gitea/models/db/list.go
2024-01-30 02:37:24 +00:00

216 lines
5.0 KiB
Go

// Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package db
import (
"context"
"code.gitea.io/gitea/modules/setting"
"xorm.io/builder"
"xorm.io/xorm"
)
const (
// DefaultMaxInSize represents default variables number on IN () in SQL
DefaultMaxInSize = 50
defaultFindSliceSize = 10
)
// Paginator is the base for different ListOptions types
type Paginator interface {
GetSkipTake() (skip, take int)
IsListAll() bool
}
// SetSessionPagination sets pagination for a database session
func SetSessionPagination(sess Engine, p Paginator) *xorm.Session {
skip, take := p.GetSkipTake()
return sess.Limit(take, skip)
}
// ListOptions options to paginate results
type ListOptions struct {
PageSize int
Page int // start from 1
ListAll bool // if true, then PageSize and Page will not be taken
}
var ListOptionsAll = ListOptions{ListAll: true}
var (
_ Paginator = &ListOptions{}
_ FindOptions = ListOptions{}
)
// GetSkipTake returns the skip and take values
func (opts *ListOptions) GetSkipTake() (skip, take int) {
opts.SetDefaultValues()
return (opts.Page - 1) * opts.PageSize, opts.PageSize
}
func (opts ListOptions) GetPage() int {
return opts.Page
}
func (opts ListOptions) GetPageSize() int {
return opts.PageSize
}
// IsListAll indicates PageSize and Page will be ignored
func (opts ListOptions) IsListAll() bool {
return opts.ListAll
}
// SetDefaultValues sets default values
func (opts *ListOptions) SetDefaultValues() {
if opts.PageSize <= 0 {
opts.PageSize = setting.API.DefaultPagingNum
}
if opts.PageSize > setting.API.MaxResponseItems {
opts.PageSize = setting.API.MaxResponseItems
}
if opts.Page <= 0 {
opts.Page = 1
}
}
func (opts ListOptions) ToConds() builder.Cond {
return builder.NewCond()
}
// AbsoluteListOptions absolute options to paginate results
type AbsoluteListOptions struct {
skip int
take int
}
var _ Paginator = &AbsoluteListOptions{}
// NewAbsoluteListOptions creates a list option with applied limits
func NewAbsoluteListOptions(skip, take int) *AbsoluteListOptions {
if skip < 0 {
skip = 0
}
if take <= 0 {
take = setting.API.DefaultPagingNum
}
if take > setting.API.MaxResponseItems {
take = setting.API.MaxResponseItems
}
return &AbsoluteListOptions{skip, take}
}
// IsListAll will always return false
func (opts *AbsoluteListOptions) IsListAll() bool {
return false
}
// GetSkipTake returns the skip and take values
func (opts *AbsoluteListOptions) GetSkipTake() (skip, take int) {
return opts.skip, opts.take
}
// FindOptions represents a find options
type FindOptions interface {
GetPage() int
GetPageSize() int
IsListAll() bool
ToConds() builder.Cond
}
type JoinFunc func(sess Engine) error
type FindOptionsJoin interface {
ToJoins() []JoinFunc
}
type FindOptionsOrder interface {
ToOrders() string
}
// Find represents a common find function which accept an options interface
func Find[T any](ctx context.Context, opts FindOptions) ([]*T, error) {
sess := GetEngine(ctx).Where(opts.ToConds())
if joinOpt, ok := opts.(FindOptionsJoin); ok {
for _, joinFunc := range joinOpt.ToJoins() {
if err := joinFunc(sess); err != nil {
return nil, err
}
}
}
if orderOpt, ok := opts.(FindOptionsOrder); ok {
if order := orderOpt.ToOrders(); order != "" {
sess.OrderBy(order)
}
}
page, pageSize := opts.GetPage(), opts.GetPageSize()
if !opts.IsListAll() && pageSize > 0 {
if page == 0 {
page = 1
}
sess.Limit(pageSize, (page-1)*pageSize)
}
findPageSize := defaultFindSliceSize
if pageSize > 0 {
findPageSize = pageSize
}
objects := make([]*T, 0, findPageSize)
if err := sess.Find(&objects); err != nil {
return nil, err
}
return objects, nil
}
// Count represents a common count function which accept an options interface
func Count[T any](ctx context.Context, opts FindOptions) (int64, error) {
sess := GetEngine(ctx).Where(opts.ToConds())
if joinOpt, ok := opts.(FindOptionsJoin); ok {
for _, joinFunc := range joinOpt.ToJoins() {
if err := joinFunc(sess); err != nil {
return 0, err
}
}
}
var object T
return sess.Count(&object)
}
// FindAndCount represents a common findandcount function which accept an options interface
func FindAndCount[T any](ctx context.Context, opts FindOptions) ([]*T, int64, error) {
sess := GetEngine(ctx).Where(opts.ToConds())
page, pageSize := opts.GetPage(), opts.GetPageSize()
if !opts.IsListAll() && pageSize > 0 && page >= 1 {
sess.Limit(pageSize, (page-1)*pageSize)
}
if joinOpt, ok := opts.(FindOptionsJoin); ok {
for _, joinFunc := range joinOpt.ToJoins() {
if err := joinFunc(sess); err != nil {
return nil, 0, err
}
}
}
if orderOpt, ok := opts.(FindOptionsOrder); ok {
if order := orderOpt.ToOrders(); order != "" {
sess.OrderBy(order)
}
}
findPageSize := defaultFindSliceSize
if pageSize > 0 {
findPageSize = pageSize
}
objects := make([]*T, 0, findPageSize)
cnt, err := sess.FindAndCount(&objects)
if err != nil {
return nil, 0, err
}
return objects, cnt, nil
}