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sql/jsonb_apply--0.1.0.sql

@@ -4,8 +4,20 @@ AS
 'jsonb_apply_nofilter'
     LANGUAGE C;
 
+CREATE FUNCTION jsonb_apply(jsonb, regproc, variadic "any" default null) RETURNS jsonb
+AS
+'MODULE_PATHNAME',
+'jsonb_apply_nofilter'
+    LANGUAGE C;
+
 CREATE FUNCTION jsonb_filter_apply(jsonb, text[], text, variadic "any" default null) RETURNS jsonb
 AS
 'MODULE_PATHNAME',
-'jsonb_filter_apply'
+'jsonb_apply_withfilter'
+    LANGUAGE C;
+
+CREATE FUNCTION jsonb_filter_apply(jsonb, text[], regproc, variadic "any" default null) RETURNS jsonb
+AS
+'MODULE_PATHNAME',
+'jsonb_apply_withfilter'
     LANGUAGE C;

src/jsonb_apply.c

@@ -225,51 +225,65 @@ jsonb_apply_worker(Jsonb *jb, text *funcdef,
     PG_RETURN_JSONB_P(out);
 }
 
-
+/* Actual implementation for jsonb_apply(jsonb, text/regproc/regprocedure, variadic "any" default null) */
 Datum jsonb_apply_internal(FunctionCallInfo fcinfo, bool withfilter) {
-    Jsonb *jb;
+    /* Input */
+    Jsonb *jb; /* That's always the first argument */
+    Datum funcdefDatum;
+    Oid funcdefOid;
+
+    bool variadic_null = false;
+    bool withvarargs;
+    int nvarargs;
+    Datum *varargs;
+    bool *varnulls;
+    Oid *vartypes;
+
     text *funcdef;
-    bool with_filter = false;
     Datum filter;
-    bool variadic_null = false;
     int variadic_start;
 
-    if (withfilter) {
+    if (!withfilter) {
+        /* jsonb_apply(jsonb, text/regproc/regprocedure, args) */
+        jb = PG_GETARG_JSONB_P(0);
+        funcdefDatum = PG_GETARG_DATUM(1);
+        funcdefOid = PG_GETARG_OID(1);
+        Assert((funcdefDatum == TEXTOID) || (funcdefOid == REGPROCOID));
+        funcdef = PG_GETARG_TEXT_PP(1);
+        variadic_start = 2;
+        variadic_null = PG_NARGS() == 3 && PG_ARGISNULL(2);
+    } else {
+        /*
+         * jsonb_apply(jsonb, text[], text/regproc/regprocedure, args).
+         * We have a filter which is idx_arg=1,
+         * so we apply the filter first,
+         * and then like the if-block above but the rest of the indices are shifted by +1
+         */
         filter = PG_GETARG_DATUM(1);
+        /* We apply the filter before anything else */
         jb = DatumGetJsonbP(DirectFunctionCall2(jsonb_extract_path, PG_GETARG_DATUM(0), filter));
         funcdef = PG_GETARG_TEXT_PP(2);
-        variadic_null = PG_NARGS() == 4 && PG_ARGISNULL(3);
+
         variadic_start = 3;
-    } else {
-        // filter = PG_GETARG_DATUM(1);
-        jb = PG_GETARG_JSONB_P(0);
-        funcdef = PG_GETARG_TEXT_PP(1);
-        variadic_null = PG_NARGS() == 3 && PG_ARGISNULL(2);
-        variadic_start = 2;
+        variadic_null = PG_NARGS() == 4 && PG_ARGISNULL(3);
     }
 
-    /* A hack to trick the parser. true when call with (jsonb, text, null) */
-
-    Datum *varargs;
-    bool *varnulls;
-    Oid *vartypes;
-
     /* build argument values to build the object */
-    int nvarargs = extract_variadic_args(fcinfo, variadic_start, true,
+    nvarargs = extract_variadic_args(fcinfo, variadic_start, true,
                                          &varargs, &vartypes, &varnulls);
 
-    bool withvarargs = (nvarargs == -1 || variadic_null) ? false : true;
+    withvarargs = (nvarargs == -1 || variadic_null) ? false : true;
 
     printf("withvarargs=%d\n", withvarargs);
     PG_RETURN_DATUM(
         jsonb_apply_worker(jb, funcdef, PG_NARGS(), withvarargs, nvarargs, varargs, varnulls, vartypes, fcinfo->
             fncollation));
 }
 
-PG_FUNCTION_INFO_V1(jsonb_filter_apply);
+PG_FUNCTION_INFO_V1(jsonb_apply_withfilter);
 
 Datum
-jsonb_filter_apply(PG_FUNCTION_ARGS) {
+jsonb_apply_withfilter(PG_FUNCTION_ARGS) {
     return jsonb_apply_internal(fcinfo, true);
 }