[tarantool-patches] Re: [PATCH v5 4/9] lib: introduce json_path_cmp, json_path_validate
Kirill Shcherbatov
kshcherbatov at tarantool.org
Thu Dec 6 10:56:52 MSK 2018
Introduced json_path_validate routine to ensure user-defined
JSON path is valid. This will be required to raise an error if
an incorrect user-defined jason-path is detected.
Introduced json_path_cmp routine to compare JSON paths that may
have different representation.
Note that:
- in case of paths that have same token-sequence prefix,
the path having more tokens is assumed to be greater
- both paths to compare should be valid
Needed for #1012
---
src/lib/json/json.c | 29 +++++++++++++++++++++++++++++
src/lib/json/json.h | 28 ++++++++++++++++++++++++++++
test/unit/json_path.c | 37 ++++++++++++++++++++++++++++++++++++-
test/unit/json_path.result | 13 ++++++++++++-
4 files changed, 105 insertions(+), 2 deletions(-)
diff --git a/src/lib/json/json.c b/src/lib/json/json.c
index 65169b047..5586e59fc 100644
--- a/src/lib/json/json.c
+++ b/src/lib/json/json.c
@@ -500,3 +500,32 @@ json_tree_postorder_next(struct json_token *root, struct json_token *pos)
return json_tree_leftmost(next);
return pos->parent;
}
+
+int
+json_path_cmp(const char *a, uint32_t a_len, const char *b, uint32_t b_len,
+ uint32_t index_base)
+{
+ struct json_lexer lexer_a, lexer_b;
+ json_lexer_create(&lexer_a, a, a_len, index_base);
+ json_lexer_create(&lexer_b, b, b_len, index_base);
+ struct json_token token_a, token_b;
+ token_a.parent = NULL;
+ token_b.parent = NULL;
+ int rc_a, rc_b;
+ while ((rc_a = json_lexer_next_token(&lexer_a, &token_a)) == 0 &&
+ (rc_b = json_lexer_next_token(&lexer_b, &token_b)) == 0 &&
+ token_a.type != JSON_TOKEN_END &&
+ token_b.type != JSON_TOKEN_END) {
+ int rc = json_token_cmp(&token_a, &token_b);
+ if (rc != 0)
+ return rc;
+ }
+ /* Paths a and b should be valid. */
+ assert(rc_b == 0 && rc_b == 0);
+ /*
+ * The parser stopped because the end of one of the paths
+ * was reached. As JSON_TOKEN_END > JSON_TOKEN_{NUM, STR},
+ * the path having more tokens has lower key.type value.
+ */
+ return token_b.type - token_a.type;
+}
diff --git a/src/lib/json/json.h b/src/lib/json/json.h
index 594d59a08..baf26143d 100644
--- a/src/lib/json/json.h
+++ b/src/lib/json/json.h
@@ -30,6 +30,7 @@
* THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
+#include <stdbool.h>
#include "trivia/util.h"
#ifdef __cplusplus
@@ -222,6 +223,33 @@ json_lexer_create(struct json_lexer *lexer, const char *src, int src_len,
int
json_lexer_next_token(struct json_lexer *lexer, struct json_token *token);
+/**
+ * Compare two JSON paths using Lexer class.
+ * - in case of paths that have same token-sequence prefix,
+ * the path having more tokens is assumed to be greater
+ * - both paths should be valid
+ * (may be tested with json_path_validate).
+ */
+int
+json_path_cmp(const char *a, uint32_t a_len, const char *b, uint32_t b_len,
+ uint32_t index_base);
+
+/**
+ * Check if the passed JSON path is valid.
+ * Return 0 for valid path and error position for invalid.
+ */
+static inline int
+json_path_validate(const char *path, uint32_t path_len, uint32_t index_base)
+{
+ struct json_lexer lexer;
+ json_lexer_create(&lexer, path, path_len, index_base);
+ struct json_token token;
+ int rc;
+ while ((rc = json_lexer_next_token(&lexer, &token)) == 0 &&
+ token.type != JSON_TOKEN_END) {};
+ return rc;
+}
+
/** Create a JSON tree object to manage data relations. */
int
json_tree_create(struct json_tree *tree);
diff --git a/test/unit/json_path.c b/test/unit/json_path.c
index 1b224f9c2..72e50e143 100644
--- a/test/unit/json_path.c
+++ b/test/unit/json_path.c
@@ -405,15 +405,50 @@ test_tree()
footer();
}
+void
+test_path_cmp()
+{
+ const char *a = "Data[1][\"FIO\"].fname";
+ uint32_t a_len = strlen(a);
+ const struct path_and_errpos rc[] = {
+ {a, 0},
+ {"[\"Data\"][1].FIO[\"fname\"]", 0},
+ {"Data[1]", 1},
+ {"Data[1][\"FIO\"].fname[1]", -1},
+ {"Data[1][\"Info\"].fname[1]", -1},
+ };
+ header();
+ plan(lengthof(rc) + 2);
+ for (size_t i = 0; i < lengthof(rc); ++i) {
+ const char *path = rc[i].path;
+ int errpos = rc[i].errpos;
+ int rc = json_path_cmp(a, a_len, path, strlen(path),
+ TUPLE_INDEX_BASE);
+ if (rc > 0) rc = 1;
+ if (rc < 0) rc = -1;
+ is(rc, errpos, "path cmp result \"%s\" with \"%s\": "
+ "have %d, expected %d", a, path, rc, errpos);
+ }
+ const char *invalid = "Data[[1][\"FIO\"].fname";
+ int ret = json_path_validate(a, strlen(a), TUPLE_INDEX_BASE);
+ is(ret, 0, "path %s is valid", a);
+ ret = json_path_validate(invalid, strlen(invalid), TUPLE_INDEX_BASE);
+ is(ret, 6, "path %s error pos %d expected %d", invalid, ret, 6);
+
+ check_plan();
+ footer();
+}
+
int
main()
{
header();
- plan(3);
+ plan(4);
test_basic();
test_errors();
test_tree();
+ test_path_cmp();
int rc = check_plan();
footer();
diff --git a/test/unit/json_path.result b/test/unit/json_path.result
index 0ee970c8c..cf0fa51c4 100644
--- a/test/unit/json_path.result
+++ b/test/unit/json_path.result
@@ -1,5 +1,5 @@
*** main ***
-1..3
+1..4
*** test_basic ***
1..71
ok 1 - parse <[1]>
@@ -158,4 +158,15 @@ ok 2 - subtests
ok 54 - records iterated count 4 of 4
ok 3 - subtests
*** test_tree: done ***
+ *** test_path_cmp ***
+ 1..7
+ ok 1 - path cmp result "Data[1]["FIO"].fname" with "Data[1]["FIO"].fname": have 0, expected 0
+ ok 2 - path cmp result "Data[1]["FIO"].fname" with "["Data"][1].FIO["fname"]": have 0, expected 0
+ ok 3 - path cmp result "Data[1]["FIO"].fname" with "Data[1]": have 1, expected 1
+ ok 4 - path cmp result "Data[1]["FIO"].fname" with "Data[1]["FIO"].fname[1]": have -1, expected -1
+ ok 5 - path cmp result "Data[1]["FIO"].fname" with "Data[1]["Info"].fname[1]": have -1, expected -1
+ ok 6 - path Data[1]["FIO"].fname is valid
+ ok 7 - path Data[[1]["FIO"].fname error pos 6 expected 6
+ok 4 - subtests
+ *** test_path_cmp: done ***
*** main: done ***
--
2.19.2
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