Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
AbstractHeaderBasedCachingWire |
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| 2.2857142857142856;2.286 |
1 | /** | |
2 | * Copyright (c) 2011-2017, jcabi.com | |
3 | * All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: 1) Redistributions of source code must retain the above | |
8 | * copyright notice, this list of conditions and the following | |
9 | * disclaimer. 2) Redistributions in binary form must reproduce the above | |
10 | * copyright notice, this list of conditions and the following | |
11 | * disclaimer in the documentation and/or other materials provided | |
12 | * with the distribution. 3) Neither the name of the jcabi.com nor | |
13 | * the names of its contributors may be used to endorse or promote | |
14 | * products derived from this software without specific prior written | |
15 | * permission. | |
16 | * | |
17 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
18 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT | |
19 | * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND | |
20 | * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL | |
21 | * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, | |
22 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | |
23 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR | |
24 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
25 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
26 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
27 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | |
28 | * OF THE POSSIBILITY OF SUCH DAMAGE. | |
29 | */ | |
30 | package com.jcabi.http.wire; | |
31 | ||
32 | import com.jcabi.http.Request; | |
33 | import com.jcabi.http.Response; | |
34 | import com.jcabi.http.Wire; | |
35 | import java.io.IOException; | |
36 | import java.io.InputStream; | |
37 | import java.net.HttpURLConnection; | |
38 | import java.util.Collection; | |
39 | import java.util.Map; | |
40 | import java.util.concurrent.ConcurrentHashMap; | |
41 | ||
42 | /** | |
43 | * This is the base class to handle http responses with 304 state. | |
44 | * | |
45 | * @author Ievgen Degtiarenko (ievgen.degtiarenko@gmail.com) | |
46 | * @version $Id: f9f1d1a719d819fc3f8d25a2091a25f265e1cd3b $ | |
47 | * @since 2.0 | |
48 | */ | |
49 | public abstract class AbstractHeaderBasedCachingWire implements Wire { | |
50 | ||
51 | /** | |
52 | * Cache. | |
53 | */ | |
54 | private final transient Map<Request, Response> cache; | |
55 | ||
56 | /** | |
57 | * Original wire. | |
58 | */ | |
59 | private final transient Wire origin; | |
60 | ||
61 | /** | |
62 | * This header will be return by server to identify content version. | |
63 | */ | |
64 | private final transient String scvh; | |
65 | ||
66 | /** | |
67 | * This header will be sent by client to check if server content has | |
68 | * been changed. | |
69 | */ | |
70 | private final transient String cmch; | |
71 | ||
72 | /** | |
73 | * Ctor. | |
74 | * @param scvh Server Response Version Header name | |
75 | * @param cmch Client Modification Check Header name | |
76 | * @param wire Original wire | |
77 | */ | |
78 | AbstractHeaderBasedCachingWire( | |
79 | final String scvh, final String cmch, final Wire wire | |
80 | 8 | ) { |
81 | 8 | this.scvh = scvh; |
82 | 8 | this.cmch = cmch; |
83 | 8 | this.origin = wire; |
84 | 8 | this.cache = new ConcurrentHashMap<>(); |
85 | 8 | } |
86 | ||
87 | // @checkstyle ParameterNumber (3 lines) | |
88 | @Override | |
89 | public final Response send( | |
90 | final Request req, final String home, final String method, | |
91 | final Collection<Map.Entry<String, String>> headers, | |
92 | final InputStream content, final int connect, final int read | |
93 | ) throws IOException { | |
94 | final Response rsp; | |
95 | 27 | if (method.equals(Request.GET) && !this.requestHasCmcHeader(headers)) { |
96 | 25 | rsp = this.consultCache( |
97 | req, home, method, headers, content, connect, read | |
98 | ); | |
99 | } else { | |
100 | 2 | rsp = this.origin.send( |
101 | req, home, method, headers, content, connect, read | |
102 | ); | |
103 | } | |
104 | 27 | return rsp; |
105 | } | |
106 | ||
107 | /** | |
108 | * Check cache and update if needed. | |
109 | * | |
110 | * @param req Request | |
111 | * @param home URI to fetch | |
112 | * @param method HTTP method | |
113 | * @param headers Headers | |
114 | * @param content HTTP body | |
115 | * @param connect The connect timeout | |
116 | * @param read The read timeout | |
117 | * @return Response obtained | |
118 | * @throws IOException if fails | |
119 | * @checkstyle ParameterNumber (6 lines) | |
120 | */ | |
121 | private Response consultCache( | |
122 | final Request req, final String home, final String method, | |
123 | final Collection<Map.Entry<String, String>> headers, | |
124 | final InputStream content, final int connect, final int read | |
125 | ) throws IOException { | |
126 | final Response rsp; | |
127 | 25 | if (this.cache.containsKey(req)) { |
128 | 17 | rsp = this.validateCacheWithServer( |
129 | req, home, method, headers, content, connect, read | |
130 | ); | |
131 | } else { | |
132 | 8 | rsp = this.origin.send( |
133 | req, home, method, headers, content, connect, read | |
134 | ); | |
135 | 8 | this.updateCache(req, rsp); |
136 | } | |
137 | 25 | return rsp; |
138 | } | |
139 | ||
140 | /** | |
141 | * Check response and update cache or evict from cache if needed. | |
142 | * @param req Request | |
143 | * @param home URI to fetch | |
144 | * @param method HTTP method | |
145 | * @param headers Headers | |
146 | * @param content HTTP body | |
147 | * @param connect The connect timeout | |
148 | * @param read The read timeout | |
149 | * @return Response obtained | |
150 | * @throws IOException if fails | |
151 | * @checkstyle ParameterNumber (8 lines) | |
152 | */ | |
153 | private Response validateCacheWithServer( | |
154 | final Request req, final String home, final String method, | |
155 | final Collection<Map.Entry<String, String>> headers, | |
156 | final InputStream content, final int connect, final int read | |
157 | ) throws IOException { | |
158 | 17 | final Response cached = this.cache.get(req); |
159 | 17 | final Collection<Map.Entry<String, String>> hdrs = this.enrich( |
160 | headers, cached | |
161 | ); | |
162 | 17 | Response result = this.origin.send( |
163 | req, home, method, hdrs, content, connect, read | |
164 | ); | |
165 | 17 | if (result.status() == HttpURLConnection.HTTP_NOT_MODIFIED) { |
166 | 13 | result = cached; |
167 | } else { | |
168 | 4 | this.updateCache(req, result); |
169 | } | |
170 | 17 | return result; |
171 | } | |
172 | ||
173 | /** | |
174 | * Add, update or evict response in cache. | |
175 | * @param req The request to be used as key | |
176 | * @param rsp The response to add/update | |
177 | */ | |
178 | private void updateCache(final Request req, final Response rsp) { | |
179 | 12 | if (rsp.headers().containsKey(this.scvh)) { |
180 | 8 | this.cache.put(req, rsp); |
181 | 4 | } else if (rsp.status() == HttpURLConnection.HTTP_OK) { |
182 | 3 | this.cache.remove(req); |
183 | } | |
184 | 12 | } |
185 | ||
186 | /** | |
187 | * Add identify content version header. | |
188 | * | |
189 | * @param headers Original headers | |
190 | * @param rsp Cached response | |
191 | * @return Map with extra header | |
192 | */ | |
193 | private Collection<Map.Entry<String, String>> enrich( | |
194 | final Collection<Map.Entry<String, String>> headers, final Response rsp | |
195 | ) { | |
196 | 17 | final Collection<String> list = rsp.headers().get( |
197 | this.scvh | |
198 | ); | |
199 | 17 | final Map<String, String> map = |
200 | new ConcurrentHashMap<>(headers.size() + 1); | |
201 | 17 | for (final Map.Entry<String, String> entry : headers) { |
202 | 0 | map.put(entry.getKey(), entry.getValue()); |
203 | 0 | } |
204 | 17 | map.put( |
205 | this.cmch, list.iterator().next() | |
206 | ); | |
207 | 17 | return map.entrySet(); |
208 | } | |
209 | /** | |
210 | * Check if the request send through this Wire has the cmch header. | |
211 | * @param headers The headers of the request. | |
212 | * @return True if the request contains the cmch header, false otherwise. | |
213 | */ | |
214 | private boolean requestHasCmcHeader( | |
215 | final Collection<Map.Entry<String, String>> headers | |
216 | ) { | |
217 | 27 | boolean requestHasCmch = false; |
218 | 27 | for (final Map.Entry<String, String> header : headers) { |
219 | 2 | if (header.getKey().equals(this.cmch)) { |
220 | 2 | requestHasCmch = true; |
221 | 2 | break; |
222 | } | |
223 | 0 | } |
224 | 27 | return requestHasCmch; |
225 | } | |
226 | } |