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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:21:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:21:29 +0000 |
commit | 29cd838eab01ed7110f3ccb2e8c6a35c8a31dbcc (patch) | |
tree | 63ef546b10a81d461e5cf5ed9e98a68cd7dee1aa /src/grep/lib/i-ring.h | |
parent | Initial commit. (diff) | |
download | kbuild-29cd838eab01ed7110f3ccb2e8c6a35c8a31dbcc.tar.xz kbuild-29cd838eab01ed7110f3ccb2e8c6a35c8a31dbcc.zip |
Adding upstream version 1:0.1.9998svn3589+dfsg.upstream/1%0.1.9998svn3589+dfsg
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/grep/lib/i-ring.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/grep/lib/i-ring.h b/src/grep/lib/i-ring.h new file mode 100644 index 0000000..e75e846 --- /dev/null +++ b/src/grep/lib/i-ring.h @@ -0,0 +1,44 @@ +/* definitions for a simple ring buffer + Copyright (C) 2006, 2009-2021 Free Software Foundation, Inc. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 3 of the + License, or (at your option) any later version. + + This file 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 Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +#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) _GL_ATTRIBUTE_PURE; |