annotate m4/i-ring.m4 @ 7639:1670d42131d7

Make fts (in FTS_CWDFD mode) more efficient by caching a few open file descriptors. This also averts a failure on systems with native openat support when a traversed directory lacks "x" access. * lib/fts_.h: Include "i-ring.h" (struct FTS) [fts_fd_ring]: New member. * lib/fts.c (RESTORE_INITIAL_CWD): Also call fd_ring_clear. (FCHDIR): Add parentheses. (fd_ring_check, fd_ring_print) [!FTS_DEBUG]: Define away. (cwd_advance_fd): Add a 3rd parameter. Adjust all callers. When descending, rather than simply closing the previous fts_cwd_fd value, push that file descriptor onto the ring. (same_fd, fd_ring_print, fd_ring_check) [FTS_DEBUG]: New functions. (fts_open): Initialize the new fd_ring member. (fts_close): Clear the ring. (fts_safe_changedir): When possible, use our new fd_ring to skip the diropen and fstat and dev/ino comparison that would normally accompany a virtual `chdir ("..")'. * modules/fts (Depends-on): Add i-ring. * modules/i-ring: New module. * lib/i-ring.c, lib/i-ring.h, lib/i-ring-test.c: New files. * m4/i-ring.m4: New file.
author Jim Meyering <jim@meyering.net>
date Sun, 12 Nov 2006 17:35:38 +0000
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children b5e42ef33b49
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1670d42131d7 Make fts (in FTS_CWDFD mode) more efficient by caching a few open
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1 # serial 1
1670d42131d7 Make fts (in FTS_CWDFD mode) more efficient by caching a few open
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2 dnl Copyright (C) 2006 Free Software Foundation, Inc.
1670d42131d7 Make fts (in FTS_CWDFD mode) more efficient by caching a few open
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3 dnl This file is free software; the Free Software Foundation
1670d42131d7 Make fts (in FTS_CWDFD mode) more efficient by caching a few open
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4 dnl gives unlimited permission to copy and/or distribute it,
1670d42131d7 Make fts (in FTS_CWDFD mode) more efficient by caching a few open
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5 dnl with or without modifications, as long as this notice is preserved.
1670d42131d7 Make fts (in FTS_CWDFD mode) more efficient by caching a few open
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6
1670d42131d7 Make fts (in FTS_CWDFD mode) more efficient by caching a few open
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7 AC_DEFUN([gl_I_RING],
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8 [
1670d42131d7 Make fts (in FTS_CWDFD mode) more efficient by caching a few open
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9 AC_LIBOBJ([i-ring])
1670d42131d7 Make fts (in FTS_CWDFD mode) more efficient by caching a few open
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10 ])