Dragonfly2

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/*
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 *     Copyright 2022 The Dragonfly Authors
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 *
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 * Licensed under the Apache License, Version 2.0 (the "License");
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 * you may not use this file except in compliance with the License.
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 * You may obtain a copy of the License at
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 *
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 *      http://www.apache.org/licenses/LICENSE-2.0
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 *
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 * Unless required by applicable law or agreed to in writing, software
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * See the License for the specific language governing permissions and
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 * limitations under the License.
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 */
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package cache
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import (
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	"context"
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	"crypto/tls"
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	"github.com/johanbrandhorst/certify"
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)
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const (
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	// CertifyCacheDirName is dir name of certify cache.
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	CertifyCacheDirName = "certs"
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)
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type certifyCache struct {
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	caches []certify.Cache
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}
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// NewCertifyMutliCache returns a certify.Cache with multiple caches
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// Such as, cache.NewCertifyMutliCache(certify.NewMemCache(), certify.DirCache("certs"))
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// This multiple cache will get certs from mem cache first, then dir cache to avoid read from filesystem every times.
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func NewCertifyMutliCache(caches ...certify.Cache) certify.Cache {
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	return &certifyCache{caches: caches}
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}
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// Get gets cert from cache one by one, if found, puts it back to all previous caches.
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func (c *certifyCache) Get(ctx context.Context, key string) (cert *tls.Certificate, err error) {
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	var foundCacheIdx int = -1
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	for i, cache := range c.caches {
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		if cert, err = cache.Get(ctx, key); err == nil {
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			foundCacheIdx = i
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			break
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		}
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	}
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	// put cert in previous cache
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	for i := 0; i < foundCacheIdx; i++ {
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		_ = c.caches[i].Put(ctx, key, cert)
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	}
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	if err == nil {
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		return
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	}
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	return nil, certify.ErrCacheMiss
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}
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// Put puts cert to all caches.
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func (c *certifyCache) Put(ctx context.Context, key string, cert *tls.Certificate) error {
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	for _, cache := range c.caches {
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		if err := cache.Put(ctx, key, cert); err != nil {
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			return err
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		}
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	}
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	return nil
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}
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// Delete deletes cert from all caches.
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func (c *certifyCache) Delete(ctx context.Context, key string) error {
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	for _, cache := range c.caches {
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		if err := cache.Delete(ctx, key); err != nil {
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			return err
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		}
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	}
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	return nil
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}
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