]>
Commit | Line | Data |
---|---|---|
9487bae9 AR |
1 | /* |
2 | * $Id$ | |
3 | * | |
4 | * DEBUG: section 20 Memory Cache | |
5 | * | |
6 | */ | |
7 | ||
8 | #include "config.h" | |
9 | #include "ipc/mem/Page.h" | |
10 | #include "ipc/mem/Pages.h" | |
11 | #include "MemObject.h" | |
12 | #include "MemStore.h" | |
13 | #include "HttpReply.h" | |
14 | ||
15 | ||
16 | // XXX: support storage using more than one page per entry | |
17 | ||
18 | ||
19 | MemStore::MemStore(): map(NULL) | |
20 | { | |
21 | } | |
22 | ||
23 | MemStore::~MemStore() | |
24 | { | |
25 | delete map; | |
26 | } | |
27 | ||
28 | void | |
29 | MemStore::init() | |
30 | { | |
31 | if (!map && Config.memMaxSize && (!UsingSmp() || IamWorkerProcess())) { | |
32 | // TODO: warn if we cannot support the configured maximum entry size | |
33 | const int64_t entrySize = Ipc::Mem::PageSize(); // for now | |
34 | const int64_t entryCount = Config.memMaxSize / entrySize; | |
35 | // TODO: warn if we cannot cache at least one item (misconfiguration) | |
7f6748c8 | 36 | if (entryCount > 0) { |
9487bae9 | 37 | map = new MemStoreMap("cache_mem", entryCount); |
7f6748c8 AR |
38 | map->cleaner = this; |
39 | } | |
9487bae9 AR |
40 | } |
41 | } | |
42 | ||
43 | void | |
c4e688b7 | 44 | MemStore::stat(StoreEntry &e) const |
9487bae9 | 45 | { |
c4e688b7 AR |
46 | storeAppendPrintf(&e, "\n\nShared Memory Cache\n"); |
47 | ||
48 | storeAppendPrintf(&e, "Maximum Size: %.0f KB\n", Config.memMaxSize/1024.0); | |
49 | ||
50 | if (map) { | |
51 | const int limit = map->entryLimit(); | |
52 | storeAppendPrintf(&e, "Maximum entries: %9d\n", limit); | |
53 | if (limit > 0) { | |
54 | const int entryCount = map->entryCount(); | |
55 | storeAppendPrintf(&e, "Current entries: %9d %.2f%%\n", | |
56 | entryCount, (100.0 * entryCount / limit)); | |
57 | ||
58 | if (limit < 100) { // XXX: otherwise too expensive to count | |
59 | Ipc::ReadWriteLockStats stats; | |
60 | map->updateStats(stats); | |
61 | stats.dump(e); | |
62 | } | |
63 | } | |
64 | } | |
9487bae9 AR |
65 | } |
66 | ||
67 | void | |
68 | MemStore::maintain() | |
69 | { | |
70 | } | |
71 | ||
72 | uint64_t | |
73 | MemStore::minSize() const | |
74 | { | |
75 | return 0; // XXX: irrelevant, but Store parent forces us to implement this | |
76 | } | |
77 | ||
78 | uint64_t | |
79 | MemStore::maxSize() const | |
80 | { | |
81 | return 0; // XXX: make configurable | |
82 | } | |
83 | ||
84 | void | |
85 | MemStore::updateSize(int64_t eSize, int sign) | |
86 | { | |
87 | // XXX: irrelevant, but Store parent forces us to implement this | |
88 | fatal("MemStore::updateSize should not be called"); | |
89 | } | |
90 | ||
91 | void | |
92 | MemStore::reference(StoreEntry &) | |
93 | { | |
94 | } | |
95 | ||
96 | void | |
97 | MemStore::dereference(StoreEntry &) | |
98 | { | |
99 | } | |
100 | ||
101 | int | |
102 | MemStore::callback() | |
103 | { | |
104 | return 0; | |
105 | } | |
106 | ||
107 | StoreSearch * | |
108 | MemStore::search(String const, HttpRequest *) | |
109 | { | |
110 | fatal("not implemented"); | |
111 | return NULL; | |
112 | } | |
113 | ||
114 | StoreEntry * | |
115 | MemStore::get(const cache_key *key) | |
116 | { | |
117 | if (!map) | |
118 | return NULL; | |
119 | ||
120 | // XXX: replace sfileno with a bigger word (sfileno is only for cache_dirs) | |
121 | sfileno index; | |
122 | const Ipc::StoreMapSlot *const slot = map->openForReading(key, index); | |
123 | if (!slot) | |
124 | return NULL; | |
125 | ||
126 | const Ipc::StoreMapSlot::Basics &basics = slot->basics; | |
127 | const MemStoreMap::Extras &extras = map->extras(index); | |
128 | ||
129 | // create a brand new store entry and initialize it with stored info | |
130 | StoreEntry *e = new StoreEntry(); | |
131 | e->lock_count = 0; | |
132 | ||
133 | e->swap_file_sz = basics.swap_file_sz; | |
134 | e->lastref = basics.lastref; | |
135 | e->timestamp = basics.timestamp; | |
136 | e->expires = basics.expires; | |
137 | e->lastmod = basics.lastmod; | |
138 | e->refcount = basics.refcount; | |
139 | e->flags = basics.flags; | |
140 | ||
141 | e->store_status = STORE_OK; | |
142 | e->mem_status = IN_MEMORY; // setMemStatus(IN_MEMORY) requires mem_obj | |
143 | //e->swap_status = set in StoreEntry constructor to SWAPOUT_NONE; | |
144 | e->ping_status = PING_NONE; | |
145 | ||
146 | EBIT_SET(e->flags, ENTRY_CACHABLE); | |
147 | EBIT_CLR(e->flags, RELEASE_REQUEST); | |
148 | EBIT_CLR(e->flags, KEY_PRIVATE); | |
149 | EBIT_SET(e->flags, ENTRY_VALIDATED); | |
150 | ||
151 | const bool copied = copyFromShm(*e, extras); | |
152 | ||
153 | // we copied everything we could to local memory; no more need to lock | |
154 | map->closeForReading(index); | |
155 | ||
156 | if (copied) { | |
157 | e->hashInsert(key); | |
158 | return e; | |
159 | } | |
160 | ||
161 | debugs(20, 3, HERE << "mem-loading failed; freeing " << index); | |
162 | map->free(index); // do not let others into the same trap | |
163 | return NULL; | |
164 | } | |
165 | ||
166 | void | |
167 | MemStore::get(String const key, STOREGETCLIENT aCallback, void *aCallbackData) | |
168 | { | |
169 | // XXX: not needed but Store parent forces us to implement this | |
170 | fatal("MemStore::get(key,callback,data) should not be called"); | |
171 | } | |
172 | ||
173 | bool | |
174 | MemStore::copyFromShm(StoreEntry &e, const MemStoreMap::Extras &extras) | |
175 | { | |
176 | const Ipc::Mem::PageId &page = extras.page; | |
177 | ||
178 | StoreIOBuffer sourceBuf(extras.storedSize, 0, | |
179 | static_cast<char*>(PagePointer(page))); | |
180 | ||
181 | // XXX: We do not know the URLs yet, only the key, but we need to parse and | |
182 | // store the response for the Root().get() callers to be happy because they | |
183 | // expect IN_MEMORY entries to already have the response headers and body. | |
184 | // At least one caller calls createMemObject() if there is not one, so | |
185 | // we hide the true object until that happens (to avoid leaking TBD URLs). | |
186 | e.createMemObject("TBD", "TBD"); | |
187 | ||
188 | // emulate the usual Store code but w/o inapplicable checks and callbacks: | |
189 | ||
190 | // from store_client::readBody(): | |
191 | HttpReply *rep = (HttpReply *)e.getReply(); | |
192 | const ssize_t end = headersEnd(sourceBuf.data, sourceBuf.length); | |
193 | if (!rep->parseCharBuf(sourceBuf.data, end)) { | |
194 | debugs(20, DBG_IMPORTANT, "Could not parse mem-cached headers: " << e); | |
195 | return false; | |
196 | } | |
197 | // local memory stores both headers and body | |
198 | e.mem_obj->object_sz = sourceBuf.length; // from StoreEntry::complete() | |
199 | ||
200 | storeGetMemSpace(sourceBuf.length); // from StoreEntry::write() | |
201 | ||
202 | assert(e.mem_obj->data_hdr.write(sourceBuf)); // from MemObject::write() | |
203 | const int64_t written = e.mem_obj->endOffset(); | |
30204d23 AR |
204 | // we should write all because StoreEntry::write() never fails |
205 | assert(written >= 0 && | |
206 | static_cast<size_t>(written) == sourceBuf.length); | |
9487bae9 AR |
207 | // would be nice to call validLength() here, but it needs e.key |
208 | ||
209 | debugs(20, 7, HERE << "mem-loaded all " << written << " bytes of " << e << | |
210 | " from " << page); | |
211 | ||
212 | e.hideMemObject(); | |
213 | ||
214 | return true; | |
215 | } | |
216 | ||
217 | void | |
218 | MemStore::considerKeeping(StoreEntry &e) | |
219 | { | |
220 | if (!e.memoryCachable()) { | |
221 | debugs(20, 7, HERE << "Not memory cachable: " << e); | |
222 | return; // cannot keep due to entry state or properties | |
223 | } | |
224 | ||
225 | assert(e.mem_obj); | |
226 | if (!willFit(e.mem_obj->endOffset())) { | |
227 | debugs(20, 5, HERE << "No mem-cache space for " << e); | |
228 | return; // failed to free enough space | |
229 | } | |
230 | ||
231 | keep(e); // may still fail | |
232 | } | |
233 | ||
234 | bool | |
235 | MemStore::willFit(int64_t need) | |
236 | { | |
237 | // TODO: obey configured maximum entry size (with page-based rounding) | |
30204d23 | 238 | return need <= static_cast<int64_t>(Ipc::Mem::PageSize()); |
9487bae9 AR |
239 | } |
240 | ||
241 | /// allocates map slot and calls copyToShm to store the entry in shared memory | |
242 | void | |
243 | MemStore::keep(StoreEntry &e) | |
244 | { | |
245 | if (!map) { | |
246 | debugs(20, 5, HERE << "No map to mem-cache " << e); | |
247 | return; | |
248 | } | |
249 | ||
250 | sfileno index = 0; | |
251 | Ipc::StoreMapSlot *slot = map->openForWriting(reinterpret_cast<const cache_key *>(e.key), index); | |
252 | if (!slot) { | |
253 | debugs(20, 5, HERE << "No room in mem-cache map to index " << e); | |
254 | return; | |
255 | } | |
256 | ||
257 | MemStoreMap::Extras &extras = map->extras(index); | |
258 | if (copyToShm(e, extras)) { | |
259 | slot->set(e); | |
260 | map->closeForWriting(index, false); | |
261 | } else { | |
262 | map->abortIo(index); | |
263 | } | |
264 | } | |
265 | ||
266 | /// uses mem_hdr::copy() to copy local data to shared memory | |
267 | bool | |
268 | MemStore::copyToShm(StoreEntry &e, MemStoreMap::Extras &extras) | |
269 | { | |
270 | Ipc::Mem::PageId page; | |
271 | if (!Ipc::Mem::GetPage(page)) { | |
272 | debugs(20, 5, HERE << "No mem-cache page for " << e); | |
273 | return false; // GetPage is responsible for any cleanup on failures | |
274 | } | |
275 | ||
276 | const int64_t bufSize = Ipc::Mem::PageSize(); | |
277 | const int64_t eSize = e.mem_obj->endOffset(); | |
278 | ||
279 | StoreIOBuffer sharedSpace(bufSize, 0, | |
280 | static_cast<char*>(PagePointer(page))); | |
281 | ||
282 | // check that we kept everything or purge incomplete/sparse cached entry | |
283 | const ssize_t copied = e.mem_obj->data_hdr.copy(sharedSpace); | |
284 | if (eSize != copied) { | |
285 | debugs(20, 2, HERE << "Failed to mem-cache " << e << ": " << | |
286 | eSize << "!=" << copied); | |
287 | // cleanup | |
288 | PutPage(page); | |
289 | return false; | |
290 | } | |
291 | ||
292 | debugs(20, 7, HERE << "mem-cached all " << eSize << " bytes of " << e << | |
293 | " in " << page); | |
294 | ||
295 | // remember storage location and size | |
296 | extras.page = page; | |
297 | extras.storedSize = copied; | |
298 | return true; | |
299 | } | |
7f6748c8 AR |
300 | |
301 | void | |
302 | MemStore::cleanReadable(const sfileno fileno) | |
303 | { | |
304 | Ipc::Mem::PutPage(map->extras(fileno).page); | |
305 | } | |
306 |