libdap++ Updated for version 3.8.2
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00001 00002 // -*- mode: c++; c-basic-offset:4 -*- 00003 00004 // This file is part of libdap, A C++ implementation of the OPeNDAP Data 00005 // Access Protocol. 00006 00007 // Copyright (c) 2002,2003 OPeNDAP, Inc. 00008 // Author: James Gallagher <jgallagher@opendap.org> 00009 // 00010 // This library is free software; you can redistribute it and/or 00011 // modify it under the terms of the GNU Lesser General Public 00012 // License as published by the Free Software Foundation; either 00013 // version 2.1 of the License, or (at your option) any later version. 00014 // 00015 // This library is distributed in the hope that it will be useful, 00016 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00017 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00018 // Lesser General Public License for more details. 00019 // 00020 // You should have received a copy of the GNU Lesser General Public 00021 // License along with this library; if not, write to the Free Software 00022 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 00023 // 00024 // You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112. 00025 00026 #include "config.h" 00027 00028 //#define DODS_DEBUG 00029 00030 // TODO: Remove unneeded includes. 00031 00032 #include <pthread.h> 00033 #include <limits.h> 00034 #include <unistd.h> // for stat 00035 #include <sys/types.h> // for stat and mkdir 00036 #include <sys/stat.h> 00037 00038 #include <cstring> 00039 #include <iostream> 00040 #include <sstream> 00041 #include <algorithm> 00042 #include <iterator> 00043 #include <set> 00044 00045 #include "Error.h" 00046 #include "InternalErr.h" 00047 #include "ResponseTooBigErr.h" 00048 #ifndef WIN32 00049 #include "SignalHandler.h" 00050 #endif 00051 #include "HTTPCacheInterruptHandler.h" 00052 #include "HTTPCacheTable.h" 00053 00054 #include "util_mit.h" 00055 #include "debug.h" 00056 00057 #ifdef WIN32 00058 #include <direct.h> 00059 #include <time.h> 00060 #include <fcntl.h> 00061 #define MKDIR(a,b) _mkdir((a)) 00062 #define REMOVE(a) remove((a)) 00063 #define MKSTEMP(a) _open(_mktemp((a)),_O_CREAT,_S_IREAD|_S_IWRITE) 00064 #define DIR_SEPARATOR_CHAR '\\' 00065 #define DIR_SEPARATOR_STR "\\" 00066 #else 00067 #define MKDIR(a,b) mkdir((a), (b)) 00068 #define REMOVE(a) remove((a)) 00069 #define MKSTEMP(a) mkstemp((a)) 00070 #define DIR_SEPARATOR_CHAR '/' 00071 #define DIR_SEPARATOR_STR "/" 00072 #endif 00073 00074 #define CACHE_META ".meta" 00075 #define CACHE_INDEX ".index" 00076 #define CACHE_EMPTY_ETAG "@cache@" 00077 00078 #define NO_LM_EXPIRATION 24*3600 // 24 hours 00079 #define MAX_LM_EXPIRATION 48*3600 // Max expiration from LM 00080 00081 // If using LM to find the expiration then take 10% and no more than 00082 // MAX_LM_EXPIRATION. 00083 #ifndef LM_EXPIRATION 00084 #define LM_EXPIRATION(t) (min((MAX_LM_EXPIRATION), static_cast<int>((t) / 10))) 00085 #endif 00086 00087 const int CACHE_TABLE_SIZE = 1499; 00088 00089 using namespace std; 00090 00091 namespace libdap { 00092 00096 int 00097 get_hash(const string &url) 00098 { 00099 int hash = 0; 00100 00101 for (const char *ptr = url.c_str(); *ptr; ptr++) 00102 hash = (int)((hash * 3 + (*(unsigned char *)ptr)) % CACHE_TABLE_SIZE); 00103 00104 return hash; 00105 } 00106 00107 HTTPCacheTable::HTTPCacheTable(const string &cache_root, int block_size) : 00108 d_cache_root(cache_root), 00109 d_block_size(block_size), 00110 d_current_size(0), 00111 d_new_entries(0) 00112 { 00113 d_cache_index = cache_root + CACHE_INDEX; 00114 00115 d_cache_table = new CacheEntries*[CACHE_TABLE_SIZE]; 00116 00117 // Initialize the cache table. 00118 for (int i = 0; i < CACHE_TABLE_SIZE; ++i) 00119 d_cache_table[i] = 0; 00120 00121 cache_index_read(); 00122 } 00123 00127 static inline void 00128 delete_cache_entry(HTTPCacheTable::CacheEntry *e) 00129 { 00130 DBG2(cerr << "Deleting CacheEntry: " << e << endl); 00131 delete e; 00132 } 00133 00134 HTTPCacheTable::~HTTPCacheTable() { 00135 for (int i = 0; i < CACHE_TABLE_SIZE; ++i) { 00136 HTTPCacheTable::CacheEntries *cp = get_cache_table()[i]; 00137 if (cp) { 00138 // delete each entry 00139 for_each(cp->begin(), cp->end(), delete_cache_entry); 00140 00141 // now delete the vector that held the entries 00142 delete get_cache_table()[i]; 00143 get_cache_table()[i] = 0; 00144 } 00145 } 00146 00147 delete[] d_cache_table; 00148 } 00149 00157 class DeleteExpired : public unary_function<HTTPCacheTable::CacheEntry *&, void> { 00158 time_t d_time; 00159 HTTPCacheTable &d_table; 00160 00161 public: 00162 DeleteExpired(HTTPCacheTable &table, time_t t) : 00163 d_time(t), d_table(table) { 00164 if (!t) 00165 d_time = time(0); // 0 == now 00166 } 00167 00168 void operator()(HTTPCacheTable::CacheEntry *&e) { 00169 if (e && !e->readers && (e->freshness_lifetime 00170 < (e->corrected_initial_age + (d_time - e->response_time)))) { 00171 DBG(cerr << "Deleting expired cache entry: " << e->url << endl); 00172 d_table.remove_cache_entry(e); 00173 delete e; e = 0; 00174 } 00175 } 00176 }; 00177 00178 // @param time base deletes againt this time, defaults to 0 (now) 00179 void HTTPCacheTable::delete_expired_entries(time_t time) { 00180 // Walk through and delete all the expired entries. 00181 for (int cnt = 0; cnt < CACHE_TABLE_SIZE; cnt++) { 00182 HTTPCacheTable::CacheEntries *slot = get_cache_table()[cnt]; 00183 if (slot) { 00184 for_each(slot->begin(), slot->end(), DeleteExpired(*this, time)); 00185 slot->erase(remove(slot->begin(), slot->end(), 00186 static_cast<HTTPCacheTable::CacheEntry *>(0)), slot->end()); 00187 } 00188 } 00189 } 00190 00197 class DeleteByHits : public unary_function<HTTPCacheTable::CacheEntry *&, void> { 00198 HTTPCacheTable &d_table; 00199 int d_hits; 00200 00201 public: 00202 DeleteByHits(HTTPCacheTable &table, int hits) : 00203 d_table(table), d_hits(hits) { 00204 } 00205 00206 void operator()(HTTPCacheTable::CacheEntry *&e) { 00207 if (e && !e->readers && e->hits <= d_hits) { 00208 DBG(cerr << "Deleting cache entry: " << e->url << endl); 00209 d_table.remove_cache_entry(e); 00210 delete e; e = 0; 00211 } 00212 } 00213 }; 00214 00215 void 00216 HTTPCacheTable::delete_by_hits(int hits) { 00217 for (int cnt = 0; cnt < CACHE_TABLE_SIZE; cnt++) { 00218 if (get_cache_table()[cnt]) { 00219 HTTPCacheTable::CacheEntries *slot = get_cache_table()[cnt]; 00220 for_each(slot->begin(), slot->end(), DeleteByHits(*this, hits)); 00221 slot->erase(remove(slot->begin(), slot->end(), 00222 static_cast<HTTPCacheTable::CacheEntry*>(0)), 00223 slot->end()); 00224 00225 } 00226 } 00227 } 00228 00233 class DeleteBySize : public unary_function<HTTPCacheTable::CacheEntry *&, void> { 00234 HTTPCacheTable &d_table; 00235 unsigned int d_size; 00236 00237 public: 00238 DeleteBySize(HTTPCacheTable &table, unsigned int size) : 00239 d_table(table), d_size(size) { 00240 } 00241 00242 void operator()(HTTPCacheTable::CacheEntry *&e) { 00243 if (e && !e->readers && e->size > d_size) { 00244 DBG(cerr << "Deleting cache entry: " << e->url << endl); 00245 d_table.remove_cache_entry(e); 00246 delete e; e = 0; 00247 } 00248 } 00249 }; 00250 00251 void HTTPCacheTable::delete_by_size(unsigned int size) { 00252 for (int cnt = 0; cnt < CACHE_TABLE_SIZE; cnt++) { 00253 if (get_cache_table()[cnt]) { 00254 HTTPCacheTable::CacheEntries *slot = get_cache_table()[cnt]; 00255 for_each(slot->begin(), slot->end(), DeleteBySize(*this, size)); 00256 slot->erase(remove(slot->begin(), slot->end(), 00257 static_cast<HTTPCacheTable::CacheEntry*>(0)), 00258 slot->end()); 00259 00260 } 00261 } 00262 } 00263 00270 00277 bool 00278 HTTPCacheTable::cache_index_delete() 00279 { 00280 d_new_entries = 0; 00281 00282 return (REMOVE(d_cache_index.c_str()) == 0); 00283 } 00284 00293 bool 00294 HTTPCacheTable::cache_index_read() 00295 { 00296 FILE *fp = fopen(d_cache_index.c_str(), "r"); 00297 // If the cache index can't be opened that's OK; start with an empty 00298 // cache. 09/05/02 jhrg 00299 if (!fp) { 00300 return false; 00301 } 00302 00303 char line[1024]; 00304 while (!feof(fp) && fgets(line, 1024, fp)) { 00305 add_entry_to_cache_table(cache_index_parse_line(line)); 00306 DBG2(cerr << line << endl); 00307 } 00308 00309 int res = fclose(fp) ; 00310 if (res) { 00311 DBG(cerr << "HTTPCache::cache_index_read - Failed to close " << (void *)fp << endl); 00312 } 00313 00314 d_new_entries = 0; 00315 00316 return true; 00317 } 00318 00326 HTTPCacheTable::CacheEntry * 00327 HTTPCacheTable::cache_index_parse_line(const char *line) 00328 { 00329 // Read the line and create the cache object 00330 HTTPCacheTable::CacheEntry *entry = new HTTPCacheTable::CacheEntry; 00331 istringstream iss(line); 00332 iss >> entry->url; 00333 iss >> entry->cachename; 00334 00335 iss >> entry->etag; 00336 if (entry->etag == CACHE_EMPTY_ETAG) 00337 entry->etag = ""; 00338 00339 iss >> entry->lm; 00340 iss >> entry->expires; 00341 iss >> entry->size; 00342 iss >> entry->range; // range is not used. 10/02/02 jhrg 00343 00344 iss >> entry->hash; 00345 iss >> entry->hits; 00346 iss >> entry->freshness_lifetime; 00347 iss >> entry->response_time; 00348 iss >> entry->corrected_initial_age; 00349 00350 iss >> entry->must_revalidate; 00351 00352 return entry; 00353 } 00354 00357 class WriteOneCacheEntry : 00358 public unary_function<HTTPCacheTable::CacheEntry *, void> 00359 { 00360 00361 FILE *d_fp; 00362 00363 public: 00364 WriteOneCacheEntry(FILE *fp) : d_fp(fp) 00365 {} 00366 00367 void operator()(HTTPCacheTable::CacheEntry *e) 00368 { 00369 if (e && fprintf(d_fp, 00370 "%s %s %s %ld %ld %ld %c %d %d %ld %ld %ld %c\r\n", 00371 e->url.c_str(), 00372 e->cachename.c_str(), 00373 e->etag == "" ? CACHE_EMPTY_ETAG : e->etag.c_str(), 00374 (long)(e->lm), 00375 (long)(e->expires), 00376 e->size, 00377 e->range ? '1' : '0', // not used. 10/02/02 jhrg 00378 e->hash, 00379 e->hits, 00380 (long)(e->freshness_lifetime), 00381 (long)(e->response_time), 00382 (long)(e->corrected_initial_age), 00383 e->must_revalidate ? '1' : '0') < 0) 00384 throw Error("Cache Index. Error writing cache index\n"); 00385 } 00386 }; 00387 00397 void 00398 HTTPCacheTable::cache_index_write() 00399 { 00400 DBG(cerr << "Cache Index. Writing index " << d_cache_index << endl); 00401 00402 // Open the file for writing. 00403 FILE * fp = NULL; 00404 if ((fp = fopen(d_cache_index.c_str(), "wb")) == NULL) { 00405 throw Error(string("Cache Index. Can't open `") + d_cache_index 00406 + string("' for writing")); 00407 } 00408 00409 // Walk through the list and write it out. The format is really 00410 // simple as we keep it all in ASCII. 00411 00412 for (int cnt = 0; cnt < CACHE_TABLE_SIZE; cnt++) { 00413 HTTPCacheTable::CacheEntries *cp = get_cache_table()[cnt]; 00414 if (cp) 00415 for_each(cp->begin(), cp->end(), WriteOneCacheEntry(fp)); 00416 } 00417 00418 /* Done writing */ 00419 int res = fclose(fp); 00420 if (res) { 00421 DBG(cerr << "HTTPCache::cache_index_write - Failed to close " 00422 << (void *)fp << endl); 00423 } 00424 00425 d_new_entries = 0; 00426 } 00427 00429 00442 string 00443 HTTPCacheTable::create_hash_directory(int hash) 00444 { 00445 struct stat stat_info; 00446 ostringstream path; 00447 00448 path << d_cache_root << hash; 00449 string p = path.str(); 00450 00451 if (stat(p.c_str(), &stat_info) == -1) { 00452 DBG2(cerr << "Cache....... Create dir " << p << endl); 00453 if (MKDIR(p.c_str(), 0777) < 0) { 00454 DBG2(cerr << "Cache....... Can't create..." << endl); 00455 throw Error("Could not create cache slot to hold response! Check the write permissions on your disk cache directory. Cache root: " + d_cache_root + "."); 00456 } 00457 } 00458 else { 00459 DBG2(cerr << "Cache....... Directory " << p << " already exists" 00460 << endl); 00461 } 00462 00463 return p; 00464 } 00465 00480 void 00481 HTTPCacheTable::create_location(HTTPCacheTable::CacheEntry *entry) 00482 { 00483 string hash_dir = create_hash_directory(entry->hash); 00484 #ifdef WIN32 00485 hash_dir += "\\dodsXXXXXX"; 00486 #else 00487 hash_dir += "/dodsXXXXXX"; // mkstemp uses six characters. 00488 #endif 00489 00490 // mkstemp uses the storage passed to it; must be writable and local. 00491 char *templat = new char[hash_dir.size() + 1]; 00492 strcpy(templat, hash_dir.c_str()); 00493 00494 // Open truncated for update. NB: mkstemp() returns a file descriptor. 00495 // man mkstemp says "... The file is opened with the O_EXCL flag, 00496 // guaranteeing that when mkstemp returns successfully we are the only 00497 // user." 09/19/02 jhrg 00498 int fd = MKSTEMP(templat); // fd mode is 666 or 600 (Unix) 00499 if (fd < 0) { 00500 delete[] templat; templat = 0; 00501 close(fd); 00502 throw Error("The HTTP Cache could not create a file to hold the response; it will not be cached."); 00503 } 00504 00505 entry->cachename = templat; 00506 delete[] templat; templat = 0; 00507 close(fd); 00508 } 00509 00510 00512 static inline int 00513 entry_disk_space(int size, unsigned int block_size) 00514 { 00515 unsigned int num_of_blocks = (size + block_size) / block_size; 00516 00517 DBG(cerr << "size: " << size << ", block_size: " << block_size 00518 << ", num_of_blocks: " << num_of_blocks << endl); 00519 00520 return num_of_blocks * block_size; 00521 } 00522 00526 00532 void 00533 HTTPCacheTable::add_entry_to_cache_table(CacheEntry *entry) 00534 { 00535 int hash = entry->hash; 00536 00537 if (!d_cache_table[hash]) 00538 d_cache_table[hash] = new CacheEntries; 00539 00540 d_cache_table[hash]->push_back(entry); 00541 00542 DBG(cerr << "add_entry_to_cache_table, current_size: " << d_current_size 00543 << ", entry->size: " << entry->size << ", block size: " << d_block_size 00544 << endl); 00545 00546 d_current_size += entry_disk_space(entry->size, d_block_size); 00547 00548 DBG(cerr << "add_entry_to_cache_table, current_size: " << d_current_size << endl); 00549 00550 increment_new_entries(); 00551 } 00552 00556 HTTPCacheTable::CacheEntry * 00557 HTTPCacheTable::get_locked_entry_from_cache_table(const string &url) /*const*/ 00558 { 00559 return get_locked_entry_from_cache_table(get_hash(url), url); 00560 } 00561 00569 HTTPCacheTable::CacheEntry * 00570 HTTPCacheTable::get_locked_entry_from_cache_table(int hash, const string &url) /*const*/ 00571 { 00572 DBG(cerr << "url: " << url << "; hash: " << hash << endl); 00573 DBG(cerr << "d_cache_table: " << hex << d_cache_table << dec << endl); 00574 if (d_cache_table[hash]) { 00575 CacheEntries *cp = d_cache_table[hash]; 00576 for (CacheEntriesIter i = cp->begin(); i != cp->end(); ++i) { 00577 // Must test *i because perform_garbage_collection may have 00578 // removed this entry; the CacheEntry will then be null. 00579 if ((*i) && (*i)->url == url) { 00580 (*i)->lock_read_response(); // Lock the response 00581 return *i; 00582 } 00583 } 00584 } 00585 00586 return 0; 00587 } 00588 00595 HTTPCacheTable::CacheEntry * 00596 HTTPCacheTable::get_write_locked_entry_from_cache_table(const string &url) 00597 { 00598 int hash = get_hash(url); 00599 if (d_cache_table[hash]) { 00600 CacheEntries *cp = d_cache_table[hash]; 00601 for (CacheEntriesIter i = cp->begin(); i != cp->end(); ++i) { 00602 // Must test *i because perform_garbage_collection may have 00603 // removed this entry; the CacheEntry will then be null. 00604 if ((*i) && (*i)->url == url) { 00605 (*i)->lock_write_response(); // Lock the response 00606 return *i; 00607 } 00608 } 00609 } 00610 00611 return 0; 00612 } 00613 00621 void 00622 HTTPCacheTable::remove_cache_entry(HTTPCacheTable::CacheEntry *entry) 00623 { 00624 // This should never happen; all calls to this method are protected by 00625 // the caller, hence the InternalErr. 00626 if (entry->readers) 00627 throw InternalErr(__FILE__, __LINE__, "Tried to delete a cache entry that is in use."); 00628 00629 REMOVE(entry->cachename.c_str()); 00630 REMOVE(string(entry->cachename + CACHE_META).c_str()); 00631 00632 DBG(cerr << "remove_cache_entry, current_size: " << get_current_size() << endl); 00633 00634 unsigned int eds = entry_disk_space(entry->size, get_block_size()); 00635 set_current_size((eds > get_current_size()) ? 0 : get_current_size() - eds); 00636 00637 DBG(cerr << "remove_cache_entry, current_size: " << get_current_size() << endl); 00638 } 00639 00642 class DeleteCacheEntry: public unary_function<HTTPCacheTable::CacheEntry *&, void> 00643 { 00644 string d_url; 00645 HTTPCacheTable *d_cache_table; 00646 00647 public: 00648 DeleteCacheEntry(HTTPCacheTable *c, const string &url) 00649 : d_url(url), d_cache_table(c) 00650 {} 00651 00652 void operator()(HTTPCacheTable::CacheEntry *&e) 00653 { 00654 if (e && e->url == d_url) { 00655 e->lock_write_response(); 00656 d_cache_table->remove_cache_entry(e); 00657 e->unlock_write_response(); 00658 delete e; e = 0; 00659 } 00660 } 00661 }; 00662 00669 void 00670 HTTPCacheTable::remove_entry_from_cache_table(const string &url) 00671 { 00672 int hash = get_hash(url); 00673 if (d_cache_table[hash]) { 00674 CacheEntries *cp = d_cache_table[hash]; 00675 for_each(cp->begin(), cp->end(), DeleteCacheEntry(this, url)); 00676 cp->erase(remove(cp->begin(), cp->end(), static_cast<HTTPCacheTable::CacheEntry*>(0)), 00677 cp->end()); 00678 } 00679 } 00680 00683 class DeleteUnlockedCacheEntry : 00684 public unary_function<HTTPCacheTable::CacheEntry *&, void> { 00685 HTTPCacheTable &d_table; 00686 00687 public: 00688 DeleteUnlockedCacheEntry(HTTPCacheTable &t) : 00689 d_table(t) { 00690 } 00691 void operator()(HTTPCacheTable::CacheEntry *&e) { 00692 if (e) { 00693 d_table.remove_cache_entry(e); 00694 delete e; e = 0; 00695 } 00696 } 00697 }; 00698 00699 void HTTPCacheTable::delete_all_entries() { 00700 // Walk through the cache table and, for every entry in the cache, delete 00701 // it on disk and in the cache table. 00702 for (int cnt = 0; cnt < CACHE_TABLE_SIZE; cnt++) { 00703 HTTPCacheTable::CacheEntries *slot = get_cache_table()[cnt]; 00704 if (slot) { 00705 for_each(slot->begin(), slot->end(), DeleteUnlockedCacheEntry(*this)); 00706 slot->erase(remove(slot->begin(), slot->end(), static_cast<HTTPCacheTable::CacheEntry *>(0)), 00707 slot->end()); 00708 } 00709 } 00710 00711 cache_index_delete(); 00712 } 00713 00727 void 00728 HTTPCacheTable::calculate_time(HTTPCacheTable::CacheEntry *entry, int default_expiration, time_t request_time) 00729 { 00730 entry->response_time = time(NULL); 00731 time_t apparent_age = max(0, static_cast<int>(entry->response_time - entry->date)); 00732 time_t corrected_received_age = max(apparent_age, entry->age); 00733 time_t response_delay = entry->response_time - request_time; 00734 entry->corrected_initial_age = corrected_received_age + response_delay; 00735 00736 // Estimate an expires time using the max-age and expires time. If we 00737 // don't have an explicit expires time then set it to 10% of the LM date 00738 // (although max 24 h). If no LM date is available then use 24 hours. 00739 time_t freshness_lifetime = entry->max_age; 00740 if (freshness_lifetime < 0) { 00741 if (entry->expires < 0) { 00742 if (entry->lm < 0) { 00743 freshness_lifetime = default_expiration; 00744 } 00745 else { 00746 freshness_lifetime = LM_EXPIRATION(entry->date - entry->lm); 00747 } 00748 } 00749 else 00750 freshness_lifetime = entry->expires - entry->date; 00751 } 00752 00753 entry->freshness_lifetime = max(0, static_cast<int>(freshness_lifetime)); 00754 00755 DBG2(cerr << "Cache....... Received Age " << entry->age 00756 << ", corrected " << entry->corrected_initial_age 00757 << ", freshness lifetime " << entry->freshness_lifetime << endl); 00758 } 00759 00771 void HTTPCacheTable::parse_headers(HTTPCacheTable::CacheEntry *entry, 00772 unsigned long max_entry_size, const vector<string> &headers) { 00773 vector<string>::const_iterator i; 00774 for (i = headers.begin(); i != headers.end(); ++i) { 00775 // skip a blank header. 00776 if ((*i).empty()) 00777 continue; 00778 00779 string::size_type colon = (*i).find(':'); 00780 00781 // skip a header with no colon in it. 00782 if (colon == string::npos) 00783 continue; 00784 00785 string header = (*i).substr(0, (*i).find(':')); 00786 string value = (*i).substr((*i).find(": ") + 2); 00787 DBG2(cerr << "Header: " << header << endl);DBG2(cerr << "Value: " << value << endl); 00788 00789 if (header == "ETag") { 00790 entry->etag = value; 00791 } else if (header == "Last-Modified") { 00792 entry->lm = parse_time(value.c_str()); 00793 } else if (header == "Expires") { 00794 entry->expires = parse_time(value.c_str()); 00795 } else if (header == "Date") { 00796 entry->date = parse_time(value.c_str()); 00797 } else if (header == "Age") { 00798 entry->age = parse_time(value.c_str()); 00799 } else if (header == "Content-Length") { 00800 unsigned long clength = strtoul(value.c_str(), 0, 0); 00801 if (clength > max_entry_size) 00802 entry->set_no_cache(true); 00803 } else if (header == "Cache-Control") { 00804 // Ignored Cache-Control values: public, private, no-transform, 00805 // proxy-revalidate, s-max-age. These are used by shared caches. 00806 // See section 14.9 of RFC 2612. 10/02/02 jhrg 00807 if (value == "no-cache" || value == "no-store") 00808 // Note that we *can* store a 'no-store' response in volatile 00809 // memory according to RFC 2616 (section 14.9.2) but those 00810 // will be rare coming from DAP servers. 10/02/02 jhrg 00811 entry->set_no_cache(true); 00812 else if (value == "must-revalidate") 00813 entry->must_revalidate = true; 00814 else if (value.find("max-age") != string::npos) { 00815 string max_age = value.substr(value.find("=" + 1)); 00816 entry->max_age = parse_time(max_age.c_str()); 00817 } 00818 } 00819 } 00820 } 00821 00823 00824 // @TODO Change name to record locked response 00825 void HTTPCacheTable::bind_entry_to_data(HTTPCacheTable::CacheEntry *entry, FILE *body) { 00826 entry->hits++; // Mark hit 00827 d_locked_entries[body] = entry; // record lock, see release_cached_r... 00828 } 00829 00830 void HTTPCacheTable::uncouple_entry_from_data(FILE *body) { 00831 HTTPCacheTable::CacheEntry *entry = d_locked_entries[body]; 00832 if (!entry) 00833 throw InternalErr("There is no cache entry for the response given."); 00834 00835 d_locked_entries.erase(body); 00836 entry->unlock_read_response(); 00837 00838 if (entry->readers < 0) 00839 throw InternalErr("An unlocked entry was released"); 00840 } 00841 00842 bool HTTPCacheTable::is_locked_read_responses() { 00843 return !d_locked_entries.empty(); 00844 } 00845 00846 } // namespace libdap