Move db related basic functions to models/db (#17075)

* Move db related basic functions to models/db

* Fix lint

* Fix lint

* Fix test

* Fix lint

* Fix lint

* revert unnecessary change

* Fix test

* Fix wrong replace string

* Use *Context

* Correct committer spelling and fix wrong replaced words

Co-authored-by: zeripath <art27@cantab.net>

1 files changed, 0 insertions, 113 deletions

diff --git a/models/index.go b/models/index.go
deleted file mode 100644
index 121a149ca0..0000000000
--- a/models/index.go
+++ /dev/null
@@ -1,113 +0,0 @@
-// Copyright 2021 The Gitea Authors. All rights reserved.
-// Use of this source code is governed by a MIT-style
-// license that can be found in the LICENSE file.
-
-package models
-
-import (
-	"errors"
-	"fmt"
-
-	"code.gitea.io/gitea/modules/setting"
-)
-
-// ResourceIndex represents a resource index which could be used as issue/release and others
-// We can create different tables i.e. issue_index, release_index and etc.
-type ResourceIndex struct {
-	GroupID  int64 `xorm:"pk"`
-	MaxIndex int64 `xorm:"index"`
-}
-
-// IssueIndex represents the issue index table
-type IssueIndex ResourceIndex
-
-// upsertResourceIndex the function will not return until it acquires the lock or receives an error.
-func upsertResourceIndex(e Engine, tableName string, groupID int64) (err error) {
-	// An atomic UPSERT operation (INSERT/UPDATE) is the only operation
-	// that ensures that the key is actually locked.
-	switch {
-	case setting.Database.UseSQLite3 || setting.Database.UsePostgreSQL:
-		_, err = e.Exec(fmt.Sprintf("INSERT INTO %s (group_id, max_index) "+
-			"VALUES (?,1) ON CONFLICT (group_id) DO UPDATE SET max_index = %s.max_index+1",
-			tableName, tableName), groupID)
-	case setting.Database.UseMySQL:
-		_, err = e.Exec(fmt.Sprintf("INSERT INTO %s (group_id, max_index) "+
-			"VALUES (?,1) ON DUPLICATE KEY UPDATE max_index = max_index+1", tableName),
-			groupID)
-	case setting.Database.UseMSSQL:
-		// https://weblogs.sqlteam.com/dang/2009/01/31/upsert-race-condition-with-merge/
-		_, err = e.Exec(fmt.Sprintf("MERGE %s WITH (HOLDLOCK) as target "+
-			"USING (SELECT ? AS group_id) AS src "+
-			"ON src.group_id = target.group_id "+
-			"WHEN MATCHED THEN UPDATE SET target.max_index = target.max_index+1 "+
-			"WHEN NOT MATCHED THEN INSERT (group_id, max_index) "+
-			"VALUES (src.group_id, 1);", tableName),
-			groupID)
-	default:
-		return fmt.Errorf("database type not supported")
-	}
-	return
-}
-
-var (
-	// ErrResouceOutdated represents an error when request resource outdated
-	ErrResouceOutdated = errors.New("resource outdated")
-	// ErrGetResourceIndexFailed represents an error when resource index retries 3 times
-	ErrGetResourceIndexFailed = errors.New("get resource index failed")
-)
-
-const (
-	maxDupIndexAttempts = 3
-)
-
-// GetNextResourceIndex retried 3 times to generate a resource index
-func GetNextResourceIndex(tableName string, groupID int64) (int64, error) {
-	for i := 0; i < maxDupIndexAttempts; i++ {
-		idx, err := getNextResourceIndex(tableName, groupID)
-		if err == ErrResouceOutdated {
-			continue
-		}
-		if err != nil {
-			return 0, err
-		}
-		return idx, nil
-	}
-	return 0, ErrGetResourceIndexFailed
-}
-
-// deleteResouceIndex delete resource index
-func deleteResouceIndex(e Engine, tableName string, groupID int64) error {
-	_, err := e.Exec(fmt.Sprintf("DELETE FROM %s WHERE group_id=?", tableName), groupID)
-	return err
-}
-
-// getNextResourceIndex return the next index
-func getNextResourceIndex(tableName string, groupID int64) (int64, error) {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err := sess.Begin(); err != nil {
-		return 0, err
-	}
-	var preIdx int64
-	_, err := sess.SQL(fmt.Sprintf("SELECT max_index FROM %s WHERE group_id = ?", tableName), groupID).Get(&preIdx)
-	if err != nil {
-		return 0, err
-	}
-
-	if err := upsertResourceIndex(sess, tableName, groupID); err != nil {
-		return 0, err
-	}
-
-	var curIdx int64
-	has, err := sess.SQL(fmt.Sprintf("SELECT max_index FROM %s WHERE group_id = ? AND max_index=?", tableName), groupID, preIdx+1).Get(&curIdx)
-	if err != nil {
-		return 0, err
-	}
-	if !has {
-		return 0, ErrResouceOutdated
-	}
-	if err := sess.Commit(); err != nil {
-		return 0, err
-	}
-	return curIdx, nil
-}