[tarantool-patches] Re: [PATCH] Set format for spaces with sysview engine

[Kirill Yukhin]

Hello,

Thanks for review! I'll send updated patch as v2.
My answers are inlined.

On 16 апр 18:13, Vladislav Shpilevoy wrote:
> Hi! Thanks for the patch! See 17 comments below.
> 
> 1. Please, prepend a subsystem name to the commit title.
> Here I would use 'sysview' (by analogue with 'memtx', 'vinyl').
> Do not forget to omit capital letter in 'Set' when the prefix
> is added.

Didn't know we have spacial prefix for sysview. Done.

> On 15/04/2019 16:35, Kirill Yukhin wrote:
> > The patch sets format for spaces with sysview engine.
> > This is done due to following reasons:
> >   1. To allow to create an SQL view, which looks at format of
> >      space being used.
> 
> 2. But it does exactly this even before your patch. Elaborate
> please, that before your patch not all spaces had formats - the
> ones of sysview engine. This is because sysview was invented as
> a filter-engine for normal engines and nothing more. Therefore it
> hasn't its own tuples and didn't need a format.
> 
> But SQL may want to work with sysview spaces, and it expects that
> every space has struct tuple_format, no exceptions. So as not to
> patch SQL with shit like
> 
>     if engine == sysview then do not use tuple_format
> 
> we've decided to create bogus formats even for sysview spaces.

I've updated commment.

> >   2. To unify sysview's engine spaces with SQL views. This
> >      will allow to use sysview machinery to query SQL views from
> >      Lua land.
> 
> 3. This will *completely replace* SQL views. The latter will become
> just another interface to sysview.

Updated comment.

> > 
> > Closes #4111
> > ---
> 
> 4. Please, specify branch and issue links here.

Done.

> > diff --git a/src/box/index_def.c b/src/box/index_def.c
> > index c743d12..31dac33 100644
> > --- a/src/box/index_def.c
> > +++ b/src/box/index_def.c
> > @@ -245,6 +246,25 @@ index_def_cmp(const struct index_def *key1, const struct index_def *key2)
> >  			    key2->key_def->parts, key2->key_def->part_count);
> >  }
> >  
> > +struct key_def **
> > +key_def_array(struct rlist *index_defs, int *size)
> > +{
> > +	/* Create a format from key and field definitions. */
> 
> 5. You do not create a format here. Just a key_def array.
> The comment can be dropped.

Done.

> > +	int key_count = 0;
> > +	struct index_def *index_def;
> > +	rlist_foreach_entry(index_def, index_defs, link)
> > +		key_count++;
> > +	struct key_def **keys = (struct key_def **) region_alloc(&fiber()->gc,
> > +					     sizeof(*keys) * key_count);
> 
> 6. Please, align the code according to the code style. We violate
> the alignment only in rare cases when indentation is huge (usually it
> is about internal still raw SQLite functions).

Done.

> > +	if (keys == NULL)
> > +		return NULL;
> 
> 7. Please, set diag. Region_alloc does not set it itself.

Done.
 
> > diff --git a/src/box/index_def.h b/src/box/index_def.h
> > index 7717ecd..628342d 100644
> > --- a/src/box/index_def.h
> > +++ b/src/box/index_def.h
> > @@ -336,6 +336,17 @@ index_def_new(uint32_t space_id, uint32_t iid, const char *name,
> >  	      const struct index_opts *opts,
> >  	      struct key_def *key_def, struct key_def *pk_def);
> >  
> > +/**
> > + * Create an array of key_defs from array of index definitions.
> 
> 8. Please, add a comment that the array is created on region.

Done.
 
> 9. It is not an array of index definitions. It is a list. The
> same below about @param index_defs.

Done.

> 10. Please, do not write comments just for the sake of them.
> Here 'size' is an [out] variable. From your comment it looks
> like it is a ready-at-hand size of index_defs list.

Fixed.

> > diff --git a/src/box/memtx_space.c b/src/box/memtx_space.c
> > index 7bb46c7..89b04c1 100644
> > --- a/src/box/memtx_space.c
> > +++ b/src/box/memtx_space.c
> > @@ -975,23 +975,16 @@ memtx_space_new(struct memtx_engine *memtx,
> >  	}
> >  
> >  	/* Create a format from key and field definitions. */
> > +
> 
> 11. Stray empty line.

Removed.

> >  	struct tuple_format *format =
> > -		tuple_format_new(&memtx_tuple_format_vtab, memtx, keys, key_count,
> > -				 def->fields, def->field_count,
> > +		tuple_format_new(&memtx_tuple_format_vtab, memtx, keys,
> > +				 key_count, def->fields, def->field_count,
> 
> 12. This diff changes nothing, even names are the same. Please, drop.

Reverted.

> > diff --git a/src/box/sysview.c b/src/box/sysview.c
> > index f9edd2d..768cd02 100644
> > --- a/src/box/sysview.c
> > +++ b/src/box/sysview.c
> > @@ -517,8 +517,31 @@ sysview_engine_create_space(struct engine *engine, struct space_def *def,
> >  			 "malloc", "struct space");
> >  		return NULL;
> >  	}
> > +	int key_count = 0;
> > +	/* 
> > +	 * Despite of the fact that space with sysview engine
> 
> 13. In English 'despite' is never followed by 'of'. You either write
> 'despite', or 'in spite of', no exceptions.

Fixed.

> > diff --git a/test/box/access_sysview.result b/test/box/access_sysview.result
> > index ae04266..6b51566 100644
> > --- a/test/box/access_sysview.result
> > +++ b/test/box/access_sysview.result
> > @@ -642,7 +643,72 @@ box.space._vspace.index[1]:select('xxx')
> >  ...
> >  box.space._vspace.index[1]:select(1)
> >  ---
> > -- error: 'Supplied key type of part 0 does not match index part type: expected string'
> > +- - [257, 1, '_vinyl_deferred_delete', 'blackhole', 0, {'group_id': 1}, [{'name': 'space_id',
> > +        'type': 'unsigned'}, {'name': 'lsn', 'type': 'unsigned'}, {'name': 'tuple',
> > +        'type': 'array'}]]
> > +  - [272, 1, '_schema', 'memtx', 0, {}, [{'type': 'string', 'name': 'key'}, {'type': 'any',
> > +        'name': 'value', 'is_nullable': true}]]
> > +  - [276, 1, '_collation', 'memtx', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {
> > +        'name': 'name', 'type': 'string'}, {'name': 'owner', 'type': 'unsigned'},
> > +      {'name': 'type', 'type': 'string'}, {'name': 'locale', 'type': 'string'}, {
> > +        'name': 'opts', 'type': 'map'}]]
> > +  - [280, 1, '_space', 'memtx', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'owner',
> > +        'type': 'unsigned'}, {'name': 'name', 'type': 'string'}, {'name': 'engine',
> > +        'type': 'string'}, {'name': 'field_count', 'type': 'unsigned'}, {'name': 'flags',
> > +        'type': 'map'}, {'name': 'format', 'type': 'array'}]]
> > +  - [281, 1, '_vspace', 'sysview', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'owner',
> > +        'type': 'unsigned'}, {'name': 'name', 'type': 'string'}, {'name': 'engine',
> > +        'type': 'string'}, {'name': 'field_count', 'type': 'unsigned'}, {'name': 'flags',
> > +        'type': 'map'}, {'name': 'format', 'type': 'array'}]]
> > +  - [284, 1, '_sequence', 'memtx', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'owner',
> > +        'type': 'unsigned'}, {'name': 'name', 'type': 'string'}, {'name': 'step',
> > +        'type': 'integer'}, {'name': 'min', 'type': 'integer'}, {'name': 'max', 'type': 'integer'},
> > +      {'name': 'start', 'type': 'integer'}, {'name': 'cache', 'type': 'integer'},
> > +      {'name': 'cycle', 'type': 'boolean'}]]
> > +  - [285, 1, '_sequence_data', 'memtx', 0, {}, [{'name': 'id', 'type': 'unsigned'},
> > +      {'name': 'value', 'type': 'integer'}]]
> > +  - [286, 1, '_vsequence', 'sysview', 0, {}, [{'name': 'id', 'type': 'unsigned'},
> > +      {'name': 'owner', 'type': 'unsigned'}, {'name': 'name', 'type': 'string'}, {
> > +        'name': 'step', 'type': 'integer'}, {'name': 'min', 'type': 'integer'}, {
> > +        'name': 'max', 'type': 'integer'}, {'name': 'start', 'type': 'integer'}, {
> > +        'name': 'cache', 'type': 'integer'}, {'name': 'cycle', 'type': 'boolean'}]]
> > +  - [288, 1, '_index', 'memtx', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'iid',
> > +        'type': 'unsigned'}, {'name': 'name', 'type': 'string'}, {'name': 'type',
> > +        'type': 'string'}, {'name': 'opts', 'type': 'map'}, {'name': 'parts', 'type': 'array'}]]
> > +  - [289, 1, '_vindex', 'sysview', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'iid',
> > +        'type': 'unsigned'}, {'name': 'name', 'type': 'string'}, {'name': 'type',
> > +        'type': 'string'}, {'name': 'opts', 'type': 'map'}, {'name': 'parts', 'type': 'array'}]]
> > +  - [296, 1, '_func', 'memtx', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'owner',
> > +        'type': 'unsigned'}, {'name': 'name', 'type': 'string'}, {'name': 'setuid',
> > +        'type': 'unsigned'}]]
> > +  - [297, 1, '_vfunc', 'sysview', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'owner',
> > +        'type': 'unsigned'}, {'name': 'name', 'type': 'string'}, {'name': 'setuid',
> > +        'type': 'unsigned'}]]
> > +  - [304, 1, '_user', 'memtx', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'owner',
> > +        'type': 'unsigned'}, {'name': 'name', 'type': 'string'}, {'name': 'type',
> > +        'type': 'string'}, {'name': 'auth', 'type': 'map'}]]
> > +  - [305, 1, '_vuser', 'sysview', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'owner',
> > +        'type': 'unsigned'}, {'name': 'name', 'type': 'string'}, {'name': 'type',
> > +        'type': 'string'}, {'name': 'auth', 'type': 'map'}]]
> > +  - [312, 1, '_priv', 'memtx', 0, {}, [{'name': 'grantor', 'type': 'unsigned'}, {
> > +        'name': 'grantee', 'type': 'unsigned'}, {'name': 'object_type', 'type': 'string'},
> > +      {'name': 'object_id', 'type': 'scalar'}, {'name': 'privilege', 'type': 'unsigned'}]]
> > +  - [313, 1, '_vpriv', 'sysview', 0, {}, [{'name': 'grantor', 'type': 'unsigned'},
> > +      {'name': 'grantee', 'type': 'unsigned'}, {'name': 'object_type', 'type': 'string'},
> > +      {'name': 'object_id', 'type': 'scalar'}, {'name': 'privilege', 'type': 'unsigned'}]]
> > +  - [320, 1, '_cluster', 'memtx', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'uuid',
> > +        'type': 'string'}]]
> > +  - [328, 1, '_trigger', 'memtx', 0, {}, [{'name': 'name', 'type': 'string'}, {'name': 'space_id',
> > +        'type': 'unsigned'}, {'name': 'opts', 'type': 'map'}]]
> > +  - [330, 1, '_truncate', 'memtx', 0, {}, [{'name': 'id', 'type': 'unsigned'}, {'name': 'count',
> > +        'type': 'unsigned'}]]
> > +  - [340, 1, '_space_sequence', 'memtx', 0, {}, [{'name': 'id', 'type': 'unsigned'},
> > +      {'name': 'sequence_id', 'type': 'unsigned'}, {'name': 'is_generated', 'type': 'boolean'}]]
> > +  - [356, 1, '_fk_constraint', 'memtx', 0, {}, [{'name': 'name', 'type': 'string'},
> > +      {'name': 'child_id', 'type': 'unsigned'}, {'name': 'parent_id', 'type': 'unsigned'},
> > +      {'name': 'is_deferred', 'type': 'boolean'}, {'name': 'match', 'type': 'string'},
> > +      {'name': 'on_delete', 'type': 'string'}, {'name': 'on_update', 'type': 'string'},
> > +      {'name': 'child_cols', 'type': 'array'}, {'name': 'parent_cols', 'type': 'array'}]]
> 
> 14. Too huge output, which will change on each update in system
> spaces set and format. We already have similar tests printing
> everything out, and usually it is not a pleasant business to fix
> them after each touch of upgrade.lua. I would rather replaced it
> like this:
> 
>     box.space._vspace.index[1]:count(1) > 0

Done.

> > diff --git a/test/sql/gh-4111-format-in-sysview.result b/test/sql/gh-4111-format-in-sysview.result
> > new file mode 100644
> > index 0000000..1d6c1f0
> > --- /dev/null
> > +++ b/test/sql/gh-4111-format-in-sysview.result
> 
> 15. Please, move it to 'access_sysview' test. Because
> basically it is exactly about this: accessing a sysview
> from SQL.

No, this is a regression test for the bug #4111. I can move it to another suite if you like.

> > @@ -0,0 +1,51 @@
> > +-- Make sure, that it is possible to create a VIEW which
> > +-- refers to "_v" space, i.e. to sysview engine.
> > +-- Boefore gh-4111 was fixed, attempt to create such a view
> 
> 16. Boefore -> before.

Fixed.
 
> > +-- failed due to lack of format in a space with sysview
> > +-- engine.
> > +test_run = require('test_run').new()
> > +---
> > +...
> > +box.space._vspace:format()
> > +---
> > +- [{'name': 'id', 'type': 'unsigned'}, {'name': 'owner', 'type': 'unsigned'}, {'name': 'name',
> > +    'type': 'string'}, {'name': 'engine', 'type': 'string'}, {'name': 'field_count',
> > +    'type': 'unsigned'}, {'name': 'flags', 'type': 'map'}, {'name': 'format', 'type': 'array'}]
> > +...
> > +box.execute([[CREATE VIEW t AS SELECT "name" FROM "_vspace" y]])
> > +---
> > +- row_count: 1
> > +...
> > +box.execute([[SELECT * from t]])
> > +---
> > +- metadata:
> > +  - name: name
> > +    type: string
> > +  rows:
> > +  - ['_vinyl_deferred_delete']
> > +  - ['_schema']
> > +  - ['_collation']
> > +  - ['_space']
> > +  - ['_vspace']
> > +  - ['_sequence']
> > +  - ['_sequence_data']
> > +  - ['_vsequence']
> > +  - ['_index']
> > +  - ['_vindex']
> > +  - ['_func']
> > +  - ['_vfunc']
> > +  - ['_user']
> > +  - ['_vuser']
> > +  - ['_priv']
> > +  - ['_vpriv']
> > +  - ['_cluster']
> > +  - ['_trigger']
> > +  - ['_truncate']
> > +  - ['_space_sequence']
> > +  - ['_fk_constraint']
> > +  - ['T']
> 
> 17. The same objection as 14. Probably it would be less
> flaky to call
> 
>     box.execute([[SELECT * from t WHERE "name" = "T"]])
> 
> Then it will print one line only and still test the issue
> good.

Done.

--
Regards, Kirill Yukhin