extension: init tidb new extension framework

br/pkg/glue/BUILD.bazel

@@ -10,6 +10,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//br/pkg/logutil",
+        "//ddl",
         "//domain",
         "//kv",
         "//parser/model",

br/pkg/restore/BUILD.bazel

@@ -33,6 +33,7 @@ go_library(
         "//br/pkg/metautil",
         "//br/pkg/pdutil",
         "//br/pkg/redact",
+        "//br/pkg/restore/prealloc_table_id",
         "//br/pkg/restore/split",
         "//br/pkg/restore/tiflashrec",
         "//br/pkg/rtree",
@@ -41,6 +42,7 @@ go_library(
         "//br/pkg/summary",
         "//br/pkg/utils",
         "//config",
+        "//ddl",
         "//ddl/util",
         "//domain",
         "//kv",

br/pkg/restore/prealloc_table_id/BUILD.bazel

@@ -0,0 +1,20 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "prealloc_table_id",
+    srcs = ["alloc.go"],
+    importpath = "github.com/pingcap/tidb/br/pkg/restore/prealloc_table_id",
+    visibility = ["//visibility:public"],
+    deps = ["//br/pkg/metautil"],
+)
+
+go_test(
+    name = "prealloc_table_id_test",
+    srcs = ["alloc_test.go"],
+    deps = [
+        ":prealloc_table_id",
+        "//br/pkg/metautil",
+        "//parser/model",
+        "@com_github_stretchr_testify//require",
+    ],
+)

build/nogo_config.json

@@ -213,7 +213,8 @@
       "server/conn_stmt.go": "server/conn_stmt.go",
       "server/conn_test.go": "server/conn_test.go",
       "planner/core/plan.go": "planner/core/plan.go",
-      "errno/": "only table code"
+      "errno/": "only table code",
+      "extension/": "extension code"
     }
   },
   "gofmt": {
@@ -332,7 +333,8 @@
       "kv/": "kv code",
       "util/memory": "util/memory",
       "ddl/": "ddl",
-      "planner/": "planner"
+      "planner/": "planner",
+      "extension/": "extension code"
     }
   },
   "pkgfact": {
@@ -399,7 +401,8 @@
       "planner/core/util.go": "planner/core/util.go",
       "util/": "util code",
       "parser/": "parser code",
-      "meta/": "parser code"
+      "meta/": "parser code",
+      "extension/": "extension code"
     }
   },
   "shift": {
@@ -757,7 +760,8 @@
       "planner/core/plan.go": "planner/core/plan.go",
       "server/conn.go": "server/conn.go",
       "server/conn_stmt.go": "server/conn_stmt.go",
-      "server/conn_test.go": "server/conn_test.go"
+      "server/conn_test.go": "server/conn_test.go",
+      "extension/": "extension code"
     }
   },
   "SA2000": {

extension/BUILD.bazel

@@ -0,0 +1,29 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "extension",
+    srcs = [
+        "extensions.go",
+        "manifest.go",
+        "registry.go",
+        "util.go",
+    ],
+    importpath = "github.com/pingcap/tidb/extension",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//sessionctx/variable",
+        "@com_github_pingcap_errors//:errors",
+    ],
+)
+
+go_test(
+    name = "extension_test",
+    srcs = ["registry_test.go"],
+    deps = [
+        ":extension",
+        "//privilege/privileges",
+        "//sessionctx/variable",
+        "@com_github_pingcap_errors//:errors",
+        "@com_github_stretchr_testify//require",
+    ],
+)

extension/extensions.go

@@ -0,0 +1,30 @@
+// Copyright 2022 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package extension
+
+// Extensions contains all extensions that have already setup
+type Extensions struct {
+	manifests []*Manifest
+}
+
+// Manifests returns a extension manifests
+func (es *Extensions) Manifests() []*Manifest {
+	if es == nil {
+		return nil
+	}
+	manifests := make([]*Manifest, len(es.manifests))
+	copy(manifests, es.manifests)
+	return manifests
+}

extension/manifest.go

@@ -0,0 +1,136 @@
+// Copyright 2022 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package extension
+
+import (
+	"github.com/pingcap/errors"
+	"github.com/pingcap/tidb/sessionctx/variable"
+)
+
+// Option represents an option to initialize an extension
+type Option func(m *Manifest)
+
+// WithCustomSysVariables specifies custom variables of an extension
+func WithCustomSysVariables(vars []*variable.SysVar) Option {
+	return func(m *Manifest) {
+		m.sysVariables = vars
+	}
+}
+
+// WithCustomDynPrivs specifies dynamic privileges of an extension
+func WithCustomDynPrivs(privs []string) Option {
+	return func(m *Manifest) {
+		m.dynPrivs = privs
+	}
+}
+
+// WithClose specifies the close function of an extension.
+// It will be invoked when `extension.Reset` is called
+func WithClose(fn func()) Option {
+	return func(m *Manifest) {
+		m.close = fn
+	}
+}
+
+// Manifest is an extension's manifest
+type Manifest struct {
+	name         string
+	sysVariables []*variable.SysVar
+	dynPrivs     []string
+	close        func()
+}
+
+// Name returns the extension's name
+func (m *Manifest) Name() string {
+	return m.name
+}
+
+func newManifestWithSetup(name string, factory func() ([]Option, error)) (_ *Manifest, _ func(), err error) {
+	clearBuilder := &clearFuncBuilder{}
+	defer func() {
+		if err != nil {
+			clearBuilder.Build()()
+		}
+	}()
+
+	// new manifest with factory
+	m := &Manifest{name: name}
+	err = clearBuilder.DoWithCollectClear(func() (func(), error) {
+		options, err := factory()
+		if err != nil {
+			return nil, err
+		}
+
+		for _, opt := range options {
+			opt(m)
+		}
+
+		return m.close, nil
+	})
+
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// setup dynamic privileges
+	for i := range m.dynPrivs {
+		priv := m.dynPrivs[i]
+		err = clearBuilder.DoWithCollectClear(func() (func(), error) {
+			if err = RegisterDynamicPrivilege(priv); err != nil {
+				return nil, err
+			}
+			return func() {
+				RemoveDynamicPrivilege(priv)
+			}, nil
+		})
+		if err != nil {
+			return nil, nil, err
+		}
+	}
+
+	// setup sys vars
+	for i := range m.sysVariables {
+		sysVar := m.sysVariables[i]
+		err = clearBuilder.DoWithCollectClear(func() (func(), error) {
+			if sysVar == nil {
+				return nil, errors.New("system var should not be nil")
+			}
+
+			if sysVar.Name == "" {
+				return nil, errors.New("system var name should not be empty")
+			}
+
+			if variable.GetSysVar(sysVar.Name) != nil {
+				return nil, errors.Errorf("system var '%s' has already registered", sysVar.Name)
+			}
+
+			variable.RegisterSysVar(sysVar)
+			return func() {
+				variable.UnregisterSysVar(sysVar.Name)
+			}, nil
+		})
+
+		if err != nil {
+			return nil, nil, err
+		}
+	}
+	return m, clearBuilder.Build(), nil
+}
+
+// RegisterDynamicPrivilege is used to resolve dependency cycle
+var RegisterDynamicPrivilege func(string) error
+
+// RemoveDynamicPrivilege is used to resolve dependency cycle
+var RemoveDynamicPrivilege func(string) bool