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| author | Cojocaru Alexandru <xojoc@gmx.com> | 2012-12-09 10:43:10 +0100 |
|---|---|---|
| committer | Pádraig Brady <P@draigBrady.com> | 2013-04-29 17:54:27 +0100 |
| commit | 3e466ad05181d95057e6612ff11059c91396cd0e (patch) | |
| tree | 2110ad15ceb663c914eb61edb50d0df5408f4866 /tests/local.mk | |
| parent | e414ff4c4c3fe029a9702c9909bf4eccbef68c21 (diff) | |
| download | coreutils-3e466ad05181d95057e6612ff11059c91396cd0e.tar.xz | |
cut: make memory allocation independent of range width
The current implementation of cut, uses a bit array,
an array of `struct range_pair's, and (when --output-delimiter
is specified) a hash_table. The new implementation will use
only an array of `struct range_pair's.
The old implementation is memory inefficient because:
1. When -b with a big num is specified, it allocates a lot of
memory for `printable_field'.
2. When --output-delimiter is specified, it will allocate 31 buckets.
Even if only a few ranges are specified.
Note CPU overhead is increased to determine if an item is to be printed,
as shown by:
$ yes abcdfeg | head -n1MB > big-file
$ for c in with-bitarray without-bitarray; do
src/cut-$c 2>/dev/null
echo -ne "\n== $c =="
time src/cut-$c -b1,3 big-file > /dev/null
done
== with-bitarray ==
real 0m0.084s
user 0m0.078s
sys 0m0.006s
== without-bitarray ==
real 0m0.111s
user 0m0.108s
sys 0m0.002s
Subsequent patches will reduce this overhead.
* src/cut.c (set_fields): Set and initialize RP
instead of printable_field.
* src/cut.c (is_range_start_index): Use CURRENT_RP rather than a hash.
* tests/misc/cut.pl: Check if `eol_range_start' is set correctly.
* tests/misc/cut-huge-range.sh: Rename from cut-huge-to-eol-range.sh,
and add a test to verify large amounts of mem aren't allocated.
Fixes http://bugs.gnu.org/13127
Diffstat (limited to 'tests/local.mk')
| -rw-r--r-- | tests/local.mk | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tests/local.mk b/tests/local.mk index f47da8d3a..fb5cc63b6 100644 --- a/tests/local.mk +++ b/tests/local.mk @@ -245,7 +245,7 @@ all_tests = \ tests/misc/pwd-option.sh \ tests/misc/chcon-fail.sh \ tests/misc/cut.pl \ - tests/misc/cut-huge-to-eol-range.sh \ + tests/misc/cut-huge-range.sh \ tests/misc/wc.pl \ tests/misc/wc-files0-from.pl \ tests/misc/wc-files0.sh \ |