[API] Add pagination to ListBranches (#14524)

* make PaginateUserSlice generic -> PaginateSlice

* Add pagination to ListBranches

* add skip, limit to Repository.GetBranches()

* Move routers/api/v1/utils/utils PaginateSlice -> modules/util/paginate.go

* repo_module.GetBranches paginate

* fix & rename & more logging

* better description

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: a1012112796 <1012112796@qq.com>

3 files changed, 18 insertions, 22 deletions

diff --git a/routers/api/v1/org/org.go b/routers/api/v1/org/org.go
index 61e09e1126..e0f36aa1e6 100644
--- a/routers/api/v1/org/org.go
+++ b/routers/api/v1/org/org.go
@@ -13,6 +13,7 @@ import (
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/convert"
 	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/routers/api/v1/user"
 	"code.gitea.io/gitea/routers/api/v1/utils"
@@ -28,9 +29,9 @@ func listUserOrgs(ctx *context.APIContext, u *models.User) {
 		ctx.Error(http.StatusInternalServerError, "GetOrgsByUserID", err)
 		return
 	}
-	maxResults := len(orgs)
 
-	orgs = utils.PaginateUserSlice(orgs, listOptions.Page, listOptions.PageSize)
+	maxResults := len(orgs)
+	orgs, _ = util.PaginateSlice(orgs, listOptions.Page, listOptions.PageSize).([]*models.User)
 
 	apiOrgs := make([]*api.Organization, len(orgs))
 	for i := range orgs {
diff --git a/routers/api/v1/repo/branch.go b/routers/api/v1/repo/branch.go
index 790464c8bc..451fdcf516 100644
--- a/routers/api/v1/repo/branch.go
+++ b/routers/api/v1/repo/branch.go
@@ -17,6 +17,7 @@ import (
 	repo_module "code.gitea.io/gitea/modules/repository"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/web"
+	"code.gitea.io/gitea/routers/api/v1/utils"
 	pull_service "code.gitea.io/gitea/services/pull"
 	repo_service "code.gitea.io/gitea/services/repository"
 )
@@ -284,11 +285,21 @@ func ListBranches(ctx *context.APIContext) {
 	//   description: name of the repo
 	//   type: string
 	//   required: true
+	// - name: page
+	//   in: query
+	//   description: page number of results to return (1-based)
+	//   type: integer
+	// - name: limit
+	//   in: query
+	//   description: page size of results
+	//   type: integer
 	// responses:
 	//   "200":
 	//     "$ref": "#/responses/BranchList"
 
-	branches, err := repo_module.GetBranches(ctx.Repo.Repository)
+	listOptions := utils.GetListOptions(ctx)
+	skip, _ := listOptions.GetStartEnd()
+	branches, totalNumOfBranches, err := repo_module.GetBranches(ctx.Repo.Repository, skip, listOptions.PageSize)
 	if err != nil {
 		ctx.Error(http.StatusInternalServerError, "GetBranches", err)
 		return
@@ -313,6 +324,9 @@ func ListBranches(ctx *context.APIContext) {
 		}
 	}
 
+	ctx.SetLinkHeader(int(totalNumOfBranches), listOptions.PageSize)
+	ctx.Header().Set("X-Total-Count", fmt.Sprintf("%d", totalNumOfBranches))
+	ctx.Header().Set("Access-Control-Expose-Headers", "X-Total-Count, Link")
 	ctx.JSON(http.StatusOK, &apiBranches)
 }
 
diff --git a/routers/api/v1/utils/utils.go b/routers/api/v1/utils/utils.go
index 5732ea7f7d..ad1a136db4 100644
--- a/routers/api/v1/utils/utils.go
+++ b/routers/api/v1/utils/utils.go
@@ -66,22 +66,3 @@ func GetListOptions(ctx *context.APIContext) models.ListOptions {
 		PageSize: convert.ToCorrectPageSize(ctx.QueryInt("limit")),
 	}
 }
-
-// PaginateUserSlice cut a slice of Users as per pagination options
-// TODO: make it generic
-func PaginateUserSlice(items []*models.User, page, pageSize int) []*models.User {
-	if page != 0 {
-		page--
-	}
-
-	if page*pageSize >= len(items) {
-		return items[len(items):]
-	}
-
-	items = items[page*pageSize:]
-
-	if len(items) > pageSize {
-		return items[:pageSize]
-	}
-	return items
-}