summaryrefslogtreecommitdiffstats
path: root/vendor/github.com/minio/minio-go/bucket-cache.go
blob: 4ad1069597edfcd38e5461d4ae64322a41fd8cda (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
/*
 * Minio Go Library for Amazon S3 Compatible Cloud Storage (C) 2015 Minio, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package minio

import (
	"encoding/hex"
	"net/http"
	"net/url"
	"path"
	"strings"
	"sync"
)

// bucketLocationCache - Provides simple mechanism to hold bucket
// locations in memory.
type bucketLocationCache struct {
	// mutex is used for handling the concurrent
	// read/write requests for cache.
	sync.RWMutex

	// items holds the cached bucket locations.
	items map[string]string
}

// newBucketLocationCache - Provides a new bucket location cache to be
// used internally with the client object.
func newBucketLocationCache() *bucketLocationCache {
	return &bucketLocationCache{
		items: make(map[string]string),
	}
}

// Get - Returns a value of a given key if it exists.
func (r *bucketLocationCache) Get(bucketName string) (location string, ok bool) {
	r.RLock()
	defer r.RUnlock()
	location, ok = r.items[bucketName]
	return
}

// Set - Will persist a value into cache.
func (r *bucketLocationCache) Set(bucketName string, location string) {
	r.Lock()
	defer r.Unlock()
	r.items[bucketName] = location
}

// Delete - Deletes a bucket name from cache.
func (r *bucketLocationCache) Delete(bucketName string) {
	r.Lock()
	defer r.Unlock()
	delete(r.items, bucketName)
}

// GetBucketLocation - get location for the bucket name from location cache, if not
// fetch freshly by making a new request.
func (c Client) GetBucketLocation(bucketName string) (string, error) {
	if err := isValidBucketName(bucketName); err != nil {
		return "", err
	}
	return c.getBucketLocation(bucketName)
}

// getBucketLocation - Get location for the bucketName from location map cache, if not
// fetch freshly by making a new request.
func (c Client) getBucketLocation(bucketName string) (string, error) {
	if err := isValidBucketName(bucketName); err != nil {
		return "", err
	}
	if location, ok := c.bucketLocCache.Get(bucketName); ok {
		return location, nil
	}

	if isAmazonChinaEndpoint(c.endpointURL) {
		// For china specifically we need to set everything to
		// cn-north-1 for now, there is no easier way until AWS S3
		// provides a cleaner compatible API across "us-east-1" and
		// China region.
		return "cn-north-1", nil
	}

	// Initialize a new request.
	req, err := c.getBucketLocationRequest(bucketName)
	if err != nil {
		return "", err
	}

	// Initiate the request.
	resp, err := c.do(req)
	defer closeResponse(resp)
	if err != nil {
		return "", err
	}
	location, err := processBucketLocationResponse(resp, bucketName)
	if err != nil {
		return "", err
	}
	c.bucketLocCache.Set(bucketName, location)
	return location, nil
}

// processes the getBucketLocation http response from the server.
func processBucketLocationResponse(resp *http.Response, bucketName string) (bucketLocation string, err error) {
	if resp != nil {
		if resp.StatusCode != http.StatusOK {
			err = httpRespToErrorResponse(resp, bucketName, "")
			errResp := ToErrorResponse(err)
			// For access denied error, it could be an anonymous
			// request. Move forward and let the top level callers
			// succeed if possible based on their policy.
			if errResp.Code == "AccessDenied" && strings.Contains(errResp.Message, "Access Denied") {
				return "us-east-1", nil
			}
			return "", err
		}
	}

	// Extract location.
	var locationConstraint string
	err = xmlDecoder(resp.Body, &locationConstraint)
	if err != nil {
		return "", err
	}

	location := locationConstraint
	// Location is empty will be 'us-east-1'.
	if location == "" {
		location = "us-east-1"
	}

	// Location can be 'EU' convert it to meaningful 'eu-west-1'.
	if location == "EU" {
		location = "eu-west-1"
	}

	// Save the location into cache.

	// Return.
	return location, nil
}

// getBucketLocationRequest - Wrapper creates a new getBucketLocation request.
func (c Client) getBucketLocationRequest(bucketName string) (*http.Request, error) {
	// Set location query.
	urlValues := make(url.Values)
	urlValues.Set("location", "")

	// Set get bucket location always as path style.
	targetURL, err := url.Parse(c.endpointURL)
	if err != nil {
		return nil, err
	}
	targetURL.Path = path.Join(bucketName, "") + "/"
	targetURL.RawQuery = urlValues.Encode()

	// Get a new HTTP request for the method.
	req, err := http.NewRequest("GET", targetURL.String(), nil)
	if err != nil {
		return nil, err
	}

	// Set UserAgent for the request.
	c.setUserAgent(req)

	// Set sha256 sum for signature calculation only with signature version '4'.
	if c.signature.isV4() {
		var contentSha256 string
		if c.secure {
			contentSha256 = unsignedPayload
		} else {
			contentSha256 = hex.EncodeToString(sum256([]byte{}))
		}
		req.Header.Set("X-Amz-Content-Sha256", contentSha256)
	}

	// Sign the request.
	if c.signature.isV4() {
		req = signV4(*req, c.accessKeyID, c.secretAccessKey, "us-east-1")
	} else if c.signature.isV2() {
		req = signV2(*req, c.accessKeyID, c.secretAccessKey)
	}
	return req, nil
}