Re: [Tarantool-patches] [PATCH v2 12/15] sql: rework GROUP_CONCAT()

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

I found out that I forgot to free allocated memory in zeroblob case. Fixed. Diff
in this patch and changed diffs in "sql: remove copying of result in finalizers"
and "sql: remove field argv from struct sql_context" below. Also I rebased this
branch to current master.

On Sat, Sep 25, 2021 at 02:42:36PM +0300, Mergen Imeev via Tarantool-patches wrote:
> Thank you for the review! My answers, diff and new patch below.
> 
> On Thu, Sep 23, 2021 at 12:49:52AM +0200, Vladislav Shpilevoy wrote:
> > Thanks for the patch!
> > 
> > > diff --git a/src/box/sql/func.c b/src/box/sql/func.c
> > > index f699aa927..001a8641c 100644
> > > --- a/src/box/sql/func.c
> > > +++ b/src/box/sql/func.c
> > > @@ -213,6 +213,52 @@ fin_minmax(struct sql_context *ctx)
> > >  	mem_copy(ctx->pOut, ctx->pMem);
> > >  }
> > >  
> > > +/** Implementation of the GROUP_CONCAT() function. */
> > > +static void
> > > +step_group_concat(struct sql_context *ctx, int argc, struct Mem **argv)
> > > +{
> > > +	assert(argc == 1 || argc == 2);
> > > +	(void)argc;
> > > +	if (argv[0]->type == MEM_TYPE_NULL)
> > > +		return;
> > > +	assert(mem_is_str(argv[0]) || mem_is_bin(argv[0]));
> > > +	if (ctx->pMem->type == MEM_TYPE_NULL) {
> > > +		if (mem_copy_str(ctx->pMem, argv[0]->z, argv[0]->n) != 0)
> > 
> > 1. What if the argument is zeroblob with no actual memory allocated yet?
> > 
> There will be '', which is wrong. I fixed this and added a test.
> 
> > > +			ctx->is_aborted = true;
> > > +		return;
> > > +	}
> > > +	const char *sep = NULL;
> > > +	int sep_len = 0;
> > > +	if (argc == 1) {
> > > +		sep = ",";
> > > +		sep_len = 1;
> > > +	} else if (argv[1]->type == MEM_TYPE_NULL) {
> > > +		sep = "";
> > > +		sep_len = 0;
> > > +	} else {
> > > +		assert(mem_is_same_type(argv[0], argv[0]));
> > > +		sep = argv[1]->z;
> > > +		sep_len = argv[1]->n;
> > > +	}
> > > +	if (sep_len > 0) {
> > > +		if (mem_append(ctx->pMem, sep, sep_len) != 0) {
> > 
> > 2. Will it work if sep_len == 0? If yes, then I would propose to
> > drop the len check here and call the append always.
> > 
> Fixed. I moved this check to mem_append().
> 
> > > +			ctx->is_aborted = true;
> > > +			return;
> > > +		}
> 
> 
> Diff:
> 
> diff --git a/src/box/sql/func.c b/src/box/sql/func.c
> index 182fb85be..28094e258 100644
> --- a/src/box/sql/func.c
> +++ b/src/box/sql/func.c
> @@ -223,34 +223,43 @@ step_group_concat(struct sql_context *ctx, int argc, struct Mem **argv)
>  {
>  	assert(argc == 1 || argc == 2);
>  	(void)argc;
> -	if (argv[0]->type == MEM_TYPE_NULL)
> +	if (mem_is_null(argv[0]))
>  		return;
>  	assert(mem_is_str(argv[0]) || mem_is_bin(argv[0]));
> -	if (ctx->pMem->type == MEM_TYPE_NULL) {
> -		if (mem_copy_str(ctx->pMem, argv[0]->z, argv[0]->n) != 0)
> +	if (mem_is_null(ctx->pMem)) {
> +		if (mem_copy(ctx->pMem, argv[0]) != 0)
>  			ctx->is_aborted = true;
>  		return;
>  	}
> +	assert(!mem_is_zerobin(ctx->pMem));
>  	const char *sep = NULL;
>  	int sep_len = 0;
>  	if (argc == 1) {
>  		sep = ",";
>  		sep_len = 1;
> -	} else if (argv[1]->type == MEM_TYPE_NULL) {
> +	} else if (mem_is_null(argv[1])) {
>  		sep = "";
>  		sep_len = 0;
>  	} else {
> -		assert(mem_is_same_type(argv[0], argv[0]));
> +		assert(mem_is_same_type(argv[0], argv[1]));
>  		sep = argv[1]->z;
>  		sep_len = argv[1]->n;
>  	}
> -	if (sep_len > 0) {
> -		if (mem_append(ctx->pMem, sep, sep_len) != 0) {
> -			ctx->is_aborted = true;
> -			return;
> -		}
> +	if (mem_append(ctx->pMem, sep, sep_len) != 0) {
> +		ctx->is_aborted = true;
> +		return;
> +	}
> +	uint32_t size;
> +	char *str;
> +	if (mem_is_zerobin(argv[0])) {
> +		size = argv[0]->u.nZero;
> +		str = sqlDbMallocRawNN(sql_get(), size);
> +		memset(str, 0, size);
> +	} else {
> +		size = argv[0]->n;
> +		str = argv[0]->z;
>  	}
> -	if (mem_append(ctx->pMem, argv[0]->z, argv[0]->n) != 0) {
> +	if (mem_append(ctx->pMem, str, size) != 0) {
>  		ctx->is_aborted = true;
>  		return;
>  	}
> diff --git a/test/sql-tap/func.test.lua b/test/sql-tap/func.test.lua
> index 416f27d69..bd8a8fe78 100755
> --- a/test/sql-tap/func.test.lua
> +++ b/test/sql-tap/func.test.lua
> @@ -1,6 +1,6 @@
>  #!/usr/bin/env tarantool
>  local test = require("sqltester")
> -test:plan(14680)
> +test:plan(14681)
>  
>  --!./tcltestrunner.lua
>  -- 2001 September 15
> @@ -2142,11 +2142,14 @@ test:do_execsql_test(
>          -- </func-24.2>
>      })
>  
> --- do_test func-24.3 {
> ---   execsql {
> ---     SELECT group_concat(t1,' ' || rowid || ' ') FROM tbl1
> ---   }
> --- } {{this 2 program 3 is 4 free 5 software}}
> +test:do_execsql_test(
> +    "func-24.3",
> +    [[
> +        SELECT group_concat(zeroblob(10));
> +    ]], {
> +        '\0\0\0\0\0\0\0\0\0\0'
> +    })
> +
>  test:do_execsql_test(
>      "func-24.4",
>      [[
> 
> 
> New patch:
> 
> commit 5b8563e9b884c86885a3a91fc608fb144afb69a0
> Author: Mergen Imeev <imeevma@gmail.com>
> Date:   Thu Sep 9 18:37:00 2021 +0300
> 
>     sql: rework GROUP_CONCAT()
>     
>     This patch simplifies SQL built-in aggregate function GROUP_CONCAT().
>     
>     Part of #4145
> 
> diff --git a/src/box/sql/func.c b/src/box/sql/func.c
> index 3708440e3..28094e258 100644
> --- a/src/box/sql/func.c
> +++ b/src/box/sql/func.c
> @@ -217,6 +217,61 @@ fin_minmax(struct sql_context *ctx)
>  	mem_copy(ctx->pOut, ctx->pMem);
>  }
>  
> +/** Implementation of the GROUP_CONCAT() function. */
> +static void
> +step_group_concat(struct sql_context *ctx, int argc, struct Mem **argv)
> +{
> +	assert(argc == 1 || argc == 2);
> +	(void)argc;
> +	if (mem_is_null(argv[0]))
> +		return;
> +	assert(mem_is_str(argv[0]) || mem_is_bin(argv[0]));
> +	if (mem_is_null(ctx->pMem)) {
> +		if (mem_copy(ctx->pMem, argv[0]) != 0)
> +			ctx->is_aborted = true;
> +		return;
> +	}
> +	assert(!mem_is_zerobin(ctx->pMem));
> +	const char *sep = NULL;
> +	int sep_len = 0;
> +	if (argc == 1) {
> +		sep = ",";
> +		sep_len = 1;
> +	} else if (mem_is_null(argv[1])) {
> +		sep = "";
> +		sep_len = 0;
> +	} else {
> +		assert(mem_is_same_type(argv[0], argv[1]));
> +		sep = argv[1]->z;
> +		sep_len = argv[1]->n;
> +	}
> +	if (mem_append(ctx->pMem, sep, sep_len) != 0) {
> +		ctx->is_aborted = true;
> +		return;
> +	}
> +	uint32_t size;
> +	char *str;
> +	if (mem_is_zerobin(argv[0])) {
> +		size = argv[0]->u.nZero;
> +		str = sqlDbMallocRawNN(sql_get(), size);
> +		memset(str, 0, size);
> +	} else {
> +		size = argv[0]->n;
> +		str = argv[0]->z;
> +	}
> +	if (mem_append(ctx->pMem, str, size) != 0) {
> +		ctx->is_aborted = true;
> +		return;
> +	}
> +}
> +
> +/** Finalizer for the GROUP_CONCAT() function. */
> +static void
> +fin_group_concat(struct sql_context *ctx)
> +{
> +	mem_copy(ctx->pOut, ctx->pMem);
> +}
> +
>  static const unsigned char *
>  mem_as_ustr(struct Mem *mem)
>  {
> @@ -1761,73 +1816,6 @@ soundexFunc(sql_context * context, int argc, sql_value ** argv)
>  	}
>  }
>  
> -/*
> - * group_concat(EXPR, ?SEPARATOR?)
> - */
> -static void
> -groupConcatStep(sql_context * context, int argc, sql_value ** argv)
> -{
> -	const char *zVal;
> -	StrAccum *pAccum;
> -	const char *zSep;
> -	int nVal, nSep;
> -	if (argc != 1 && argc != 2) {
> -		diag_set(ClientError, ER_FUNC_WRONG_ARG_COUNT,
> -			 "GROUP_CONCAT", "1 or 2", argc);
> -		context->is_aborted = true;
> -		return;
> -	}
> -	if (mem_is_null(argv[0]))
> -		return;
> -	pAccum =
> -	    (StrAccum *) sql_aggregate_context(context, sizeof(*pAccum));
> -
> -	if (pAccum) {
> -		sql *db = sql_context_db_handle(context);
> -		int firstTerm = pAccum->mxAlloc == 0;
> -		pAccum->mxAlloc = db->aLimit[SQL_LIMIT_LENGTH];
> -		if (!firstTerm) {
> -			if (argc == 2) {
> -				zSep = mem_as_str0(argv[1]);
> -				nSep = mem_len_unsafe(argv[1]);
> -			} else {
> -				zSep = ",";
> -				nSep = 1;
> -			}
> -			if (zSep)
> -				sqlStrAccumAppend(pAccum, zSep, nSep);
> -		}
> -		zVal = mem_as_str0(argv[0]);
> -		nVal = mem_len_unsafe(argv[0]);
> -		if (zVal)
> -			sqlStrAccumAppend(pAccum, zVal, nVal);
> -	}
> -}
> -
> -static void
> -groupConcatFinalize(sql_context * context)
> -{
> -	StrAccum *pAccum;
> -	pAccum = sql_aggregate_context(context, 0);
> -	if (pAccum) {
> -		if (pAccum->accError == STRACCUM_TOOBIG) {
> -			diag_set(ClientError, ER_SQL_EXECUTE, "string or binary"\
> -				 "string is too big");
> -			context->is_aborted = true;
> -		} else if (pAccum->accError == STRACCUM_NOMEM) {
> -			context->is_aborted = true;
> -		} else {
> -			char *str = sqlStrAccumFinish(pAccum);
> -			int len = pAccum->nChar;
> -			assert(len >= 0);
> -			if (context->func->def->returns == FIELD_TYPE_STRING)
> -				mem_set_str_dynamic(context->pOut, str, len);
> -			else
> -				mem_set_bin_dynamic(context->pOut, str, len);
> -		}
> -	}
> -}
> -
>  int
>  sql_is_like_func(struct Expr *expr)
>  {
> @@ -1995,13 +1983,13 @@ static struct sql_func_definition definitions[] = {
>  	 NULL},
>  
>  	{"GROUP_CONCAT", 1, {FIELD_TYPE_STRING}, FIELD_TYPE_STRING,
> -	 groupConcatStep, groupConcatFinalize},
> +	 step_group_concat, fin_group_concat},
>  	{"GROUP_CONCAT", 2, {FIELD_TYPE_STRING, FIELD_TYPE_STRING},
> -	 FIELD_TYPE_STRING, groupConcatStep, groupConcatFinalize},
> +	 FIELD_TYPE_STRING, step_group_concat, fin_group_concat},
>  	{"GROUP_CONCAT", 1, {FIELD_TYPE_VARBINARY}, FIELD_TYPE_VARBINARY,
> -	 groupConcatStep, groupConcatFinalize},
> +	 step_group_concat, fin_group_concat},
>  	{"GROUP_CONCAT", 2, {FIELD_TYPE_VARBINARY, FIELD_TYPE_VARBINARY},
> -	 FIELD_TYPE_VARBINARY, groupConcatStep, groupConcatFinalize},
> +	 FIELD_TYPE_VARBINARY, step_group_concat, fin_group_concat},
>  
>  	{"HEX", 1, {FIELD_TYPE_VARBINARY}, FIELD_TYPE_STRING, hexFunc, NULL},
>  	{"IFNULL", 2, {FIELD_TYPE_ANY, FIELD_TYPE_ANY}, FIELD_TYPE_SCALAR,
> diff --git a/test/sql-tap/func.test.lua b/test/sql-tap/func.test.lua
> index 416f27d69..bd8a8fe78 100755
> --- a/test/sql-tap/func.test.lua
> +++ b/test/sql-tap/func.test.lua
> @@ -1,6 +1,6 @@
>  #!/usr/bin/env tarantool
>  local test = require("sqltester")
> -test:plan(14680)
> +test:plan(14681)
>  
>  --!./tcltestrunner.lua
>  -- 2001 September 15
> @@ -2142,11 +2142,14 @@ test:do_execsql_test(
>          -- </func-24.2>
>      })
>  
> --- do_test func-24.3 {
> ---   execsql {
> ---     SELECT group_concat(t1,' ' || rowid || ' ') FROM tbl1
> ---   }
> --- } {{this 2 program 3 is 4 free 5 software}}
> +test:do_execsql_test(
> +    "func-24.3",
> +    [[
> +        SELECT group_concat(zeroblob(10));
> +    ]], {
> +        '\0\0\0\0\0\0\0\0\0\0'
> +    })
> +
>  test:do_execsql_test(
>      "func-24.4",
>      [[



Changes in "sql: rework GROUP_CONCAT()":

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 28094e258..e1566e150 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -259,10 +259,10 @@ step_group_concat(struct sql_context *ctx, int argc, struct Mem **argv)
 		size = argv[0]->n;
 		str = argv[0]->z;
 	}
-	if (mem_append(ctx->pMem, str, size) != 0) {
+	if (mem_append(ctx->pMem, str, size) != 0)
 		ctx->is_aborted = true;
-		return;
-	}
+	if (mem_is_zerobin(argv[0]))
+		sqlDbFree(sql_get(), str);
 }
 
 /** Finalizer for the GROUP_CONCAT() function. */


Changed diff in "sql: remove copying of result in finalizers":

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index e1566e150..cd256eef2 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -259,19 +244,12 @@ step_group_concat(struct sql_context *ctx, int argc, struct Mem **argv)
 		size = argv[0]->n;
 		str = argv[0]->z;
 	}
-	if (mem_append(ctx->pMem, str, size) != 0)
+	if (mem_append(ctx->pOut, str, size) != 0)
 		ctx->is_aborted = true;
 	if (mem_is_zerobin(argv[0]))
 		sqlDbFree(sql_get(), str);
 }
 
-/** Finalizer for the GROUP_CONCAT() function. */
-static void
-fin_group_concat(struct sql_context *ctx)
-{
-	mem_copy(ctx->pOut, ctx->pMem);
-}
-
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {


Changed diff in "sql: remove field argv from struct sql_context":

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index cd256eef2..41b3de89b 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -236,17 +236,17 @@ step_group_concat(struct sql_context *ctx, int argc, struct Mem **argv)
 	}
 	uint32_t size;
 	char *str;
-	if (mem_is_zerobin(argv[0])) {
-		size = argv[0]->u.nZero;
+	if (mem_is_zerobin(&argv[0])) {
+		size = argv[0].u.nZero;
 		str = sqlDbMallocRawNN(sql_get(), size);
 		memset(str, 0, size);
 	} else {
-		size = argv[0]->n;
-		str = argv[0]->z;
+		size = argv[0].n;
+		str = argv[0].z;
 	}
 	if (mem_append(ctx->pOut, str, size) != 0)
 		ctx->is_aborted = true;
-	if (mem_is_zerobin(argv[0]))
+	if (mem_is_zerobin(&argv[0]))
 		sqlDbFree(sql_get(), str);
 }