[Tarantool-patches] [PATCH 1.10 15/16] WIP: module api: expose box_tuple_extract_key_ex()

[Alexander Turenko <alexander.turenko@tarantool.org>]

Unlike box_tuple_extract_key() it accepts a key_def structure, not
space_id, index_id pair.

Another difference from box_tuple_extract_key() is that this function
allows to pass so called multikey index. See commit 2.2.0-259-gf1d9f2575
('box: introduce multikey indexes in memtx') for details.

Note: The <multikey_idx> parameter is ignored on the backported version
of the patch on 1.10. Also there is no <MULTIKEY_NONE> constant in the
backport.

XXX: Add a module API test.

Part of #5273

(backported from commit c89c9a8c647943bff138f980fcd44ca7bc96bd25)
---
 extra/exports         |  1 +
 src/box/key_def_api.c |  8 ++++++++
 src/box/key_def_api.h | 20 ++++++++++++++++++++
 3 files changed, 29 insertions(+)

diff --git a/extra/exports b/extra/exports
index 696ff2f30..1684da57d 100644
--- a/extra/exports
+++ b/extra/exports
@@ -172,6 +172,7 @@ box_tuple_next
 box_tuple_update
 box_tuple_upsert
 box_tuple_extract_key
+box_tuple_extract_key_ex
 box_tuple_validate_key_parts
 box_tuple_compare
 box_tuple_compare_with_key
diff --git a/src/box/key_def_api.c b/src/box/key_def_api.c
index a9cd95173..cce605e35 100644
--- a/src/box/key_def_api.c
+++ b/src/box/key_def_api.c
@@ -274,4 +274,12 @@ box_key_def_merge(const box_key_def_t *first, const box_key_def_t *second)
 	return key_def_merge(first, second);
 }
 
+char *
+box_tuple_extract_key_ex(box_tuple_t *tuple, box_key_def_t *key_def,
+			 int ignored, uint32_t *key_size_ptr)
+{
+	(void) ignored;
+	return tuple_extract_key(tuple, key_def, key_size_ptr);
+}
+
 /* }}} API functions implementations */
diff --git a/src/box/key_def_api.h b/src/box/key_def_api.h
index e3febe69e..cf4f3c9b7 100644
--- a/src/box/key_def_api.h
+++ b/src/box/key_def_api.h
@@ -222,6 +222,26 @@ box_tuple_compare_with_key(const box_tuple_t *tuple_a, const char *key_b,
 API_EXPORT box_key_def_t *
 box_key_def_merge(const box_key_def_t *first, const box_key_def_t *second);
 
+/**
+ * Extract key from tuple by given key definition and return
+ * buffer allocated on the box region with this key.
+ * @sa <box_region_truncate>().
+ *
+ * This function has O(n) complexity, where n is the number of key
+ * parts.
+ *
+ * @param tuple - tuple from which need to extract key
+ * @param key_def - definition of key that need to extract
+ * @param ignored - ignored on this version of tarantool
+ * @param key_size_ptr - here will be size of extracted key
+ *
+ * @retval not NULL Success
+ * @retval NULL     Memory allocation error
+ */
+API_EXPORT char *
+box_tuple_extract_key_ex(box_tuple_t *tuple, box_key_def_t *key_def,
+			 int ignored, uint32_t *key_size_ptr);
+
 /** \endcond public */
 
 /*
-- 
2.25.0