Nils O. Selåsdal
82 lines
1.9 KiB
C
82 lines
1.9 KiB
C
#ifndef BITEVEC_H_
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#define BITEVEC_H_
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#ifdef __cplusplus
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extern "C" {
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#endif
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struct bitvec {
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//storage for the bits
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unsigned long *vec;
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//length of the above vec. (Not the number of bits !)
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size_t vec_len;
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};
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/**
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* Evaluates the length required for a bitvec to store nbit bits.
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*/
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#define BITVEC_VEC_LEN(nbits) ((nbits/(sizeof(unsigned long)*CHAR_BIT)) + (nbits % (sizeof(unsigned long)*CHAR_BIT) == 0 ? 0 : 1))
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/**
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* Use as :
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* unsigned long v[10];
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* struct bitvec v = BITVEC_STATIC_INIT(v);
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*/
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#define BITVEC_STATIC_INIT(vec_data)\
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{\
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vec_data,\
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sizeof vec_data/sizeof vec_data[0]}
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/**
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* Returns a newly malloced bitvec, capable of storing at least nbits bits
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* All bits are initially zero.
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*
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*/
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struct bitvec *bitvec_new(size_t nbits);
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/** free a bitvec previously allocated by bitvec_new
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*/
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void bitvec_free(struct bitvec *v);
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//Note that accessing a bit beyond the nbits originally initialized
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//for the given bitvec is undedefined
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/** Sets bit no. b */
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void set_bit(struct bitvec *v,int b);
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/** Clears bit no. b*/
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void clear_bit(struct bitvec *v,int b);
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/** Gets the current value (0 or 1) of bit no. b*/
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int get_bit(const struct bitvec *v,int b);
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/** Sets all bits to zero */
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void clear_all(struct bitvec *v);
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/** Sets all bits to one */
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void set_all(struct bitvec *v);
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/** Initialize bits from a array of ints, each array element maps to one bit.
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* The bits are initialized from the int array so zero maps to zero and non-zero maps to one.
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* e..g to set the 5 first bits, to 01110:
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* int a[] = {0,1,1,1,0};
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* set_bits_from_array(v,a,5);
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* */
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void set_bits_from_array(struct bitvec *v,char *array,size_t array_len);
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// The _s ("secure") versions does boundary checking and assert() if they
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// try to access a bit out of bounds.
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void set_bit_s(struct bitvec *v,int b);
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void clear_bit_s(struct bitvec *v,int b);
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int get_bit_s(const struct bitvec *v,int b);
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#ifdef __cplusplus
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}
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#endif
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#endif
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