum OidFunctionCall2(Oid functionId, Datum arg1, Datum arg2); +extern Datum OidFunctionCall3(Oid functionId, Datum arg1, Datum arg2, + Datum arg3); +extern Datum OidFunctionCall4(Oid functionId, Datum arg1, Datum arg2, + Datum arg3, Datum arg4); +extern Datum OidFunctionCall5(Oid functionId, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5); +extern Datum OidFunctionCall6(Oid functionId, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6); +extern Datum OidFunctionCall7(Oid functionId, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6, Datum arg7); +extern Datum OidFunctionCall8(Oid functionId, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6, Datum arg7, Datum arg8); +extern Datum OidFunctionCall9(Oid functionId, Datum arg1, Datum arg2, + Datum arg3, Datum arg4, Datum arg5, + Datum arg6, Datum arg7, Datum arg8, + Datum arg9); + + +/* + * Routines in fmgr.c + */ +extern Oid fmgr_internal_language(const char *proname); + +/* + * Routines in dfmgr.c + */ +extern PGFunction fmgr_dynamic(Oid functionId); +extern PGFunction load_external_function(char *filename, char *funcname); +extern void load_file(char *filename); + + +/*------------------------------------------------------------------------- + * + * !!! OLD INTERFACE !!! + * + * All the definitions below here are associated with the old fmgr API. + * They will go away as soon as we have converted all call points to use + * the new API. Note that old-style callee functions do not depend on + * these definitions, so we don't need to have converted all of them before + * dropping the old API ... just all the old-style call points. + * + *------------------------------------------------------------------------- + */ + +/* ptr to func returning (char *) */ +#if defined(__mc68000__) && defined(__ELF__) +/* The m68k SVR4 ABI defines that pointers are returned in %a0 instead of + * %d0. So if a function pointer is declared to return a pointer, the + * compiler may look only into %a0, but if the called function was declared + * to return return an integer type, it puts its value only into %d0. So the + * caller doesn't pink up the correct return value. The solution is to + * declare the function pointer to return int, so the compiler picks up the + * return value from %d0. (Functions returning pointers put their value + * *additionally* into %d0 for compability.) The price is that there are + * some warnings about int->pointer conversions... + */ +typedef int32 ((*func_ptr) ()); +#else +typedef char *((*func_ptr) ()); +#endif + +typedef struct { + char *data[FUNC_MAX_ARGS]; +} FmgrValues; + +/* + * defined in fmgr.c + */ +extern char *fmgr(Oid procedureId, ... ); +extern char *fmgr_faddr_link(char *arg0, ...); + +/* + * Macros for calling through the result of fmgr_info. + */ + +/* We don't make this static so fmgr_faddr() macros can access it */ +extern FmgrInfo *fmgr_pl_finfo; + +#define fmgr_faddr(finfo) (fmgr_pl_finfo = (finfo), (func_ptr) fmgr_faddr_link) + +#define FMGR_PTR2(FINFO, ARG1, ARG2) ((*(fmgr_faddr(FINFO))) (ARG1, ARG2)) + +/* + * Flags for the builtin oprrest selectivity routines. + * XXX These do not belong here ... put 'em in some planner/optimizer header. + */ +#define SEL_CONSTANT 1 /* operator's non-var arg is a constant */ +#define SEL_RIGHT 2 /* operator's non-var arg is on the right */ + +#endif /* FMGR_H */ |