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/*
* Copyright (c) 2020 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* \file bitmap.h
* \brief Bitmap
*
* A bitmap is implemented as a wrapper over a vector made of bit elements
*/
#ifndef UTIL_BITMAP_H
#define UTIL_BITMAP_H
#include <string.h>
#include "common.h"
#define BITMAP_WIDTH(bitmap) (sizeof((bitmap)[0]) * 8)
/**
* @brief Allocate and initialize a bitmap
*
* @param[in,out] bitmap Bitmap to allocate and initialize
* @param[in] max_size Bitmap max_size
*/
#define bitmap_init(bitmap, max_size) \
vector_init(bitmap, next_pow2(max_size / BITMAP_WIDTH(bitmap)))
/*
* @brief Ensures a bitmap is sufficiently large to hold an element at the
* given position.
*
* @param[in] bitmap The bitmap for which to validate the position.
* @param[in] pos The position to validate.
*
* NOTE:
* - This function should always be called before writing to a bitmap element
* to eventually make room for it (the bitmap will eventually be resized).
*/
#define bitmap_ensure_pos(bitmap, pos) vector_ensure_pos(bitmap, pos / BITMAP_WIDTH(bitmap))
/**
* @brief Retrieve the state of the i-th bit in the bitmap.
*
* @param[in] bitmap The bitmap to access.
* @param[in] i The bit position.
*/
#define bitmap_get(bitmap, i) ((bitmap)[(i) / BITMAP_WIDTH(bitmap)] & (1 << ((i) % BITMAP_WIDTH(bitmap))))
/*
* @brief Returns whether the i-th bit is set (equal to 1) in a bitmap.
*
* @param[in] bitmap The bitmap to access.
* @param[in] i The bit position.
*
* @return bool
*/
#define bitmap_is_set(bitmap, i) (bitmap_get((bitmap), (i)) == 1)
/*
* @brief Returns whether the i-th bit is unset (equal to 0) in a bitmap.
*
* @param[in] bitmap The bitmap to access.
* @param[in] i The bit position.
*
* @return bool
*/
#define bitmap_is_unset(bitmap, i) (bitmap_get((bitmap), (i)) == 0)
#define bitmap_set(bitmap, i) bitmap[(i) / BITMAP_WIDTH(bitmap)] |= 1 << ((i) % BITMAP_WIDTH(bitmap))
#define bitmap_unset(bitmap, i) bitmap[(i) / BITMAP_WIDTH(bitmap)] &= ~ (1 << ((i) % BITMAP_WIDTH(bitmap)))
#define bitmap_set_to(bitmap, pos) \
do { \
size_t offset = (pos / BITMAP_WIDTH(bitmap) + 1); \
memset(bitmap, 0xFF, pos * sizeof(bitmap[0])); \
size_t set_bits = offset * BITMAP_WIDTH(bitmap); \
for (unsigned i = pos; i < set_bits; i++) \
bitmap_unset(bitmap, i); \
} while(0);
#endif /* UTIL_BITMAP_H */
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