[PATCH 1/1] identifier: do not use ICU UConverter for checks

[Vladislav Shpilevoy]

I makes no sense to create a converter, when there is
nothing to convert. To check an identifier it is
enough to use stateless ICU macros: U8_NEXT_OR_FFFD,
that also allows to eliminate 0xFFFD symbol as a
special one - this macros returns this code on any
error, or when it is actually this symbol.
---
Branch: https://github.com/tarantool/tarantool/tree/identifier-do-not-use-uconverter

 src/box/box.cc              |  2 --
 src/box/identifier.c        | 51 ++++++++++-----------------------------------
 src/box/identifier.h        | 13 ------------
 test/unit/vy_point_lookup.c |  2 --
 4 files changed, 11 insertions(+), 57 deletions(-)

diff --git a/src/box/box.cc b/src/box/box.cc
index cb3199624..d2dfc5b5f 100644
--- a/src/box/box.cc
+++ b/src/box/box.cc
@@ -1518,7 +1518,6 @@ box_free(void)
 		gc_free();
 		engine_shutdown();
 		wal_thread_stop();
-		identifier_destroy();
 	}
 
 	fiber_cond_destroy(&ro_cond);
@@ -1724,7 +1723,6 @@ box_cfg_xc(void)
 	engine_init();
 	if (module_init() != 0)
 		diag_raise();
-	identifier_init();
 	schema_init();
 	replication_init();
 	port_init();
diff --git a/src/box/identifier.c b/src/box/identifier.c
index e73e666b7..318f914f6 100644
--- a/src/box/identifier.c
+++ b/src/box/identifier.c
@@ -33,44 +33,34 @@
 #include "say.h"
 #include "diag.h"
 
-#include <unicode/ucnv.h>
+#include <unicode/utf8.h>
 #include <unicode/uchar.h>
-/* ICU returns this character in case of unknown symbol */
-#define REPLACEMENT_CHARACTER (0xFFFD)
-
-static UConverter* utf8conv = NULL;
 
 int
 identifier_check(const char *str, size_t str_len)
 {
-	assert(utf8conv);
 	const char *end = str + str_len;
 	if (str == end)
 		goto error;
 
-	ucnv_reset(utf8conv);
-
-	while (str < end) {
-		int8_t type;
-		UErrorCode status = U_ZERO_ERROR;
-		UChar32 c = ucnv_getNextUChar(utf8conv, &str, end, &status);
-
-		if (U_FAILURE(status))
+	UChar32 c;
+	uint32_t offset = 0;
+	while (offset < str_len) {
+		U8_NEXT_OR_FFFD(str, offset, str_len, c)
+		if (c == 0xFFFD)
 			goto error;
 
-		type = u_charType(c);
+		int8_t type = u_charType(c);
 		/**
 		 * The icu library has a function named u_isprint, however,
 		 * this function does not return any errors.
 		 * Here the `c` symbol printability is determined by comparison
 		 * with unicode category types explicitly.
 		 */
-		if (c == REPLACEMENT_CHARACTER ||
-			type == U_UNASSIGNED ||
-			type == U_LINE_SEPARATOR ||
-			type == U_CONTROL_CHAR ||
-			type == U_PARAGRAPH_SEPARATOR)
-
+		if (type == U_UNASSIGNED ||
+		    type == U_LINE_SEPARATOR ||
+		    type == U_CONTROL_CHAR ||
+		    type == U_PARAGRAPH_SEPARATOR)
 			goto error;
 	}
 	return 0;
@@ -78,22 +68,3 @@ error:
 	diag_set(ClientError, ER_IDENTIFIER, tt_cstr(str, str_len));
 	return -1;
 }
-
-void
-identifier_init()
-{
-	assert(utf8conv == NULL);
-	UErrorCode status = U_ZERO_ERROR ;
-	utf8conv = ucnv_open("utf8", &status);
-	if (U_FAILURE(status))
-		panic("ICU ucnv_open(\"utf8\") failed");
-}
-
-void
-identifier_destroy()
-{
-	assert(utf8conv);
-	ucnv_close(utf8conv);
-	utf8conv = NULL;
-}
-
diff --git a/src/box/identifier.h b/src/box/identifier.h
index f1e36fe2a..30e6fdb69 100644
--- a/src/box/identifier.h
+++ b/src/box/identifier.h
@@ -49,19 +49,6 @@ extern "C" {
 int
 identifier_check(const char *str, size_t str_len);
 
-/**
- * Init identifier check mechanism.
- * This function allocates necessary for icu structures.
- */
-void
-identifier_init();
-
-/**
- * Clean icu structures.
- */
-void
-identifier_destroy();
-
 #if defined(__cplusplus)
 } /* extern "C" */
 
diff --git a/test/unit/vy_point_lookup.c b/test/unit/vy_point_lookup.c
index 6a3802def..629cd3efa 100644
--- a/test/unit/vy_point_lookup.c
+++ b/test/unit/vy_point_lookup.c
@@ -327,7 +327,6 @@ test_basic()
 int
 main()
 {
-	identifier_init();
 	plan(1);
 
 	vy_iterator_C_test_init(128 * 1024);
@@ -337,6 +336,5 @@ main()
 
 	vy_iterator_C_test_finish();
 
-	identifier_destroy();
 	return check_plan();
 }
-- 
2.14.3 (Apple Git-98)