kc3-lang/gnulib/lib/i-ring.h
Tag
-
Show log
Commit
-
Hash : 7f01591a
Author :
Date : 2006-11-12T17:35:38
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.
-
lib/i-ring.h
-
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
/* definitions for a simple ring buffer Copyright (C) 2006 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 2, 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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include <stdbool.h> #include "verify.h" enum { I_RING_SIZE = 4 }; verify (1 <= I_RING_SIZE); /* When ir_empty is true, the ring is empty. Otherwise, ir_data[B..F] are defined, where B..F is the contiguous range of indices, modulo I_RING_SIZE, from back to front, inclusive. Undefined elements of ir_data are always set to ir_default_val. Popping from an empty ring aborts. Pushing onto a full ring returns the displaced value. An empty ring has F==B and ir_empty == true. A ring with one entry still has F==B, but now ir_empty == false. */ struct I_ring { int ir_data[I_RING_SIZE]; int ir_default_val; unsigned int ir_front; unsigned int ir_back; bool ir_empty; }; typedef struct I_ring I_ring; void i_ring_init (I_ring *ir, int ir_default_val); int i_ring_push (I_ring *ir, int val); int i_ring_pop (I_ring *ir); bool i_ring_empty (I_ring const *ir);