diff options
Diffstat (limited to 'src/backend/utils/adt/varbit.c')
| -rw-r--r-- | src/backend/utils/adt/varbit.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/src/backend/utils/adt/varbit.c b/src/backend/utils/adt/varbit.c index adb08369ed2..1227e5a5082 100644 --- a/src/backend/utils/adt/varbit.c +++ b/src/backend/utils/adt/varbit.c @@ -18,6 +18,8 @@ #include "access/htup.h" #include "libpq/pqformat.h" +#include "nodes/nodeFuncs.h" +#include "parser/parse_clause.h" #include "utils/array.h" #include "utils/varbit.h" @@ -646,6 +648,39 @@ varbit_send(PG_FUNCTION_ARGS) } /* + * varbit_transform() + * Flatten calls to our length coercion function that leave the new maximum + * length >= the previous maximum length. We ignore the isExplicit argument, + * which only affects truncation. + */ +Datum +varbit_transform(PG_FUNCTION_ARGS) +{ + FuncExpr *expr = (FuncExpr *) PG_GETARG_POINTER(0); + Node *typmod; + Node *ret = NULL; + + if (!IsA(expr, FuncExpr)) + PG_RETURN_POINTER(ret); + + Assert(list_length(expr->args) == 3); + typmod = lsecond(expr->args); + + if (IsA(typmod, Const)) + { + Node *source = linitial(expr->args); + int32 new_typmod = DatumGetInt32(((Const *) typmod)->constvalue); + int32 old_max = exprTypmod(source); + int32 new_max = new_typmod; + + if (new_max <= 0 || (old_max >= 0 && old_max <= new_max)) + ret = relabel_to_typmod(source, new_typmod); + } + + PG_RETURN_POINTER(ret); +} + +/* * varbit() * Converts a varbit() type to a specific internal length. * len is the maximum bitlength specified in the column definition. |