src/include/fmgr.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * fmgr.h
   4  *        Definitions for the Postgres function manager and function-call
   5  *        interface.
   6  *
   7  * This file must be included by all Postgres modules that either define
   8  * or call fmgr-callable functions.
   9  *
  10  *
  11  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  12  * Portions Copyright (c) 1994, Regents of the University of California
  13  *
  14  * $PostgreSQL$
  15  *
  16  *-------------------------------------------------------------------------
  17  */
  18 #ifndef FMGR_H
  19 #define FMGR_H
  20
  21 /* We don't want to include primnodes.h here, so make a stub reference */
  22 typedef struct Node *fmNodePtr;
  23
  24 /* Likewise, avoid including stringinfo.h here */
  25 typedef struct StringInfoData *fmStringInfo;
  26
  27
  28 /*
  29  * All functions that can be called directly by fmgr must have this signature.
  30  * (Other functions can be called by using a handler that does have this
  31  * signature.)
  32  */
  33
  34 typedef struct FunctionCallInfoData *FunctionCallInfo;
  35
  36 typedef Datum (*PGFunction) (FunctionCallInfo fcinfo);
  37
  38 /*
  39  * This struct holds the system-catalog information that must be looked up
  40  * before a function can be called through fmgr.  If the same function is
  41  * to be called multiple times, the lookup need be done only once and the
  42  * info struct saved for re-use.
  43  */
  44 typedef struct FmgrInfo
  45 {
  46         PGFunction      fn_addr;                /* pointer to function or handler to be called */
  47         Oid                     fn_oid;                 /* OID of function (NOT of handler, if any) */
  48         short           fn_nargs;               /* 0..FUNC_MAX_ARGS, or -1 if variable arg
  49                                                                  * count */
  50         bool            fn_strict;              /* function is "strict" (NULL in => NULL out) */
  51         bool            fn_retset;              /* function returns a set */
  52         unsigned char fn_stats;         /* collect stats if track_functions > this */
  53         void       *fn_extra;           /* extra space for use by handler */
  54         MemoryContext fn_mcxt;          /* memory context to store fn_extra in */
  55         fmNodePtr       fn_expr;                /* expression parse tree for call, or NULL */
  56 } FmgrInfo;
  57
  58 /*
  59  * This struct is the data actually passed to an fmgr-called function.
  60  */
  61 typedef struct FunctionCallInfoData
  62 {
  63         FmgrInfo   *flinfo;                     /* ptr to lookup info used for this call */
  64         fmNodePtr       context;                /* pass info about context of call */
  65         fmNodePtr       resultinfo;             /* pass or return extra info about result */
  66         bool            isnull;                 /* function must set true if result is NULL */
  67         short           nargs;                  /* # arguments actually passed */
  68         Datum           arg[FUNC_MAX_ARGS];             /* Arguments passed to function */
  69         bool            argnull[FUNC_MAX_ARGS]; /* T if arg[i] is actually NULL */
  70 } FunctionCallInfoData;
  71
  72 /*
  73  * This routine fills a FmgrInfo struct, given the OID
  74  * of the function to be called.
  75  */
  76 extern void fmgr_info(Oid functionId, FmgrInfo *finfo);
  77
  78 /*
  79  * Same, when the FmgrInfo struct is in a memory context longer-lived than
  80  * CurrentMemoryContext.  The specified context will be set as fn_mcxt
  81  * and used to hold all subsidiary data of finfo.
  82  */
  83 extern void fmgr_info_cxt(Oid functionId, FmgrInfo *finfo,
  84                           MemoryContext mcxt);
  85
  86 /*
  87  * Copy an FmgrInfo struct
  88  */
  89 extern void fmgr_info_copy(FmgrInfo *dstinfo, FmgrInfo *srcinfo,
  90                            MemoryContext destcxt);
  91
  92 /*
  93  * This macro initializes all the fields of a FunctionCallInfoData except
  94  * for the arg[] and argnull[] arrays.  Performance testing has shown that
  95  * the fastest way to set up argnull[] for small numbers of arguments is to
  96  * explicitly set each required element to false, so we don't try to zero
  97  * out the argnull[] array in the macro.
  98  */
  99 #define InitFunctionCallInfoData(Fcinfo, Flinfo, Nargs, Context, Resultinfo) \
 100         do { \
 101                 (Fcinfo).flinfo = (Flinfo); \
 102                 (Fcinfo).context = (Context); \
 103                 (Fcinfo).resultinfo = (Resultinfo); \
 104                 (Fcinfo).isnull = false; \
 105                 (Fcinfo).nargs = (Nargs); \
 106         } while (0)
 107
 108 /*
 109  * This macro invokes a function given a filled-in FunctionCallInfoData
 110  * struct.      The macro result is the returned Datum --- but note that
 111  * caller must still check fcinfo->isnull!      Also, if function is strict,
 112  * it is caller's responsibility to verify that no null arguments are present
 113  * before calling.
 114  */
 115 #define FunctionCallInvoke(fcinfo)      ((* (fcinfo)->flinfo->fn_addr) (fcinfo))
 116
 117
 118 /*-------------------------------------------------------------------------
 119  *              Support macros to ease writing fmgr-compatible functions
 120  *
 121  * A C-coded fmgr-compatible function should be declared as
 122  *
 123  *              Datum
 124  *              function_name(PG_FUNCTION_ARGS)
 125  *              {
 126  *                      ...
 127  *              }
 128  *
 129  * It should access its arguments using appropriate PG_GETARG_xxx macros
 130  * and should return its result using PG_RETURN_xxx.
 131  *
 132  *-------------------------------------------------------------------------
 133  */
 134
 135 /* Standard parameter list for fmgr-compatible functions */
 136 #define PG_FUNCTION_ARGS        FunctionCallInfo fcinfo
 137
 138 /*
 139  * Get number of arguments passed to function.
 140  */
 141 #define PG_NARGS() (fcinfo->nargs)
 142
 143 /*
 144  * If function is not marked "proisstrict" in pg_proc, it must check for
 145  * null arguments using this macro.  Do not try to GETARG a null argument!
 146  */
 147 #define PG_ARGISNULL(n)  (fcinfo->argnull[n])
 148
 149 /*
 150  * Support for fetching detoasted copies of toastable datatypes (all of
 151  * which are varlena types).  pg_detoast_datum() gives you either the input
 152  * datum (if not toasted) or a detoasted copy allocated with palloc().
 153  * pg_detoast_datum_copy() always gives you a palloc'd copy --- use it
 154  * if you need a modifiable copy of the input.  Caller is expected to have
 155  * checked for null inputs first, if necessary.
 156  *
 157  * pg_detoast_datum_packed() will return packed (1-byte header) datums
 158  * unmodified.  It will still expand an externally toasted or compressed datum.
 159  * The resulting datum can be accessed using VARSIZE_ANY() and VARDATA_ANY()
 160  * (beware of multiple evaluations in those macros!)
 161  *
 162  * WARNING: It is only safe to use pg_detoast_datum_packed() and
 163  * VARDATA_ANY() if you really don't care about the alignment. Either because
 164  * you're working with something like text where the alignment doesn't matter
 165  * or because you're not going to access its constituent parts and just use
 166  * things like memcpy on it anyways.
 167  *
 168  * Note: it'd be nice if these could be macros, but I see no way to do that
 169  * without evaluating the arguments multiple times, which is NOT acceptable.
 170  */
 171 extern struct varlena *pg_detoast_datum(struct varlena * datum);
 172 extern struct varlena *pg_detoast_datum_copy(struct varlena * datum);
 173 extern struct varlena *pg_detoast_datum_slice(struct varlena * datum,
 174                                            int32 first, int32 count);
 175 extern struct varlena *pg_detoast_datum_packed(struct varlena * datum);
 176
 177 #define PG_DETOAST_DATUM(datum) \
 178         pg_detoast_datum((struct varlena *) DatumGetPointer(datum))
 179 #define PG_DETOAST_DATUM_COPY(datum) \
 180         pg_detoast_datum_copy((struct varlena *) DatumGetPointer(datum))
 181 #define PG_DETOAST_DATUM_SLICE(datum,f,c) \
 182                 pg_detoast_datum_slice((struct varlena *) DatumGetPointer(datum), \
 183                 (int32) (f), (int32) (c))
 184 /* WARNING -- unaligned pointer */
 185 #define PG_DETOAST_DATUM_PACKED(datum) \
 186         pg_detoast_datum_packed((struct varlena *) DatumGetPointer(datum))
 187
 188 /*
 189  * Support for cleaning up detoasted copies of inputs.  This must only
 190  * be used for pass-by-ref datatypes, and normally would only be used
 191  * for toastable types.  If the given pointer is different from the
 192  * original argument, assume it's a palloc'd detoasted copy, and pfree it.
 193  * NOTE: most functions on toastable types do not have to worry about this,
 194  * but we currently require that support functions for indexes not leak
 195  * memory.
 196  */
 197 #define PG_FREE_IF_COPY(ptr,n) \
 198         do { \
 199                 if ((Pointer) (ptr) != PG_GETARG_POINTER(n)) \
 200                         pfree(ptr); \
 201         } while (0)
 202
 203 /* Macros for fetching arguments of standard types */
 204
 205 #define PG_GETARG_DATUM(n)       (fcinfo->arg[n])
 206 #define PG_GETARG_INT32(n)       DatumGetInt32(PG_GETARG_DATUM(n))
 207 #define PG_GETARG_UINT32(n)  DatumGetUInt32(PG_GETARG_DATUM(n))
 208 #define PG_GETARG_INT16(n)       DatumGetInt16(PG_GETARG_DATUM(n))
 209 #define PG_GETARG_UINT16(n)  DatumGetUInt16(PG_GETARG_DATUM(n))
 210 #define PG_GETARG_CHAR(n)        DatumGetChar(PG_GETARG_DATUM(n))
 211 #define PG_GETARG_BOOL(n)        DatumGetBool(PG_GETARG_DATUM(n))
 212 #define PG_GETARG_OID(n)         DatumGetObjectId(PG_GETARG_DATUM(n))
 213 #define PG_GETARG_POINTER(n) DatumGetPointer(PG_GETARG_DATUM(n))
 214 #define PG_GETARG_CSTRING(n) DatumGetCString(PG_GETARG_DATUM(n))
 215 #define PG_GETARG_NAME(n)        DatumGetName(PG_GETARG_DATUM(n))
 216 /* these macros hide the pass-by-reference-ness of the datatype: */
 217 #define PG_GETARG_FLOAT4(n)  DatumGetFloat4(PG_GETARG_DATUM(n))
 218 #define PG_GETARG_FLOAT8(n)  DatumGetFloat8(PG_GETARG_DATUM(n))
 219 #define PG_GETARG_INT64(n)       DatumGetInt64(PG_GETARG_DATUM(n))
 220 /* use this if you want the raw, possibly-toasted input datum: */
 221 #define PG_GETARG_RAW_VARLENA_P(n)      ((struct varlena *) PG_GETARG_POINTER(n))
 222 /* use this if you want the input datum de-toasted: */
 223 #define PG_GETARG_VARLENA_P(n) PG_DETOAST_DATUM(PG_GETARG_DATUM(n))
 224 /* and this if you can handle 1-byte-header datums: */
 225 #define PG_GETARG_VARLENA_PP(n) PG_DETOAST_DATUM_PACKED(PG_GETARG_DATUM(n))
 226 /* DatumGetFoo macros for varlena types will typically look like this: */
 227 #define DatumGetByteaP(X)                       ((bytea *) PG_DETOAST_DATUM(X))
 228 #define DatumGetByteaPP(X)                      ((bytea *) PG_DETOAST_DATUM_PACKED(X))
 229 #define DatumGetTextP(X)                        ((text *) PG_DETOAST_DATUM(X))
 230 #define DatumGetTextPP(X)                       ((text *) PG_DETOAST_DATUM_PACKED(X))
 231 #define DatumGetBpCharP(X)                      ((BpChar *) PG_DETOAST_DATUM(X))
 232 #define DatumGetBpCharPP(X)                     ((BpChar *) PG_DETOAST_DATUM_PACKED(X))
 233 #define DatumGetVarCharP(X)                     ((VarChar *) PG_DETOAST_DATUM(X))
 234 #define DatumGetVarCharPP(X)            ((VarChar *) PG_DETOAST_DATUM_PACKED(X))
 235 #define DatumGetHeapTupleHeader(X)      ((HeapTupleHeader) PG_DETOAST_DATUM(X))
 236 /* And we also offer variants that return an OK-to-write copy */
 237 #define DatumGetByteaPCopy(X)           ((bytea *) PG_DETOAST_DATUM_COPY(X))
 238 #define DatumGetTextPCopy(X)            ((text *) PG_DETOAST_DATUM_COPY(X))
 239 #define DatumGetBpCharPCopy(X)          ((BpChar *) PG_DETOAST_DATUM_COPY(X))
 240 #define DatumGetVarCharPCopy(X)         ((VarChar *) PG_DETOAST_DATUM_COPY(X))
 241 #define DatumGetHeapTupleHeaderCopy(X)  ((HeapTupleHeader) PG_DETOAST_DATUM_COPY(X))
 242 /* Variants which return n bytes starting at pos. m */
 243 #define DatumGetByteaPSlice(X,m,n)      ((bytea *) PG_DETOAST_DATUM_SLICE(X,m,n))
 244 #define DatumGetTextPSlice(X,m,n)       ((text *) PG_DETOAST_DATUM_SLICE(X,m,n))
 245 #define DatumGetBpCharPSlice(X,m,n) ((BpChar *) PG_DETOAST_DATUM_SLICE(X,m,n))
 246 #define DatumGetVarCharPSlice(X,m,n) ((VarChar *) PG_DETOAST_DATUM_SLICE(X,m,n))
 247 /* GETARG macros for varlena types will typically look like this: */
 248 #define PG_GETARG_BYTEA_P(n)            DatumGetByteaP(PG_GETARG_DATUM(n))
 249 #define PG_GETARG_BYTEA_PP(n)           DatumGetByteaPP(PG_GETARG_DATUM(n))
 250 #define PG_GETARG_TEXT_P(n)                     DatumGetTextP(PG_GETARG_DATUM(n))
 251 #define PG_GETARG_TEXT_PP(n)            DatumGetTextPP(PG_GETARG_DATUM(n))
 252 #define PG_GETARG_BPCHAR_P(n)           DatumGetBpCharP(PG_GETARG_DATUM(n))
 253 #define PG_GETARG_BPCHAR_PP(n)          DatumGetBpCharPP(PG_GETARG_DATUM(n))
 254 #define PG_GETARG_VARCHAR_P(n)          DatumGetVarCharP(PG_GETARG_DATUM(n))
 255 #define PG_GETARG_VARCHAR_PP(n)         DatumGetVarCharPP(PG_GETARG_DATUM(n))
 256 #define PG_GETARG_HEAPTUPLEHEADER(n)    DatumGetHeapTupleHeader(PG_GETARG_DATUM(n))
 257 /* And we also offer variants that return an OK-to-write copy */
 258 #define PG_GETARG_BYTEA_P_COPY(n)       DatumGetByteaPCopy(PG_GETARG_DATUM(n))
 259 #define PG_GETARG_TEXT_P_COPY(n)        DatumGetTextPCopy(PG_GETARG_DATUM(n))
 260 #define PG_GETARG_BPCHAR_P_COPY(n)      DatumGetBpCharPCopy(PG_GETARG_DATUM(n))
 261 #define PG_GETARG_VARCHAR_P_COPY(n) DatumGetVarCharPCopy(PG_GETARG_DATUM(n))
 262 #define PG_GETARG_HEAPTUPLEHEADER_COPY(n)       DatumGetHeapTupleHeaderCopy(PG_GETARG_DATUM(n))
 263 /* And a b-byte slice from position a -also OK to write */
 264 #define PG_GETARG_BYTEA_P_SLICE(n,a,b) DatumGetByteaPSlice(PG_GETARG_DATUM(n),a,b)
 265 #define PG_GETARG_TEXT_P_SLICE(n,a,b)  DatumGetTextPSlice(PG_GETARG_DATUM(n),a,b)
 266 #define PG_GETARG_BPCHAR_P_SLICE(n,a,b) DatumGetBpCharPSlice(PG_GETARG_DATUM(n),a,b)
 267 #define PG_GETARG_VARCHAR_P_SLICE(n,a,b) DatumGetVarCharPSlice(PG_GETARG_DATUM(n),a,b)
 268
 269 /* To return a NULL do this: */
 270 #define PG_RETURN_NULL()  \
 271         do { fcinfo->isnull = true; return (Datum) 0; } while (0)
 272
 273 /* A few internal functions return void (which is not the same as NULL!) */
 274 #define PG_RETURN_VOID()         return (Datum) 0
 275
 276 /* Macros for returning results of standard types */
 277
 278 #define PG_RETURN_DATUM(x)       return (x)
 279 #define PG_RETURN_INT32(x)       return Int32GetDatum(x)
 280 #define PG_RETURN_UINT32(x)  return UInt32GetDatum(x)
 281 #define PG_RETURN_INT16(x)       return Int16GetDatum(x)
 282 #define PG_RETURN_CHAR(x)        return CharGetDatum(x)
 283 #define PG_RETURN_BOOL(x)        return BoolGetDatum(x)
 284 #define PG_RETURN_OID(x)         return ObjectIdGetDatum(x)
 285 #define PG_RETURN_POINTER(x) return PointerGetDatum(x)
 286 #define PG_RETURN_CSTRING(x) return CStringGetDatum(x)
 287 #define PG_RETURN_NAME(x)        return NameGetDatum(x)
 288 /* these macros hide the pass-by-reference-ness of the datatype: */
 289 #define PG_RETURN_FLOAT4(x)  return Float4GetDatum(x)
 290 #define PG_RETURN_FLOAT8(x)  return Float8GetDatum(x)
 291 #define PG_RETURN_INT64(x)       return Int64GetDatum(x)
 292 /* RETURN macros for other pass-by-ref types will typically look like this: */
 293 #define PG_RETURN_BYTEA_P(x)   PG_RETURN_POINTER(x)
 294 #define PG_RETURN_TEXT_P(x)    PG_RETURN_POINTER(x)
 295 #define PG_RETURN_BPCHAR_P(x)  PG_RETURN_POINTER(x)
 296 #define PG_RETURN_VARCHAR_P(x) PG_RETURN_POINTER(x)
 297 #define PG_RETURN_HEAPTUPLEHEADER(x)  PG_RETURN_POINTER(x)
 298
 299
 300 /*-------------------------------------------------------------------------
 301  *              Support for detecting call convention of dynamically-loaded functions
 302  *
 303  * Dynamically loaded functions may use either the version-1 ("new style")
 304  * or version-0 ("old style") calling convention.  Version 1 is the call
 305  * convention defined in this header file; version 0 is the old "plain C"
 306  * convention.  A version-1 function must be accompanied by the macro call
 307  *
 308  *              PG_FUNCTION_INFO_V1(function_name);
 309  *
 310  * Note that internal functions do not need this decoration since they are
 311  * assumed to be version-1.
 312  *
 313  *-------------------------------------------------------------------------
 314  */
 315
 316 typedef struct
 317 {
 318         int                     api_version;    /* specifies call convention version number */
 319         /* More fields may be added later, for version numbers > 1. */
 320 } Pg_finfo_record;
 321
 322 /* Expected signature of an info function */
 323 typedef const Pg_finfo_record *(*PGFInfoFunction) (void);
 324
 325 /*
 326  *      Macro to build an info function associated with the given function name.
 327  *      Win32 loadable functions usually link with 'dlltool --export-all', but it
 328  *      doesn't hurt to add PGDLLIMPORT in case they don't.
 329  */
 330 #define PG_FUNCTION_INFO_V1(funcname) \
 331 extern PGDLLIMPORT const Pg_finfo_record * CppConcat(pg_finfo_,funcname)(void); \
 332 const Pg_finfo_record * \
 333 CppConcat(pg_finfo_,funcname) (void) \
 334 { \
 335         static const Pg_finfo_record my_finfo = { 1 }; \
 336         return &my_finfo; \
 337 } \
 338 extern int no_such_variable
 339
 340
 341 /*-------------------------------------------------------------------------
 342  *              Support for verifying backend compatibility of loaded modules
 343  *
 344  * We require dynamically-loaded modules to include the macro call
 345  *              PG_MODULE_MAGIC;
 346  * so that we can check for obvious incompatibility, such as being compiled
 347  * for a different major PostgreSQL version.
 348  *
 349  * To compile with versions of PostgreSQL that do not support this,
 350  * you may put an #ifdef/#endif test around it.  Note that in a multiple-
 351  * source-file module, the macro call should only appear once.
 352  *
 353  * The specific items included in the magic block are intended to be ones that
 354  * are custom-configurable and especially likely to break dynamically loaded
 355  * modules if they were compiled with other values.  Also, the length field
 356  * can be used to detect definition changes.
 357  *
 358  * Note: we compare magic blocks with memcmp(), so there had better not be
 359  * any alignment pad bytes in them.
 360  *
 361  * Note: when changing the contents of magic blocks, be sure to adjust the
 362  * incompatible_module_error() function in dfmgr.c.
 363  *-------------------------------------------------------------------------
 364  */
 365
 366 /* Definition of the magic block structure */
 367 typedef struct
 368 {
 369         int                     len;                    /* sizeof(this struct) */
 370         int                     version;                /* PostgreSQL major version */
 371         int                     funcmaxargs;    /* FUNC_MAX_ARGS */
 372         int                     indexmaxkeys;   /* INDEX_MAX_KEYS */
 373         int                     namedatalen;    /* NAMEDATALEN */
 374         int                     float4byval;    /* FLOAT4PASSBYVAL */
 375         int                     float8byval;    /* FLOAT8PASSBYVAL */
 376 } Pg_magic_struct;
 377
 378 /* The actual data block contents */
 379 #define PG_MODULE_MAGIC_DATA \
 380 { \
 381         sizeof(Pg_magic_struct), \
 382         PG_VERSION_NUM / 100, \
 383         FUNC_MAX_ARGS, \
 384         INDEX_MAX_KEYS, \
 385         NAMEDATALEN, \
 386         FLOAT4PASSBYVAL, \
 387         FLOAT8PASSBYVAL \
 388 }
 389
 390 /*
 391  * Declare the module magic function.  It needs to be a function as the dlsym
 392  * in the backend is only guaranteed to work on functions, not data
 393  */
 394 typedef const Pg_magic_struct *(*PGModuleMagicFunction) (void);
 395
 396 #define PG_MAGIC_FUNCTION_NAME Pg_magic_func
 397 #define PG_MAGIC_FUNCTION_NAME_STRING "Pg_magic_func"
 398
 399 #define PG_MODULE_MAGIC \
 400 extern PGDLLIMPORT const Pg_magic_struct *PG_MAGIC_FUNCTION_NAME(void); \
 401 const Pg_magic_struct * \
 402 PG_MAGIC_FUNCTION_NAME(void) \
 403 { \
 404         static const Pg_magic_struct Pg_magic_data = PG_MODULE_MAGIC_DATA; \
 405         return &Pg_magic_data; \
 406 } \
 407 extern int no_such_variable
 408
 409
 410 /*-------------------------------------------------------------------------
 411  *              Support routines and macros for callers of fmgr-compatible functions
 412  *-------------------------------------------------------------------------
 413  */
 414
 415 /* These are for invocation of a specifically named function with a
 416  * directly-computed parameter list.  Note that neither arguments nor result
 417  * are allowed to be NULL.
 418  */
 419 extern Datum DirectFunctionCall1(PGFunction func, Datum arg1);
 420 extern Datum DirectFunctionCall2(PGFunction func, Datum arg1, Datum arg2);
 421 extern Datum DirectFunctionCall3(PGFunction func, Datum arg1, Datum arg2,
 422                                         Datum arg3);
 423 extern Datum DirectFunctionCall4(PGFunction func, Datum arg1, Datum arg2,
 424                                         Datum arg3, Datum arg4);
 425 extern Datum DirectFunctionCall5(PGFunction func, Datum arg1, Datum arg2,
 426                                         Datum arg3, Datum arg4, Datum arg5);
 427 extern Datum DirectFunctionCall6(PGFunction func, Datum arg1, Datum arg2,
 428                                         Datum arg3, Datum arg4, Datum arg5,
 429                                         Datum arg6);
 430 extern Datum DirectFunctionCall7(PGFunction func, Datum arg1, Datum arg2,
 431                                         Datum arg3, Datum arg4, Datum arg5,
 432                                         Datum arg6, Datum arg7);
 433 extern Datum DirectFunctionCall8(PGFunction func, Datum arg1, Datum arg2,
 434                                         Datum arg3, Datum arg4, Datum arg5,
 435                                         Datum arg6, Datum arg7, Datum arg8);
 436 extern Datum DirectFunctionCall9(PGFunction func, Datum arg1, Datum arg2,
 437                                         Datum arg3, Datum arg4, Datum arg5,
 438                                         Datum arg6, Datum arg7, Datum arg8,
 439                                         Datum arg9);
 440
 441 /* These are for invocation of a previously-looked-up function with a
 442  * directly-computed parameter list.  Note that neither arguments nor result
 443  * are allowed to be NULL.
 444  */
 445 extern Datum FunctionCall1(FmgrInfo *flinfo, Datum arg1);
 446 extern Datum FunctionCall2(FmgrInfo *flinfo, Datum arg1, Datum arg2);
 447 extern Datum FunctionCall3(FmgrInfo *flinfo, Datum arg1, Datum arg2,
 448                           Datum arg3);
 449 extern Datum FunctionCall4(FmgrInfo *flinfo, Datum arg1, Datum arg2,
 450                           Datum arg3, Datum arg4);
 451 extern Datum FunctionCall5(FmgrInfo *flinfo, Datum arg1, Datum arg2,
 452                           Datum arg3, Datum arg4, Datum arg5);
 453 extern Datum FunctionCall6(FmgrInfo *flinfo, Datum arg1, Datum arg2,
 454                           Datum arg3, Datum arg4, Datum arg5,
 455                           Datum arg6);
 456 extern Datum FunctionCall7(FmgrInfo *flinfo, Datum arg1, Datum arg2,
 457                           Datum arg3, Datum arg4, Datum arg5,
 458                           Datum arg6, Datum arg7);
 459 extern Datum FunctionCall8(FmgrInfo *flinfo, Datum arg1, Datum arg2,
 460                           Datum arg3, Datum arg4, Datum arg5,
 461                           Datum arg6, Datum arg7, Datum arg8);
 462 extern Datum FunctionCall9(FmgrInfo *flinfo, Datum arg1, Datum arg2,
 463                           Datum arg3, Datum arg4, Datum arg5,
 464                           Datum arg6, Datum arg7, Datum arg8,
 465                           Datum arg9);
 466
 467 /* These are for invocation of a function identified by OID with a
 468  * directly-computed parameter list.  Note that neither arguments nor result
 469  * are allowed to be NULL.      These are essentially FunctionLookup() followed
 470  * by FunctionCallN().  If the same function is to be invoked repeatedly,
 471  * do the FunctionLookup() once and then use FunctionCallN().
 472  */
 473 extern Datum OidFunctionCall1(Oid functionId, Datum arg1);
 474 extern Datum OidFunctionCall2(Oid functionId, Datum arg1, Datum arg2);
 475 extern Datum OidFunctionCall3(Oid functionId, Datum arg1, Datum arg2,
 476                                  Datum arg3);
 477 extern Datum OidFunctionCall4(Oid functionId, Datum arg1, Datum arg2,
 478                                  Datum arg3, Datum arg4);
 479 extern Datum OidFunctionCall5(Oid functionId, Datum arg1, Datum arg2,
 480                                  Datum arg3, Datum arg4, Datum arg5);
 481 extern Datum OidFunctionCall6(Oid functionId, Datum arg1, Datum arg2,
 482                                  Datum arg3, Datum arg4, Datum arg5,
 483                                  Datum arg6);
 484 extern Datum OidFunctionCall7(Oid functionId, Datum arg1, Datum arg2,
 485                                  Datum arg3, Datum arg4, Datum arg5,
 486                                  Datum arg6, Datum arg7);
 487 extern Datum OidFunctionCall8(Oid functionId, Datum arg1, Datum arg2,
 488                                  Datum arg3, Datum arg4, Datum arg5,
 489                                  Datum arg6, Datum arg7, Datum arg8);
 490 extern Datum OidFunctionCall9(Oid functionId, Datum arg1, Datum arg2,
 491                                  Datum arg3, Datum arg4, Datum arg5,
 492                                  Datum arg6, Datum arg7, Datum arg8,
 493                                  Datum arg9);
 494
 495 /* Special cases for convenient invocation of datatype I/O functions. */
 496 extern Datum InputFunctionCall(FmgrInfo *flinfo, char *str,
 497                                   Oid typioparam, int32 typmod);
 498 extern Datum OidInputFunctionCall(Oid functionId, char *str,
 499                                          Oid typioparam, int32 typmod);
 500 extern char *OutputFunctionCall(FmgrInfo *flinfo, Datum val);
 501 extern char *OidOutputFunctionCall(Oid functionId, Datum val);
 502 extern Datum ReceiveFunctionCall(FmgrInfo *flinfo, fmStringInfo buf,
 503                                         Oid typioparam, int32 typmod);
 504 extern Datum OidReceiveFunctionCall(Oid functionId, fmStringInfo buf,
 505                                            Oid typioparam, int32 typmod);
 506 extern bytea *SendFunctionCall(FmgrInfo *flinfo, Datum val);
 507 extern bytea *OidSendFunctionCall(Oid functionId, Datum val);
 508
 509
 510 /*
 511  * Routines in fmgr.c
 512  */
 513 extern const Pg_finfo_record *fetch_finfo_record(void *filehandle, char *funcname);
 514 extern void clear_external_function_hash(void *filehandle);
 515 extern Oid      fmgr_internal_function(const char *proname);
 516 extern Oid      get_fn_expr_rettype(FmgrInfo *flinfo);
 517 extern Oid      get_fn_expr_argtype(FmgrInfo *flinfo, int argnum);
 518 extern Oid      get_call_expr_argtype(fmNodePtr expr, int argnum);
 519
 520 /*
 521  * Routines in dfmgr.c
 522  */
 523 extern char *Dynamic_library_path;
 524
 525 extern PGFunction load_external_function(char *filename, char *funcname,
 526                                            bool signalNotFound, void **filehandle);
 527 extern PGFunction lookup_external_function(void *filehandle, char *funcname);
 528 extern void load_file(const char *filename, bool restricted);
 529 extern void **find_rendezvous_variable(const char *varName);
 530
 531
 532 /*
 533  * !!! OLD INTERFACE !!!
 534  *
 535  * fmgr() is the only remaining vestige of the old-style caller support
 536  * functions.  It's no longer used anywhere in the Postgres distribution,
 537  * but we should leave it around for a release or two to ease the transition
 538  * for user-supplied C functions.  OidFunctionCallN() replaces it for new
 539  * code.
 540  */
 541
 542 /*
 543  * DEPRECATED, DO NOT USE IN NEW CODE
 544  */
 545 extern char *fmgr(Oid procedureId,...);
 546
 547 #endif   /* FMGR_H */