diff options
Diffstat (limited to 'src/backend/utils/adt/varlena.c')
| -rw-r--r-- | src/backend/utils/adt/varlena.c | 181 |
1 files changed, 176 insertions, 5 deletions
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c index ce6443647e2..37413bcd59f 100644 --- a/src/backend/utils/adt/varlena.c +++ b/src/backend/utils/adt/varlena.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.100 2003/06/25 21:30:32 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.101 2003/06/27 00:33:25 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -19,11 +19,14 @@ #include "mb/pg_wchar.h" #include "miscadmin.h" #include "access/tuptoaster.h" +#include "catalog/pg_type.h" #include "lib/stringinfo.h" #include "libpq/crypt.h" #include "libpq/pqformat.h" +#include "utils/array.h" #include "utils/builtins.h" #include "utils/pg_locale.h" +#include "utils/lsyscache.h" typedef struct varlena unknown; @@ -1983,8 +1986,7 @@ split_text(PG_FUNCTION_ARGS) if (fldnum == 1) /* first field - just return the input * string */ PG_RETURN_TEXT_P(inputstring); - else -/* otherwise return an empty string */ + else /* otherwise return an empty string */ PG_RETURN_TEXT_P(PG_STR_GET_TEXT("")); } @@ -2004,8 +2006,7 @@ split_text(PG_FUNCTION_ARGS) if (fldnum == 1) /* first field - just return the input * string */ PG_RETURN_TEXT_P(inputstring); - else -/* otherwise return an empty string */ + else /* otherwise return an empty string */ PG_RETURN_TEXT_P(PG_STR_GET_TEXT("")); } else if ((start_posn != 0) && (end_posn == 0)) @@ -2028,6 +2029,176 @@ split_text(PG_FUNCTION_ARGS) } } +/* + * text_to_array + * parse input string + * return text array of elements + * based on provided field separator + */ +Datum +text_to_array(PG_FUNCTION_ARGS) +{ + text *inputstring = PG_GETARG_TEXT_P(0); + int inputstring_len = TEXTLEN(inputstring); + text *fldsep = PG_GETARG_TEXT_P(1); + int fldsep_len = TEXTLEN(fldsep); + int fldnum; + int start_posn = 0; + int end_posn = 0; + text *result_text = NULL; + ArrayBuildState *astate = NULL; + MemoryContext oldcontext = CurrentMemoryContext; + + /* return NULL for empty input string */ + if (inputstring_len < 1) + PG_RETURN_NULL(); + + /* empty field separator + * return one element, 1D, array using the input string */ + if (fldsep_len < 1) + PG_RETURN_ARRAYTYPE_P(create_singleton_array(fcinfo, TEXTOID, + CStringGetDatum(inputstring), 1)); + + /* start with end position holding the initial start position */ + end_posn = 0; + for (fldnum=1;;fldnum++) /* field number is 1 based */ + { + Datum dvalue; + bool disnull = false; + + start_posn = end_posn; + end_posn = text_position(PointerGetDatum(inputstring), + PointerGetDatum(fldsep), + fldnum); + + if ((start_posn == 0) && (end_posn == 0)) /* fldsep not found */ + { + if (fldnum == 1) + { + /* first element + * return one element, 1D, array using the input string */ + PG_RETURN_ARRAYTYPE_P(create_singleton_array(fcinfo, TEXTOID, + CStringGetDatum(inputstring), 1)); + } + else + { + /* otherwise create array and exit */ + PG_RETURN_ARRAYTYPE_P(makeArrayResult(astate, oldcontext)); + } + } + else if ((start_posn != 0) && (end_posn == 0)) + { + /* last field requested */ + result_text = text_substring(PointerGetDatum(inputstring), start_posn + fldsep_len, -1, true); + } + else if ((start_posn == 0) && (end_posn != 0)) + { + /* first field requested */ + result_text = LEFT(inputstring, fldsep); + } + else + { + /* prior to last field requested */ + result_text = text_substring(PointerGetDatum(inputstring), start_posn + fldsep_len, end_posn - start_posn - fldsep_len, false); + } + + /* stash away current value */ + dvalue = PointerGetDatum(result_text); + astate = accumArrayResult(astate, dvalue, + disnull, TEXTOID, oldcontext); + + } + + /* never reached -- keep compiler quiet */ + PG_RETURN_NULL(); +} + +/* + * array_to_text + * concatenate Cstring representation of input array elements + * using provided field separator + */ +Datum +array_to_text(PG_FUNCTION_ARGS) +{ + ArrayType *v = PG_GETARG_ARRAYTYPE_P(0); + char *fldsep = PG_TEXTARG_GET_STR(1); + int nitems, *dims, ndims; + char *p; + Oid element_type; + int typlen; + bool typbyval; + char typalign; + Oid typelem; + StringInfo result_str = makeStringInfo(); + int i; + ArrayMetaState *my_extra; + + p = ARR_DATA_PTR(v); + ndims = ARR_NDIM(v); + dims = ARR_DIMS(v); + nitems = ArrayGetNItems(ndims, dims); + + /* if there are no elements, return an empty string */ + if (nitems == 0) + PG_RETURN_TEXT_P(PG_STR_GET_TEXT("")); + + element_type = ARR_ELEMTYPE(v); + + /* + * We arrange to look up info about element type, including its output + * conversion proc, only once per series of calls, assuming the element + * type doesn't change underneath us. + */ + my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra; + if (my_extra == NULL) + { + fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt, + sizeof(ArrayMetaState)); + my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra; + my_extra->element_type = InvalidOid; + } + + if (my_extra->element_type != element_type) + { + /* Get info about element type, including its output conversion proc */ + get_type_io_data(element_type, IOFunc_output, + &my_extra->typlen, &my_extra->typbyval, + &my_extra->typalign, &my_extra->typdelim, + &my_extra->typelem, &my_extra->typiofunc); + fmgr_info_cxt(my_extra->typiofunc, &my_extra->proc, + fcinfo->flinfo->fn_mcxt); + my_extra->element_type = element_type; + } + typlen = my_extra->typlen; + typbyval = my_extra->typbyval; + typalign = my_extra->typalign; + typelem = my_extra->typelem; + + for (i = 0; i < nitems; i++) + { + Datum itemvalue; + char *value; + + itemvalue = fetch_att(p, typbyval, typlen); + + value = DatumGetCString(FunctionCall3(&my_extra->proc, + itemvalue, + ObjectIdGetDatum(typelem), + Int32GetDatum(-1))); + + if (i > 0) + appendStringInfo(result_str, "%s%s", fldsep, value); + else + appendStringInfo(result_str, "%s", value); + + p = att_addlength(p, typlen, PointerGetDatum(p)); + p = (char *) att_align(p, typalign); + } + + PG_RETURN_TEXT_P(PG_STR_GET_TEXT(result_str->data)); +} + #define HEXBASE 16 /* * Convert a int32 to a string containing a base 16 (hex) representation of |