67 lines
3.1 KiB
C
67 lines
3.1 KiB
C
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/*
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* Copyright (c) 2018, Sam Kumar <samkumar@cs.berkeley.edu>
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* Copyright (c) 2018, University of California, Berkeley
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the copyright holder nor the
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* names of its contributors may be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef BITMAP_H_
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#define BITMAP_H_
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#include <stdint.h>
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#include <stdlib.h>
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/* Computes the number of bytes required to store the specified number of bits. */
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#define BITS_TO_BYTES(bits) (((bits) >> 3) + (((bits) & 0x7) ? 1 : 0))
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/* Initializes a bitmap to all zeros. */
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void bmp_init(uint8_t* buf, size_t numbytes);
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/* Sets the specified range of bits. START is the index
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of the first bit to be set. LEN is the number of bits
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to be set. */
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void bmp_setrange(uint8_t* buf, size_t start, size_t len);
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/* Clears the specified range of bits. START is the index
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of the first bit to be cleared. LEN is the number of bits
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to be cleared. */
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void bmp_clrrange(uint8_t* buf, size_t start, size_t len);
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/* Counts the number of set bits in BUF starting at START. BUF has length
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BUFLEN, in bytes. Counts the number of set bits until it either (1) finds
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a bit that isn't set, in which case it returns the number of set bits,
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(2) it has counted at least LIMIT bits, in which case it returns a number
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greater than or equal to LIMIT, or (3) reaches the end of the buffer, in
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which case it returns exactly the number of set bits it found. */
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size_t bmp_countset(uint8_t* buf, size_t buflen, size_t start, size_t limit);
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/* Returns 1 if the bitmap is all zeros, and 0 otherwise. */
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int bmp_isempty(uint8_t* buf, size_t buflen);
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/* Prints out the bitmap in hexadecimal (used for debugging). */
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void bmp_print(uint8_t* buf, size_t buflen);
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#endif
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