43#include "InternalErr.h"
44#include "ResponseTooBigErr.h"
46#include "SignalHandler.h"
48#include "HTTPCacheInterruptHandler.h"
49#include "HTTPCacheTable.h"
50#include "HTTPCacheMacros.h"
59#define MKDIR(a,b) _mkdir((a))
60#define REMOVE(a) do { \
61 int s = remove((a)); \
63 throw InternalErr(__FILE__, __LINE__, "Cache error; could not remove file: " + long_to_string(s)); \
65#define MKSTEMP(a) _open(_mktemp((a)),_O_CREAT,_S_IREAD|_S_IWRITE)
66#define DIR_SEPARATOR_CHAR '\\'
67#define DIR_SEPARATOR_STR "\\"
69#define MKDIR(a,b) mkdir((a), (b))
70#define MKSTEMP(a) mkstemp((a))
71#define DIR_SEPARATOR_CHAR '/'
72#define DIR_SEPARATOR_STR "/"
75#define CACHE_META ".meta"
76#define CACHE_INDEX ".index"
77#define CACHE_EMPTY_ETAG "@cache@"
79#define NO_LM_EXPIRATION 24*3600
80#define MAX_LM_EXPIRATION 48*3600
85#define LM_EXPIRATION(t) (min((MAX_LM_EXPIRATION), static_cast<int>((t) / 10)))
88const int CACHE_TABLE_SIZE = 1499;
102 for (
const char *ptr = url.c_str(); *ptr; ptr++)
103 hash = (int)((hash * 3 + (*(
unsigned char *)ptr)) % CACHE_TABLE_SIZE);
108HTTPCacheTable::HTTPCacheTable(
const string &cache_root,
int block_size) :
109 d_cache_root(cache_root), d_block_size(block_size), d_current_size(0), d_new_entries(0)
111 d_cache_index = cache_root + CACHE_INDEX;
113 d_cache_table =
new CacheEntries*[CACHE_TABLE_SIZE];
116 for (
int i = 0; i < CACHE_TABLE_SIZE; ++i)
117 d_cache_table[i] = 0;
126delete_cache_entry(HTTPCacheTable::CacheEntry *e)
128 DBG2(cerr <<
"Deleting CacheEntry: " << e << endl);
132HTTPCacheTable::~HTTPCacheTable()
134 for (
int i = 0; i < CACHE_TABLE_SIZE; ++i) {
135 HTTPCacheTable::CacheEntries *cp = get_cache_table()[i];
138 for_each(cp->begin(), cp->end(), delete_cache_entry);
141 delete get_cache_table()[i];
142 get_cache_table()[i] = 0;
146 delete[] d_cache_table;
156class DeleteExpired :
public unary_function<HTTPCacheTable::CacheEntry *&, void> {
158 HTTPCacheTable &d_table;
161 DeleteExpired(HTTPCacheTable &table, time_t t) :
162 d_time(t), d_table(table) {
167 void operator()(HTTPCacheTable::CacheEntry *&e) {
168 if (e && !e->readers && (e->freshness_lifetime
169 < (e->corrected_initial_age + (d_time - e->response_time)))) {
170 DBG(cerr <<
"Deleting expired cache entry: " << e->url << endl);
171 d_table.remove_cache_entry(e);
178void HTTPCacheTable::delete_expired_entries(time_t time) {
180 for (
int cnt = 0; cnt < CACHE_TABLE_SIZE; cnt++) {
181 HTTPCacheTable::CacheEntries *slot = get_cache_table()[cnt];
183 for_each(slot->begin(), slot->end(), DeleteExpired(*
this, time));
184 slot->erase(remove(slot->begin(), slot->end(),
185 static_cast<HTTPCacheTable::CacheEntry *
>(0)), slot->end());
196class DeleteByHits :
public unary_function<HTTPCacheTable::CacheEntry *&, void> {
197 HTTPCacheTable &d_table;
201 DeleteByHits(HTTPCacheTable &table,
int hits) :
202 d_table(table), d_hits(hits) {
205 void operator()(HTTPCacheTable::CacheEntry *&e) {
206 if (e && !e->readers && e->hits <= d_hits) {
207 DBG(cerr <<
"Deleting cache entry: " << e->url << endl);
208 d_table.remove_cache_entry(e);
215HTTPCacheTable::delete_by_hits(
int hits) {
216 for (
int cnt = 0; cnt < CACHE_TABLE_SIZE; cnt++) {
217 if (get_cache_table()[cnt]) {
218 HTTPCacheTable::CacheEntries *slot = get_cache_table()[cnt];
219 for_each(slot->begin(), slot->end(), DeleteByHits(*
this, hits));
220 slot->erase(remove(slot->begin(), slot->end(),
221 static_cast<HTTPCacheTable::CacheEntry*
>(0)),
232class DeleteBySize :
public unary_function<HTTPCacheTable::CacheEntry *&, void> {
233 HTTPCacheTable &d_table;
237 DeleteBySize(HTTPCacheTable &table,
unsigned int size) :
238 d_table(table), d_size(size) {
241 void operator()(HTTPCacheTable::CacheEntry *&e) {
242 if (e && !e->readers && e->size > d_size) {
243 DBG(cerr <<
"Deleting cache entry: " << e->url << endl);
244 d_table.remove_cache_entry(e);
250void HTTPCacheTable::delete_by_size(
unsigned int size) {
251 for (
int cnt = 0; cnt < CACHE_TABLE_SIZE; cnt++) {
252 if (get_cache_table()[cnt]) {
253 HTTPCacheTable::CacheEntries *slot = get_cache_table()[cnt];
254 for_each(slot->begin(), slot->end(), DeleteBySize(*
this, size));
255 slot->erase(remove(slot->begin(), slot->end(),
256 static_cast<HTTPCacheTable::CacheEntry*
>(0)),
281 return (REMOVE_BOOL(d_cache_index.c_str()) == 0);
295 FILE *fp = fopen(d_cache_index.c_str(),
"r");
303 while (!feof(fp) && fgets(line, 1024, fp)) {
305 DBG2(cerr << line << endl);
308 int res = fclose(fp) ;
310 DBG(cerr <<
"HTTPCache::cache_index_read - Failed to close " << (
void *)fp << endl);
330 istringstream iss(line);
332 iss >> entry->cachename;
335 if (entry->etag == CACHE_EMPTY_ETAG)
339 iss >> entry->expires;
345 iss >> entry->freshness_lifetime;
346 iss >> entry->response_time;
347 iss >> entry->corrected_initial_age;
349 iss >> entry->must_revalidate;
356class WriteOneCacheEntry :
357 public unary_function<HTTPCacheTable::CacheEntry *, void>
363 WriteOneCacheEntry(FILE *fp) : d_fp(fp)
366 void operator()(HTTPCacheTable::CacheEntry *e)
368 if (e && fprintf(d_fp,
369 "%s %s %s %ld %ld %ld %c %d %d %ld %ld %ld %c\r\n",
371 e->cachename.c_str(),
372 e->etag ==
"" ? CACHE_EMPTY_ETAG : e->etag.c_str(),
376 e->range ?
'1' :
'0',
379 (
long)(e->freshness_lifetime),
380 (
long)(e->response_time),
381 (
long)(e->corrected_initial_age),
382 e->must_revalidate ?
'1' :
'0') < 0)
383 throw Error(internal_error,
"Cache Index. Error writing cache index\n");
399 DBG(cerr <<
"Cache Index. Writing index " << d_cache_index << endl);
403 if ((fp = fopen(d_cache_index.c_str(),
"wb")) == NULL) {
404 throw Error(
string(
"Cache Index. Can't open `") + d_cache_index
405 +
string(
"' for writing"));
411 for (
int cnt = 0; cnt < CACHE_TABLE_SIZE; cnt++) {
412 HTTPCacheTable::CacheEntries *cp = get_cache_table()[cnt];
414 for_each(cp->begin(), cp->end(), WriteOneCacheEntry(fp));
418 int res = fclose(fp);
420 DBG(cerr <<
"HTTPCache::cache_index_write - Failed to close "
421 << (
void *)fp << endl);
445 path << d_cache_root << hash;
448 mode_t mask = umask(0);
452 if (mkdir(path.str().c_str(), 0777) < 0 && errno != EEXIST) {
454 throw Error(internal_error,
"Could not create the directory for the cache at '" + path.str() +
"' (" + strerror(errno) +
").");
482 hash_dir +=
"\\dodsXXXXXX";
484 hash_dir +=
"/dodsXXXXXX";
489 vector<char> templat(hash_dir.size() + 1);
490 strncpy(templat.data(), hash_dir.c_str(), hash_dir.size() + 1);
500 int fd = MKSTEMP(templat.data());
504 throw Error(internal_error,
"The HTTP Cache could not create a file to hold the response; it will not be cached.");
507 entry->cachename = templat.data();
515entry_disk_space(
int size,
unsigned int block_size)
517 unsigned int num_of_blocks = (size + block_size) / block_size;
519 DBG(cerr <<
"size: " << size <<
", block_size: " << block_size
520 <<
", num_of_blocks: " << num_of_blocks << endl);
522 return num_of_blocks * block_size;
537 int hash = entry->hash;
538 if (hash > CACHE_TABLE_SIZE-1 || hash < 0)
539 throw InternalErr(__FILE__, __LINE__,
"Hash value too large!");
541 if (!d_cache_table[hash])
542 d_cache_table[hash] =
new CacheEntries;
544 d_cache_table[hash]->push_back(entry);
546 DBG(cerr <<
"add_entry_to_cache_table, current_size: " << d_current_size
547 <<
", entry->size: " << entry->size <<
", block size: " << d_block_size
550 d_current_size += entry_disk_space(entry->size, d_block_size);
552 DBG(cerr <<
"add_entry_to_cache_table, current_size: " << d_current_size << endl);
554 increment_new_entries();
561HTTPCacheTable::get_locked_entry_from_cache_table(
const string &url)
563 return get_locked_entry_from_cache_table(
get_hash(url), url);
574HTTPCacheTable::get_locked_entry_from_cache_table(
int hash,
const string &url)
576 DBG(cerr <<
"url: " << url <<
"; hash: " << hash << endl);
577 DBG(cerr <<
"d_cache_table: " << hex << d_cache_table << dec << endl);
578 if (d_cache_table[hash]) {
579 CacheEntries *cp = d_cache_table[hash];
580 for (CacheEntriesIter i = cp->begin(); i != cp->end(); ++i) {
583 if ((*i) && (*i)->url == url) {
584 (*i)->lock_read_response();
599HTTPCacheTable::CacheEntry *
603 if (d_cache_table[hash]) {
604 CacheEntries *cp = d_cache_table[hash];
605 for (CacheEntriesIter i = cp->begin(); i != cp->end(); ++i) {
608 if ((*i) && (*i)->url == url) {
609 (*i)->lock_write_response();
631 throw InternalErr(__FILE__, __LINE__,
"Tried to delete a cache entry that is in use.");
633 REMOVE(entry->cachename.c_str());
634 REMOVE(
string(entry->cachename + CACHE_META).c_str());
636 DBG(cerr <<
"remove_cache_entry, current_size: " << get_current_size() << endl);
638 unsigned int eds = entry_disk_space(entry->size, get_block_size());
639 set_current_size((eds > get_current_size()) ? 0 : get_current_size() - eds);
641 DBG(cerr <<
"remove_cache_entry, current_size: " << get_current_size() << endl);
646class DeleteCacheEntry:
public unary_function<HTTPCacheTable::CacheEntry *&, void>
653 : d_url(url), d_cache_table(c)
656 void operator()(HTTPCacheTable::CacheEntry *&e)
658 if (e && e->url == d_url) {
659 e->lock_write_response();
661 e->unlock_write_response();
677 if (d_cache_table[hash]) {
678 CacheEntries *cp = d_cache_table[hash];
679 for_each(cp->begin(), cp->end(), DeleteCacheEntry(
this, url));
687class DeleteUnlockedCacheEntry:
public unary_function<HTTPCacheTable::CacheEntry *&, void> {
695 void operator()(HTTPCacheTable::CacheEntry *&e)
705void HTTPCacheTable::delete_all_entries()
709 for (
int cnt = 0; cnt < CACHE_TABLE_SIZE; cnt++) {
710 HTTPCacheTable::CacheEntries *slot = get_cache_table()[cnt];
712 for_each(slot->begin(), slot->end(), DeleteUnlockedCacheEntry(*
this));
713 slot->erase(remove(slot->begin(), slot->end(),
static_cast<HTTPCacheTable::CacheEntry *
> (0)), slot->end());
717 cache_index_delete();
736 entry->response_time = time(NULL);
737 time_t apparent_age = max(0,
static_cast<int>(entry->response_time - entry->date));
738 time_t corrected_received_age = max(apparent_age, entry->age);
739 time_t response_delay = entry->response_time - request_time;
740 entry->corrected_initial_age = corrected_received_age + response_delay;
745 time_t freshness_lifetime = entry->max_age;
746 if (freshness_lifetime < 0) {
747 if (entry->expires < 0) {
749 freshness_lifetime = default_expiration;
752 freshness_lifetime = LM_EXPIRATION(entry->date - entry->lm);
756 freshness_lifetime = entry->expires - entry->date;
759 entry->freshness_lifetime = max(0,
static_cast<int>(freshness_lifetime));
761 DBG2(cerr <<
"Cache....... Received Age " << entry->age
762 <<
", corrected " << entry->corrected_initial_age
763 <<
", freshness lifetime " << entry->freshness_lifetime << endl);
778 const vector<string> &headers)
781 for (i = headers.begin(); i != headers.end(); ++i) {
786 string::size_type colon = (*i).find(
':');
789 if (colon == string::npos)
792 string header = (*i).substr(0, (*i).find(
':'));
793 string value = (*i).substr((*i).find(
": ") + 2);
794 DBG2(cerr <<
"Header: " << header << endl);DBG2(cerr <<
"Value: " << value << endl);
796 if (header ==
"ETag") {
799 else if (header ==
"Last-Modified") {
802 else if (header ==
"Expires") {
805 else if (header ==
"Date") {
808 else if (header ==
"Age") {
811 else if (header ==
"Content-Length") {
812 unsigned long clength = strtoul(value.c_str(), 0, 0);
813 if (clength > max_entry_size)
814 entry->set_no_cache(
true);
816 else if (header ==
"Cache-Control") {
820 if (value ==
"no-cache" || value ==
"no-store")
824 entry->set_no_cache(
true);
825 else if (value ==
"must-revalidate")
826 entry->must_revalidate =
true;
827 else if (value.find(
"max-age") != string::npos) {
828 string max_age = value.substr(value.find(
"=") + 1);
840 d_locked_entries[body] = entry;
843void HTTPCacheTable::uncouple_entry_from_data(FILE *body) {
845 HTTPCacheTable::CacheEntry *entry = d_locked_entries[body];
847 throw InternalErr(
"There is no cache entry for the response given.");
849 d_locked_entries.erase(body);
850 entry->unlock_read_response();
852 if (entry->readers < 0)
853 throw InternalErr(
"An unlocked entry was released");
856bool HTTPCacheTable::is_locked_read_responses() {
857 return !d_locked_entries.empty();
A class for error processing.
void create_location(CacheEntry *entry)
void calculate_time(HTTPCacheTable::CacheEntry *entry, int default_expiration, time_t request_time)
string create_hash_directory(int hash)
bool cache_index_delete()
CacheEntry * cache_index_parse_line(const char *line)
void parse_headers(HTTPCacheTable::CacheEntry *entry, unsigned long max_entry_size, const vector< string > &headers)
CacheEntry * get_write_locked_entry_from_cache_table(const string &url)
void remove_cache_entry(HTTPCacheTable::CacheEntry *entry)
void add_entry_to_cache_table(CacheEntry *entry)
void remove_entry_from_cache_table(const string &url)
A class for software fault reporting.
top level DAP object to house generic methods
int get_hash(const string &url)
time_t parse_time(const char *str, bool expand)