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Commit | Line | Data |
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9487bae9 AR |
1 | /* |
2 | * $Id$ | |
3 | * | |
4 | * DEBUG: section 20 Memory Cache | |
5 | * | |
6 | */ | |
7 | ||
f7f3304a | 8 | #include "squid.h" |
a4555399 | 9 | #include "base/RunnersRegistry.h" |
582c2af2 | 10 | #include "HttpReply.h" |
9487bae9 AR |
11 | #include "ipc/mem/Page.h" |
12 | #include "ipc/mem/Pages.h" | |
13 | #include "MemObject.h" | |
14 | #include "MemStore.h" | |
582c2af2 | 15 | #include "protos.h" |
93bc1434 | 16 | #include "StoreStats.h" |
9487bae9 | 17 | |
a4555399 AR |
18 | /// shared memory segment path to use for MemStore maps |
19 | static const char *ShmLabel = "cache_mem"; | |
9487bae9 AR |
20 | |
21 | // XXX: support storage using more than one page per entry | |
22 | ||
17cf0a47 | 23 | MemStore::MemStore(): map(NULL), theCurrentSize(0) |
9487bae9 AR |
24 | { |
25 | } | |
26 | ||
27 | MemStore::~MemStore() | |
28 | { | |
29 | delete map; | |
30 | } | |
31 | ||
32 | void | |
9199139f AR |
33 | MemStore::init() |
34 | { | |
a4555399 AR |
35 | const int64_t entryLimit = EntryLimit(); |
36 | if (entryLimit <= 0) | |
37 | return; // no memory cache configured or a misconfiguration | |
38 | ||
ed5d80d3 AR |
39 | const int64_t diskMaxSize = Store::Root().maxObjectSize(); |
40 | const int64_t memMaxSize = maxObjectSize(); | |
41 | if (diskMaxSize == -1) { | |
42 | debugs(20, DBG_IMPORTANT, "WARNING: disk-cache maximum object size " | |
43 | "is unlimited but mem-cache maximum object size is " << | |
44 | memMaxSize / 1024.0 << " KB"); | |
45 | } else if (diskMaxSize > memMaxSize) { | |
46 | debugs(20, DBG_IMPORTANT, "WARNING: disk-cache maximum object size " | |
47 | "is too large for mem-cache: " << | |
48 | diskMaxSize / 1024.0 << " KB > " << | |
49 | memMaxSize / 1024.0 << " KB"); | |
af2fda07 DK |
50 | } |
51 | ||
a4555399 AR |
52 | map = new MemStoreMap(ShmLabel); |
53 | map->cleaner = this; | |
9487bae9 AR |
54 | } |
55 | ||
93bc1434 AR |
56 | void |
57 | MemStore::getStats(StoreInfoStats &stats) const | |
58 | { | |
59 | const size_t pageSize = Ipc::Mem::PageSize(); | |
60 | ||
61 | stats.mem.shared = true; | |
62 | stats.mem.capacity = | |
63 | Ipc::Mem::PageLimit(Ipc::Mem::PageId::cachePage) * pageSize; | |
64 | stats.mem.size = | |
65 | Ipc::Mem::PageLevel(Ipc::Mem::PageId::cachePage) * pageSize; | |
66 | stats.mem.count = currentCount(); | |
67 | } | |
68 | ||
9487bae9 | 69 | void |
c4e688b7 | 70 | MemStore::stat(StoreEntry &e) const |
9487bae9 | 71 | { |
c4e688b7 AR |
72 | storeAppendPrintf(&e, "\n\nShared Memory Cache\n"); |
73 | ||
74 | storeAppendPrintf(&e, "Maximum Size: %.0f KB\n", Config.memMaxSize/1024.0); | |
75 | ||
76 | if (map) { | |
77 | const int limit = map->entryLimit(); | |
78 | storeAppendPrintf(&e, "Maximum entries: %9d\n", limit); | |
79 | if (limit > 0) { | |
c91ca3ce | 80 | storeAppendPrintf(&e, "Current entries: %" PRId64 " %.2f%%\n", |
9199139f | 81 | currentCount(), (100.0 * currentCount() / limit)); |
c4e688b7 AR |
82 | |
83 | if (limit < 100) { // XXX: otherwise too expensive to count | |
84 | Ipc::ReadWriteLockStats stats; | |
85 | map->updateStats(stats); | |
86 | stats.dump(e); | |
9199139f AR |
87 | } |
88 | } | |
89 | } | |
9487bae9 AR |
90 | } |
91 | ||
92 | void | |
93 | MemStore::maintain() | |
94 | { | |
95 | } | |
96 | ||
97 | uint64_t | |
98 | MemStore::minSize() const | |
99 | { | |
100 | return 0; // XXX: irrelevant, but Store parent forces us to implement this | |
101 | } | |
102 | ||
103 | uint64_t | |
104 | MemStore::maxSize() const | |
105 | { | |
106 | return 0; // XXX: make configurable | |
107 | } | |
108 | ||
39c1e1d9 DK |
109 | uint64_t |
110 | MemStore::currentSize() const | |
111 | { | |
57f583f1 | 112 | return theCurrentSize; |
39c1e1d9 DK |
113 | } |
114 | ||
115 | uint64_t | |
116 | MemStore::currentCount() const | |
117 | { | |
118 | return map ? map->entryCount() : 0; | |
119 | } | |
120 | ||
af2fda07 DK |
121 | int64_t |
122 | MemStore::maxObjectSize() const | |
123 | { | |
124 | return Ipc::Mem::PageSize(); | |
125 | } | |
126 | ||
9487bae9 AR |
127 | void |
128 | MemStore::reference(StoreEntry &) | |
129 | { | |
130 | } | |
131 | ||
4c973beb | 132 | bool |
9487bae9 AR |
133 | MemStore::dereference(StoreEntry &) |
134 | { | |
4c973beb AR |
135 | // no need to keep e in the global store_table for us; we have our own map |
136 | return false; | |
9487bae9 AR |
137 | } |
138 | ||
139 | int | |
140 | MemStore::callback() | |
141 | { | |
142 | return 0; | |
143 | } | |
144 | ||
145 | StoreSearch * | |
146 | MemStore::search(String const, HttpRequest *) | |
147 | { | |
148 | fatal("not implemented"); | |
149 | return NULL; | |
150 | } | |
151 | ||
152 | StoreEntry * | |
153 | MemStore::get(const cache_key *key) | |
154 | { | |
155 | if (!map) | |
156 | return NULL; | |
157 | ||
158 | // XXX: replace sfileno with a bigger word (sfileno is only for cache_dirs) | |
159 | sfileno index; | |
160 | const Ipc::StoreMapSlot *const slot = map->openForReading(key, index); | |
161 | if (!slot) | |
162 | return NULL; | |
163 | ||
164 | const Ipc::StoreMapSlot::Basics &basics = slot->basics; | |
165 | const MemStoreMap::Extras &extras = map->extras(index); | |
166 | ||
167 | // create a brand new store entry and initialize it with stored info | |
168 | StoreEntry *e = new StoreEntry(); | |
169 | e->lock_count = 0; | |
170 | ||
171 | e->swap_file_sz = basics.swap_file_sz; | |
172 | e->lastref = basics.lastref; | |
173 | e->timestamp = basics.timestamp; | |
174 | e->expires = basics.expires; | |
175 | e->lastmod = basics.lastmod; | |
176 | e->refcount = basics.refcount; | |
177 | e->flags = basics.flags; | |
178 | ||
179 | e->store_status = STORE_OK; | |
180 | e->mem_status = IN_MEMORY; // setMemStatus(IN_MEMORY) requires mem_obj | |
181 | //e->swap_status = set in StoreEntry constructor to SWAPOUT_NONE; | |
182 | e->ping_status = PING_NONE; | |
183 | ||
184 | EBIT_SET(e->flags, ENTRY_CACHABLE); | |
185 | EBIT_CLR(e->flags, RELEASE_REQUEST); | |
186 | EBIT_CLR(e->flags, KEY_PRIVATE); | |
187 | EBIT_SET(e->flags, ENTRY_VALIDATED); | |
188 | ||
189 | const bool copied = copyFromShm(*e, extras); | |
190 | ||
191 | // we copied everything we could to local memory; no more need to lock | |
192 | map->closeForReading(index); | |
193 | ||
194 | if (copied) { | |
195 | e->hashInsert(key); | |
196 | return e; | |
197 | } | |
198 | ||
199 | debugs(20, 3, HERE << "mem-loading failed; freeing " << index); | |
200 | map->free(index); // do not let others into the same trap | |
201 | return NULL; | |
202 | } | |
203 | ||
204 | void | |
205 | MemStore::get(String const key, STOREGETCLIENT aCallback, void *aCallbackData) | |
206 | { | |
207 | // XXX: not needed but Store parent forces us to implement this | |
208 | fatal("MemStore::get(key,callback,data) should not be called"); | |
209 | } | |
210 | ||
211 | bool | |
212 | MemStore::copyFromShm(StoreEntry &e, const MemStoreMap::Extras &extras) | |
213 | { | |
214 | const Ipc::Mem::PageId &page = extras.page; | |
215 | ||
216 | StoreIOBuffer sourceBuf(extras.storedSize, 0, | |
9199139f | 217 | static_cast<char*>(PagePointer(page))); |
9487bae9 AR |
218 | |
219 | // XXX: We do not know the URLs yet, only the key, but we need to parse and | |
220 | // store the response for the Root().get() callers to be happy because they | |
221 | // expect IN_MEMORY entries to already have the response headers and body. | |
222 | // At least one caller calls createMemObject() if there is not one, so | |
223 | // we hide the true object until that happens (to avoid leaking TBD URLs). | |
224 | e.createMemObject("TBD", "TBD"); | |
225 | ||
226 | // emulate the usual Store code but w/o inapplicable checks and callbacks: | |
227 | ||
228 | // from store_client::readBody(): | |
229 | HttpReply *rep = (HttpReply *)e.getReply(); | |
230 | const ssize_t end = headersEnd(sourceBuf.data, sourceBuf.length); | |
231 | if (!rep->parseCharBuf(sourceBuf.data, end)) { | |
232 | debugs(20, DBG_IMPORTANT, "Could not parse mem-cached headers: " << e); | |
233 | return false; | |
234 | } | |
235 | // local memory stores both headers and body | |
236 | e.mem_obj->object_sz = sourceBuf.length; // from StoreEntry::complete() | |
237 | ||
238 | storeGetMemSpace(sourceBuf.length); // from StoreEntry::write() | |
239 | ||
240 | assert(e.mem_obj->data_hdr.write(sourceBuf)); // from MemObject::write() | |
241 | const int64_t written = e.mem_obj->endOffset(); | |
30204d23 AR |
242 | // we should write all because StoreEntry::write() never fails |
243 | assert(written >= 0 && | |
244 | static_cast<size_t>(written) == sourceBuf.length); | |
9487bae9 AR |
245 | // would be nice to call validLength() here, but it needs e.key |
246 | ||
247 | debugs(20, 7, HERE << "mem-loaded all " << written << " bytes of " << e << | |
248 | " from " << page); | |
249 | ||
250 | e.hideMemObject(); | |
251 | ||
252 | return true; | |
253 | } | |
254 | ||
96a7de88 DK |
255 | bool |
256 | MemStore::keepInLocalMemory(const StoreEntry &e) const | |
9487bae9 AR |
257 | { |
258 | if (!e.memoryCachable()) { | |
259 | debugs(20, 7, HERE << "Not memory cachable: " << e); | |
96a7de88 DK |
260 | return false; // will not cache due to entry state or properties |
261 | } | |
262 | ||
263 | assert(e.mem_obj); | |
264 | const int64_t loadedSize = e.mem_obj->endOffset(); | |
265 | const int64_t expectedSize = e.mem_obj->expectedReplySize(); // may be < 0 | |
266 | const int64_t ramSize = max(loadedSize, expectedSize); | |
267 | ||
268 | if (ramSize > static_cast<int64_t>(Config.Store.maxInMemObjSize)) { | |
269 | debugs(20, 5, HERE << "Too big max(" << | |
270 | loadedSize << ", " << expectedSize << "): " << e); | |
271 | return false; // will not cache due to cachable entry size limits | |
272 | } | |
273 | ||
274 | if (!willFit(ramSize)) { | |
275 | debugs(20, 5, HERE << "Wont fit max(" << | |
276 | loadedSize << ", " << expectedSize << "): " << e); | |
277 | return false; // will not cache due to memory cache slot limit | |
9487bae9 AR |
278 | } |
279 | ||
96a7de88 DK |
280 | return true; |
281 | } | |
282 | ||
283 | void | |
284 | MemStore::considerKeeping(StoreEntry &e) | |
285 | { | |
286 | if (!keepInLocalMemory(e)) | |
287 | return; | |
288 | ||
449ca8c5 AR |
289 | // since we copy everything at once, we can only keep complete entries |
290 | if (e.store_status != STORE_OK) { | |
291 | debugs(20, 7, HERE << "Incomplete: " << e); | |
292 | return; | |
293 | } | |
294 | ||
9487bae9 | 295 | assert(e.mem_obj); |
449ca8c5 AR |
296 | |
297 | const int64_t loadedSize = e.mem_obj->endOffset(); | |
298 | const int64_t expectedSize = e.mem_obj->expectedReplySize(); | |
299 | ||
96a7de88 DK |
300 | // objects of unknown size are not allowed into memory cache, for now |
301 | if (expectedSize < 0) { | |
302 | debugs(20, 5, HERE << "Unknown expected size: " << e); | |
303 | return; | |
304 | } | |
305 | ||
449ca8c5 AR |
306 | // since we copy everything at once, we can only keep fully loaded entries |
307 | if (loadedSize != expectedSize) { | |
308 | debugs(20, 7, HERE << "partially loaded: " << loadedSize << " != " << | |
309 | expectedSize); | |
310 | return; | |
311 | } | |
312 | ||
9487bae9 AR |
313 | keep(e); // may still fail |
314 | } | |
315 | ||
316 | bool | |
96a7de88 | 317 | MemStore::willFit(int64_t need) const |
9487bae9 | 318 | { |
30204d23 | 319 | return need <= static_cast<int64_t>(Ipc::Mem::PageSize()); |
9487bae9 AR |
320 | } |
321 | ||
322 | /// allocates map slot and calls copyToShm to store the entry in shared memory | |
323 | void | |
324 | MemStore::keep(StoreEntry &e) | |
325 | { | |
326 | if (!map) { | |
327 | debugs(20, 5, HERE << "No map to mem-cache " << e); | |
328 | return; | |
329 | } | |
330 | ||
331 | sfileno index = 0; | |
332 | Ipc::StoreMapSlot *slot = map->openForWriting(reinterpret_cast<const cache_key *>(e.key), index); | |
333 | if (!slot) { | |
334 | debugs(20, 5, HERE << "No room in mem-cache map to index " << e); | |
335 | return; | |
336 | } | |
337 | ||
338 | MemStoreMap::Extras &extras = map->extras(index); | |
339 | if (copyToShm(e, extras)) { | |
340 | slot->set(e); | |
341 | map->closeForWriting(index, false); | |
342 | } else { | |
343 | map->abortIo(index); | |
344 | } | |
345 | } | |
346 | ||
347 | /// uses mem_hdr::copy() to copy local data to shared memory | |
348 | bool | |
349 | MemStore::copyToShm(StoreEntry &e, MemStoreMap::Extras &extras) | |
350 | { | |
351 | Ipc::Mem::PageId page; | |
551f8a18 | 352 | if (!Ipc::Mem::GetPage(Ipc::Mem::PageId::cachePage, page)) { |
9487bae9 AR |
353 | debugs(20, 5, HERE << "No mem-cache page for " << e); |
354 | return false; // GetPage is responsible for any cleanup on failures | |
355 | } | |
356 | ||
357 | const int64_t bufSize = Ipc::Mem::PageSize(); | |
358 | const int64_t eSize = e.mem_obj->endOffset(); | |
359 | ||
360 | StoreIOBuffer sharedSpace(bufSize, 0, | |
361 | static_cast<char*>(PagePointer(page))); | |
9199139f | 362 | |
9487bae9 AR |
363 | // check that we kept everything or purge incomplete/sparse cached entry |
364 | const ssize_t copied = e.mem_obj->data_hdr.copy(sharedSpace); | |
365 | if (eSize != copied) { | |
366 | debugs(20, 2, HERE << "Failed to mem-cache " << e << ": " << | |
367 | eSize << "!=" << copied); | |
368 | // cleanup | |
369 | PutPage(page); | |
370 | return false; | |
371 | } | |
372 | ||
373 | debugs(20, 7, HERE << "mem-cached all " << eSize << " bytes of " << e << | |
374 | " in " << page); | |
375 | ||
17cf0a47 | 376 | theCurrentSize += Ipc::Mem::PageSize(); |
9487bae9 AR |
377 | // remember storage location and size |
378 | extras.page = page; | |
379 | extras.storedSize = copied; | |
380 | return true; | |
381 | } | |
7f6748c8 AR |
382 | |
383 | void | |
384 | MemStore::cleanReadable(const sfileno fileno) | |
385 | { | |
386 | Ipc::Mem::PutPage(map->extras(fileno).page); | |
17cf0a47 | 387 | theCurrentSize -= Ipc::Mem::PageSize(); |
7f6748c8 AR |
388 | } |
389 | ||
a4555399 AR |
390 | /// calculates maximum number of entries we need to store and map |
391 | int64_t | |
392 | MemStore::EntryLimit() | |
393 | { | |
45e8762c | 394 | if (!Config.memShared || !Config.memMaxSize) |
a4555399 AR |
395 | return 0; // no memory cache configured |
396 | ||
a4555399 AR |
397 | const int64_t entrySize = Ipc::Mem::PageSize(); // for now |
398 | const int64_t entryLimit = Config.memMaxSize / entrySize; | |
a4555399 AR |
399 | return entryLimit; |
400 | } | |
401 | ||
ea2cdeb6 DK |
402 | /// reports our needs for shared memory pages to Ipc::Mem::Pages |
403 | class MemStoreClaimMemoryNeedsRr: public RegisteredRunner | |
404 | { | |
405 | public: | |
406 | /* RegisteredRunner API */ | |
407 | virtual void run(const RunnerRegistry &r); | |
408 | }; | |
409 | ||
410 | RunnerRegistrationEntry(rrClaimMemoryNeeds, MemStoreClaimMemoryNeedsRr); | |
411 | ||
ea2cdeb6 DK |
412 | void |
413 | MemStoreClaimMemoryNeedsRr::run(const RunnerRegistry &) | |
414 | { | |
415 | Ipc::Mem::NotePageNeed(Ipc::Mem::PageId::cachePage, MemStore::EntryLimit()); | |
416 | } | |
417 | ||
45e8762c AR |
418 | /// decides whether to use a shared memory cache or checks its configuration |
419 | class MemStoreCfgRr: public ::RegisteredRunner | |
a4555399 AR |
420 | { |
421 | public: | |
422 | /* RegisteredRunner API */ | |
423 | virtual void run(const RunnerRegistry &); | |
a4555399 AR |
424 | }; |
425 | ||
45e8762c | 426 | RunnerRegistrationEntry(rrFinalizeConfig, MemStoreCfgRr); |
a4555399 | 427 | |
45e8762c | 428 | void MemStoreCfgRr::run(const RunnerRegistry &r) |
a4555399 | 429 | { |
57af1e3f AR |
430 | // decide whether to use a shared memory cache if the user did not specify |
431 | if (!Config.memShared.configured()) { | |
794d4c0c | 432 | Config.memShared.configure(Ipc::Atomic::Enabled() && |
9199139f AR |
433 | Ipc::Mem::Segment::Enabled() && UsingSmp() && |
434 | Config.memMaxSize > 0); | |
794d4c0c | 435 | } else if (Config.memShared && !Ipc::Atomic::Enabled()) { |
65b81b27 AR |
436 | // bail if the user wants shared memory cache but we cannot support it |
437 | fatal("memory_cache_shared is on, but no support for atomic operations detected"); | |
9199139f | 438 | } else if (Config.memShared && !Ipc::Mem::Segment::Enabled()) { |
c975f532 | 439 | fatal("memory_cache_shared is on, but no support for shared memory detected"); |
53bbccec DK |
440 | } else if (Config.memShared && !UsingSmp()) { |
441 | debugs(20, DBG_IMPORTANT, "WARNING: memory_cache_shared is on, but only" | |
442 | " a single worker is running"); | |
57af1e3f | 443 | } |
45e8762c AR |
444 | } |
445 | ||
45e8762c AR |
446 | /// initializes shared memory segments used by MemStore |
447 | class MemStoreRr: public Ipc::Mem::RegisteredRunner | |
448 | { | |
449 | public: | |
450 | /* RegisteredRunner API */ | |
451 | MemStoreRr(): owner(NULL) {} | |
452 | virtual void run(const RunnerRegistry &); | |
453 | virtual ~MemStoreRr(); | |
454 | ||
455 | protected: | |
456 | virtual void create(const RunnerRegistry &); | |
57af1e3f | 457 | |
45e8762c AR |
458 | private: |
459 | MemStoreMap::Owner *owner; | |
460 | }; | |
461 | ||
462 | RunnerRegistrationEntry(rrAfterConfig, MemStoreRr); | |
463 | ||
45e8762c AR |
464 | void MemStoreRr::run(const RunnerRegistry &r) |
465 | { | |
466 | assert(Config.memShared.configured()); | |
4404f1c5 DK |
467 | Ipc::Mem::RegisteredRunner::run(r); |
468 | } | |
469 | ||
470 | void MemStoreRr::create(const RunnerRegistry &) | |
471 | { | |
57af1e3f | 472 | if (!Config.memShared) |
60be8b2d | 473 | return; |
a4555399 | 474 | |
4404f1c5 DK |
475 | Must(!owner); |
476 | const int64_t entryLimit = MemStore::EntryLimit(); | |
ea2cdeb6 DK |
477 | if (entryLimit <= 0) { |
478 | if (Config.memMaxSize > 0) { | |
479 | debugs(20, DBG_IMPORTANT, "WARNING: mem-cache size is too small (" | |
480 | << (Config.memMaxSize / 1024.0) << " KB), should be >= " << | |
481 | (Ipc::Mem::PageSize() / 1024.0) << " KB"); | |
482 | } | |
4404f1c5 | 483 | return; // no memory cache configured or a misconfiguration |
ea2cdeb6 | 484 | } |
4404f1c5 | 485 | owner = MemStoreMap::Init(ShmLabel, entryLimit); |
a4555399 | 486 | } |
c011f9bc DK |
487 | |
488 | MemStoreRr::~MemStoreRr() | |
489 | { | |
68353d5a | 490 | delete owner; |
c011f9bc | 491 | } |