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bertos/struct/bitarray.h

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+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos 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 2 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2010 Develer S.r.l. (http://www.develer.com/)
+ * -->
+ *
+ * \brief Bitarray module
+ *
+ * \author Daniele Basile <asterix@develer.com>
+ *
+ * $WIZ$ module_name = "bitarray"
+ */
+
+#ifndef STRUCT_BITARRAY_H
+#define STRUCT_BITARRAY_H
+
+#include <cfg/compiler.h>
+#include <cfg/macros.h>
+#include <cfg/debug.h>
+
+#include <cpu/types.h>
+
+typedef struct BitArray
+{
+	size_t size;          /// Size in bytes of the bitarray
+	size_t bitarray_len;  /// Number of bits used
+	uint8_t *array;       /// Pointer to memory occupied by the bitarray
+} BitArray;
+
+/**
+ * Convenience macro to create a memory area for the BitArray.
+ * \param name Name of the variable.
+ * \param size Number of bits requested. It will be rounded to the nearest
+ *             byte
+ */
+#define BITARRAY_ALLOC(name, size)   uint8_t name[DIV_ROUNDUP((size), 8)]
+
+/**
+ * Set one bit into the bit array.
+ * \param bitx BitArray context
+ * \param idx The bit to set
+ */
+INLINE void bitarray_set(BitArray *bitx, int idx)
+{
+	ASSERT((size_t)idx <= bitx->bitarray_len);
+
+	int page = idx / 8;
+	uint8_t bit = idx % 8;
+
+	bitx->array[page] |= BV(bit);
+}
+
+/**
+ * Clear one bit in the bit array.
+ * \param bitx BitArray context
+ * \param idx The bit to clear
+ */
+INLINE void bitarray_clear(BitArray *bitx, int idx)
+{
+	ASSERT((size_t)idx <= bitx->bitarray_len);
+
+	int page = idx / 8;
+	uint8_t bit = idx % 8;
+
+	bitx->array[page] &= ~BV(bit);
+}
+
+/**
+ * Set a range of bits.
+ *
+ * The range starts from \a idx (inclusive) and spans \a offset bits.
+ *
+ * \param bitx BitArray context
+ * \param idx Starting bit
+ * \param offset Number of bit to set
+ */
+INLINE void bitarray_setRange(BitArray *bitx, int idx, int offset)
+{
+	ASSERT((size_t)idx <= bitx->bitarray_len);
+
+	for (int i = idx; i < offset + idx; i++)
+		bitarray_set(bitx, i);
+}
+
+/**
+ * Clear a range of bits.
+ *
+ * The range starts from \a idx (inclusive) and spans \a offset bits.
+ *
+ * \param bitx BitArray context
+ * \param idx Starting bit
+ * \param offset Number of bits to clear
+ */
+INLINE void bitarray_clearRange(BitArray *bitx, int idx, int offset)
+{
+	ASSERT((size_t)idx <= bitx->bitarray_len);
+
+	for (int i = idx; i < offset + idx; i++)
+		bitarray_clear(bitx, i);
+}
+
+/**
+ * Test a bit.
+ *
+ * \param bitx BitArray context
+ * \param idx Bit to test
+ * \return True if bit is set, false otherwise.
+ */
+INLINE bool bitarray_test(BitArray *bitx, int idx)
+{
+	ASSERT((size_t)idx <= bitx->bitarray_len);
+	int page = idx / 8;
+	uint8_t bit = idx % 8;
+
+	return (bitx->array[page] & BV(bit));
+}
+
+/**
+ * Check if the bitarray is full
+ *
+ * Only \a bitarray_len bits are tested.
+ *
+ * \param bitx BitArray to test
+ * \return True if \a bitx is full, false otherwise
+ */
+INLINE bool bitarray_isFull(BitArray *bitx)
+{
+	// test full bytes except the last one
+	for (size_t page = 0; page <= bitx->size - 2; page++)
+	{
+		if (!(bitx->array[page] == 0xff))
+			return 0;
+	}
+	// test the last byte using the correct bitmask
+	uint8_t mask = BV(bitx->bitarray_len >> 3) - 1;
+	if (!(bitx->array[bitx->size - 1] & mask))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * Ugly!.. reformat it.
+ */
+/**
+ * Test if a range of bit is full.
+ *
+ * \param bitx BitArray context
+ * \param idx Starting bit
+ * \param offset Number of bits to test
+ * \return True if range is full, false otherwise
+ */
+INLINE bool bitarray_isRangeFull(BitArray *bitx, int idx, int offset)
+{
+	ASSERT((size_t)(idx + offset) <= bitx->bitarray_len);
+
+	for (int i = idx; i <= idx + offset; i++)
+		if (!bitarray_test(bitx, i))
+			return 0;
+
+	return 1;
+}
+
+/*
+ * Ugly!.. reformat it.
+ */
+/**
+ * Test if a range of bit is empty.
+ *
+ * \param bitx BitArray context
+ * \param idx Starting bit
+ * \param offset Number of bits to test
+ * \return True if range is empty, false otherwise
+ */
+INLINE bool bitarray_isRangeEmpty(BitArray *bitx, int idx, int offset)
+{
+	ASSERT((size_t)(idx + offset) <= bitx->bitarray_len);
+
+	for (int i = idx; i <= idx + offset; i++)
+		if (bitarray_test(bitx, i))
+			return 0;
+
+	return 1;
+}
+
+/**
+ * Print on debug serial a BitArray.
+ * \note This module does not use the logging module, so you
+ *       can't decide the logging level.
+ * \param bitx BitArray to be printed.
+ */
+INLINE void bitarray_dump(BitArray *bitx)
+{
+	kprintf("bitarray size[%zu]bits on [%zu]bytes\n", bitx->bitarray_len, bitx->size);
+
+	int i = 0;
+	int j = 0;
+	int count = bitx->bitarray_len;
+
+	while (count--)
+	{
+		kprintf("%d", bitarray_test(bitx, i++));
+		if (j == 7)
+		{
+			kprintf("..%02x [%d]\n", bitx->array[(i / 8) - 1], i);
+			j = 0;
+			continue;
+		}
+		j++;
+	}
+
+	if (j != 0)
+		kprintf("..%02x [%d]\n", bitx->array[i / 8], i);
+}
+
+/**
+ * Init a BitArray.
+ *
+ * The BitArray uses an external array for storage. You can use the macro
+ * BITARRAY_ALLOC to declare an appropriate memory size. Example usage:
+ * \code
+ * BITARRAY_ALLOC(bits_mem, 17);
+ * BitArray bits;
+ * bitarray_init(&bits, 17, bits_mem, sizeof(bits_mem))
+ * \endcode
+ *
+ * \param bitx BitArray context
+ * \param bitarray_len Number of bits in the BitArray
+ * \param array Memory area for the BitArray
+ * \param size Size (in bytes) of the memory area \a array
+ */
+INLINE void bitarray_init(BitArray *bitx, size_t bitarray_len, uint8_t *array, size_t size)
+{
+	bitx->size = size;
+	bitx->array = array;
+	bitx->bitarray_len = bitarray_len;
+}
+
+
+int bitarray_testSetup(void);
+int bitarray_testRun(void);
+int bitarray_testTearDown(void);
+
+#endif /* STRUCT_BITARRAY_H */