From 758f820bcc0f68aeebac1717e537ca13a320b909 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:11:47 +0200 Subject: Adding upstream version 9.1. Signed-off-by: Daniel Baumann --- lib/i-ring.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 lib/i-ring.c (limited to 'lib/i-ring.c') diff --git a/lib/i-ring.c b/lib/i-ring.c new file mode 100644 index 0000000..659c61c --- /dev/null +++ b/lib/i-ring.c @@ -0,0 +1,68 @@ +/* a simple ring buffer + Copyright (C) 2006, 2009-2022 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 . */ + +/* written by Jim Meyering */ + +#include +#include "i-ring.h" + +#include + +void +i_ring_init (I_ring *ir, int default_val) +{ + int i; + ir->ir_empty = true; + ir->ir_front = 0; + ir->ir_back = 0; + for (i = 0; i < I_RING_SIZE; i++) + ir->ir_data[i] = default_val; + ir->ir_default_val = default_val; +} + +bool +i_ring_empty (I_ring const *ir) +{ + return ir->ir_empty; +} + +int +i_ring_push (I_ring *ir, int val) +{ + unsigned int dest_idx = (ir->ir_front + !ir->ir_empty) % I_RING_SIZE; + int old_val = ir->ir_data[dest_idx]; + ir->ir_data[dest_idx] = val; + ir->ir_front = dest_idx; + if (dest_idx == ir->ir_back) + ir->ir_back = (ir->ir_back + !ir->ir_empty) % I_RING_SIZE; + ir->ir_empty = false; + return old_val; +} + +int +i_ring_pop (I_ring *ir) +{ + int top_val; + if (i_ring_empty (ir)) + abort (); + top_val = ir->ir_data[ir->ir_front]; + ir->ir_data[ir->ir_front] = ir->ir_default_val; + if (ir->ir_front == ir->ir_back) + ir->ir_empty = true; + else + ir->ir_front = ((ir->ir_front + I_RING_SIZE - 1) % I_RING_SIZE); + return top_val; +} -- cgit v1.2.3