Separate modules for working with conditions from select module

For `count` implementation with the support of the
query by conditions there is a need to use query plan
and condition filters that has been already written
for select. This commit separates common methods from
select module and moves them in common folders.

Part of #74

Author: AnaNek

crud/common/sharding.lua

@@ -2,12 +2,24 @@ local vshard = require('vshard')
 local errors = require('errors')
 
 local BucketIDError = errors.new_class("BucketIDError", {capture_stack = false})
+local GetReplicasetsError = errors.new_class('GetReplicasetsError', {capture_stack = false})
 
 local utils = require('crud.common.utils')
 local sharding_key_module = require('crud.common.sharding_key')
 
 local sharding = {}
 
+function sharding.get_replicasets_by_bucket_id(bucket_id)
+    local replicaset, err = vshard.router.route(bucket_id)
+    if replicaset == nil then
+        return nil, GetReplicasetsError:new("Failed to get replicaset for bucket_id %s: %s", bucket_id, err.err)
+    end
+
+    return {
+        [replicaset.uuid] = replicaset,
+    }
+end
+
 function sharding.key_get_bucket_id(key, specified_bucket_id)
     if specified_bucket_id ~= nil then
         return specified_bucket_id

crud/select/filters.lua renamed to crud/compare/filters.lua

@@ -12,11 +12,14 @@ if has_keydef then
     keydef_lib = compat.require('tuple.keydef', 'key_def')
 end
 
-local select_plan = {}
+local plan = {}
 
 local IndexTypeError = errors.new_class('IndexTypeError', {capture_stack = false})
 local FilterFieldsError = errors.new_class('FilterFieldsError', {capture_stack = false})
 
+-- TREE index helps reducing the number of tuples to scan.
+-- Otherwise a full scan is performed. So at least one of
+-- condition indexes or primary index should be of type TREE
 local function index_is_allowed(index)
     return index.type == 'TREE'
 end
@@ -157,7 +160,7 @@ local function construct_after_tuple_by_fields(fieldno_map, field_names, tuple)
     return transformed_tuple
 end
 
-function select_plan.new(space, conditions, opts)
+function plan.new(space, conditions, opts)
     dev_checks('table', '?table', {
         first = '?number',
         after_tuple = '?table|cdata',
@@ -292,9 +295,9 @@ function select_plan.new(space, conditions, opts)
     return plan
 end
 
-select_plan.internal = {
+plan.internal = {
     get_sharding_key_from_scan_value = get_sharding_key_from_scan_value,
     extract_sharding_key_from_conditions = extract_sharding_key_from_conditions
 }
 
-return select_plan
+return plan

crud/select/plan.lua renamed to crud/compare/plan.lua

@@ -2,7 +2,7 @@ local errors = require('errors')
 
 local utils = require('crud.common.utils')
 local select_executor = require('crud.select.executor')
-local select_filters = require('crud.select.filters')
+local select_filters = require('crud.compare.filters')
 local dev_checks = require('crud.common.dev_checks')
 local schema = require('crud.common.schema')
 

crud/select.lua

@@ -1,24 +1,6 @@
-local vshard = require('vshard')
-local errors = require('errors')
+local common = {}
 
-local GetReplicasetsError = errors.new_class('GetReplicasetsError')
+common.SELECT_FUNC_NAME = '_crud.select_on_storage'
+common.DEFAULT_BATCH_SIZE = 100
 
-local SELECT_FUNC_NAME = '_crud.select_on_storage'
-local DEFAULT_BATCH_SIZE = 100
-
-local function get_replicasets_by_sharding_key(bucket_id)
-    local replicaset, err = vshard.router.route(bucket_id)
-    if replicaset == nil then
-        return nil, GetReplicasetsError:new("Failed to get replicaset for bucket_id %s: %s", bucket_id, err.err)
-    end
-
-    return {
-        [replicaset.uuid] = replicaset,
-    }
-end
-
-return {
-    get_replicasets_by_sharding_key = get_replicasets_by_sharding_key,
-    SELECT_FUNC_NAME = SELECT_FUNC_NAME,
-    DEFAULT_BATCH_SIZE = DEFAULT_BATCH_SIZE,
-}
+return common

crud/select/compat/common.lua

@@ -10,7 +10,7 @@ local schema = require('crud.common.schema')
 local sharding_key_module = require('crud.common.sharding_key')
 
 local compare_conditions = require('crud.compare.conditions')
-local select_plan = require('crud.select.plan')
+local select_plan = require('crud.compare.plan')
 
 local Merger = require('crud.select.merger')
 
@@ -107,7 +107,7 @@ local function build_select_iterator(space_name, user_conditions, opts)
         assert(bucket_id ~= nil)
 
         local err
-        replicasets_to_select, err = common.get_replicasets_by_sharding_key(bucket_id)
+        replicasets_to_select, err = sharding.get_replicasets_by_bucket_id(bucket_id)
         if err ~= nil then
             return nil, err, true
         end

crud/select/compat/select.lua

@@ -11,7 +11,7 @@ local schema = require('crud.common.schema')
 local sharding_key_module = require('crud.common.sharding_key')
 
 local compare_conditions = require('crud.compare.conditions')
-local select_plan = require('crud.select.plan')
+local select_plan = require('crud.compare.plan')
 local select_comparators = require('crud.compare.comparators')
 local common = require('crud.select.compat.common')
 
@@ -133,7 +133,7 @@ local function build_select_iterator(space_name, user_conditions, opts)
         assert(bucket_id ~= nil)
 
         local err
-        replicasets_to_select, err = common.get_replicasets_by_sharding_key(bucket_id)
+        replicasets_to_select, err = sharding.get_replicasets_by_bucket_id(bucket_id)
         if err ~= nil then
             return nil, err, true
         end

crud/select/compat/select_old.lua

@@ -3,25 +3,25 @@ local helpers = require('test.helper')
 
 local storage_stat = {}
 
--- Wrap crud's select_on_storage() function to count selects
--- and add storage_stat() function that returns resulting
--- statistics.
+-- Wrap crud's select_on_storage()/count_on_storage()
+-- function to count selects/counts and add storage_stat()
+-- function that returns resulting statistics.
 --
 -- Call it after crud's initialization.
-function storage_stat.init_on_storage()
-    assert(_G._crud.select_on_storage ~= nil)
+function storage_stat.init_on_storage(method_on_storage_name)
+    assert(_G._crud[method_on_storage_name] ~= nil)
 
     -- Here we count requests.
     local storage_stat_table = {
-        select_requests = 0,
+        requests = 0,
     }
 
-    -- Wrap select_on_storage() function.
-    local select_on_storage_saved = _G._crud.select_on_storage
-    _G._crud.select_on_storage = function(...)
-        local requests = storage_stat_table.select_requests
-        storage_stat_table.select_requests = requests + 1
-        return select_on_storage_saved(...)
+    -- Wrap method on storage function.
+    local requests_on_storage_saved = _G._crud[method_on_storage_name]
+    _G._crud[method_on_storage_name] = function(...)
+        local requests = storage_stat_table.requests
+        storage_stat_table.requests = requests + 1
+        return requests_on_storage_saved(...)
     end
 
     -- Accessor for the statistics.
@@ -30,6 +30,14 @@ function storage_stat.init_on_storage()
     end)
 end
 
+function storage_stat.init_on_storage_for_select()
+    storage_stat.init_on_storage('select_on_storage')
+end
+
+function storage_stat.init_on_storage_for_count()
+    storage_stat.init_on_storage('count_on_storage')
+end
+
 -- Accumulate statistics from storages.
 --
 -- The statistics is grouped by replicasets.
@@ -96,12 +104,12 @@ function storage_stat.diff(a, b)
 end
 
 -- Accepts collect (or diff) return value and returns
--- total number of select requests across all storages.
+-- total number of select/count requests across all storages.
 function storage_stat.total(stats)
     local total = 0
 
     for _, stat in pairs(stats) do
-        total = total + (stat.select_requests or 0)
+        total = total + (stat.requests or 0)
     end
 
     return total

test/helpers/storage_stat.lua

@@ -38,7 +38,7 @@ pgroup.before_all(function(g)
     helpers.call_on_storages(g.cluster, function(server)
         server.net_box:eval([[
             local storage_stat = require('test.helpers.storage_stat')
-            storage_stat.init_on_storage()
+            storage_stat.init_on_storage_for_select()
         ]])
     end)
 end)

test/integration/ddl_sharding_key_test.lua

@@ -30,7 +30,7 @@ pgroup.before_all(function(g)
     helpers.call_on_storages(g.cluster, function(server)
         server.net_box:eval([[
             local storage_stat = require('test.helpers.storage_stat')
-            storage_stat.init_on_storage()
+            storage_stat.init_on_storage_for_select()
         ]])
     end)
 end)
@@ -861,10 +861,10 @@ pgroup.test_pairs_no_map_reduce = function(g)
     local stat_b = storage_stat.collect(g.cluster)
     t.assert_equals(storage_stat.diff(stat_b, stat_a), {
         ['s-1'] = {
-            select_requests = 1,
+            requests = 1,
         },
         ['s-2'] = {
-            select_requests = 0,
+            requests = 0,
         },
     })
 
@@ -886,10 +886,10 @@ pgroup.test_pairs_no_map_reduce = function(g)
     local stat_c = storage_stat.collect(g.cluster)
     t.assert_equals(storage_stat.diff(stat_c, stat_b), {
         ['s-1'] = {
-            select_requests = 0,
+            requests = 0,
         },
         ['s-2'] = {
-            select_requests = 1,
+            requests = 1,
         },
     })
 end

test/integration/pairs_test.lua

@@ -31,7 +31,7 @@ pgroup.before_all(function(g)
     helpers.call_on_storages(g.cluster, function(server)
         server.net_box:eval([[
             local storage_stat = require('test.helpers.storage_stat')
-            storage_stat.init_on_storage()
+            storage_stat.init_on_storage_for_select()
         ]])
     end)
 end)
@@ -1631,10 +1631,10 @@ pgroup.test_select_no_map_reduce = function(g)
     local stat_b = storage_stat.collect(g.cluster)
     t.assert_equals(storage_stat.diff(stat_b, stat_a), {
         ['s-1'] = {
-            select_requests = 1,
+            requests = 1,
         },
         ['s-2'] = {
-            select_requests = 0,
+            requests = 0,
         },
     })
 
@@ -1653,10 +1653,10 @@ pgroup.test_select_no_map_reduce = function(g)
     local stat_c = storage_stat.collect(g.cluster)
     t.assert_equals(storage_stat.diff(stat_c, stat_b), {
         ['s-1'] = {
-            select_requests = 0,
+            requests = 0,
         },
         ['s-2'] = {
-            select_requests = 1,
+            requests = 1,
         },
     })
 end

test/integration/select_test.lua

@@ -1,4 +1,4 @@
-local select_plan = require('crud.select.plan')
+local select_plan = require('crud.compare.plan')
 
 local compare_conditions = require('crud.compare.conditions')
 local cond_funcs = compare_conditions.funcs

test/unit/select_dropped_indexes_test.lua

@@ -1,8 +1,8 @@
 local crud = require('crud')
 
-local select_plan = require('crud.select.plan')
+local select_plan = require('crud.compare.plan')
 local select_executor = require('crud.select.executor')
-local select_filters = require('crud.select.filters')
+local select_filters = require('crud.compare.filters')
 
 local compare_conditions = require('crud.compare.conditions')
 local cond_funcs = compare_conditions.funcs

test/unit/select_executor_test.lua

@@ -2,8 +2,8 @@
 
 local compare_conditions = require('crud.compare.conditions')
 local cond_funcs = compare_conditions.funcs
-local select_filters = require('crud.select.filters')
-local select_plan = require('crud.select.plan')
+local select_filters = require('crud.compare.filters')
+local select_plan = require('crud.compare.plan')
 local collations = require('crud.common.collations')
 
 local t = require('luatest')

test/unit/select_filters_test.lua

@@ -5,9 +5,9 @@ local uuid = require('uuid')
 local crud_utils = require('crud.common.utils')
 local compare_conditions = require('crud.compare.conditions')
 local cond_funcs = compare_conditions.funcs
-local select_filters = require('crud.select.filters')
+local select_filters = require('crud.compare.filters')
 local collations = require('crud.common.collations')
-local select_plan = require('crud.select.plan')
+local select_plan = require('crud.compare.plan')
 
 local t = require('luatest')
 local g = t.group('select_filters_uuid')

test/unit/select_filters_uuid_test.lua

@@ -1,4 +1,4 @@
-local select_plan = require('crud.select.plan')
+local select_plan = require('crud.compare.plan')
 
 local compare_conditions = require('crud.compare.conditions')
 local cond_funcs = compare_conditions.funcs

test/unit/select_plan_bad_indexes_test.lua

@@ -1,4 +1,4 @@
-local select_plan = require('crud.select.plan')
+local select_plan = require('crud.compare.plan')
 local compare_conditions = require('crud.compare.conditions')
 local utils = require('crud.common.utils')
 local cond_funcs = compare_conditions.funcs