Use "merger" for fetch&sort tuples on router (#38)

Before this patch we used hand-crafted heap to sort tuples on
router. This patch removes it and changes to "merger" module
written in C.

"Merger" is available since Tarantool 2.2. Later "tuple-merger"
was introduced it's a version that is compatible with some
Tarantool 1.10 versions. In fact support several Tarantool
versions is quite complex task. Some msgpack helpers is not
avaliable in Tarantool 1.10 to solve this problem small
compatibility lawer is implemented.
Also "tuple-keydef" doesn't support collation_id options and it's
not so for built-in "key_def" module. We need to normalize index
parts and change "collation_id" to "collation" when create
"key_def" instance.

For versions where merger is not supported/available yet
(before 1.10.8 and before 2.3.3) we use previous approach with
lua-implemented heap.

crud.select.compat.select - default module with merged
crud.select.compat.select_old - compatibility module without 
merger support written in Lua

Co-authored-by: AnaNek <neknas28@gmail.com>

Author: olegrok

.github/workflows/test_on_push.yaml

@@ -21,6 +21,7 @@ jobs:
         run: |
           curl -L https://tarantool.io/installer.sh | sudo VER=${{ matrix.tarantool-version }} bash
           sudo apt install -y tarantool-dev
+          tarantool --version
           ./deps.sh
 
       # This server starts and listen on 8084 port that is used for tests
@@ -50,6 +51,7 @@ jobs:
           rm -f tarantool-enterprise-bundle-${{ matrix.bundle_version }}.tar.gz
           sudo cp tarantool-enterprise/tarantool /usr/bin/tarantool
           source tarantool-enterprise/env.sh
+          tarantool --version
           ./deps.sh
 
       # This server starts and listen on 8084 port that is used for tests

CMakeLists.txt

@@ -28,3 +28,9 @@ install(
   DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/cartridge
   DESTINATION ${TARANTOOL_INSTALL_LUADIR}
 )
+
+# Don't include to rockspec as some Tarantool versions (e.g. 2.2 and 2.3)
+# don't have symbols required by "tuple-merger" and "tuple-keydef" modules.
+execute_process(
+    COMMAND bash "-c" "tarantoolctl rocks install tuple-merger 0.0.1"
+)

crud/common/call.lua

@@ -10,9 +10,9 @@ local NotInitializedError = errors.new_class('NotInitialized')
 
 local call = {}
 
-local DEFAULT_VSHARD_CALL_TIMEOUT = 2
+call.DEFAULT_VSHARD_CALL_TIMEOUT = 2
 
-local function get_vshard_call_name(mode, prefer_replica, balance)
+function call.get_vshard_call_name(mode, prefer_replica, balance)
     dev_checks('string', '?boolean', '?boolean')
 
     if mode == 'write' then
@@ -74,9 +74,9 @@ function call.map(func_name, func_args, opts)
     })
     opts = opts or {}
 
-    local vshard_call_name = get_vshard_call_name(opts.mode, opts.prefer_replica, opts.balance)
+    local vshard_call_name = call.get_vshard_call_name(opts.mode, opts.prefer_replica, opts.balance)
 
-    local timeout = opts.timeout or DEFAULT_VSHARD_CALL_TIMEOUT
+    local timeout = opts.timeout or call.DEFAULT_VSHARD_CALL_TIMEOUT
 
     local replicasets, err
     if opts.replicasets ~= nil then
@@ -112,7 +112,7 @@ function call.map(func_name, func_args, opts)
             return nil, wrap_vshard_err(err, func_name, replicaset_uuid)
         end
 
-        results[replicaset_uuid] = result[1]
+        results[replicaset_uuid] = result
     end
 
     return results
@@ -126,9 +126,9 @@ function call.single(bucket_id, func_name, func_args, opts)
         timeout = '?number',
     })
 
-    local vshard_call_name = get_vshard_call_name(opts.mode, opts.prefer_replica, opts.balance, opts.mode)
+    local vshard_call_name = call.get_vshard_call_name(opts.mode, opts.prefer_replica, opts.balance, opts.mode)
 
-    local timeout = opts.timeout or DEFAULT_VSHARD_CALL_TIMEOUT
+    local timeout = opts.timeout or call.DEFAULT_VSHARD_CALL_TIMEOUT
 
     local res, err = vshard.router[vshard_call_name](bucket_id, func_name, func_args, {
         timeout = timeout,