docs: add docstrings

internal/cookies/jar.go

@@ -0,0 +1,81 @@
+// Copyright (c) 2020 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+// Package cookies implements a persistent cookie jar which satisfies the http.CookieJar interface.
+package cookies
+
+import (
+	"net/http"
+	"net/http/cookiejar"
+	"net/url"
+	"sync"
+
+	"github.com/sirupsen/logrus"
+)
+
+// Jar implements http.CookieJar by wrapping the standard library's cookiejar.Jar.
+// The jar uses a Persister to load cookies at startup and save cookies when set.
+type Jar struct {
+	jar       *cookiejar.Jar
+	persister *Persister
+	locker    sync.Locker
+}
+
+func NewCookieJar(persister *Persister) (*Jar, error) {
+	jar, err := cookiejar.New(nil)
+	if err != nil {
+		return nil, err
+	}
+
+	cookies, err := persister.Load()
+	if err != nil {
+		return nil, err
+	}
+
+	for rawURL, cookies := range cookies {
+		url, err := url.Parse(rawURL)
+		if err != nil {
+			continue
+		}
+
+		jar.SetCookies(url, cookies)
+	}
+
+	return &Jar{
+		jar:       jar,
+		persister: persister,
+		locker:    &sync.Mutex{},
+	}, nil
+}
+
+func (j *Jar) SetCookies(u *url.URL, cookies []*http.Cookie) {
+	j.locker.Lock()
+	defer j.locker.Unlock()
+
+	j.jar.SetCookies(u, cookies)
+
+	if err := j.persister.Persist(u.String(), cookies); err != nil {
+		logrus.WithError(err).Warn("Failed to persist cookie")
+	}
+}
+
+func (j *Jar) Cookies(u *url.URL) []*http.Cookie {
+	j.locker.Lock()
+	defer j.locker.Unlock()
+
+	return j.jar.Cookies(u)
+}