1 /*-------------------------------------------------------------------------
4 * Definitions for the Postgres function manager and function-call
7 * This file must be included by all Postgres modules that either define
8 * or call fmgr-callable functions.
11 * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
12 * Portions Copyright (c) 1994, Regents of the University of California
14 * $PostgreSQL: pgsql/src/include/fmgr.h,v 1.42 2006/03/05 15:58:52 momjian Exp $
16 *-------------------------------------------------------------------------
21 /* We don't want to include primnodes.h here, so make a stub reference */
22 typedef struct Node *fmNodePtr;
26 * All functions that can be called directly by fmgr must have this signature.
27 * (Other functions can be called by using a handler that does have this
31 typedef struct FunctionCallInfoData *FunctionCallInfo;
33 typedef Datum (*PGFunction) (FunctionCallInfo fcinfo);
36 * This struct holds the system-catalog information that must be looked up
37 * before a function can be called through fmgr. If the same function is
38 * to be called multiple times, the lookup need be done only once and the
39 * info struct saved for re-use.
41 typedef struct FmgrInfo
43 PGFunction fn_addr; /* pointer to function or handler to be called */
44 Oid fn_oid; /* OID of function (NOT of handler, if any) */
45 short fn_nargs; /* 0..FUNC_MAX_ARGS, or -1 if variable arg
47 bool fn_strict; /* function is "strict" (NULL in => NULL out) */
48 bool fn_retset; /* function returns a set */
49 void *fn_extra; /* extra space for use by handler */
50 MemoryContext fn_mcxt; /* memory context to store fn_extra in */
51 fmNodePtr fn_expr; /* expression parse tree for call, or NULL */
55 * This struct is the data actually passed to an fmgr-called function.
57 typedef struct FunctionCallInfoData
59 FmgrInfo *flinfo; /* ptr to lookup info used for this call */
60 fmNodePtr context; /* pass info about context of call */
61 fmNodePtr resultinfo; /* pass or return extra info about result */
62 bool isnull; /* function must set true if result is NULL */
63 short nargs; /* # arguments actually passed */
64 Datum arg[FUNC_MAX_ARGS]; /* Arguments passed to function */
65 bool argnull[FUNC_MAX_ARGS]; /* T if arg[i] is actually NULL */
66 } FunctionCallInfoData;
69 * This routine fills a FmgrInfo struct, given the OID
70 * of the function to be called.
72 extern void fmgr_info(Oid functionId, FmgrInfo *finfo);
75 * Same, when the FmgrInfo struct is in a memory context longer-lived than
76 * CurrentMemoryContext. The specified context will be set as fn_mcxt
77 * and used to hold all subsidiary data of finfo.
79 extern void fmgr_info_cxt(Oid functionId, FmgrInfo *finfo,
83 * Copy an FmgrInfo struct
85 extern void fmgr_info_copy(FmgrInfo *dstinfo, FmgrInfo *srcinfo,
86 MemoryContext destcxt);
89 * This macro initializes all the fields of a FunctionCallInfoData except
90 * for the arg[] and argnull[] arrays. Performance testing has shown that
91 * the fastest way to set up argnull[] for small numbers of arguments is to
92 * explicitly set each required element to false, so we don't try to zero
93 * out the argnull[] array in the macro.
95 #define InitFunctionCallInfoData(Fcinfo, Flinfo, Nargs, Context, Resultinfo) \
97 (Fcinfo).flinfo = (Flinfo); \
98 (Fcinfo).context = (Context); \
99 (Fcinfo).resultinfo = (Resultinfo); \
100 (Fcinfo).isnull = false; \
101 (Fcinfo).nargs = (Nargs); \
105 * This macro invokes a function given a filled-in FunctionCallInfoData
106 * struct. The macro result is the returned Datum --- but note that
107 * caller must still check fcinfo->isnull! Also, if function is strict,
108 * it is caller's responsibility to verify that no null arguments are present
111 #define FunctionCallInvoke(fcinfo) ((* (fcinfo)->flinfo->fn_addr) (fcinfo))
114 /*-------------------------------------------------------------------------
115 * Support macros to ease writing fmgr-compatible functions
117 * A C-coded fmgr-compatible function should be declared as
120 * function_name(PG_FUNCTION_ARGS)
125 * It should access its arguments using appropriate PG_GETARG_xxx macros
126 * and should return its result using PG_RETURN_xxx.
128 *-------------------------------------------------------------------------
131 /* Standard parameter list for fmgr-compatible functions */
132 #define PG_FUNCTION_ARGS FunctionCallInfo fcinfo
135 * Get number of arguments passed to function.
137 #define PG_NARGS() (fcinfo->nargs)
140 * If function is not marked "proisstrict" in pg_proc, it must check for
141 * null arguments using this macro. Do not try to GETARG a null argument!
143 #define PG_ARGISNULL(n) (fcinfo->argnull[n])
146 * Support for fetching detoasted copies of toastable datatypes (all of
147 * which are varlena types). pg_detoast_datum() gives you either the input
148 * datum (if not toasted) or a detoasted copy allocated with palloc().
149 * pg_detoast_datum_copy() always gives you a palloc'd copy --- use it
150 * if you need a modifiable copy of the input. Caller is expected to have
151 * checked for null inputs first, if necessary.
153 * Note: it'd be nice if these could be macros, but I see no way to do that
154 * without evaluating the arguments multiple times, which is NOT acceptable.
156 extern struct varlena *pg_detoast_datum(struct varlena * datum);
157 extern struct varlena *pg_detoast_datum_copy(struct varlena * datum);
158 extern struct varlena *pg_detoast_datum_slice(struct varlena * datum,
159 int32 first, int32 count);
161 #define PG_DETOAST_DATUM(datum) \
162 pg_detoast_datum((struct varlena *) DatumGetPointer(datum))
163 #define PG_DETOAST_DATUM_COPY(datum) \
164 pg_detoast_datum_copy((struct varlena *) DatumGetPointer(datum))
165 #define PG_DETOAST_DATUM_SLICE(datum,f,c) \
166 pg_detoast_datum_slice((struct varlena *) DatumGetPointer(datum), \
167 (int32) f, (int32) c)
170 * Support for cleaning up detoasted copies of inputs. This must only
171 * be used for pass-by-ref datatypes, and normally would only be used
172 * for toastable types. If the given pointer is different from the
173 * original argument, assume it's a palloc'd detoasted copy, and pfree it.
174 * NOTE: most functions on toastable types do not have to worry about this,
175 * but we currently require that support functions for indexes not leak
178 #define PG_FREE_IF_COPY(ptr,n) \
180 if ((Pointer) (ptr) != PG_GETARG_POINTER(n)) \
184 /* Macros for fetching arguments of standard types */
186 #define PG_GETARG_DATUM(n) (fcinfo->arg[n])
187 #define PG_GETARG_INT32(n) DatumGetInt32(PG_GETARG_DATUM(n))
188 #define PG_GETARG_UINT32(n) DatumGetUInt32(PG_GETARG_DATUM(n))
189 #define PG_GETARG_INT16(n) DatumGetInt16(PG_GETARG_DATUM(n))
190 #define PG_GETARG_UINT16(n) DatumGetUInt16(PG_GETARG_DATUM(n))
191 #define PG_GETARG_CHAR(n) DatumGetChar(PG_GETARG_DATUM(n))
192 #define PG_GETARG_BOOL(n) DatumGetBool(PG_GETARG_DATUM(n))
193 #define PG_GETARG_OID(n) DatumGetObjectId(PG_GETARG_DATUM(n))
194 #define PG_GETARG_POINTER(n) DatumGetPointer(PG_GETARG_DATUM(n))
195 #define PG_GETARG_CSTRING(n) DatumGetCString(PG_GETARG_DATUM(n))
196 #define PG_GETARG_NAME(n) DatumGetName(PG_GETARG_DATUM(n))
197 /* these macros hide the pass-by-reference-ness of the datatype: */
198 #define PG_GETARG_FLOAT4(n) DatumGetFloat4(PG_GETARG_DATUM(n))
199 #define PG_GETARG_FLOAT8(n) DatumGetFloat8(PG_GETARG_DATUM(n))
200 #define PG_GETARG_INT64(n) DatumGetInt64(PG_GETARG_DATUM(n))
201 /* use this if you want the raw, possibly-toasted input datum: */
202 #define PG_GETARG_RAW_VARLENA_P(n) ((struct varlena *) PG_GETARG_POINTER(n))
203 /* use this if you want the input datum de-toasted: */
204 #define PG_GETARG_VARLENA_P(n) PG_DETOAST_DATUM(PG_GETARG_DATUM(n))
205 /* DatumGetFoo macros for varlena types will typically look like this: */
206 #define DatumGetByteaP(X) ((bytea *) PG_DETOAST_DATUM(X))
207 #define DatumGetTextP(X) ((text *) PG_DETOAST_DATUM(X))
208 #define DatumGetBpCharP(X) ((BpChar *) PG_DETOAST_DATUM(X))
209 #define DatumGetVarCharP(X) ((VarChar *) PG_DETOAST_DATUM(X))
210 #define DatumGetHeapTupleHeader(X) ((HeapTupleHeader) PG_DETOAST_DATUM(X))
211 /* And we also offer variants that return an OK-to-write copy */
212 #define DatumGetByteaPCopy(X) ((bytea *) PG_DETOAST_DATUM_COPY(X))
213 #define DatumGetTextPCopy(X) ((text *) PG_DETOAST_DATUM_COPY(X))
214 #define DatumGetBpCharPCopy(X) ((BpChar *) PG_DETOAST_DATUM_COPY(X))
215 #define DatumGetVarCharPCopy(X) ((VarChar *) PG_DETOAST_DATUM_COPY(X))
216 #define DatumGetHeapTupleHeaderCopy(X) ((HeapTupleHeader) PG_DETOAST_DATUM_COPY(X))
217 /* Variants which return n bytes starting at pos. m */
218 #define DatumGetByteaPSlice(X,m,n) ((bytea *) PG_DETOAST_DATUM_SLICE(X,m,n))
219 #define DatumGetTextPSlice(X,m,n) ((text *) PG_DETOAST_DATUM_SLICE(X,m,n))
220 #define DatumGetBpCharPSlice(X,m,n) ((BpChar *) PG_DETOAST_DATUM_SLICE(X,m,n))
221 #define DatumGetVarCharPSlice(X,m,n) ((VarChar *) PG_DETOAST_DATUM_SLICE(X,m,n))
222 /* GETARG macros for varlena types will typically look like this: */
223 #define PG_GETARG_BYTEA_P(n) DatumGetByteaP(PG_GETARG_DATUM(n))
224 #define PG_GETARG_TEXT_P(n) DatumGetTextP(PG_GETARG_DATUM(n))
225 #define PG_GETARG_BPCHAR_P(n) DatumGetBpCharP(PG_GETARG_DATUM(n))
226 #define PG_GETARG_VARCHAR_P(n) DatumGetVarCharP(PG_GETARG_DATUM(n))
227 #define PG_GETARG_HEAPTUPLEHEADER(n) DatumGetHeapTupleHeader(PG_GETARG_DATUM(n))
228 /* And we also offer variants that return an OK-to-write copy */
229 #define PG_GETARG_BYTEA_P_COPY(n) DatumGetByteaPCopy(PG_GETARG_DATUM(n))
230 #define PG_GETARG_TEXT_P_COPY(n) DatumGetTextPCopy(PG_GETARG_DATUM(n))
231 #define PG_GETARG_BPCHAR_P_COPY(n) DatumGetBpCharPCopy(PG_GETARG_DATUM(n))
232 #define PG_GETARG_VARCHAR_P_COPY(n) DatumGetVarCharPCopy(PG_GETARG_DATUM(n))
233 #define PG_GETARG_HEAPTUPLEHEADER_COPY(n) DatumGetHeapTupleHeaderCopy(PG_GETARG_DATUM(n))
234 /* And a b-byte slice from position a -also OK to write */
235 #define PG_GETARG_BYTEA_P_SLICE(n,a,b) DatumGetByteaPSlice(PG_GETARG_DATUM(n),a,b)
236 #define PG_GETARG_TEXT_P_SLICE(n,a,b) DatumGetTextPSlice(PG_GETARG_DATUM(n),a,b)
237 #define PG_GETARG_BPCHAR_P_SLICE(n,a,b) DatumGetBpCharPSlice(PG_GETARG_DATUM(n),a,b)
238 #define PG_GETARG_VARCHAR_P_SLICE(n,a,b) DatumGetVarCharPSlice(PG_GETARG_DATUM(n),a,b)
240 /* To return a NULL do this: */
241 #define PG_RETURN_NULL() \
242 do { fcinfo->isnull = true; return (Datum) 0; } while (0)
244 /* A few internal functions return void (which is not the same as NULL!) */
245 #define PG_RETURN_VOID() return (Datum) 0
247 /* Macros for returning results of standard types */
249 #define PG_RETURN_DATUM(x) return (x)
250 #define PG_RETURN_INT32(x) return Int32GetDatum(x)
251 #define PG_RETURN_UINT32(x) return UInt32GetDatum(x)
252 #define PG_RETURN_INT16(x) return Int16GetDatum(x)
253 #define PG_RETURN_CHAR(x) return CharGetDatum(x)
254 #define PG_RETURN_BOOL(x) return BoolGetDatum(x)
255 #define PG_RETURN_OID(x) return ObjectIdGetDatum(x)
256 #define PG_RETURN_POINTER(x) return PointerGetDatum(x)
257 #define PG_RETURN_CSTRING(x) return CStringGetDatum(x)
258 #define PG_RETURN_NAME(x) return NameGetDatum(x)
259 /* these macros hide the pass-by-reference-ness of the datatype: */
260 #define PG_RETURN_FLOAT4(x) return Float4GetDatum(x)
261 #define PG_RETURN_FLOAT8(x) return Float8GetDatum(x)
262 #define PG_RETURN_INT64(x) return Int64GetDatum(x)
263 /* RETURN macros for other pass-by-ref types will typically look like this: */
264 #define PG_RETURN_BYTEA_P(x) PG_RETURN_POINTER(x)
265 #define PG_RETURN_TEXT_P(x) PG_RETURN_POINTER(x)
266 #define PG_RETURN_BPCHAR_P(x) PG_RETURN_POINTER(x)
267 #define PG_RETURN_VARCHAR_P(x) PG_RETURN_POINTER(x)
268 #define PG_RETURN_HEAPTUPLEHEADER(x) PG_RETURN_POINTER(x)
271 /*-------------------------------------------------------------------------
272 * Support for detecting call convention of dynamically-loaded functions
274 * Dynamically loaded functions may use either the version-1 ("new style")
275 * or version-0 ("old style") calling convention. Version 1 is the call
276 * convention defined in this header file; version 0 is the old "plain C"
277 * convention. A version-1 function must be accompanied by the macro call
279 * PG_FUNCTION_INFO_V1(function_name);
281 * Note that internal functions do not need this decoration since they are
282 * assumed to be version-1.
284 *-------------------------------------------------------------------------
289 int api_version; /* specifies call convention version number */
290 /* More fields may be added later, for version numbers > 1. */
293 /* Expected signature of an info function */
294 typedef Pg_finfo_record *(*PGFInfoFunction) (void);
297 * Macro to build an info function associated with the given function name.
298 * Win32 loadable functions usually link with 'dlltool --export-all', but it
299 * doesn't hurt to add DLLIMPORT in case they don't.
301 #define PG_FUNCTION_INFO_V1(funcname) \
302 extern DLLIMPORT Pg_finfo_record * CppConcat(pg_finfo_,funcname) (void); \
304 CppConcat(pg_finfo_,funcname) (void) \
306 static Pg_finfo_record my_finfo = { 1 }; \
309 extern int no_such_variable
312 /*-------------------------------------------------------------------------
313 * Support routines and macros for callers of fmgr-compatible functions
314 *-------------------------------------------------------------------------
317 /* These are for invocation of a specifically named function with a
318 * directly-computed parameter list. Note that neither arguments nor result
319 * are allowed to be NULL.
321 extern Datum DirectFunctionCall1(PGFunction func, Datum arg1);
322 extern Datum DirectFunctionCall2(PGFunction func, Datum arg1, Datum arg2);
323 extern Datum DirectFunctionCall3(PGFunction func, Datum arg1, Datum arg2,
325 extern Datum DirectFunctionCall4(PGFunction func, Datum arg1, Datum arg2,
326 Datum arg3, Datum arg4);
327 extern Datum DirectFunctionCall5(PGFunction func, Datum arg1, Datum arg2,
328 Datum arg3, Datum arg4, Datum arg5);
329 extern Datum DirectFunctionCall6(PGFunction func, Datum arg1, Datum arg2,
330 Datum arg3, Datum arg4, Datum arg5,
332 extern Datum DirectFunctionCall7(PGFunction func, Datum arg1, Datum arg2,
333 Datum arg3, Datum arg4, Datum arg5,
334 Datum arg6, Datum arg7);
335 extern Datum DirectFunctionCall8(PGFunction func, Datum arg1, Datum arg2,
336 Datum arg3, Datum arg4, Datum arg5,
337 Datum arg6, Datum arg7, Datum arg8);
338 extern Datum DirectFunctionCall9(PGFunction func, Datum arg1, Datum arg2,
339 Datum arg3, Datum arg4, Datum arg5,
340 Datum arg6, Datum arg7, Datum arg8,
343 /* These are for invocation of a previously-looked-up function with a
344 * directly-computed parameter list. Note that neither arguments nor result
345 * are allowed to be NULL.
347 extern Datum FunctionCall1(FmgrInfo *flinfo, Datum arg1);
348 extern Datum FunctionCall2(FmgrInfo *flinfo, Datum arg1, Datum arg2);
349 extern Datum FunctionCall3(FmgrInfo *flinfo, Datum arg1, Datum arg2,
351 extern Datum FunctionCall4(FmgrInfo *flinfo, Datum arg1, Datum arg2,
352 Datum arg3, Datum arg4);
353 extern Datum FunctionCall5(FmgrInfo *flinfo, Datum arg1, Datum arg2,
354 Datum arg3, Datum arg4, Datum arg5);
355 extern Datum FunctionCall6(FmgrInfo *flinfo, Datum arg1, Datum arg2,
356 Datum arg3, Datum arg4, Datum arg5,
358 extern Datum FunctionCall7(FmgrInfo *flinfo, Datum arg1, Datum arg2,
359 Datum arg3, Datum arg4, Datum arg5,
360 Datum arg6, Datum arg7);
361 extern Datum FunctionCall8(FmgrInfo *flinfo, Datum arg1, Datum arg2,
362 Datum arg3, Datum arg4, Datum arg5,
363 Datum arg6, Datum arg7, Datum arg8);
364 extern Datum FunctionCall9(FmgrInfo *flinfo, Datum arg1, Datum arg2,
365 Datum arg3, Datum arg4, Datum arg5,
366 Datum arg6, Datum arg7, Datum arg8,
369 /* These are for invocation of a function identified by OID with a
370 * directly-computed parameter list. Note that neither arguments nor result
371 * are allowed to be NULL. These are essentially FunctionLookup() followed
372 * by FunctionCallN(). If the same function is to be invoked repeatedly,
373 * do the FunctionLookup() once and then use FunctionCallN().
375 extern Datum OidFunctionCall1(Oid functionId, Datum arg1);
376 extern Datum OidFunctionCall2(Oid functionId, Datum arg1, Datum arg2);
377 extern Datum OidFunctionCall3(Oid functionId, Datum arg1, Datum arg2,
379 extern Datum OidFunctionCall4(Oid functionId, Datum arg1, Datum arg2,
380 Datum arg3, Datum arg4);
381 extern Datum OidFunctionCall5(Oid functionId, Datum arg1, Datum arg2,
382 Datum arg3, Datum arg4, Datum arg5);
383 extern Datum OidFunctionCall6(Oid functionId, Datum arg1, Datum arg2,
384 Datum arg3, Datum arg4, Datum arg5,
386 extern Datum OidFunctionCall7(Oid functionId, Datum arg1, Datum arg2,
387 Datum arg3, Datum arg4, Datum arg5,
388 Datum arg6, Datum arg7);
389 extern Datum OidFunctionCall8(Oid functionId, Datum arg1, Datum arg2,
390 Datum arg3, Datum arg4, Datum arg5,
391 Datum arg6, Datum arg7, Datum arg8);
392 extern Datum OidFunctionCall9(Oid functionId, Datum arg1, Datum arg2,
393 Datum arg3, Datum arg4, Datum arg5,
394 Datum arg6, Datum arg7, Datum arg8,
401 extern Pg_finfo_record *fetch_finfo_record(void *filehandle, char *funcname);
402 extern void clear_external_function_hash(void *filehandle);
403 extern Oid fmgr_internal_function(const char *proname);
404 extern Oid get_fn_expr_rettype(FmgrInfo *flinfo);
405 extern Oid get_fn_expr_argtype(FmgrInfo *flinfo, int argnum);
406 extern Oid get_call_expr_argtype(fmNodePtr expr, int argnum);
409 * Routines in dfmgr.c
411 extern char *Dynamic_library_path;
413 extern PGFunction load_external_function(char *filename, char *funcname,
414 bool signalNotFound, void **filehandle);
415 extern PGFunction lookup_external_function(void *filehandle, char *funcname);
416 extern void load_file(char *filename);
420 * !!! OLD INTERFACE !!!
422 * fmgr() is the only remaining vestige of the old-style caller support
423 * functions. It's no longer used anywhere in the Postgres distribution,
424 * but we should leave it around for a release or two to ease the transition
425 * for user-supplied C functions. OidFunctionCallN() replaces it for new
430 * DEPRECATED, DO NOT USE IN NEW CODE
432 extern char *fmgr(Oid procedureId,...);