lighttpd1.4

4110 Commits

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48 MiB

Tree: 614250b4d8

Commit Graph

Author	SHA1	Message	Date
Glenn Strauss	af3df29ae8	[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	10 months ago
Glenn Strauss	655453a195	[core] inet_ntop_cache -> sock_addr_cache * rename inet_ntop_cache.[ch] to sock_addr_cache.[ch] * reimplement as separate caches for IPv4 and IPv6	2 years ago

Author

SHA1

Message

Date

Glenn Strauss

af3df29ae8

[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

10 months ago

Glenn Strauss

655453a195

[core] inet_ntop_cache -> sock_addr_cache

* rename inet_ntop_cache.[ch] to sock_addr_cache.[ch]
* reimplement as separate caches for IPv4 and IPv6

2 years ago

2 Commits (614250b4d82b7c471cc68ba011e7b3d658417f22)