simple interface to cache open file by extending struct stat_cache_entry
future: should probably create fd cache separate from stat_cache,
perhaps along w/ http-specific fields like etag and content_type
gamin should be used instead of fam; fam is no longer maintained
This patch makes it safe to build lighttpd with gamin, but run on
systems with the (deprecated) fam installed, which can happen due
to historical package dependency declarations on some platforms
(Debian, Ubuntu).
gamin and fam are not 100% binary compatible.
(Among other things, fam does not provide FAMNoExists())
x-ref:
"llibgamin vs libfam conflict solving"
https://salsa.debian.org/debian/lighttpd/-/merge_requests/18
"libgamin0: libfam shlib dependency wrongly set to libfam0"
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=510368
"undefined symbol: FAMNoExists"
https://bugs.launchpad.net/bugs/1453463
auth.cache = ("max-age" => "600")
vhostdb.cache = ("max-age" => "600")
If specified with an empty array, default max-age is 600 secs (10 mins)
auth.cache = ()
vhostdb.cache = ()
(Note: cache expiration occurs every 8 seconds, so maximum cache time
might be up to max-age + 8 seconds)
x-ref:
"mod_auth caching"
https://redmine.lighttpd.net/issues/2805
(expansion of buffer_string_lenth() inline function and CONST_BUF_LEN()
macro, which always check for NULL, appears to cause the analyzer to
believe that a pointer might be NULL in cases where it otherwise can
not be NULL)
x-ref:
http://clang-analyzer.llvm.org/faq.html
NB: r->tmp_buf == srv->tmp_buf (pointer is copied for quicker access)
NB: request read and write chunkqueues currently point to connection
chunkqueues; per-request and per-connection chunkqueues are
not distinct from one another
con->read_queue == r->read_queue
con->write_queue == r->write_queue
NB: in the future, a separate connection config may be needed for
connection-level module hooks. Similarly, might need to have
per-request chunkqueues separate from per-connection chunkqueues.
Should probably also have a request_reset() which is distinct from
connection_reset().
convert all log_error_write() to log_error() and pass (log_error_st *)
use con->errh in preference to srv->errh (even though currently same)
avoid passing (server *) when previously used only for logging (errh)
array_get_element_klen() is now intended for read-only access
array_get_data_unset() is used by config processing for r/w access
array_get_buf_ptr() is used for r/w access to ds->value (string buffer)
specialized buffer_eq_icase_ssn func replace strncasecmp()
in cases where string lengths are known to be at least as
large as the len being compared case-insensitively
improve FAM monitoring to use reference counting in internal cache
revalidate entries upon use after 16 sec to recover from missed events
(see comments in commit for more details about limitations)
do not open file in stat_cache_get_entry()
no longer stat() followed by open() and close() just for stat()
callers should open() file to validate readability (and then reuse fd)
