From 8daa83a594a2e98f39d764422bfbdbc62c9efd44 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 19:20:00 +0200 Subject: Adding upstream version 2:4.20.0+dfsg. Signed-off-by: Daniel Baumann --- lib/util/bitmap.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 144 insertions(+) create mode 100644 lib/util/bitmap.c (limited to 'lib/util/bitmap.c') diff --git a/lib/util/bitmap.c b/lib/util/bitmap.c new file mode 100644 index 0000000..12cdfe4 --- /dev/null +++ b/lib/util/bitmap.c @@ -0,0 +1,144 @@ +/* + Unix SMB/CIFS implementation. + simple bitmap functions + Copyright (C) Andrew Tridgell 1992-1998 + + 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 . +*/ + +#include "replace.h" +#include +#include "lib/util/bitmap.h" +#include "lib/util/debug.h" +#include "lib/util/fault.h" + +struct bitmap { + unsigned int n; + uint32_t b[1]; /* We allocate more */ +}; + +/* these functions provide a simple way to allocate integers from a + pool without repetition */ + +/**************************************************************************** +talloc a bitmap +****************************************************************************/ +struct bitmap *bitmap_talloc(TALLOC_CTX *mem_ctx, int n) +{ + struct bitmap *bm; + + bm = (struct bitmap *)talloc_zero_size( + mem_ctx, + offsetof(struct bitmap, b) + sizeof(uint32_t)*((n+31)/32)); + + if (!bm) return NULL; + + talloc_set_name_const(bm, "struct bitmap"); + + bm->n = n; + return bm; +} + +/**************************************************************************** +copy as much of the source bitmap as will fit in the destination bitmap. +****************************************************************************/ + +int bitmap_copy(struct bitmap * const dst, const struct bitmap * const src) +{ + int count = MIN(dst->n, src->n); + + SMB_ASSERT(dst->b != src->b); + memcpy(dst->b, src->b, sizeof(uint32_t)*((count+31)/32)); + + return count; +} + +/**************************************************************************** +set a bit in a bitmap +****************************************************************************/ +bool bitmap_set(struct bitmap *bm, unsigned i) +{ + if (i >= bm->n) { + DEBUG(0,("Setting invalid bitmap entry %d (of %d)\n", + i, bm->n)); + return false; + } + bm->b[i/32] |= (1U<<(i%32)); + return true; +} + +/**************************************************************************** +clear a bit in a bitmap +****************************************************************************/ +bool bitmap_clear(struct bitmap *bm, unsigned i) +{ + if (i >= bm->n) { + DEBUG(0,("clearing invalid bitmap entry %d (of %d)\n", + i, bm->n)); + return false; + } + bm->b[i/32] &= ~(1U<<(i%32)); + return true; +} + +/**************************************************************************** +query a bit in a bitmap +****************************************************************************/ +bool bitmap_query(struct bitmap *bm, unsigned i) +{ + if (i >= bm->n) return false; + if (bm->b[i/32] & (1U<<(i%32))) { + return true; + } + return false; +} + +/**************************************************************************** +find a zero bit in a bitmap starting at the specified offset, with +wraparound +****************************************************************************/ +int bitmap_find(struct bitmap *bm, unsigned ofs) +{ + unsigned int i, j; + + if (ofs > bm->n) ofs = 0; + + i = ofs; + while (i < bm->n) { + if (~(bm->b[i/32])) { + j = i; + do { + if (!bitmap_query(bm, j)) return j; + j++; + } while (j & 31 && j < bm->n); + } + i += 32; + i &= ~31; + } + + i = 0; + while (i < ofs) { + if (~(bm->b[i/32])) { + j = i; + do { + if (!bitmap_query(bm, j)) return j; + j++; + } while (j & 31 && j < bm->n); + } + i += 32; + i &= ~31; + } + + return -1; +} -- cgit v1.2.3