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df92bd2a | 1 | |
30a4f2a8 | 2 | /* |
6f6f0853 | 3 | * DEBUG: section 19 Store Memory Primitives |
30a4f2a8 | 4 | * AUTHOR: Harvest Derived |
5 | * | |
2b6662ba | 6 | * SQUID Web Proxy Cache http://www.squid-cache.org/ |
e25c139f | 7 | * ---------------------------------------------------------- |
30a4f2a8 | 8 | * |
2b6662ba | 9 | * Squid is the result of efforts by numerous individuals from |
10 | * the Internet community; see the CONTRIBUTORS file for full | |
11 | * details. Many organizations have provided support for Squid's | |
12 | * development; see the SPONSORS file for full details. Squid is | |
13 | * Copyrighted (C) 2001 by the Regents of the University of | |
14 | * California; see the COPYRIGHT file for full details. Squid | |
15 | * incorporates software developed and/or copyrighted by other | |
16 | * sources; see the CREDITS file for full details. | |
30a4f2a8 | 17 | * |
18 | * This program is free software; you can redistribute it and/or modify | |
19 | * it under the terms of the GNU General Public License as published by | |
20 | * the Free Software Foundation; either version 2 of the License, or | |
21 | * (at your option) any later version. | |
26ac0430 | 22 | * |
30a4f2a8 | 23 | * This program is distributed in the hope that it will be useful, |
24 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
25 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
26 | * GNU General Public License for more details. | |
26ac0430 | 27 | * |
30a4f2a8 | 28 | * You should have received a copy of the GNU General Public License |
29 | * along with this program; if not, write to the Free Software | |
cbdec147 | 30 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. |
e25c139f | 31 | * |
42a503bd | 32 | * Copyright (c) 2003, Robert Collins <robertc@squid-cache.org> |
019dd986 | 33 | */ |
ed43818f | 34 | |
582c2af2 FC |
35 | #include "squid.h" |
36 | #include "Generic.h" | |
528b2c61 | 37 | #include "mem_node.h" |
38 | #include "MemObject.h" | |
582c2af2 FC |
39 | #include "profiler/Profiler.h" |
40 | #include "stmem.h" | |
528b2c61 | 41 | |
12d74f96 | 42 | /* |
43 | * NodeGet() is called to get the data buffer to pass to storeIOWrite(). | |
44 | * By setting the write_pending flag here we are assuming that there | |
45 | * will be no other users of NodeGet(). The storeIOWrite() callback | |
46 | * is memNodeWriteComplete(), which, for whatever reason, lives in | |
47 | * mem_node.cc. | |
48 | */ | |
d06925a4 | 49 | char * |
50 | mem_hdr::NodeGet(mem_node * aNode) | |
51 | { | |
12d74f96 | 52 | assert(!aNode->write_pending); |
3dd52a0b | 53 | aNode->write_pending = true; |
d06925a4 | 54 | return aNode->data; |
55 | } | |
56 | ||
47f6e231 | 57 | int64_t |
528b2c61 | 58 | mem_hdr::lowestOffset () const |
59 | { | |
42a503bd | 60 | const SplayNode<mem_node *> *theStart = nodes.start(); |
61 | ||
62 | if (theStart) | |
63 | return theStart->data->nodeBuffer.offset; | |
62e76326 | 64 | |
528b2c61 | 65 | return 0; |
66 | } | |
67 | ||
47f6e231 | 68 | int64_t |
528b2c61 | 69 | mem_hdr::endOffset () const |
70 | { | |
47f6e231 | 71 | int64_t result = 0; |
b8bad68c | 72 | const SplayNode<mem_node *> *theEnd = nodes.finish(); |
62e76326 | 73 | |
42a503bd | 74 | if (theEnd) |
75 | result = theEnd->data->dataRange().end; | |
62e76326 | 76 | |
528b2c61 | 77 | assert (result == inmem_hi); |
62e76326 | 78 | |
528b2c61 | 79 | return result; |
80 | } | |
090089c4 | 81 | |
d89d1fb6 | 82 | void |
528b2c61 | 83 | mem_hdr::freeContent() |
84 | { | |
42a503bd | 85 | nodes.destroy(SplayNode<mem_node *>::DefaultFree); |
528b2c61 | 86 | inmem_hi = 0; |
e2851fe7 | 87 | debugs(19, 9, HERE << this << " hi: " << inmem_hi); |
528b2c61 | 88 | } |
89 | ||
12d74f96 | 90 | bool |
42a503bd | 91 | mem_hdr::unlink(mem_node *aNode) |
528b2c61 | 92 | { |
12d74f96 | 93 | if (aNode->write_pending) { |
fa84c01d | 94 | debugs(0, DBG_CRITICAL, "cannot unlink mem_node " << aNode << " while write_pending"); |
12d74f96 | 95 | return false; |
96 | } | |
d06925a4 | 97 | |
12d74f96 | 98 | nodes.remove (aNode, NodeCompare); |
99 | delete aNode; | |
100 | return true; | |
090089c4 | 101 | } |
102 | ||
47f6e231 | 103 | int64_t |
104 | mem_hdr::freeDataUpto(int64_t target_offset) | |
528b2c61 | 105 | { |
106 | /* keep the last one to avoid change to other part of code */ | |
810635e3 | 107 | SplayNode<mem_node*> const * theStart; |
42a503bd | 108 | |
12d74f96 | 109 | while ((theStart = nodes.start())) { |
110 | if (theStart == nodes.finish()) | |
111 | break; | |
112 | ||
47f6e231 | 113 | if (theStart->data->end() > target_offset ) |
12d74f96 | 114 | break; |
115 | ||
116 | if (!unlink(theStart->data)) | |
117 | break; | |
42a503bd | 118 | } |
62e76326 | 119 | |
528b2c61 | 120 | assert (lowestOffset () <= target_offset); |
62e76326 | 121 | |
528b2c61 | 122 | return lowestOffset (); |
123 | } | |
124 | ||
62e76326 | 125 | int |
528b2c61 | 126 | mem_hdr::appendToNode(mem_node *aNode, const char *data, int maxLength) |
127 | { | |
128 | size_t result = writeAvailable (aNode, aNode->nodeBuffer.offset + aNode->nodeBuffer.length ,maxLength, data); | |
129 | return result; | |
130 | } | |
131 | ||
132 | size_t | |
47f6e231 | 133 | mem_hdr::writeAvailable(mem_node *aNode, int64_t location, size_t amount, char const *source) |
528b2c61 | 134 | { |
135 | /* if we attempt to overwrite existing data or leave a gap within a node */ | |
ed013b6c | 136 | assert (location == aNode->nodeBuffer.offset + (int64_t)aNode->nodeBuffer.length); |
528b2c61 | 137 | /* And we are not at the end of the node */ |
138 | assert (aNode->canAccept (location)); | |
62e76326 | 139 | |
528b2c61 | 140 | /* these two can go I think */ |
ed013b6c | 141 | assert (location - aNode->nodeBuffer.offset == (int64_t)aNode->nodeBuffer.length); |
d85c3078 | 142 | size_t copyLen = min(amount, aNode->space()); |
528b2c61 | 143 | |
41d00cd3 | 144 | memcpy(aNode->nodeBuffer.data + aNode->nodeBuffer.length, source, copyLen); |
528b2c61 | 145 | |
e2851fe7 | 146 | debugs(19, 9, HERE << this << " hi: " << inmem_hi); |
47f6e231 | 147 | if (inmem_hi <= location) |
62e76326 | 148 | inmem_hi = location + copyLen; |
149 | ||
528b2c61 | 150 | /* Adjust the ptr and len according to what was deposited in the page */ |
151 | aNode->nodeBuffer.length += copyLen; | |
62e76326 | 152 | |
e2851fe7 AR |
153 | debugs(19, 9, HERE << this << " hi: " << inmem_hi); |
154 | debugs(19, 9, HERE << this << " hi: " << endOffset()); | |
528b2c61 | 155 | return copyLen; |
156 | } | |
157 | ||
158 | void | |
159 | mem_hdr::appendNode (mem_node *aNode) | |
160 | { | |
42a503bd | 161 | nodes.insert (aNode, NodeCompare); |
090089c4 | 162 | } |
163 | ||
e6e5d90d | 164 | void |
528b2c61 | 165 | mem_hdr::makeAppendSpace() |
166 | { | |
42a503bd | 167 | if (!nodes.size()) { |
168 | appendNode (new mem_node (0)); | |
62e76326 | 169 | return; |
090089c4 | 170 | } |
62e76326 | 171 | |
b8bad68c | 172 | if (!nodes.finish()->data->space()) |
62e76326 | 173 | appendNode (new mem_node (endOffset())); |
174 | ||
b8bad68c | 175 | assert (nodes.finish()->data->space()); |
528b2c61 | 176 | } |
177 | ||
178 | void | |
179 | mem_hdr::internalAppend(const char *data, int len) | |
180 | { | |
e2851fe7 | 181 | debugs(19, 6, "memInternalAppend: " << this << " len " << len); |
62e76326 | 182 | |
090089c4 | 183 | while (len > 0) { |
62e76326 | 184 | makeAppendSpace(); |
b8bad68c | 185 | int copied = appendToNode (nodes.finish()->data, data, len); |
62e76326 | 186 | assert (copied); |
187 | ||
188 | len -= copied; | |
189 | data += copied; | |
090089c4 | 190 | } |
090089c4 | 191 | } |
192 | ||
528b2c61 | 193 | /* returns a mem_node that contains location.. |
194 | * If no node contains the start, it returns NULL. | |
195 | */ | |
196 | mem_node * | |
47f6e231 | 197 | mem_hdr::getBlockContainingLocation (int64_t location) const |
528b2c61 | 198 | { |
a5c1e941 | 199 | // Optimize: do not create a whole mem_node just to store location |
42a503bd | 200 | mem_node target (location); |
201 | target.nodeBuffer.length = 1; | |
202 | mem_node *const *result = nodes.find (&target, NodeCompare); | |
62e76326 | 203 | |
42a503bd | 204 | if (result) |
205 | return *result; | |
62e76326 | 206 | |
42a503bd | 207 | return NULL; |
528b2c61 | 208 | } |
209 | ||
210 | size_t | |
47f6e231 | 211 | mem_hdr::copyAvailable(mem_node *aNode, int64_t location, size_t amount, char *target) const |
528b2c61 | 212 | { |
47f6e231 | 213 | if (aNode->nodeBuffer.offset > location) |
62e76326 | 214 | return 0; |
215 | ||
47f6e231 | 216 | assert (aNode->nodeBuffer.offset <= location); |
62e76326 | 217 | |
528b2c61 | 218 | assert (aNode->end() > location); |
62e76326 | 219 | |
528b2c61 | 220 | size_t copyOffset = location - aNode->nodeBuffer.offset; |
62e76326 | 221 | |
d85c3078 | 222 | size_t copyLen = min(amount, aNode->nodeBuffer.length - copyOffset); |
528b2c61 | 223 | |
41d00cd3 | 224 | memcpy(target, aNode->nodeBuffer.data + copyOffset, copyLen); |
62e76326 | 225 | |
528b2c61 | 226 | return copyLen; |
227 | } | |
228 | ||
b8bad68c | 229 | void |
230 | mem_hdr::debugDump() const | |
231 | { | |
db7778f1 | 232 | debugs (19, 0, "mem_hdr::debugDump: lowest offset: " << lowestOffset() << " highest offset + 1: " << endOffset() << "."); |
b8bad68c | 233 | std::ostringstream result; |
234 | PointerPrinter<mem_node *> foo(result, " - "); | |
235 | for_each (getNodes().begin(), getNodes().end(), foo); | |
db7778f1 | 236 | debugs (19, 0, "mem_hdr::debugDump: Current available data is: " << result.str() << "."); |
b8bad68c | 237 | } |
238 | ||
62e76326 | 239 | /* FIXME: how do we deal with sparse results - |
528b2c61 | 240 | * where we have (say) |
26ac0430 | 241 | * 0-500 and 1000-1500, but are asked for |
528b2c61 | 242 | * 0-2000 |
243 | * Partial answer: | |
244 | * we supply 0-500 and stop. | |
245 | */ | |
02be0294 | 246 | ssize_t |
90703668 | 247 | mem_hdr::copy(StoreIOBuffer const &target) const |
090089c4 | 248 | { |
528b2c61 | 249 | |
47f6e231 | 250 | assert(target.range().end > target.range().start); |
e2851fe7 | 251 | debugs(19, 6, "memCopy: " << this << " " << target.range()); |
62e76326 | 252 | |
b8bad68c | 253 | /* we shouldn't ever ask for absent offsets */ |
254 | ||
42a503bd | 255 | if (nodes.size() == 0) { |
e0236918 | 256 | debugs(19, DBG_IMPORTANT, "mem_hdr::copy: No data to read"); |
b8bad68c | 257 | debugDump(); |
42a503bd | 258 | assert (0); |
62e76326 | 259 | return 0; |
42a503bd | 260 | } |
62e76326 | 261 | |
528b2c61 | 262 | /* RC: the next assert is nearly useless */ |
90703668 | 263 | assert(target.length > 0); |
528b2c61 | 264 | |
090089c4 | 265 | /* Seek our way into store */ |
47f6e231 | 266 | mem_node *p = getBlockContainingLocation(target.offset); |
62e76326 | 267 | |
528b2c61 | 268 | if (!p) { |
e0236918 | 269 | debugs(19, DBG_IMPORTANT, "memCopy: could not find start of " << target.range() << |
e4049756 | 270 | " in memory."); |
b8bad68c | 271 | debugDump(); |
14e9491b | 272 | fatal("Squid has attempted to read data from memory that is not present. This is an indication of of (pre-3.0) code that hasn't been updated to deal with sparse objects in memory. Squid should coredump.allowing to review the cause. Immediately preceding this message is a dump of the available data in the format [start,end). The [ means from the value, the ) means up to the value. I.e. [1,5) means that there are 4 bytes of data, at offsets 1,2,3,4.\n"); |
62e76326 | 273 | return 0; |
090089c4 | 274 | } |
62e76326 | 275 | |
90703668 | 276 | size_t bytes_to_go = target.length; |
277 | char *ptr_to_buf = target.data; | |
47f6e231 | 278 | int64_t location = target.offset; |
62e76326 | 279 | |
090089c4 | 280 | /* Start copying begining with this block until |
281 | * we're satiated */ | |
528b2c61 | 282 | |
090089c4 | 283 | while (p && bytes_to_go > 0) { |
62e76326 | 284 | size_t bytes_to_copy = copyAvailable (p, |
285 | location, bytes_to_go, ptr_to_buf); | |
286 | ||
287 | /* hit a sparse patch */ | |
288 | ||
289 | if (bytes_to_copy == 0) | |
90703668 | 290 | return target.length - bytes_to_go; |
62e76326 | 291 | |
292 | location += bytes_to_copy; | |
293 | ||
294 | ptr_to_buf += bytes_to_copy; | |
295 | ||
296 | bytes_to_go -= bytes_to_copy; | |
297 | ||
42a503bd | 298 | p = getBlockContainingLocation(location); |
090089c4 | 299 | } |
62e76326 | 300 | |
90703668 | 301 | return target.length - bytes_to_go; |
090089c4 | 302 | } |
528b2c61 | 303 | |
304 | bool | |
47f6e231 | 305 | mem_hdr::hasContigousContentRange(Range<int64_t> const & range) const |
528b2c61 | 306 | { |
47f6e231 | 307 | int64_t currentStart = range.start; |
62e76326 | 308 | |
528b2c61 | 309 | while (mem_node *curr = getBlockContainingLocation(currentStart)) { |
62e76326 | 310 | currentStart = curr->end(); |
311 | ||
4c50505b | 312 | if (currentStart >= range.end) |
62e76326 | 313 | return true; |
528b2c61 | 314 | } |
62e76326 | 315 | |
9cc44692 | 316 | return !range.size(); // empty range is contigous |
528b2c61 | 317 | } |
318 | ||
319 | bool | |
320 | mem_hdr::unionNotEmpty(StoreIOBuffer const &candidate) | |
321 | { | |
528b2c61 | 322 | assert (candidate.offset >= 0); |
42a503bd | 323 | mem_node target(candidate.offset); |
324 | target.nodeBuffer.length = candidate.length; | |
325 | return nodes.find (&target, NodeCompare); | |
528b2c61 | 326 | } |
327 | ||
328 | mem_node * | |
47f6e231 | 329 | mem_hdr::nodeToRecieve(int64_t offset) |
528b2c61 | 330 | { |
331 | /* case 1: Nothing in memory */ | |
62e76326 | 332 | |
42a503bd | 333 | if (!nodes.size()) { |
62e76326 | 334 | appendNode (new mem_node(offset)); |
42a503bd | 335 | return nodes.start()->data; |
528b2c61 | 336 | } |
337 | ||
42a503bd | 338 | mem_node *candidate = NULL; |
528b2c61 | 339 | /* case 2: location fits within an extant node */ |
62e76326 | 340 | |
42a503bd | 341 | if (offset > 0) { |
342 | mem_node search (offset - 1); | |
343 | search.nodeBuffer.length = 1; | |
344 | mem_node *const *leadup = nodes.find (&search, NodeCompare); | |
345 | ||
346 | if (leadup) | |
347 | candidate = *leadup; | |
528b2c61 | 348 | } |
349 | ||
42a503bd | 350 | if (candidate && candidate->canAccept(offset)) |
62e76326 | 351 | return candidate; |
528b2c61 | 352 | |
353 | /* candidate can't accept, so we need a new node */ | |
354 | candidate = new mem_node(offset); | |
62e76326 | 355 | |
528b2c61 | 356 | appendNode (candidate); |
62e76326 | 357 | |
528b2c61 | 358 | /* simpler to write than a indented if */ |
359 | return candidate; | |
360 | } | |
361 | ||
528b2c61 | 362 | bool |
363 | mem_hdr::write (StoreIOBuffer const &writeBuffer) | |
364 | { | |
1d5161bd | 365 | PROF_start(mem_hdr_write); |
e2851fe7 | 366 | debugs(19, 6, "mem_hdr::write: " << this << " " << writeBuffer.range() << " object end " << endOffset()); |
528b2c61 | 367 | |
368 | if (unionNotEmpty(writeBuffer)) { | |
fa84c01d | 369 | debugs(19, DBG_CRITICAL, "mem_hdr::write: writeBuffer: " << writeBuffer.range()); |
db7778f1 | 370 | debugDump(); |
371 | fatal("Attempt to overwrite already in-memory data. Preceeding this there should be a mem_hdr::write output that lists the attempted write, and the currently present data. Please get a 'backtrace full' from this error - using the generated core, and file a bug report with the squid developers including the last 10 lines of cache.log and the backtrace.\n"); | |
1d5161bd | 372 | PROF_stop(mem_hdr_write); |
62e76326 | 373 | return false; |
528b2c61 | 374 | } |
375 | ||
376 | assert (writeBuffer.offset >= 0); | |
377 | ||
378 | mem_node *target; | |
47f6e231 | 379 | int64_t currentOffset = writeBuffer.offset; |
528b2c61 | 380 | char *currentSource = writeBuffer.data; |
381 | size_t len = writeBuffer.length; | |
62e76326 | 382 | |
528b2c61 | 383 | while (len && (target = nodeToRecieve(currentOffset))) { |
62e76326 | 384 | size_t wrote = writeAvailable(target, currentOffset, len, currentSource); |
385 | assert (wrote); | |
386 | len -= wrote; | |
387 | currentOffset += wrote; | |
388 | currentSource += wrote; | |
528b2c61 | 389 | } |
390 | ||
1d5161bd | 391 | PROF_stop(mem_hdr_write); |
528b2c61 | 392 | return true; |
393 | } | |
4c50505b | 394 | |
42a503bd | 395 | mem_hdr::mem_hdr() : inmem_hi(0) |
e2851fe7 AR |
396 | { |
397 | debugs(19, 9, HERE << this << " hi: " << inmem_hi); | |
398 | } | |
4c50505b | 399 | |
400 | mem_hdr::~mem_hdr() | |
401 | { | |
402 | freeContent(); | |
403 | } | |
42a503bd | 404 | |
405 | /* splay of mem nodes: | |
406 | * conditions: | |
407 | * a = b if a.intersection(b).size > 0; | |
408 | * a < b if a < b | |
409 | */ | |
410 | int | |
411 | mem_hdr::NodeCompare(mem_node * const &left, mem_node * const &right) | |
412 | { | |
413 | // possibly Range can help us at some point. | |
414 | ||
415 | if (left->dataRange().intersection(right->dataRange()).size() > 0) | |
416 | return 0; | |
417 | ||
418 | return *left < *right ? -1 : 1; | |
419 | } | |
420 | ||
421 | void | |
422 | mem_hdr::dump() const | |
423 | { | |
e0236918 FC |
424 | debugs(20, DBG_IMPORTANT, "mem_hdr: " << (void *)this << " nodes.start() " << nodes.start()); |
425 | debugs(20, DBG_IMPORTANT, "mem_hdr: " << (void *)this << " nodes.finish() " << nodes.finish()); | |
42a503bd | 426 | } |
427 | ||
428 | size_t | |
429 | mem_hdr::size() const | |
430 | { | |
431 | return nodes.size(); | |
432 | } | |
433 | ||
434 | mem_node const * | |
435 | mem_hdr::start() const | |
436 | { | |
437 | const SplayNode<mem_node *> * result = nodes.start(); | |
438 | ||
439 | if (result) | |
440 | return result->data; | |
441 | ||
442 | return NULL; | |
443 | } | |
b8bad68c | 444 | |
445 | const Splay<mem_node *> & | |
446 | mem_hdr::getNodes() const | |
447 | { | |
448 | return nodes; | |
449 | } |