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91e79260f6
Remove a bunch of "extern Datum foo(PG_FUNCTION_ARGS);" declarations that
are no longer needed now that PG_FUNCTION_INFO_V1(foo) provides that.
Some of these were evidently missed in commit e7128e8dbb, but others
were cargo-culted in in code added since then. Possibly that can be blamed
in part on the fact that we'd not fixed relevant documentation examples,
which I've now done.
127 lines
2.9 KiB
C
127 lines
2.9 KiB
C
/* src/tutorial/funcs_new.c */
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/******************************************************************************
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These are user-defined functions that can be bound to a Postgres backend
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and called by Postgres to execute SQL functions of the same name.
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The calling format for these functions is defined by the CREATE FUNCTION
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SQL statement that binds them to the backend.
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NOTE: this file shows examples of "new style" function call conventions.
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See funcs.c for examples of "old style".
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*****************************************************************************/
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#include "postgres.h" /* general Postgres declarations */
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#include "executor/executor.h" /* for GetAttributeByName() */
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#include "utils/geo_decls.h" /* for point type */
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PG_MODULE_MAGIC;
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/* By Value */
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PG_FUNCTION_INFO_V1(add_one);
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Datum
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add_one(PG_FUNCTION_ARGS)
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{
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int32 arg = PG_GETARG_INT32(0);
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PG_RETURN_INT32(arg + 1);
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}
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/* By Reference, Fixed Length */
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PG_FUNCTION_INFO_V1(add_one_float8);
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Datum
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add_one_float8(PG_FUNCTION_ARGS)
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{
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/* The macros for FLOAT8 hide its pass-by-reference nature */
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float8 arg = PG_GETARG_FLOAT8(0);
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PG_RETURN_FLOAT8(arg + 1.0);
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}
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PG_FUNCTION_INFO_V1(makepoint);
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Datum
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makepoint(PG_FUNCTION_ARGS)
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{
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Point *pointx = PG_GETARG_POINT_P(0);
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Point *pointy = PG_GETARG_POINT_P(1);
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Point *new_point = (Point *) palloc(sizeof(Point));
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new_point->x = pointx->x;
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new_point->y = pointy->y;
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PG_RETURN_POINT_P(new_point);
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}
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/* By Reference, Variable Length */
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PG_FUNCTION_INFO_V1(copytext);
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Datum
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copytext(PG_FUNCTION_ARGS)
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{
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text *t = PG_GETARG_TEXT_P(0);
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/*
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* VARSIZE is the total size of the struct in bytes.
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*/
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text *new_t = (text *) palloc(VARSIZE(t));
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SET_VARSIZE(new_t, VARSIZE(t));
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/*
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* VARDATA is a pointer to the data region of the struct.
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*/
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memcpy((void *) VARDATA(new_t), /* destination */
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(void *) VARDATA(t), /* source */
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VARSIZE(t) - VARHDRSZ); /* how many bytes */
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PG_RETURN_TEXT_P(new_t);
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}
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PG_FUNCTION_INFO_V1(concat_text);
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Datum
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concat_text(PG_FUNCTION_ARGS)
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{
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text *arg1 = PG_GETARG_TEXT_P(0);
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text *arg2 = PG_GETARG_TEXT_P(1);
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int32 arg1_size = VARSIZE(arg1) - VARHDRSZ;
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int32 arg2_size = VARSIZE(arg2) - VARHDRSZ;
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int32 new_text_size = arg1_size + arg2_size + VARHDRSZ;
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text *new_text = (text *) palloc(new_text_size);
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SET_VARSIZE(new_text, new_text_size);
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memcpy(VARDATA(new_text), VARDATA(arg1), arg1_size);
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memcpy(VARDATA(new_text) + arg1_size, VARDATA(arg2), arg2_size);
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PG_RETURN_TEXT_P(new_text);
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}
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/* Composite types */
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PG_FUNCTION_INFO_V1(c_overpaid);
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Datum
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c_overpaid(PG_FUNCTION_ARGS)
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{
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HeapTupleHeader t = PG_GETARG_HEAPTUPLEHEADER(0);
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int32 limit = PG_GETARG_INT32(1);
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bool isnull;
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int32 salary;
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salary = DatumGetInt32(GetAttributeByName(t, "salary", &isnull));
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if (isnull)
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PG_RETURN_BOOL(false);
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/*
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* Alternatively, we might prefer to do PG_RETURN_NULL() for null salary
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*/
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PG_RETURN_BOOL(salary > limit);
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}
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