Add AbsoluteListOptions (#17028)

This PR adds a `ListOptions` type which is not paged but uses absolute values. It is implemented as discussed in Discord.
Extracted from #16510 to clean that PR.

models/commit_status.go

@@ -97,7 +97,7 @@ func GetCommitStatuses(repo *Repository, sha string, opts *CommitStatusOptions)
 	}
 
 	countSession := listCommitStatusesStatement(repo, sha, opts)
-	countSession = opts.setSessionPagination(countSession)
+	countSession = setSessionPagination(countSession, opts)
 	maxResults, err := countSession.Count(new(CommitStatus))
 	if err != nil {
 		log.Error("Count PRs: %v", err)
@@ -106,7 +106,7 @@ func GetCommitStatuses(repo *Repository, sha string, opts *CommitStatusOptions)
 
 	statuses := make([]*CommitStatus, 0, opts.PageSize)
 	findSession := listCommitStatusesStatement(repo, sha, opts)
-	findSession = opts.setSessionPagination(findSession)
+	findSession = setSessionPagination(findSession, opts)
 	sortCommitStatusesSession(findSession, opts.SortType)
 	return statuses, maxResults, findSession.Find(&statuses)
 }
@@ -149,7 +149,7 @@ func getLatestCommitStatus(e Engine, repoID int64, sha string, listOptions ListO
 		Select("max( id ) as id").
 		GroupBy("context_hash").OrderBy("max( id ) desc")
 
-	sess = listOptions.setSessionPagination(sess)
+	sess = setSessionPagination(sess, &listOptions)
 
 	err := sess.Find(&ids)
 	if err != nil {

models/gpg_key.go

@@ -64,7 +64,7 @@ func ListGPGKeys(uid int64, listOptions ListOptions) ([]*GPGKey, error) {
 func listGPGKeys(e Engine, uid int64, listOptions ListOptions) ([]*GPGKey, error) {
 	sess := e.Table(&GPGKey{}).Where("owner_id=? AND primary_key_id=''", uid)
 	if listOptions.Page != 0 {
-		sess = listOptions.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &listOptions)
 	}
 
 	keys := make([]*GPGKey, 0, 2)

models/issue_comment.go

@@ -1007,7 +1007,7 @@ func findComments(e Engine, opts *FindCommentsOptions) ([]*Comment, error) {
 	}
 
 	if opts.Page != 0 {
-		sess = opts.setSessionPagination(sess)
+		sess = setSessionPagination(sess, opts)
 	}
 
 	// WARNING: If you change this order you will need to fix createCodeComment

models/issue_label.go

@@ -459,7 +459,7 @@ func getLabelsByRepoID(e Engine, repoID int64, sortType string, listOptions List
 	}
 
 	if listOptions.Page != 0 {
-		sess = listOptions.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &listOptions)
 	}
 
 	return labels, sess.Find(&labels)
@@ -576,7 +576,7 @@ func getLabelsByOrgID(e Engine, orgID int64, sortType string, listOptions ListOp
 	}
 
 	if listOptions.Page != 0 {
-		sess = listOptions.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &listOptions)
 	}
 
 	return labels, sess.Find(&labels)

models/issue_milestone.go

@@ -408,7 +408,7 @@ func GetMilestones(opts GetMilestonesOption) (MilestoneList, int64, error) {
 	sess := x.Where(opts.toCond())
 
 	if opts.Page != 0 {
-		sess = opts.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &opts)
 	}
 
 	switch opts.SortType {

models/issue_reaction.go

@@ -87,7 +87,7 @@ func findReactions(e Engine, opts FindReactionsOptions) ([]*Reaction, error) {
 		In("reaction.`type`", setting.UI.Reactions).
 		Asc("reaction.issue_id", "reaction.comment_id", "reaction.created_unix", "reaction.id")
 	if opts.Page != 0 {
-		e = opts.setEnginePagination(e)
+		e = setEnginePagination(e, &opts)
 
 		reactions := make([]*Reaction, 0, opts.PageSize)
 		return reactions, e.Find(&reactions)

models/issue_stopwatch.go

@@ -45,7 +45,7 @@ func GetUserStopwatches(userID int64, listOptions ListOptions) ([]*Stopwatch, er
 	sws := make([]*Stopwatch, 0, 8)
 	sess := x.Where("stopwatch.user_id = ?", userID)
 	if listOptions.Page != 0 {
-		sess = listOptions.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &listOptions)
 	}
 
 	err := sess.Find(&sws)

models/issue_tracked_time.go

@@ -113,7 +113,7 @@ func (opts *FindTrackedTimesOptions) toSession(e Engine) Engine {
 	sess = sess.Where(opts.toCond())
 
 	if opts.Page != 0 {
-		sess = opts.setEnginePagination(sess)
+		sess = setEnginePagination(sess, opts)
 	}
 
 	return sess

models/issue_watch.go

@@ -111,7 +111,7 @@ func getIssueWatchers(e Engine, issueID int64, listOptions ListOptions) (IssueWa
 		Join("INNER", "`user`", "`user`.id = `issue_watch`.user_id")
 
 	if listOptions.Page != 0 {
-		sess = listOptions.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &listOptions)
 		watches := make([]*IssueWatch, 0, listOptions.PageSize)
 		return watches, sess.Find(&watches)
 	}

models/list_options.go

@@ -10,38 +10,49 @@ import (
 	"xorm.io/xorm"
 )
 
-// ListOptions options to paginate results
-type ListOptions struct {
-	PageSize int
-	Page     int // start from 1
+// Paginator is the base for different ListOptions types
+type Paginator interface {
+	GetSkipTake() (skip, take int)
+	GetStartEnd() (start, end int)
 }
 
-func (opts *ListOptions) getPaginatedSession() *xorm.Session {
-	opts.setDefaultValues()
+// getPaginatedSession creates a paginated database session
+func getPaginatedSession(p Paginator) *xorm.Session {
+	skip, take := p.GetSkipTake()
 
-	return x.Limit(opts.PageSize, (opts.Page-1)*opts.PageSize)
+	return x.Limit(take, skip)
 }
 
-func (opts *ListOptions) setSessionPagination(sess *xorm.Session) *xorm.Session {
-	opts.setDefaultValues()
+// setSessionPagination sets pagination for a database session
+func setSessionPagination(sess *xorm.Session, p Paginator) *xorm.Session {
+	skip, take := p.GetSkipTake()
 
-	if opts.PageSize <= 0 {
-		return sess
-	}
-	return sess.Limit(opts.PageSize, (opts.Page-1)*opts.PageSize)
+	return sess.Limit(take, skip)
 }
 
-func (opts *ListOptions) setEnginePagination(e Engine) Engine {
-	opts.setDefaultValues()
+// setSessionPagination 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
+}
 
-	return e.Limit(opts.PageSize, (opts.Page-1)*opts.PageSize)
+// 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) {
-	opts.setDefaultValues()
-	start = (opts.Page - 1) * opts.PageSize
-	end = start + opts.PageSize
+	start, take := opts.GetSkipTake()
+	end = start + take
 	return
 }
 
@@ -56,3 +67,33 @@ func (opts *ListOptions) setDefaultValues() {
 		opts.Page = 1
 	}
 }
+
+// AbsoluteListOptions absolute options to paginate results
+type AbsoluteListOptions struct {
+	skip int
+	take int
+}
+
+// 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}
+}
+
+// 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
+}

models/list_options_test.go

@@ -0,0 +1,62 @@
+// 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 (
+	"testing"
+
+	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPaginator(t *testing.T) {
+	cases := []struct {
+		Paginator
+		Skip  int
+		Take  int
+		Start int
+		End   int
+	}{
+		{
+			Paginator: &ListOptions{Page: -1, PageSize: -1},
+			Skip:      0,
+			Take:      setting.API.DefaultPagingNum,
+			Start:     0,
+			End:       setting.API.DefaultPagingNum,
+		},
+		{
+			Paginator: &ListOptions{Page: 2, PageSize: 10},
+			Skip:      10,
+			Take:      10,
+			Start:     10,
+			End:       20,
+		},
+		{
+			Paginator: NewAbsoluteListOptions(-1, -1),
+			Skip:      0,
+			Take:      setting.API.DefaultPagingNum,
+			Start:     0,
+			End:       setting.API.DefaultPagingNum,
+		},
+		{
+			Paginator: NewAbsoluteListOptions(2, 10),
+			Skip:      2,
+			Take:      10,
+			Start:     2,
+			End:       12,
+		},
+	}
+
+	for _, c := range cases {
+		skip, take := c.Paginator.GetSkipTake()
+		start, end := c.Paginator.GetStartEnd()
+
+		assert.Equal(t, c.Skip, skip)
+		assert.Equal(t, c.Take, take)
+		assert.Equal(t, c.Start, start)
+		assert.Equal(t, c.End, end)
+	}
+}

models/notification.go

@@ -110,7 +110,7 @@ func (opts *FindNotificationOptions) ToCond() builder.Cond {
 func (opts *FindNotificationOptions) ToSession(e Engine) *xorm.Session {
 	sess := e.Where(opts.ToCond())
 	if opts.Page != 0 {
-		sess = opts.setSessionPagination(sess)
+		sess = setSessionPagination(sess, opts)
 	}
 	return sess
 }

models/oauth2_application.go

@@ -275,7 +275,7 @@ func ListOAuth2Applications(uid int64, listOptions ListOptions) ([]*OAuth2Applic
 		Desc("id")
 
 	if listOptions.Page != 0 {
-		sess = listOptions.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &listOptions)
 
 		apps := make([]*OAuth2Application, 0, listOptions.PageSize)
 		total, err := sess.FindAndCount(&apps)

models/org.go

@@ -569,7 +569,7 @@ func GetOrgUsersByUserID(uid int64, opts *SearchOrganizationsOptions) ([]*OrgUse
 	}
 
 	if opts.PageSize != 0 {
-		sess = opts.setSessionPagination(sess)
+		sess = setSessionPagination(sess, opts)
 	}
 
 	err := sess.
@@ -589,7 +589,7 @@ func getOrgUsersByOrgID(e Engine, opts *FindOrgMembersOpts) ([]*OrgUser, error)
 		sess.And("is_public = ?", true)
 	}
 	if opts.ListOptions.PageSize > 0 {
-		sess = opts.setSessionPagination(sess)
+		sess = setSessionPagination(sess, opts)
 
 		ous := make([]*OrgUser, 0, opts.PageSize)
 		return ous, sess.Find(&ous)

models/org_team.go

@@ -168,7 +168,7 @@ func (t *Team) GetRepositories(opts *SearchTeamOptions) error {
 		return t.getRepositories(x)
 	}
 
-	return t.getRepositories(opts.getPaginatedSession())
+	return t.getRepositories(getPaginatedSession(opts))
 }
 
 func (t *Team) getMembers(e Engine) (err error) {
@@ -182,7 +182,7 @@ func (t *Team) GetMembers(opts *SearchMembersOptions) (err error) {
 		return t.getMembers(x)
 	}
 
-	return t.getMembers(opts.getPaginatedSession())
+	return t.getMembers(getPaginatedSession(opts))
 }
 
 // AddMember adds new membership of the team to the organization,

models/pull_list.go

@@ -100,7 +100,7 @@ func PullRequests(baseRepoID int64, opts *PullRequestsOptions) ([]*PullRequest,
 		log.Error("listPullRequestStatement: %v", err)
 		return nil, maxResults, err
 	}
-	findSession = opts.setSessionPagination(findSession)
+	findSession = setSessionPagination(findSession, opts)
 	prs := make([]*PullRequest, 0, opts.PageSize)
 	return prs, maxResults, findSession.Find(&prs)
 }

models/release.go

@@ -208,7 +208,7 @@ func GetReleasesByRepoID(repoID int64, opts FindReleasesOptions) ([]*Release, er
 		Where(opts.toConds(repoID))
 
 	if opts.PageSize != 0 {
-		sess = opts.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &opts.ListOptions)
 	}
 
 	rels := make([]*Release, 0, opts.PageSize)

models/repo.go

@@ -1770,7 +1770,7 @@ func GetUserRepositories(opts *SearchRepoOptions) ([]*Repository, int64, error)
 
 	sess.Where(cond).OrderBy(opts.OrderBy.String())
 	repos := make([]*Repository, 0, opts.PageSize)
-	return repos, count, opts.setSessionPagination(sess).Find(&repos)
+	return repos, count, setSessionPagination(sess, opts).Find(&repos)
 }
 
 // GetUserMirrorRepositories returns a list of mirror repositories of given user.
@@ -2061,7 +2061,7 @@ func (repo *Repository) GetForks(listOptions ListOptions) ([]*Repository, error)
 		return forks, x.Find(&forks, &Repository{ForkID: repo.ID})
 	}
 
-	sess := listOptions.getPaginatedSession()
+	sess := getPaginatedSession(&listOptions)
 	forks := make([]*Repository, 0, listOptions.PageSize)
 	return forks, sess.Find(&forks, &Repository{ForkID: repo.ID})
 }

models/repo_collaboration.go

@@ -65,7 +65,7 @@ func (repo *Repository) getCollaborations(e Engine, listOptions ListOptions) ([]
 		return collaborations, e.Find(&collaborations, &Collaboration{RepoID: repo.ID})
 	}
 
-	e = listOptions.setEnginePagination(e)
+	e = setEnginePagination(e, &listOptions)
 
 	collaborations := make([]*Collaboration, 0, listOptions.PageSize)
 	return collaborations, e.Find(&collaborations, &Collaboration{RepoID: repo.ID})

models/repo_watch.go

@@ -165,7 +165,7 @@ func (repo *Repository) GetWatchers(opts ListOptions) ([]*User, error) {
 		Join("LEFT", "watch", "`user`.id=`watch`.user_id").
 		And("`watch`.mode<>?", RepoWatchModeDont)
 	if opts.Page > 0 {
-		sess = opts.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &opts)
 		users := make([]*User, 0, opts.PageSize)
 
 		return users, sess.Find(&users)

models/review.go

@@ -195,7 +195,7 @@ func findReviews(e Engine, opts FindReviewOptions) ([]*Review, error) {
 	reviews := make([]*Review, 0, 10)
 	sess := e.Where(opts.toCond())
 	if opts.Page > 0 {
-		sess = opts.ListOptions.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &opts)
 	}
 	return reviews, sess.
 		Asc("created_unix").

models/ssh_key.go

@@ -195,7 +195,7 @@ func SearchPublicKey(uid int64, fingerprint string) ([]*PublicKey, error) {
 func ListPublicKeys(uid int64, listOptions ListOptions) ([]*PublicKey, error) {
 	sess := x.Where("owner_id = ? AND type != ?", uid, KeyTypePrincipal)
 	if listOptions.Page != 0 {
-		sess = listOptions.setSessionPagination(sess)
+		sess = setSessionPagination(sess, &listOptions)
 
 		keys := make([]*PublicKey, 0, listOptions.PageSize)
 		return keys, sess.Find(&keys)