Add jsonpath array constructors

Nikita Glukhov · Nikita Glukhov · commit fa17a905c427 · 2017-11-15T17:31:55.000+03:00
diff --git a/src/backend/utils/adt/jsonpath.c b/src/backend/utils/adt/jsonpath.c
@@ -122,28 +122,23 @@ flattenJsonPathParseItem(StringInfo buf, JsonPathParseItem *item,
 				*(int32 *)(buf->data + offs) = chld;
 			}
 			break;
-		case jpiDatetime:
-			if (!item->value.arg)
-			{
-				int32 arg = 0;
-
-				appendBinaryStringInfo(buf, (char *) &arg, sizeof(arg));
-				break;
-			}
-			/* fall through */
 		case jpiFilter:
 		case jpiIsUnknown:
 		case jpiNot:
 		case jpiPlus:
 		case jpiMinus:
 		case jpiExists:
+		case jpiDatetime:
 		case jpiMap:
+		case jpiArray:
 			{
-				int32 arg;
+				int32 arg = item->value.arg ? buf->len : 0;
 
-				arg = buf->len;
 				appendBinaryStringInfo(buf, (char*)&arg /* fake value */, sizeof(arg));
 
+				if (!item->value.arg)
+					break;
+
 				chld = flattenJsonPathParseItem(buf, item->value.arg,
 												item->type == jpiFilter ||
 												item->type == jpiMap ||
@@ -603,6 +598,15 @@ printJsonPathItem(StringInfo buf, JsonPathItem *v, bool inKey, bool printBracket
 			if (printBracketes || jspHasNext(v))
 				appendStringInfoChar(buf, ')');
 			break;
+		case jpiArray:
+			appendStringInfoChar(buf, '[');
+			if (v->content.arg)
+			{
+				jspGetArg(v, &elem);
+				printJsonPathItem(buf, &elem, false, false);
+			}
+			appendStringInfoChar(buf, ']');
+			break;
 		default:
 			elog(ERROR, "Unknown jsonpath item type: %d", v->type);
 	}
@@ -737,6 +741,7 @@ jspInitByBuffer(JsonPathItem *v, char *base, int32 pos)
 		case jpiFilter:
 		case jpiDatetime:
 		case jpiMap:
+		case jpiArray:
 			read_int32(v->content.arg, base, pos);
 			break;
 		case jpiIndexArray:
@@ -769,7 +774,8 @@ jspGetArg(JsonPathItem *v, JsonPathItem *a)
 		v->type == jpiPlus ||
 		v->type == jpiMinus ||
 		v->type == jpiDatetime ||
-		v->type == jpiMap
+		v->type == jpiMap ||
+		v->type == jpiArray
 	);
 
 	jspInitByBuffer(a, v->base, v->content.arg);
@@ -823,7 +829,8 @@ jspGetNext(JsonPathItem *v, JsonPathItem *a)
 			v->type == jpiKeyValue ||
 			v->type == jpiStartsWith ||
 			v->type == jpiMap ||
-			v->type == jpiSequence
+			v->type == jpiSequence ||
+			v->type == jpiArray
 		);
 
 		if (a)
diff --git a/src/backend/utils/adt/jsonpath_exec.c b/src/backend/utils/adt/jsonpath_exec.c
@@ -2181,6 +2181,24 @@ recursiveExecuteNoUnwrap(JsonPathExecContext *cxt, JsonPathItem *jsp,
 
 			break;
 		}
+		case jpiArray:
+			{
+				JsonValueList list = { 0 };
+
+				if (jsp->content.arg)
+				{
+					jspGetArg(jsp, &elem);
+					res = recursiveExecute(cxt, &elem, jb, &list);
+
+					if (jperIsError(res))
+						break;
+				}
+
+				res = recursiveExecuteNext(cxt, jsp, NULL,
+										   wrapItemsInArray(&list),
+										   found, false);
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized jsonpath item type: %d", jsp->type);
 	}
diff --git a/src/backend/utils/adt/jsonpath_gram.y b/src/backend/utils/adt/jsonpath_gram.y
@@ -390,6 +390,8 @@ path_primary:
 	| '@'							{ $$ = makeItemType(jpiCurrent); }
 	| LAST_P						{ $$ = makeItemType(jpiLast); }
 	| '(' expr_seq ')'				{ $$ = $2; }
+	| '[' ']'						{ $$ = makeItemUnary(jpiArray, NULL); }
+	| '[' expr_or_seq ']'			{ $$ = makeItemUnary(jpiArray, $2); }
 	;
 
 accessor_expr:
diff --git a/src/include/utils/jsonpath.h b/src/include/utils/jsonpath.h
@@ -86,6 +86,7 @@ typedef enum JsonPathItemType {
 		jpiLikeRegex,
 		jpiMap,
 		jpiSequence,
+		jpiArray,
 } JsonPathItemType;
 
 /* XQuery regex mode flags for LIKE_REGEX predicate */
diff --git a/src/test/regress/expected/jsonb_jsonpath.out b/src/test/regress/expected/jsonb_jsonpath.out
@@ -1621,6 +1621,12 @@ SELECT jsonb '[{"a": 1}, {"a": 2}]' @* '$[*] ? (@.a > 10)';
 ----------
 (0 rows)
 
+SELECT jsonb '[{"a": 1}, {"a": 2}]' @* '[$[*].a]';
+ ?column? 
+----------
+ [1, 2]
+(1 row)
+
 SELECT jsonb '[{"a": 1}, {"a": 2}]' @? '$[*].a ? (@ > 1)';
  ?column? 
 ----------
@@ -1720,3 +1726,48 @@ select jsonb '[1,2,3,4,5]' @* '$[(0, $[*], 5) ? (@ == 3)]';
 
 select jsonb '[1,2,3,4,5]' @* '$[(0, $[*], 3) ? (@ == 3)]';
 ERROR:  Invalid SQL/JSON subscript
+-- extension: array constructors
+select jsonb '[1, 2, 3]' @* '[]';
+ ?column? 
+----------
+ []
+(1 row)
+
+select jsonb '[1, 2, 3]' @* '[1, 2, $.map(@ + 100)[*], 4, 5]';
+          ?column?           
+-----------------------------
+ [1, 2, 101, 102, 103, 4, 5]
+(1 row)
+
+select jsonb '[1, 2, 3]' @* '[1, 2, $.map(@ + 100)[*], 4, 5][*]';
+ ?column? 
+----------
+ 1
+ 2
+ 101
+ 102
+ 103
+ 4
+ 5
+(7 rows)
+
+select jsonb '[1, 2, 3]' @* '[(1, (2, $.map(@ + 100)[*])), (4, 5)]';
+          ?column?           
+-----------------------------
+ [1, 2, 101, 102, 103, 4, 5]
+(1 row)
+
+select jsonb '[1, 2, 3]' @* '[[1, 2], [$.map(@ + 100)[*], 4], 5, [(1,2)?(@ > 5)]]';
+              ?column?               
+-------------------------------------
+ [[1, 2], [101, 102, 103, 4], 5, []]
+(1 row)
+
+select jsonb '[1, 2, 3]' @* 'strict [1, 2, $.map(@.a)[*], 4, 5]';
+ERROR:  SQL/JSON member not found
+select jsonb '[[1, 2], [3, 4, 5], [], [6, 7]]' @* '[$[*].map(@ + 10)[*] ? (@ > 13)]';
+     ?column?     
+------------------
+ [14, 15, 16, 17]
+(1 row)
+
diff --git a/src/test/regress/expected/jsonpath.out b/src/test/regress/expected/jsonpath.out
@@ -530,6 +530,18 @@ select '$[(1, (2, $.a)), 3, (4, 5)]'::jsonpath;
  $[(1, (2, $."a")),3,(4, 5)]
 (1 row)
 
+select '[]'::jsonpath;
+ jsonpath 
+----------
+ []
+(1 row)
+
+select '[[1, 2], ([(3, 4, 5), 6], []), $.a[*]]'::jsonpath;
+                 jsonpath                 
+------------------------------------------
+ [[1, 2], ([(3, 4, 5), 6], []), $."a"[*]]
+(1 row)
+
 select '$ ? (@.a < 1)'::jsonpath;
    jsonpath    
 ---------------
diff --git a/src/test/regress/sql/jsonb_jsonpath.sql b/src/test/regress/sql/jsonb_jsonpath.sql
@@ -362,6 +362,7 @@ set time zone default;
 
 SELECT jsonb '[{"a": 1}, {"a": 2}]' @* '$[*]';
 SELECT jsonb '[{"a": 1}, {"a": 2}]' @* '$[*] ? (@.a > 10)';
+SELECT jsonb '[{"a": 1}, {"a": 2}]' @* '[$[*].a]';
 
 SELECT jsonb '[{"a": 1}, {"a": 2}]' @? '$[*].a ? (@ > 1)';
 SELECT jsonb '[{"a": 1}, {"a": 2}]' @? '$[*] ? (@.a > 2)';
@@ -383,3 +384,12 @@ select jsonb '[1,2,3,4,5]' @* '-(10, 20, $[1 to 3], 30)';
 select jsonb '[1,2,3,4,5]' @* 'lax (10, 20, $[1 to 3], 30).map(@ + 100)';
 select jsonb '[1,2,3,4,5]' @* '$[(0, $[*], 5) ? (@ == 3)]';
 select jsonb '[1,2,3,4,5]' @* '$[(0, $[*], 3) ? (@ == 3)]';
+
+-- extension: array constructors
+select jsonb '[1, 2, 3]' @* '[]';
+select jsonb '[1, 2, 3]' @* '[1, 2, $.map(@ + 100)[*], 4, 5]';
+select jsonb '[1, 2, 3]' @* '[1, 2, $.map(@ + 100)[*], 4, 5][*]';
+select jsonb '[1, 2, 3]' @* '[(1, (2, $.map(@ + 100)[*])), (4, 5)]';
+select jsonb '[1, 2, 3]' @* '[[1, 2], [$.map(@ + 100)[*], 4], 5, [(1,2)?(@ > 5)]]';
+select jsonb '[1, 2, 3]' @* 'strict [1, 2, $.map(@.a)[*], 4, 5]';
+select jsonb '[[1, 2], [3, 4, 5], [], [6, 7]]' @* '[$[*].map(@ + 10)[*] ? (@ > 13)]';
diff --git a/src/test/regress/sql/jsonpath.sql b/src/test/regress/sql/jsonpath.sql
@@ -99,6 +99,9 @@ select '(1, 2, $.a) == 5'::jsonpath;
 select '$[(1, 2, $.a) to (3, 4)]'::jsonpath;
 select '$[(1, (2, $.a)), 3, (4, 5)]'::jsonpath;
 
+select '[]'::jsonpath;
+select '[[1, 2], ([(3, 4, 5), 6], []), $.a[*]]'::jsonpath;
+
 select '$ ? (@.a < 1)'::jsonpath;
 select '$ ? (@.a < -1)'::jsonpath;
 select '$ ? (@.a < +1)'::jsonpath;

Original file line number	Diff line number	Diff line change
`@@ -390,6 +390,8 @@ path_primary:`
`390`	`390`	`\| '@' { $$ = makeItemType(jpiCurrent); }`
`391`	`391`	`\| LAST_P { $$ = makeItemType(jpiLast); }`
`392`	`392`	`\| '(' expr_seq ')' { $$ = $2; }`
	`393`	`+ \| '[' ']' { $$ = makeItemUnary(jpiArray, NULL); }`
	`394`	`+ \| '[' expr_or_seq ']' { $$ = makeItemUnary(jpiArray, $2); }`
`393`	`395`	`;`
`394`	`396`
`395`	`397`	`accessor_expr:`