[Tarantool-patches] [PATCH v1 07/21] sql: rework RANDOMBLOB() function

[Mergen Imeev via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

This patch refactors RANDOMBLOB() function. Also, RANDOMBLOB(0) now
returns empty string.

part of #4145
---
 src/box/sql/func.c         | 57 +++++++++++++++++++-------------------
 test/sql-tap/func.test.lua |  4 +--
 2 files changed, 30 insertions(+), 31 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 2d83d52f8..408c56e45 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -900,6 +900,33 @@ func_random(struct sql_context *ctx, int argc, struct Mem *argv)
 	mem_set_int(ctx->pOut, r, r < 0);
 }
 
+/**
+ * Implementation of the RANDOMBLOB() function.
+ *
+ * This function returns a random VARBINARY value. The size of this value is
+ * specified as an argument of the function.
+ */
+static void
+func_randomblob(struct sql_context *ctx, int argc, struct Mem *argv)
+{
+	assert(argc == 1);
+	(void)argc;
+	struct Mem *arg = &argv[0];
+	assert(mem_is_null(arg) || mem_is_int(arg));
+	if (mem_is_null(arg) || !mem_is_uint(arg))
+		return;
+	if (arg->u.u == 0)
+		return mem_set_bin_static(ctx->pOut, "", 0);
+	uint64_t len = arg->u.u;
+	char *res = sqlDbMallocRawNN(sql_get(), len);
+	if (res == NULL) {
+		ctx->is_aborted = true;
+		return;
+	}
+	sql_randomness(len, res);
+	mem_set_bin_allocated(ctx->pOut, res, len);
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -1065,34 +1092,6 @@ contextMalloc(struct sql_context *context, i64 nByte)
 	return z;
 }
 
-/*
- * Implementation of randomblob(N).  Return a random blob
- * that is N bytes long.
- */
-static void
-randomBlob(struct sql_context *context, int argc, struct Mem *argv)
-{
-	int64_t n;
-	unsigned char *p;
-	assert(argc == 1);
-	UNUSED_PARAMETER(argc);
-	if (mem_is_bin(&argv[0]) || mem_is_map(&argv[0]) ||
-	    mem_is_array(&argv[0])) {
-		diag_set(ClientError, ER_SQL_TYPE_MISMATCH,
-			 mem_str(&argv[0]), "number");
-		context->is_aborted = true;
-		return;
-	}
-	n = mem_get_int_unsafe(&argv[0]);
-	if (n < 1)
-		return;
-	p = contextMalloc(context, n);
-	if (p) {
-		sql_randomness(n, p);
-		sql_result_blob(context, (char *)p, n, sql_free);
-	}
-}
-
 #define Utf8Read(s, e) \
 	ucnv_getNextUChar(icu_utf8_conv, &(s), (e), &status)
 
@@ -1917,7 +1916,7 @@ static struct sql_func_definition definitions[] = {
 	{"QUOTE", 1, {FIELD_TYPE_ANY}, FIELD_TYPE_STRING, quoteFunc, NULL},
 	{"RANDOM", 0, {}, FIELD_TYPE_INTEGER, func_random, NULL},
 	{"RANDOMBLOB", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_VARBINARY,
-	 randomBlob, NULL},
+	 func_randomblob, NULL},
 	{"REPLACE", 3,
 	 {FIELD_TYPE_STRING, FIELD_TYPE_STRING, FIELD_TYPE_STRING},
 	 FIELD_TYPE_STRING, replaceFunc, NULL},
diff --git a/test/sql-tap/func.test.lua b/test/sql-tap/func.test.lua
index b52d5bd4c..e2e905907 100755
--- a/test/sql-tap/func.test.lua
+++ b/test/sql-tap/func.test.lua
@@ -2545,8 +2545,8 @@ test:do_execsql_test(
 
 test:do_execsql_test(
     "func-36",
-    [[VALUES (LENGTH(RANDOMBLOB(0)))]],
-    {""})
+    [[VALUES (RANDOMBLOB(0))]],
+    {''})
 
 -- gh-3542
 -- In SQL '\0' is NOT a end-of-string signal. Tests below ensures
-- 
2.25.1