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Unix SMB/CIFS implementation.
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simple bitmap functions
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Copyright (C) Andrew Tridgell 1992-1998
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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/* these functions provide a simple way to allocate integers from a
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pool without repetition */
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/****************************************************************************
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allocate a bitmap of the specified size
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****************************************************************************/
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struct bitmap *bitmap_allocate(int n)
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bm = SMB_MALLOC_P(struct bitmap);
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bm->b = SMB_MALLOC_ARRAY(uint32, (n+31)/32);
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memset(bm->b, 0, sizeof(uint32)*((n+31)/32));
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/****************************************************************************
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****************************************************************************/
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void bitmap_free(struct bitmap *bm)
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/****************************************************************************
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****************************************************************************/
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struct bitmap *bitmap_talloc(TALLOC_CTX *mem_ctx, int n)
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if (!mem_ctx) return NULL;
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bm = TALLOC_P(mem_ctx, struct bitmap);
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bm->b = TALLOC_ARRAY(mem_ctx, uint32, (n+31)/32);
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memset(bm->b, 0, sizeof(uint32)*((n+31)/32));
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/****************************************************************************
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copy as much of the source bitmap as will fit in the destination bitmap.
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****************************************************************************/
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int bitmap_copy(struct bitmap * const dst, const struct bitmap * const src)
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int count = MIN(dst->n, src->n);
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SMB_ASSERT(dst->b != src->b);
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memcpy(dst->b, src->b, sizeof(uint32)*((count+31)/32));
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/****************************************************************************
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set a bit in a bitmap
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****************************************************************************/
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BOOL bitmap_set(struct bitmap *bm, unsigned i)
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DEBUG(0,("Setting invalid bitmap entry %d (of %d)\n",
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bm->b[i/32] |= (1<<(i%32));
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/****************************************************************************
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clear a bit in a bitmap
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****************************************************************************/
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BOOL bitmap_clear(struct bitmap *bm, unsigned i)
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DEBUG(0,("clearing invalid bitmap entry %d (of %d)\n",
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bm->b[i/32] &= ~(1<<(i%32));
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/****************************************************************************
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query a bit in a bitmap
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****************************************************************************/
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BOOL bitmap_query(struct bitmap *bm, unsigned i)
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if (i >= bm->n) return False;
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if (bm->b[i/32] & (1<<(i%32))) {
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/****************************************************************************
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find a zero bit in a bitmap starting at the specified offset, with
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****************************************************************************/
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int bitmap_find(struct bitmap *bm, unsigned ofs)
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if (ofs > bm->n) ofs = 0;
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if (~(bm->b[i/32])) {
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if (!bitmap_query(bm, j)) return j;
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} while (j & 31 && j < bm->n);
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if (~(bm->b[i/32])) {
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if (!bitmap_query(bm, j)) return j;
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} while (j & 31 && j < bm->n);