gitea/models/db/context.go

200 lines
5.4 KiB
Go

// Copyright 2019 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 db
import (
"context"
"database/sql"
"code.gitea.io/gitea/modules/setting"
"xorm.io/builder"
"xorm.io/xorm/schemas"
)
// 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"}
// Context represents a db context
type Context struct {
context.Context
e Engine
}
// WithEngine returns a db.Context from a context.Context and db.Engine
func WithEngine(ctx context.Context, e Engine) *Context {
return &Context{
Context: ctx,
e: e.Context(ctx),
}
}
// 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 interface{}) interface{} {
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 WithEngine(other, ctx.e)
}
// 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 {
if engined, ok := ctx.(Engined); ok {
return engined.Engine()
}
enginedInterface := ctx.Value(EnginedContextKey)
if enginedInterface != nil {
return enginedInterface.(Engined).Engine()
}
return x.Context(ctx)
}
// Committer represents an interface to Commit or Close the Context
type Committer interface {
Commit() error
Close() error
}
// TxContext represents a transaction Context
func TxContext() (*Context, Committer, error) {
sess := x.NewSession()
if err := sess.Begin(); err != nil {
sess.Close()
return nil, nil, err
}
return &Context{
Context: DefaultContext,
e: sess,
}, sess, nil
}
// WithContext represents executing database operations
func WithContext(f func(ctx *Context) error) error {
return f(&Context{
Context: DefaultContext,
e: x,
})
}
// WithTx represents executing database operations on a transaction
// you can optionally change the context to a parrent one
func WithTx(f func(ctx context.Context) error, stdCtx ...context.Context) error {
parentCtx := DefaultContext
if len(stdCtx) != 0 && stdCtx[0] != nil {
// TODO: make sure parent context has no open session
parentCtx = stdCtx[0]
}
sess := x.NewSession()
defer sess.Close()
if err := sess.Begin(); err != nil {
return err
}
if err := f(&Context{
Context: parentCtx,
e: sess,
}); err != nil {
return err
}
return sess.Commit()
}
// Iterate iterates the databases and doing something
func Iterate(ctx context.Context, tableBean interface{}, cond builder.Cond, fun func(idx int, bean interface{}) error) error {
return GetEngine(ctx).Where(cond).
BufferSize(setting.Database.IterateBufferSize).
Iterate(tableBean, fun)
}
// Insert inserts records into database
func Insert(ctx context.Context, beans ...interface{}) error {
_, err := GetEngine(ctx).Insert(beans...)
return err
}
// Exec executes a sql with args
func Exec(ctx context.Context, sqlAndArgs ...interface{}) (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 interface{}) (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 interface{}) (int64, error) {
return GetEngine(ctx).Delete(bean)
}
// DeleteBeans deletes all given beans, beans should contain delete conditions.
func DeleteBeans(ctx context.Context, beans ...interface{}) (err error) {
e := GetEngine(ctx)
for i := range beans {
if _, err = e.Delete(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 interface{}) (int64, error) {
return GetEngine(ctx).Count(bean)
}
// TableName returns the table name according a bean object
func TableName(bean interface{}) string {
return x.TableName(bean)
}
// EstimateCount returns an estimate of total number of rows in table
func EstimateCount(ctx context.Context, bean interface{}) (int64, error) {
e := GetEngine(ctx)
e.Context(ctx)
var rows int64
var err error
tablename := TableName(bean)
switch x.Dialect().URI().DBType {
case schemas.MYSQL:
_, err = e.Context(ctx).SQL("SELECT table_rows FROM information_schema.tables WHERE tables.table_name = ? AND tables.table_schema = ?;", tablename, x.Dialect().URI().DBName).Get(&rows)
case schemas.POSTGRES:
_, err = e.Context(ctx).SQL("SELECT reltuples AS estimate FROM pg_class WHERE relname = ?;", tablename).Get(&rows)
case schemas.MSSQL:
_, err = e.Context(ctx).SQL("sp_spaceused ?;", tablename).Get(&rows)
default:
return e.Context(ctx).Count(tablename)
}
return rows, err
}