net_box: update space objects instead of replacing them

Update netbox.space objects in-place instead of re-creating them
on every schema change.

Closes #2401

src/box/lua/net_box.lua

@@ -839,18 +839,21 @@ function remote_methods:_install_schema(schema_version, spaces, indices)
         local engine = space[4]
         local field_count = space[5]
         local format = space[7] or {}
-
-        local s = {
-            id              = id,
-            name            = name,
-            engine          = engine,
-            field_count     = field_count,
-            enabled         = true,
-            index           = {},
-            temporary       = false,
-            _format         = format,
-            connection      = self
-        }
+        local s = {}
+        if self.space ~= nil and self.space[id] ~= nil then
+            s = self.space[id]
+        else
+            setmetatable(s, space_mt)
+        end
+        s.id = id
+        s.name = name
+        s.engine = engine
+        s.field_count = field_count
+        s.enabled = true
+        s.index = {}
+        s.temporary = false
+        s._format = format
+        s.connection = self
         if #space > 5 then
             local opts = space[6]
             if type(opts) == 'table' then
@@ -862,8 +865,6 @@ function remote_methods:_install_schema(schema_version, spaces, indices)
             end
         end
 
-        setmetatable(s, space_mt)
-
         sl[id] = s
         sl[name] = s
     end

test/box/alter.result

@@ -1686,3 +1686,16 @@ s:insert({1, 1, 'a', 'b', 'c', 'd'})
 s:drop()
 ---
 ...
+s = box.schema.create_space('test')
+---
+...
+idx = s:create_index('idx')
+---
+...
+box.space.test == s
+---
+- true
+...
+s:drop()
+---
+...

test/box/alter.test.lua

@@ -641,3 +641,8 @@ s:format()
 _ = s:create_index('primary')
 s:insert({1, 1, 'a', 'b', 'c', 'd'})
 s:drop()
+
+s = box.schema.create_space('test')
+idx = s:create_index('idx')
+box.space.test == s
+s:drop()

test/box/net.box.result

@@ -1931,6 +1931,47 @@ test_run:cmd('cleanup server connecter')
 ---
 - true
 ...
+--
+-- gh-2401 update pseudo objects not replace them
+--
+space:drop()
+---
+...
+space = box.schema.space.create('test')
+---
+...
+c = net.connect(box.cfg.listen)
+---
+...
+cspace = c.space.test
+---
+...
+space.index.test_index == nil
+---
+- true
+...
+cspace.index.test_index == nil
+---
+- true
+...
+_ = space:create_index("test_index", {parts={1, 'string'}})
+---
+...
+c:reload_schema()
+---
+...
+space.index.test_index ~= nil
+---
+- true
+...
+cspace.index.test_index ~= nil
+---
+- true
+...
+c.space.test.index.test_index ~= nil
+---
+- true
+...
 -- cleanup
 box.schema.user.revoke('guest','read,write,execute','universe')
 ---

test/box/net.box.test.lua

@@ -779,6 +779,21 @@ disconnected_cnt
 test_run:cmd('stop server connecter')
 test_run:cmd('cleanup server connecter')
 
+--
+-- gh-2401 update pseudo objects not replace them
+--
+space:drop()
+space = box.schema.space.create('test')
+c = net.connect(box.cfg.listen)
+cspace = c.space.test
+space.index.test_index == nil
+cspace.index.test_index == nil
+_ = space:create_index("test_index", {parts={1, 'string'}})
+c:reload_schema()
+space.index.test_index ~= nil
+cspace.index.test_index ~= nil
+c.space.test.index.test_index ~= nil
+
 -- cleanup
 box.schema.user.revoke('guest','read,write,execute','universe')
 

test/box/sql.result

@@ -34,32 +34,29 @@ _ = box.space.test1:create_index('primary', { type = 'hash' })
 _ = box.space.test1:create_index('secondary', { type = 'hash', parts = {2, 'string'}})
 ---
 ...
-conn:ping()
+--  send request to remote server to force schema reloading
+conn:reload_schema()
 ---
-- true
 ...
--- xxx: bug  currently selects no rows
 space:select{}
 ---
-- error: 'No index #0 is defined in space ''test'''
+- []
 ...
 space:insert{1, 'I am a tuple'}
 ---
 - [1, 'I am a tuple']
 ...
 space:select{1}
 ---
-- error: 'No index #0 is defined in space ''test'''
+- - [1, 'I am a tuple']
 ...
--- currently there is no way to find out how many records
--- a space contains 
 space:select{0}
 ---
-- error: 'No index #0 is defined in space ''test'''
+- []
 ...
 space:select{2}
 ---
-- error: 'No index #0 is defined in space ''test'''
+- []
 ...
 test_run:cmd('restart server default')
 net_box = require('net.box')

test/box/sql.test.lua

@@ -13,15 +13,14 @@ space = conn.space.test
 index = box.space.test:create_index('primary', { type = 'hash' })
 _ = box.space.test1:create_index('primary', { type = 'hash' })
 _ = box.space.test1:create_index('secondary', { type = 'hash', parts = {2, 'string'}})
-conn:ping()
 
--- xxx: bug  currently selects no rows
+--  send request to remote server to force schema reloading
+conn:reload_schema()
+
 space:select{}
 space:insert{1, 'I am a tuple'}
 space:select{1}
 
--- currently there is no way to find out how many records
--- a space contains 
 space:select{0}
 space:select{2}