diff options
author | Jim Meyering <meyering@redhat.com> | 2012-09-08 15:11:20 +0200 |
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committer | Jim Meyering <meyering@redhat.com> | 2012-09-10 08:58:03 +0200 |
commit | c424de16b1c8607f2caa7c85d69196f9d8e3a103 (patch) | |
tree | fad5d543de0cef43dfa32e60a0e3937562799d15 /gl/lib/buffer-lcm.c | |
parent | 07fcfe36cee091b2dc15543dc406597bf1fffe67 (diff) | |
download | coreutils-c424de16b1c8607f2caa7c85d69196f9d8e3a103.tar.xz |
maint: move the last coreutils-specific files from lib/ to gl/
Convert the few remaining coreutils-specific files in lib/ to
gnulib-style modules under gl/, removing their corresponding .m4
files, since the information recorded in those files is better
stored in module-description file in gl/modules/.
* bootstrap.conf (gnulib_modules): Add new modules:
fd-reopen, buffer-lcm, xfts, strnumcmp.
* gl/lib/buffer-lcm.c: Renamed from the file in lib/.
* gl/lib/buffer-lcm.h: Likewise.
* gl/lib/fd-reopen.c: Likewise.
* gl/lib/fd-reopen.h: Likewise.
* gl/lib/strintcmp.c: Likewise.
* gl/lib/strnumcmp-in.h: Likewise.
* gl/lib/strnumcmp.c: Likewise.
* gl/lib/strnumcmp.h: Likewise.
* gl/lib/xfts.c: Likewise.
* gl/lib/xfts.h: Likewise.
* gl/modules/buffer-lcm: New module-description file.
* gl/modules/fd-reopen: Likewise.
* gl/modules/strnumcmp: Likewise.
* gl/modules/xfts: Likewise.
* m4/fd-reopen.m4: Remove, no longer needed.
* m4/strnumcmp.m4: Likewise.
* m4/xfts.m4: Likewise.
* m4/prereq.m4: Do not AC_REQUIRE the m4 functions from
our just-removed m4/*.m4 files.
Diffstat (limited to 'gl/lib/buffer-lcm.c')
-rw-r--r-- | gl/lib/buffer-lcm.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/gl/lib/buffer-lcm.c b/gl/lib/buffer-lcm.c new file mode 100644 index 000000000..1d22dac7d --- /dev/null +++ b/gl/lib/buffer-lcm.c @@ -0,0 +1,59 @@ +/* buffer-lcm.c - compute a good buffer size for dealing with two files + + Copyright (C) 2002-2012 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +/* Written by Paul Eggert. */ + +#include <config.h> +#include "buffer-lcm.h" + +/* Return a buffer size suitable for doing I/O with files whose block + sizes are A and B. However, never return a value greater than + LCM_MAX. */ + +size_t +buffer_lcm (size_t a, size_t b, size_t lcm_max) +{ + size_t size; + + /* Use reasonable values if buffer sizes are zero. */ + if (!a) + size = b ? b : 8 * 1024; + else + { + if (b) + { + /* Return lcm (A, B) if it is in range; otherwise, fall back + on A. */ + + size_t lcm, m, n, q, r; + + /* N = gcd (A, B). */ + for (m = a, n = b; (r = m % n) != 0; m = n, n = r) + continue; + + /* LCM = lcm (A, B), if in range. */ + q = a / n; + lcm = q * b; + if (lcm <= lcm_max && lcm / b == q) + return lcm; + } + + size = a; + } + + return size <= lcm_max ? size : lcm_max; +} |