[multiple] employ ck_calloc, ck_malloc shared code

employ ck_calloc(), ck_malloc() shared code to slightly reduce code size
(centralize the ck_assert() to check that memory allocation succeeded)

[multiple] mark mod_*_plugin_init() funcs cold

[multiple] recognize HTTP QUERY method

x-ref:
https://www.ietf.org/id/draft-ietf-httpbis-safe-method-w-body-02.html

[multiple] remove base.h include where not used

(substitute request.h if file only accesses request_st,
and not connection or server structs)

[tests] t/test_mod_staticfile

move some tests from tests/request.t to src/t/test_mod_staticfile.c

[multiple] reduce redundant NULL buffer checks

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 co

[multiple] reduce redundant NULL buffer checks

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

show more ...

[mod_staticfile] move cold paths to separate func

[multiple] static file optimization; reuse cache

reuse cache lookup in common case of serving a static file
rather than repeating the stat_cache_entry lookup
(which is more work than memcmp() to re-

[multiple] static file optimization; reuse cache

reuse cache lookup in common case of serving a static file
rather than repeating the stat_cache_entry lookup
(which is more work than memcmp() to re-check stat_cache_entry match)

show more ...

[multiple] split con, request (very large change)

NB: r->tmp_buf == srv->tmp_buf (pointer is copied for quicker access)

NB: request read and write chunkqueues currently point to connection
chun

[multiple] split con, request (very large change)

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().

show more ...

[multiple] copy small struct instead of memcpy()

when patching config

[core] store subrequest_handler instead of mode

store pointer to module in handler_module instead of con->mode id

[core] convenience macros to check req methods

[multiple] generic config array type checking

[multiple] connection hooks no longer get (srv *)

(explicit (server *) not passed; available in con->srv)

[multiple] prefer (connection *) to (srv *)

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 passi

[multiple] prefer (connection *) to (srv *)

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)

show more ...

[multiple] plugin.c handles common FREE_FUNC code

(simpler for modules; less boilerplate to cut-n-paste)

[core] use config_plugin_values_init()

[mod_staticfile] use config_plugin_values_init()

[core] const char *name in struct plugin

put void *data (always used) as first member of struct plugin

add int nconfig member to PLUGIN_DATA

calloc() inits p->data to NULL

[core] simpler config_check_cond()

optimize for common case where condition has been evaluated for
the request and a cached result exists

(also: begin isolating data_config)

[core] inline buffer key for *_patch_connection()

handle buffer key as part of DATA_UNSET in *_patch_connection()
(instead of key being (buffer *))

[multiple] cleaner calloc use in SETDEFAULTS_FUNC

github: closes #99

x-ref:
"cleaner calloc use in SETDEFAULTS_FUNC"
https://github.com/lighttpd/lighttpd1.4/pull/99

[mod_staticfile] search ext array if not empty

[multiple] code reuse: employ array_match_*()

[core] remove unused includes of stat_cache.h