implement **{} path opt in jsonpath

Author: feodor

src/backend/utils/adt/jsonpath.c

@@ -95,6 +95,14 @@ flattenJsonPathParseItem(StringInfo buf, JsonPathParseItem *item)
 								   (char*)item->array.elems,
 								   item->array.nelems * sizeof(item->array.elems[0]));
 			break;
+		case jpiAny:
+			appendBinaryStringInfo(buf,
+								   (char*)&item->anybounds.first,
+								   sizeof(item->anybounds.first));
+			appendBinaryStringInfo(buf,
+								   (char*)&item->anybounds.last,
+								   sizeof(item->anybounds.last));
+			break;
 		default:
 			elog(ERROR, "Unknown jsonpath item type: %d", item->type);
 	}
@@ -249,6 +257,23 @@ printJsonPathItem(StringInfo buf, JsonPathItem *v, bool inKey, bool printBracket
 			}
 			appendStringInfoChar(buf, ']');
 			break;
+		case jpiAny:
+			if (inKey)
+				appendStringInfoChar(buf, '.');
+
+			if (v->anybounds.first == 0 &&
+					v->anybounds.last == PG_UINT32_MAX)
+				appendBinaryStringInfo(buf, "**", 2);
+			else if (v->anybounds.first == 0)
+				appendStringInfo(buf, "**{,%u}", v->anybounds.last);
+			else if (v->anybounds.last == PG_UINT32_MAX)
+				appendStringInfo(buf, "**{%u,}", v->anybounds.first);
+			else if (v->anybounds.first == v->anybounds.last)
+				appendStringInfo(buf, "**{%u}", v->anybounds.first);
+			else
+				appendStringInfo(buf, "**{%u,%u}", v->anybounds.first,
+												   v->anybounds.last);
+			break;
 		default:
 			elog(ERROR, "Unknown jsonpath item type: %d", v->type);
 	}
@@ -348,6 +373,10 @@ jspInitByBuffer(JsonPathItem *v, char *base, int32 pos)
 			read_int32(v->array.nelems, base, pos);
 			read_int32_n(v->array.elems, base, pos, v->array.nelems);
 			break;
+		case jpiAny:
+			read_int32(v->anybounds.first, base, pos);
+			read_int32(v->anybounds.last, base, pos);
+			break;
 		default:
 			elog(ERROR, "Unknown jsonpath item type: %d", v->type);
 	}
@@ -376,6 +405,7 @@ jspGetNext(JsonPathItem *v, JsonPathItem *a)
 	{
 		Assert(
 			v->type == jpiKey ||
+			v->type == jpiAny ||
 			v->type == jpiAnyArray ||
 			v->type == jpiAnyKey ||
 			v->type == jpiIndexArray ||

src/backend/utils/adt/jsonpath_exec.c

@@ -292,6 +292,67 @@ copyJsonbValue(JsonbValue *src)
 	return dst;
 }
 
+static JsonPathExecResult
+recursiveExecute(JsonPathItem *jsp, List *vars, JsonbValue *jb, List **found);
+
+static JsonPathExecResult
+recursiveAny(JsonPathItem *jsp, List *vars, JsonbValue *jb,
+			 List **found, uint32 level, uint32 first, uint32 last)
+{
+	JsonPathExecResult	res = jperNotFound;
+	JsonbIterator		*it;
+	int32				r;
+	JsonbValue			v;
+
+	check_stack_depth();
+
+	if (level > last)
+		return res;
+
+	it = JsonbIteratorInit(jb->val.binary.data);
+
+	while((r = JsonbIteratorNext(&it, &v, true)) != WJB_DONE)
+	{
+		if (r == WJB_KEY)
+		{
+			r = JsonbIteratorNext(&it, &v, true);
+			Assert(r == WJB_VALUE);
+		}
+
+		if (r == WJB_VALUE || r == WJB_ELEM)
+		{
+
+			if (level >= first)
+			{
+				/* check expression */
+				if (jsp)
+				{
+					res = recursiveExecute(jsp, vars, &v, found);
+					if (res == jperOk && !found)
+						break;
+				}
+				else
+				{
+					res = jperOk;
+					if (!found)
+						break;
+					*found = lappend(*found, copyJsonbValue(&v));
+				}
+			}
+
+			if (level < last && v.type == jbvBinary)
+			{
+				res = recursiveAny(jsp, vars, &v, found, level + 1, first, last);
+
+				if (res == jperOk && found == NULL)
+					break;
+			}
+		}
+	}
+
+	return res;
+}
+
 static JsonPathExecResult
 recursiveExecute(JsonPathItem *jsp, List *vars, JsonbValue *jb, List **found)
 {
@@ -521,6 +582,35 @@ recursiveExecute(JsonPathItem *jsp, List *vars, JsonbValue *jb, List **found)
 			if (res == jperOk && found)
 				*found = lappend(*found, copyJsonbValue(jb));
 			break;
+		case jpiAny:
+		{
+			bool hasNext = jspGetNext(jsp, &elem);
+
+			/* first try without any intermediate steps */
+			if (jsp->anybounds.first == 0)
+			{
+				if (hasNext)
+				{
+					res = recursiveExecute(&elem, vars, jb, found);
+					if (res == jperOk && !found)
+						break;
+				}
+				else
+				{
+					res = jperOk;
+					if (!found)
+						break;
+					*found = lappend(*found, copyJsonbValue(jb));
+				}
+			}
+
+			if (jb->type == jbvBinary)
+				res = recursiveAny(hasNext ? &elem : NULL, vars, jb, found,
+								   1,
+								   jsp->anybounds.first,
+								   jsp->anybounds.last);
+			break;
+		}
 		default:
 			elog(ERROR,"Wrong state: %d", jsp->type);
 	}

src/backend/utils/adt/jsonpath_gram.y

@@ -173,6 +173,17 @@ makeIndexArray(List *list)
 	return v;
 }
 
+static JsonPathParseItem*
+makeAny(int first, int last)
+{
+	JsonPathParseItem *v = makeItemType(jpiAny);
+
+	v->anybounds.first = (first > 0) ? first : 0;
+	v->anybounds.last = (last >= 0) ? last : PG_UINT32_MAX;
+
+	return v;
+}
+
 %}
 
 /* BISON Declarations */
@@ -289,9 +300,16 @@ array_accessors:
 	;
 
 any_key:
-	key								{ $$ = $1; }
-	| array_accessor				{ $$ = $1; }
-	| '*'							{ $$ = makeItemType(jpiAnyKey); }
+	key									{ $$ = $1; }
+	| array_accessor					{ $$ = $1; }
+	| '*'								{ $$ = makeItemType(jpiAnyKey); }
+	| '*' '*'							{ $$ = makeAny(-1, -1); }
+	| '*' '*' '{' INT_P '}'				{ $$ = makeAny(pg_atoi($4.val, 4, 0),
+													   pg_atoi($4.val, 4, 0)); }
+	| '*' '*' '{' ',' INT_P '}'			{ $$ = makeAny(-1, pg_atoi($5.val, 4, 0)); }
+	| '*' '*' '{' INT_P ',' '}'			{ $$ = makeAny(pg_atoi($4.val, 4, 0), -1); }
+	| '*' '*' '{' INT_P ',' INT_P '}'	{ $$ = makeAny(pg_atoi($4.val, 4, 0),
+													   pg_atoi($6.val, 4, 0)); }
 	;
 
 joined_key:

src/backend/utils/adt/jsonpath_scan.l

@@ -64,8 +64,8 @@ fprintf_to_ereport(const char *fmt, const char *msg)
 %x xVARQUOTED
 %x xCOMMENT
 
-special		 [\?\%\$\.\[\]\(\)\|\&\!\=\<\>\@\#\,\*:\-\+\/]
-any			[^\?\%\$\.\[\]\(\)\|\&\!\=\<\>\@\#\,\*:\-\+\/\\\" \t\n\r\f]
+special		 [\?\%\$\.\[\]\{\}\(\)\|\&\!\=\<\>\@\#\,\*:\-\+\/]
+any			[^\?\%\$\.\[\]\{\}\(\)\|\&\!\=\<\>\@\#\,\*:\-\+\/\\\" \t\n\r\f]
 blank		[ \t\n\r\f]
 unicode		\\u[0-9A-Fa-f]{4}
 

src/include/utils/jsonpath.h

@@ -45,7 +45,7 @@ typedef enum JsonPathItemType {
 		jpiAnyArray,
 		jpiAnyKey,
 		jpiIndexArray,
-		//jpiAny,
+		jpiAny,
 		//jpiAll,
 		//jpiAllArray,
 		//jpiAllKey,
@@ -74,7 +74,7 @@ typedef struct JsonPathItem {
 	union {
 		struct {
 			char		*data;  /* for bool, numeric and string/key */
-			int			datalen; /* filled only for string/key */
+			int32		datalen; /* filled only for string/key */
 		} value;
 
 		struct {
@@ -85,9 +85,14 @@ typedef struct JsonPathItem {
 		int32		arg;
 
 		struct {
-			int		nelems;
+			int32		nelems;
 			int32	*elems;
 		} array;
+
+		struct {
+			uint32	first;
+			uint32	last;
+		} anybounds;
 	};
 } JsonPathItem;
 
@@ -122,14 +127,19 @@ struct JsonPathParseItem {
 		Numeric		numeric;
 		bool		boolean;
 		struct {
-			uint32		len;
-			char		*val; /* could not be not null-terminated */
+			uint32	len;
+			char	*val; /* could not be not null-terminated */
 		} string;
 
 		struct {
-			int					nelems;
-			int32				*elems;
+			int		nelems;
+			int32	*elems;
 		} array;
+
+		struct {
+			uint32	first;
+			uint32	last;
+		} anybounds;
 	};
 };