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
When writev() is available, always use writev() instead of write()
(Silently ignores config option to use write() if writev() is available)
(Still uses sendfile() instead of writev() when config selects sendfile)
(replace existing check which suffered from ToC-ToU race condition)
enhances logic from 2015 commit 593599f1 and avoids repeated fstat()
checks when sending large files
For mmap(), lighttpd catches SIGBUS if file is (externally) truncated
and lighttpd attempts to access bytes in a read-only mapping more than
a memory page boundary following the end of the file.
For sendfile(), lighttpd returns an error if sendfile() reports no error
and that no bytes have been sent after lighttpd attempts to send a
non-zero number of bytes.
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)
- a lot of code tried to handle manually adding terminating zeroes and
keeping track of the correct "used" count.
Replaced all "external" usages with simple wrapper functions:
* buffer_string_is_empty (used <= 1), buffer_is_empty (used == 0);
prefer buffer_string_is_empty
* buffer_string_set_length
* buffer_string_length
* CONST_BUF_LEN() macro
- removed "static" buffer hacks (buffers pointing to constant/stack
memory instead of malloc()ed data)
- buffer_append_strftime(): refactor buffer+strftime uses
- li_tohex(): no need for a buffer for binary-to-hex conversion:
the output data length is easy to predict
- remove "-Winline" from extra warnings: the "inline" keyword just
supresses the warning about unused but defined (static) functions;
don't care whether it actually gets inlined or not.
From: Stefan Bühler <stbuehler@web.de>
git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2979 152afb58-edef-0310-8abb-c4023f1b3aa9
* removed almost all usages of buffer as "memory" (without terminating
zero)
* refactored cgi variable name encoding
From: Stefan Bühler <stbuehler@web.de>
git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2977 152afb58-edef-0310-8abb-c4023f1b3aa9
i hope it helps with merging stuff back to 1.5
git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@1371 152afb58-edef-0310-8abb-c4023f1b3aa9
added a offset tag to the mmap part of the file-struct to allow moving mmap-windows
git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-merge-1.4.x@795 152afb58-edef-0310-8abb-c4023f1b3aa9
Marcus Rückert
