diff options
Diffstat (limited to 'src/backend/utils/adt/arrayfuncs.c')
| -rw-r--r-- | src/backend/utils/adt/arrayfuncs.c | 156 |
1 files changed, 155 insertions, 1 deletions
diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c index a4f1842e5f9..f8fe7e42229 100644 --- a/src/backend/utils/adt/arrayfuncs.c +++ b/src/backend/utils/adt/arrayfuncs.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.38 1999/02/13 23:19:00 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.39 1999/05/03 19:09:59 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -15,6 +15,7 @@ #include <ctype.h> #include <stdio.h> #include <string.h> +#include <stdarg.h> #include "postgres.h" @@ -26,6 +27,7 @@ #include "storage/fd.h" #include "fmgr.h" #include "utils/array.h" +#include "utils/elog.h" #include "libpq/libpq-fs.h" #include "libpq/be-fsstubs.h" @@ -614,7 +616,9 @@ array_out(ArrayType *v, Oid element_type) i, j, k, +#ifndef TCL_ARRAYS l, +#endif indx[MAXDIM]; bool dummy_bool; int ndim, @@ -1274,6 +1278,156 @@ array_assgn(ArrayType *array, return (char *) array; } +/* + * array_map() + * + * Map an arbitrary function to an array and return a new array with + * same dimensions and the source elements transformed by fn(). + */ +ArrayType * +array_map(ArrayType *v, + Oid type, + char *(fn)(char *p, ...), + Oid retType, + int nargs, + ...) +{ + ArrayType *result; + void *args[4]; + char **values; + char *elt; + int *dim; + int ndim; + int nitems; + int i; + int nbytes = 0; + int inp_typlen; + bool inp_typbyval; + int typlen; + bool typbyval; + char typdelim; + Oid typelem; + Oid proc; + char typalign; + char *s; + char *p; + va_list ap; + + /* Large objects not yet supported */ + if (ARR_IS_LO(v) == true) { + elog(ERROR, "array_map: large objects not supported"); + } + + /* Check nargs */ + if ((nargs < 0) || (nargs > 4)) { + elog(ERROR, "array_map: invalid nargs: %d", nargs); + } + + /* Copy extra args to local variable */ + va_start(ap, nargs); + for (i=0; i<nargs; i++) { + args[i] = (void *) va_arg(ap, char *); + } + va_end(ap); + + /* Lookup source and result types. Unneeded variables are reused. */ + system_cache_lookup(type, false, &inp_typlen, &inp_typbyval, + &typdelim, &typelem, &proc, &typalign); + system_cache_lookup(retType, false, &typlen, &typbyval, + &typdelim, &typelem, &proc, &typalign); + + /* Allocate temporary array for new values */ + ndim = ARR_NDIM(v); + dim = ARR_DIMS(v); + nitems = getNitems(ndim, dim); + values = (char **) palloc(nitems * sizeof(char *)); + MemSet(values, 0, nitems * sizeof(char *)); + + /* Loop over source data */ + s = (char *) ARR_DATA_PTR(v); + for (i=0; i<nitems; i++) { + /* Get source element */ + if (inp_typbyval) { + switch (inp_typlen) { + case 1: + elt = (char *) ((int) (*(char *) s)); + break; + case 2: + elt = (char *) ((int) (*(int16 *) s)); + break; + case 3: + case 4: + default: + elt = (char *) (*(int32 *) s); + break; + } + s += inp_typlen; + } else { + elt = s; + if (inp_typlen > 0) { + s += inp_typlen; + } else { + s += INTALIGN(*(int32 *) s); + } + } + + /* + * Apply the given function to source elt and extra args. + * nargs is the number of extra args taken by fn(). + */ + switch (nargs) { + case 0: + p = (char *) (*fn) (elt); + break; + case 1: + p = (char *) (*fn) (elt, args[0]); + break; + case 2: + p = (char *) (*fn) (elt, args[0], args[1]); + break; + case 3: + p = (char *) (*fn) (elt, args[0], args[1], args[2]); + break; + case 4: + default: + p = (char *) (*fn) (elt, args[0], args[1], args[2], args[3]); + break; + } + + /* Update values and total result size */ + if (typbyval) { + values[i] = (char *) p; + nbytes += typlen; + } else { + int len; + len = ((typlen > 0) ? typlen : INTALIGN(*(int32 *) p)); + /* Needed because _CopyArrayEls tries to pfree items */ + if (p == elt) { + p = (char *) palloc(len); + memcpy(p, elt, len); + } + values[i] = (char *) p; + nbytes += len; + } + } + + /* Allocate and initialize the result array */ + nbytes += ARR_OVERHEAD(ndim); + result = (ArrayType *) palloc(nbytes); + MemSet(result, 0, nbytes); + + memcpy((char *) result, (char *) &nbytes, sizeof(int)); + memcpy((char *) ARR_NDIM_PTR(result), (char *) &ndim, sizeof(int)); + memcpy((char *) ARR_DIMS(result), ARR_DIMS(v), 2 * ndim * sizeof(int)); + + /* Copy new values into the result array. values is pfreed. */ + _CopyArrayEls((char **) values, + ARR_DATA_PTR(result), nitems, + typlen, typalign, typbyval); + + return result; +} + /*----------------------------------------------------------------------------- * array_eq : * compares two arrays for equality |