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| author | Denis Vlasenko | 2009-03-22 19:00:05 +0000 |
|---|---|---|
| committer | Denis Vlasenko | 2009-03-22 19:00:05 +0000 |
| commit | 57abf9e947fa3f7d69f7adb97023b299916ee63c (patch) | |
| tree | bcc36a5d96b56859763bd52a52377ed1c081326a /include | |
| parent | 3fd104630020168ead90123e45d848d4d2d0a555 (diff) | |
| download | busybox-57abf9e947fa3f7d69f7adb97023b299916ee63c.zip busybox-57abf9e947fa3f7d69f7adb97023b299916ee63c.tar.gz | |
libbb: make history saving/loading concurrent-safe
* all history writers always append (not overwrite) history files
* they reload history if they detect that file length has changed since last
write
* they trim history file only when it grows 4 times longer than MAXLINES
* they do this atomically by creating new file and renaming it to old
Unfortunately, this comes at a price:
function old new delta
load_history - 346 +346
read_line_input 3155 3358 +203
new_line_input_t 17 31 +14
...irrelevant small jitter...
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 5/5 up/down: 573/-13) Total: 560 bytes
Diffstat (limited to 'include')
| -rw-r--r-- | include/libbb.h | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/include/libbb.h b/include/libbb.h index a2042fe..7bf9469 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -1187,9 +1187,9 @@ unsigned long long bb_makedev(unsigned int major, unsigned int minor) FAST_FUNC; #if ENABLE_FEATURE_EDITING /* It's NOT just ENABLEd or disabled. It's a number: */ #ifdef CONFIG_FEATURE_EDITING_HISTORY -#define MAX_HISTORY (CONFIG_FEATURE_EDITING_HISTORY + 0) +# define MAX_HISTORY (CONFIG_FEATURE_EDITING_HISTORY + 0) #else -#define MAX_HISTORY 0 +# define MAX_HISTORY 0 #endif typedef struct line_input_t { int flags; @@ -1197,7 +1197,11 @@ typedef struct line_input_t { #if MAX_HISTORY int cnt_history; int cur_history; - USE_FEATURE_EDITING_SAVEHISTORY(const char *hist_file;) +#if ENABLE_FEATURE_EDITING_SAVEHISTORY + unsigned cnt_history_in_file; + off_t last_history_end; + const char *hist_file; +#endif char *history[MAX_HISTORY + 1]; #endif } line_input_t; |