forgejo/models/db/context.go

267 lines
7.2 KiB
Go
Raw Normal View History

// Copyright 2019 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package db
import (
"context"
"database/sql"
"xorm.io/builder"
"xorm.io/xorm"
)
// DefaultContext is the default context to run xorm queries in
// will be overwritten by Init with HammerContext
var DefaultContext context.Context
// contextKey is a value for use with context.WithValue.
type contextKey struct {
name string
}
// enginedContextKey is a context key. It is used with context.Value() to get the current Engined for the context
var (
enginedContextKey = &contextKey{"engined"}
_ Engined = &Context{}
)
// Context represents a db context
type Context struct {
context.Context
e Engine
transaction bool
}
func newContext(ctx context.Context, e Engine, transaction bool) *Context {
return &Context{
Context: ctx,
e: e,
transaction: transaction,
}
}
// InTransaction if context is in a transaction
func (ctx *Context) InTransaction() bool {
return ctx.transaction
}
// Engine returns db engine
func (ctx *Context) Engine() Engine {
return ctx.e
}
// Value shadows Value for context.Context but allows us to get ourselves and an Engined object
func (ctx *Context) Value(key any) any {
if key == enginedContextKey {
return ctx
}
return ctx.Context.Value(key)
}
// WithContext returns this engine tied to this context
func (ctx *Context) WithContext(other context.Context) *Context {
return newContext(ctx, ctx.e.Context(other), ctx.transaction)
}
// Engined structs provide an Engine
type Engined interface {
Engine() Engine
}
// GetEngine will get a db Engine from this context or return an Engine restricted to this context
func GetEngine(ctx context.Context) Engine {
2023-01-08 01:34:58 +00:00
if e := getEngine(ctx); e != nil {
return e
}
return x.Context(ctx)
}
// getEngine will get a db Engine from this context or return nil
func getEngine(ctx context.Context) Engine {
if engined, ok := ctx.(Engined); ok {
return engined.Engine()
}
enginedInterface := ctx.Value(enginedContextKey)
if enginedInterface != nil {
return enginedInterface.(Engined).Engine()
}
2023-01-08 01:34:58 +00:00
return nil
}
// Committer represents an interface to Commit or Close the Context
type Committer interface {
Commit() error
Close() error
}
2023-01-08 01:34:58 +00:00
// halfCommitter is a wrapper of Committer.
// It can be closed early, but can't be committed early, it is useful for reusing a transaction.
type halfCommitter struct {
committer Committer
committed bool
2023-01-08 01:34:58 +00:00
}
func (c *halfCommitter) Commit() error {
c.committed = true
// should do nothing, and the parent committer will commit later
2023-01-08 01:34:58 +00:00
return nil
}
func (c *halfCommitter) Close() error {
if c.committed {
// it's "commit and close", should do nothing, and the parent committer will commit later
return nil
}
// it's "rollback and close", let the parent committer rollback right now
return c.committer.Close()
}
2023-01-08 01:34:58 +00:00
// TxContext represents a transaction Context,
// it will reuse the existing transaction in the parent context or create a new one.
func TxContext(parentCtx context.Context) (*Context, Committer, error) {
2023-01-08 01:34:58 +00:00
if sess, ok := inTransaction(parentCtx); ok {
return newContext(parentCtx, sess, true), &halfCommitter{committer: sess}, nil
}
sess := x.NewSession()
if err := sess.Begin(); err != nil {
sess.Close()
return nil, nil, err
}
return newContext(DefaultContext, sess, true), sess, nil
}
2023-01-08 01:34:58 +00:00
// WithTx represents executing database operations on a transaction, if the transaction exist,
// this function will reuse it otherwise will create a new one and close it when finished.
2023-01-08 01:34:58 +00:00
func WithTx(parentCtx context.Context, f func(ctx context.Context) error) error {
if sess, ok := inTransaction(parentCtx); ok {
err := f(newContext(parentCtx, sess, true))
if err != nil {
// rollback immediately, in case the caller ignores returned error and tries to commit the transaction.
_ = sess.Close()
}
return err
}
return txWithNoCheck(parentCtx, f)
}
func txWithNoCheck(parentCtx context.Context, f func(ctx context.Context) error) error {
sess := x.NewSession()
defer sess.Close()
if err := sess.Begin(); err != nil {
return err
}
if err := f(newContext(parentCtx, sess, true)); err != nil {
return err
}
return sess.Commit()
}
// Insert inserts records into database
func Insert(ctx context.Context, beans ...any) error {
_, err := GetEngine(ctx).Insert(beans...)
return err
}
// Exec executes a sql with args
func Exec(ctx context.Context, sqlAndArgs ...any) (sql.Result, error) {
return GetEngine(ctx).Exec(sqlAndArgs...)
}
// GetByBean filled empty fields of the bean according non-empty fields to query in database.
func GetByBean(ctx context.Context, bean any) (bool, error) {
return GetEngine(ctx).Get(bean)
}
// DeleteByBean deletes all records according non-empty fields of the bean as conditions.
func DeleteByBean(ctx context.Context, bean any) (int64, error) {
return GetEngine(ctx).Delete(bean)
}
// DeleteByID deletes the given bean with the given ID
func DeleteByID(ctx context.Context, id int64, bean any) (int64, error) {
return GetEngine(ctx).ID(id).NoAutoTime().Delete(bean)
}
// FindIDs finds the IDs for the given table name satisfying the given condition
// By passing a different value than "id" for "idCol", you can query for foreign IDs, i.e. the repo IDs which satisfy the condition
func FindIDs(ctx context.Context, tableName, idCol string, cond builder.Cond) ([]int64, error) {
ids := make([]int64, 0, 10)
if err := GetEngine(ctx).Table(tableName).
Cols(idCol).
Where(cond).
Find(&ids); err != nil {
return nil, err
}
return ids, nil
}
// DecrByIDs decreases the given column for entities of the "bean" type with one of the given ids by one
// Timestamps of the entities won't be updated
func DecrByIDs(ctx context.Context, ids []int64, decrCol string, bean any) error {
_, err := GetEngine(ctx).Decr(decrCol).In("id", ids).NoAutoCondition().NoAutoTime().Update(bean)
return err
}
// DeleteBeans deletes all given beans, beans must contain delete conditions.
func DeleteBeans(ctx context.Context, beans ...any) (err error) {
e := GetEngine(ctx)
for i := range beans {
if _, err = e.Delete(beans[i]); err != nil {
return err
}
}
return nil
}
// TruncateBeans deletes all given beans, beans may contain delete conditions.
func TruncateBeans(ctx context.Context, beans ...any) (err error) {
e := GetEngine(ctx)
for i := range beans {
if _, err = e.Truncate(beans[i]); err != nil {
return err
}
}
return nil
}
// CountByBean counts the number of database records according non-empty fields of the bean as conditions.
func CountByBean(ctx context.Context, bean any) (int64, error) {
return GetEngine(ctx).Count(bean)
}
// TableName returns the table name according a bean object
func TableName(bean any) string {
return x.TableName(bean)
}
// InTransaction returns true if the engine is in a transaction otherwise return false
func InTransaction(ctx context.Context) bool {
2023-01-08 01:34:58 +00:00
_, ok := inTransaction(ctx)
return ok
}
func inTransaction(ctx context.Context) (*xorm.Session, bool) {
e := getEngine(ctx)
if e == nil {
2023-01-08 01:34:58 +00:00
return nil, false
}
switch t := e.(type) {
case *xorm.Engine:
2023-01-08 01:34:58 +00:00
return nil, false
case *xorm.Session:
2023-01-08 01:34:58 +00:00
if t.IsInTx() {
return t, true
}
return nil, false
default:
2023-01-08 01:34:58 +00:00
return nil, false
}
}