1 files changed, 62 insertions, 0 deletions
diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index a103cbc7c69..d383cbdfedb 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -2227,3 +2227,65 @@ jsonb_float8(PG_FUNCTION_ARGS)
 
 	PG_RETURN_DATUM(retValue);
 }
+
+/*
+ * Construct an empty array jsonb.
+ */
+Jsonb *
+JsonbMakeEmptyArray(void)
+{
+	JsonbValue jbv;
+
+	jbv.type = jbvArray;
+	jbv.val.array.elems = NULL;
+	jbv.val.array.nElems = 0;
+	jbv.val.array.rawScalar = false;
+
+	return JsonbValueToJsonb(&jbv);
+}
+
+/*
+ * Construct an empty object jsonb.
+ */
+Jsonb *
+JsonbMakeEmptyObject(void)
+{
+	JsonbValue jbv;
+
+	jbv.type = jbvObject;
+	jbv.val.object.pairs = NULL;
+	jbv.val.object.nPairs = 0;
+
+	return JsonbValueToJsonb(&jbv);
+}
+
+/*
+ * Convert jsonb to a C-string stripping quotes from scalar strings.
+ */
+char *
+JsonbUnquote(Jsonb *jb)
+{
+	if (JB_ROOT_IS_SCALAR(jb))
+	{
+		JsonbValue	v;
+
+		JsonbExtractScalar(&jb->root, &v);
+
+		if (v.type == jbvString)
+			return pnstrdup(v.val.string.val, v.val.string.len);
+		else if (v.type == jbvBool)
+			return pstrdup(v.val.boolean ? "true" : "false");
+		else if (v.type == jbvNumeric)
+			return DatumGetCString(DirectFunctionCall1(numeric_out,
+									   PointerGetDatum(v.val.numeric)));
+		else if (v.type == jbvNull)
+			return pstrdup("null");
+		else
+		{
+			elog(ERROR, "unrecognized jsonb value type %d", v.type);
+			return NULL;
+		}
+	}
+	else
+		return JsonbToCString(NULL, &jb->root, VARSIZE(jb));
+}