snapshot of https://github.com/ory/keto.git (master, 2026-09-16; blobs > 131072B omitted)

oryx/pagination/pagepagination/pagination.go

@@ -0,0 +1,79 @@
+// Copyright © 2023 Ory Corp
+// SPDX-License-Identifier: Apache-2.0
+
+package pagepagination
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+
+	"github.com/ory/x/pagination"
+)
+
+type PagePaginator struct {
+	MaxItems     int
+	DefaultItems int
+}
+
+func (p *PagePaginator) defaults() {
+	if p.MaxItems == 0 {
+		p.MaxItems = 1000
+	}
+
+	if p.DefaultItems == 0 {
+		p.DefaultItems = 250
+	}
+}
+
+// ParsePagination parses limit and page from *http.Request with given limits and defaults.
+func (p *PagePaginator) ParsePagination(r *http.Request) (page, itemsPerPage int) {
+	p.defaults()
+
+	if offsetParam := r.URL.Query().Get("page"); offsetParam == "" {
+		page = 0
+	} else {
+		if offset, err := strconv.ParseInt(offsetParam, 10, 0); err != nil {
+			page = 0
+		} else {
+			page = int(offset)
+		}
+	}
+
+	if limitParam := r.URL.Query().Get("per_page"); limitParam == "" {
+		itemsPerPage = p.DefaultItems
+	} else {
+		if limit, err := strconv.ParseInt(limitParam, 10, 0); err != nil {
+			itemsPerPage = p.DefaultItems
+		} else {
+			itemsPerPage = int(limit)
+		}
+	}
+
+	if itemsPerPage > p.MaxItems {
+		itemsPerPage = p.MaxItems
+	}
+
+	if itemsPerPage < 1 {
+		itemsPerPage = 1
+	}
+
+	if page < 0 {
+		page = 0
+	}
+
+	return
+}
+
+func header(u *url.URL, rel string, limit, offset int64) string {
+	q := u.Query()
+	q.Set("per_page", fmt.Sprintf("%d", limit))
+	q.Set("page", fmt.Sprintf("%d", offset/limit))
+	u.RawQuery = q.Encode()
+	return fmt.Sprintf("<%s>; rel=\"%s\"", u.String(), rel)
+}
+
+func PaginationHeader(w http.ResponseWriter, u *url.URL, total int64, page, itemsPerPage int) {
+	pagination.HeaderWithFormatter(w, u, total, page, itemsPerPage, header)
+}