This commit is a large set of code changes and results in removal of
hundreds, perhaps thousands, of CPU instructions, a portion of which
are on hot code paths.
Most (buffer *) used by lighttpd are not NULL, especially since buffers
were inlined into numerous larger structs such as request_st and chunk.
In the small number of instances where that is not the case, a NULL
check is often performed earlier in a function where that buffer is
later used with a buffer_* func. In the handful of cases that remained,
a NULL check was added, e.g. with r->http_host and r->conf.server_tag.
- check for empty strings at config time and set value to NULL if blank
string will be ignored at runtime; at runtime, simple pointer check
for NULL can be used to check for a value that has been set and is not
blank ("")
- use buffer_is_blank() instead of buffer_string_is_empty(),
and use buffer_is_unset() instead of buffer_is_empty(),
where buffer is known not to be NULL so that NULL check can be skipped
- use buffer_clen() instead of buffer_string_length() when buffer is
known not to be NULL (to avoid NULL check at runtime)
- use buffer_truncate() instead of buffer_string_set_length() to
truncate string, and use buffer_extend() to extend
Examples where buffer known not to be NULL:
- cpv->v.b from config_plugin_values_init is not NULL if T_CONFIG_BOOL
(though we might set it to NULL if buffer_is_blank(cpv->v.b))
- address of buffer is arg (&foo)
(compiler optimizer detects this in most, but not all, cases)
- buffer is checked for NULL earlier in func
- buffer is accessed in same scope without a NULL check (e.g. b->ptr)
internal behavior change:
callers must not pass a NULL buffer to some funcs.
- buffer_init_buffer() requires non-null args
- buffer_copy_buffer() requires non-null args
- buffer_append_string_buffer() requires non-null args
- buffer_string_space() requires non-null arg
optimize buffer_* primitives
Other than buffer_string_set_length(), reallocate with one power-2 step
in size (or use the requested size, if larger). This replaces the fixed
BUFFER_PIECE_SIZE round-up of only 64 bytes extension each reallocation,
which could lead to excessive reallocations in some scenarios.
buffer_extend() convenience routine to prep for batch append
(combines buffer_string_prepare_append() and buffer_commit())
mod_fastcgi, mod_scgi, mod_proxy and others now leverage buffer_extend()
mod_scgi directly performs little-endian encoding of short ints
http_response_write_header() optimizes writing response header,
leveraging buffer_extend()
modify mod_proxy to append line ends
similar to how it is done in http_response_write_header()
(removes one call to buffer_append_string_len())
more consistent use of shared code config_plugin_value_tobool()
(thx tow-conf)
x-ref:
"The on/off keywords in boolean configuration options is inconsistent, which might be misleading and error-prone."
https://redmine.lighttpd.net/issues/3036
auth.backend.ldap.timeout = "2000000" # quoted-string; microseconds
vhostdb.ldap += ("timeout" => "2000000") # quoted-string; microseconds
Default is 2000000 microseconds (2 secs)
These values are converted to struct timeval and passed to
ldap_set_option(ld, LDAP_OPT_NETWORK_TIMEOUT, );
ldap_set_option(ld, LDAP_OPT_TIMEOUT, ...);
if those LDAP_OPT_* values are available (both are OpenLDAP-specific).
x-ref:
"mod_auth caching"
https://redmine.lighttpd.net/issues/2805
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)
specialized buffer_eq_icase_ssn func replace strncasecmp()
in cases where string lengths are not known to be at least
as large as the len being compared case-insensitively.
(Separate commit in case any future changes modify the
implementation to be unsafe for shorter strings, where
strncasecmp() would stop at '\0' in either string)
ldap_set_option LDAP_OPT_RESTART to handle EINTR on SIGCHLD from CGI
(ldap uses poll(), which is not restartable with sigaction SA_RESTART)
x-ref:
"mod_authn_ldap/mod_cgi race condition, "Can't contact LDAP server""
https://redmine.lighttpd.net/issues/2940
quickly clear buffer instead of buffer_string_set_length(b, 0) or
buffer_reset(b). Avoids free() of large buffers about to be reused,
or buffers that are module-scoped, persistent, and reused.
(buffer_reset() should still be used with buffers in connection *con
when the data in the buffers is supplied by external, untrusted source)
use ldap_set_rebind_proc() to provide auth when rebinding following
ldap referrals (instead of rebinding anonymously for ldap referrals)
x-ref:
"LDAP authentication vs. AD: problems with referrals"
https://redmine.lighttpd.net/issues/2846
More specific checks on contents of array lists. Each module using
lists now does better checking on the types of values in the list
(strings, integers, arrays/lists)
This helps prevent misconfiguration of things like cgi.assign,
fastcgi.server, and scgi.server, where source code might be
served as static files if parenthesis are misplaced.
x-ref:
https://redmine.lighttpd.net/boards/2/topics/6571
Glenn Strauss
Mohammed Sadiq