Allow users to update schema without restarting the connection

[rayman1104]

What has been done? Why? What problem is being solved?

If new space was created while the program is running, the schema is not updated and hence it's impossible to make queries to new spaces.

Right now if one wants to update the schema, they have to restart the connection completely, which is suboptimal. Making this loadSchema method public would allow them to trigger it manually at least. But of course in the future would be nice to update the schema automatically by the response from tarantool, as it's described in #7.

[oleg-jukovec]

Thank you for the pull request! We need tests for the pull request, since this functionality will be available in the public api.

If you are blocked by the issue, you could manually update the schema right now with a workaround:

schema := new(tarantool.Schema)
schema.SpacesById = make(map[uint32]*tarantool.Space)
schema.Spaces = make(map[string]*tarantool.Space)

// Reload spaces.
var spaces []*tarantool.Space
err = conn.SelectTyped(vspaceSpId, 0, 0, maxSchemas, IterAll, []interface{}{}, &spaces)
if err != nil {
	return err
}
for _, space := range spaces {
	schema.SpacesById[space.Id] = space
	schema.Spaces[space.Name] = space
}

// Reload indexes.
var indexes []*Index
err = conn.SelectTyped(vindexSpId, 0, 0, maxSchemas, IterAll, []interface{}{}, &indexes)
if err != nil {
	return err
}
for _, index := range indexes {
	schema.SpacesById[index.SpaceId].IndexesById[index.Id] = index
	schema.SpacesById[index.SpaceId].Indexes[index.Name] = index
}
conn.OverrideSchema(schema) // or conn.Schema = schema

But be careful, this is not safe for active requests:

#218
35939df

Therefore, I will be able to merge this pull request only after #258 .

[kokizzu]

on code above what is vspaceSpId?

[oleg-jukovec]

on code above what is vspaceSpId?

281

vindexSpId:

289

You could execute in Tarantool:

tarantool> box.space._space:select()
---
...
  - [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'}]]
...
  - [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'}]]
...

[rayman1104]

@oleg-jukovec can we merge it now since #258 is merged?

[oleg-jukovec]

@oleg-jukovec can we merge it now since #258 is merged?

First you need to add tests for the public API. At least you need to add an integration test with Tarantool to tarantool_test.go.

[oleg-jukovec]

The pull request closed due to inactivity. You can re-open it with tests for the public API.