1 /*
2 * Copyright (c) 2022 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include "cache_proxy.h"
17
18 #include <atomic>
19 #include <condition_variable>
20 #include <mutex>
21 #include <thread>
22
23 #include "base64_utils.h"
24 #include "constant.h"
25 #include "lru_cache_disk_handler.h"
26 #include "netstack_common_utils.h"
27 #include "netstack_log.h"
28 #include "request_context.h"
29
30 static constexpr const char *CACHE_FILE = "/data/storage/el2/base/cache/cache.json";
31 static constexpr int32_t WRITE_INTERVAL = 60;
32
33 namespace OHOS::NetStack {
34 std::mutex g_diskCacheMutex;
35 std::mutex g_cacheNeedRunMutex;
36 std::atomic_bool g_cacheNeedRun(false);
37 std::atomic_bool g_cacheIsRunning(false);
38 std::condition_variable g_cacheThreadCondition;
39 std::condition_variable g_cacheNeedRunCondition;
40 static LRUCacheDiskHandler DISK_LRU_CACHE(CACHE_FILE, 0); // NOLINT(cert-err58-cpp)
41
CacheProxy(HttpRequestOptions & requestOptions)42 CacheProxy::CacheProxy(HttpRequestOptions &requestOptions) : strategy_(requestOptions)
43 {
44 std::string str = requestOptions.GetUrl() + HttpConstant::HTTP_LINE_SEPARATOR +
45 CommonUtils::ToLower(requestOptions.GetMethod()) + HttpConstant::HTTP_LINE_SEPARATOR;
46 for (const auto &p : requestOptions.GetHeader()) {
47 str += p.first + HttpConstant::HTTP_HEADER_SEPARATOR + p.second + HttpConstant::HTTP_LINE_SEPARATOR;
48 }
49 str += std::to_string(requestOptions.GetHttpVersion());
50 key_ = Base64::Encode(str);
51 }
52
ReadResponseFromCache(RequestContext * context)53 bool CacheProxy::ReadResponseFromCache(RequestContext *context)
54 {
55 if (!g_cacheIsRunning.load()) {
56 return false;
57 }
58
59 if (!strategy_.CouldUseCache()) {
60 NETSTACK_LOGI("only GET/HEAD method or header has [Range] can use cache");
61 return false;
62 }
63
64 auto responseFromCache = DISK_LRU_CACHE.Get(key_);
65 if (responseFromCache.empty()) {
66 NETSTACK_LOGI("no cache with this request");
67 return false;
68 }
69 HttpResponse cachedResponse;
70 cachedResponse.SetRawHeader(Base64::Decode(responseFromCache[HttpConstant::RESPONSE_KEY_HEADER]));
71 cachedResponse.SetResult(Base64::Decode(responseFromCache[HttpConstant::RESPONSE_KEY_RESULT]));
72 cachedResponse.SetCookies(Base64::Decode(responseFromCache[HttpConstant::RESPONSE_KEY_COOKIES]));
73 cachedResponse.SetResponseTime(Base64::Decode(responseFromCache[HttpConstant::RESPONSE_TIME]));
74 cachedResponse.SetRequestTime(Base64::Decode(responseFromCache[HttpConstant::REQUEST_TIME]));
75 cachedResponse.SetResponseCode(static_cast<uint32_t>(ResponseCode::OK));
76 cachedResponse.ParseHeaders();
77
78 CacheStatus status = strategy_.RunStrategy(cachedResponse);
79 if (status == CacheStatus::FRESH) {
80 context->response = cachedResponse;
81 NETSTACK_LOGI("cache is FRESH");
82 return true;
83 }
84 if (status == CacheStatus::STALE) {
85 NETSTACK_LOGI("cache is STATE, we try to talk to the server");
86 context->SetCacheResponse(cachedResponse);
87 return false;
88 }
89 NETSTACK_LOGD("cache should not be used");
90 return false;
91 }
92
WriteResponseToCache(const HttpResponse & response)93 void CacheProxy::WriteResponseToCache(const HttpResponse &response)
94 {
95 if (!g_cacheIsRunning.load()) {
96 return;
97 }
98
99 if (!strategy_.IsCacheable(response)) {
100 NETSTACK_LOGE("do not cache this response");
101 return;
102 }
103 std::unordered_map<std::string, std::string> cacheResponse;
104 cacheResponse[HttpConstant::RESPONSE_KEY_HEADER] = Base64::Encode(response.GetRawHeader());
105 cacheResponse[HttpConstant::RESPONSE_KEY_RESULT] = Base64::Encode(response.GetResult());
106 cacheResponse[HttpConstant::RESPONSE_KEY_COOKIES] = Base64::Encode(response.GetCookies());
107 cacheResponse[HttpConstant::RESPONSE_TIME] = Base64::Encode(response.GetResponseTime());
108 cacheResponse[HttpConstant::REQUEST_TIME] = Base64::Encode(response.GetRequestTime());
109
110 DISK_LRU_CACHE.Put(key_, cacheResponse);
111 }
112
RunCache()113 void CacheProxy::RunCache()
114 {
115 RunCacheWithSize(MAX_DISK_CACHE_SIZE);
116 }
117
RunCacheWithSize(size_t capacity)118 void CacheProxy::RunCacheWithSize(size_t capacity)
119 {
120 if (g_cacheIsRunning.load()) {
121 return;
122 }
123 DISK_LRU_CACHE.SetCapacity(capacity);
124
125 g_cacheNeedRun.store(true);
126
127 DISK_LRU_CACHE.ReadCacheFromJsonFile();
128
129 std::thread([]() {
130 g_cacheIsRunning.store(true);
131 while (g_cacheNeedRun.load()) {
132 std::unique_lock<std::mutex> lock(g_cacheNeedRunMutex);
133 g_cacheNeedRunCondition.wait_for(lock, std::chrono::seconds(WRITE_INTERVAL),
134 [] { return !g_cacheNeedRun.load(); });
135
136 DISK_LRU_CACHE.WriteCacheToJsonFile();
137 }
138
139 g_cacheIsRunning.store(false);
140 g_cacheThreadCondition.notify_all();
141 }).detach();
142 }
143
FlushCache()144 void CacheProxy::FlushCache()
145 {
146 if (!g_cacheIsRunning.load()) {
147 return;
148 }
149 DISK_LRU_CACHE.WriteCacheToJsonFile();
150 }
151
StopCacheAndDelete()152 void CacheProxy::StopCacheAndDelete()
153 {
154 if (!g_cacheIsRunning.load()) {
155 return;
156 }
157 g_cacheNeedRun.store(false);
158 g_cacheNeedRunCondition.notify_all();
159
160 std::unique_lock<std::mutex> lock(g_diskCacheMutex);
161 g_cacheThreadCondition.wait(lock, [] { return !g_cacheIsRunning.load(); });
162 DISK_LRU_CACHE.Delete();
163 }
164 } // namespace OHOS::NetStack
165