Fix db.Find bug (#23115)

Caused by #20821 

Fix #23110

models/db/list.go

@@ -0,0 +1,152 @@
+// 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
+)
+
+// Paginator is the base for different ListOptions types
+type Paginator interface {
+	GetSkipTake() (skip, take int)
+	GetStartEnd() (start, end int)
+	IsListAll() bool
+}
+
+// GetPaginatedSession creates a paginated database session
+func GetPaginatedSession(p Paginator) *xorm.Session {
+	skip, take := p.GetSkipTake()
+
+	return x.Limit(take, skip)
+}
+
+// SetSessionPagination sets pagination for a database session
+func SetSessionPagination(sess Engine, p Paginator) *xorm.Session {
+	skip, take := p.GetSkipTake()
+
+	return sess.Limit(take, skip)
+}
+
+// SetEnginePagination sets pagination for a database engine
+func SetEnginePagination(e Engine, p Paginator) Engine {
+	skip, take := p.GetSkipTake()
+
+	return e.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 _ Paginator = &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
+}
+
+// GetStartEnd returns the start and end of the ListOptions
+func (opts *ListOptions) GetStartEnd() (start, end int) {
+	start, take := opts.GetSkipTake()
+	end = start + take
+	return start, end
+}
+
+// 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
+	}
+}
+
+// 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
+}
+
+// GetStartEnd returns the start and end values
+func (opts *AbsoluteListOptions) GetStartEnd() (start, end int) {
+	return opts.skip, opts.skip + opts.take
+}
+
+// FindOptions represents a find options
+type FindOptions interface {
+	Paginator
+	ToConds() builder.Cond
+}
+
+// Find represents a common find function which accept an options interface
+func Find[T any](ctx context.Context, opts FindOptions, objects *[]T) error {
+	sess := GetEngine(ctx).Where(opts.ToConds())
+	if !opts.IsListAll() {
+		sess.Limit(opts.GetSkipTake())
+	}
+	return sess.Find(objects)
+}
+
+// Count represents a common count function which accept an options interface
+func Count[T any](ctx context.Context, opts FindOptions, object T) (int64, error) {
+	return GetEngine(ctx).Where(opts.ToConds()).Count(object)
+}
+
+// FindAndCount represents a common findandcount function which accept an options interface
+func FindAndCount[T any](ctx context.Context, opts FindOptions, objects *[]T) (int64, error) {
+	sess := GetEngine(ctx).Where(opts.ToConds())
+	if !opts.IsListAll() {
+		sess.Limit(opts.GetSkipTake())
+	}
+	return sess.FindAndCount(objects)
+}