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authorDenys Vlasenko2018-04-06 16:44:50 +0200
committerDenys Vlasenko2018-04-06 16:44:50 +0200
commitd1d6d9c5d8022bcd8f2e7fbd470d293f73adae58 (patch)
treee31548816f5b868a09e21e39a4beb03451a0d693 /coreutils
parent00bd76728d44901a260f2dcdbeed52b3c85d6b6b (diff)
downloadbusybox-d1d6d9c5d8022bcd8f2e7fbd470d293f73adae58.zip
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sort: smaller and more agressive FEATURE_SORT_OPTIMIZE_MEMORY
function old new delta sort_main 1098 1037 -61 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'coreutils')
-rw-r--r--coreutils/sort.c24
1 files changed, 12 insertions, 12 deletions
diff --git a/coreutils/sort.c b/coreutils/sort.c
index 9909a44..4d741e7 100644
--- a/coreutils/sort.c
+++ b/coreutils/sort.c
@@ -18,11 +18,11 @@
//config: sort is used to sort lines of text in specified files.
//config:
//config:config FEATURE_SORT_BIG
-//config: bool "Full SuSv3 compliant sort (support -ktcbdfiozgM)"
+//config: bool "Full SuSv3 compliant sort (support -ktcbdfiogM)"
//config: default y
//config: depends on SORT
//config: help
-//config: Without this, sort only supports -r, -u, -s, and an integer version
+//config: Without this, sort only supports -rusz, and an integer version
//config: of -n. Selecting this adds sort keys, floating point support, and
//config: more. This adds a little over 3k to a nonstatic build on x86.
//config:
@@ -66,12 +66,10 @@
//usage: "\n -r Reverse sort order"
//usage: "\n -s Stable (don't sort ties alphabetically)"
//usage: "\n -u Suppress duplicate lines"
-//usage: IF_FEATURE_SORT_BIG(
//usage: "\n -z Lines are terminated by NUL, not newline"
///////: "\n -m Ignored for GNU compatibility"
///////: "\n -S BUFSZ Ignored for GNU compatibility"
///////: "\n -T TMPDIR Ignored for GNU compatibility"
-//usage: )
//usage:
//usage:#define sort_example_usage
//usage: "$ echo -e \"e\\nf\\nb\\nd\\nc\\na\" | sort\n"
@@ -413,6 +411,7 @@ int sort_main(int argc UNUSED_PARAM, char **argv)
#if ENABLE_FEATURE_SORT_OPTIMIZE_MEMORY
bool can_drop_dups;
size_t prev_len = 0;
+ char *prev_line = (char*) "";
/* Postpone optimizing if the input is small, < 16k lines:
* even just free()ing duplicate lines takes time.
*/
@@ -533,32 +532,33 @@ int sort_main(int argc UNUSED_PARAM, char **argv)
if (count_to_optimize_dups == 0) {
size_t len;
char *new_line;
- char first = *line;
/* On kernel/linux/arch/ *.[ch] files,
* this reduces memory usage by 6%.
* yes | head -99999999 | sort
* goes down from 1900Mb to 380 Mb.
*/
- if (first == '\0' || first == '\n') {
- len = !(first == '\0');
- new_line = (char*)"\n" + 1 - len;
- goto replace;
- }
len = strlen(line);
if (len <= prev_len) {
- new_line = lines[linecount-1] + (prev_len - len);
+ new_line = prev_line + (prev_len - len);
if (strcmp(line, new_line) == 0) {
+ /* it's a tail of the prev line */
if (can_drop_dups && prev_len == len) {
+ /* it's identical to prev line */
free(line);
continue;
}
- replace:
free(line);
line = new_line;
+ /* continue using longer prev_line
+ * for future tail tests.
+ */
+ goto skip;
}
}
prev_len = len;
+ prev_line = line;
+ skip: ;
}
#else
//TODO: lighter version which only drops total dups if can_drop_dups == true