Line data    Source code

       1             : /***************************************************************************//**
       2             : 
       3             :   @file         bitfield.c
       4             : 
       5             :   @author       Stephen Brennan
       6             : 
       7             :   @date         Created Wednesday, 29 January 2014
       8             : 
       9             :   @brief        Implementation of "libstephen/bf.h".
      10             : 
      11             :   @copyright    Copyright (c) 2013-2016, Stephen Brennan.  Released under the
      12             :                 Revised BSD License.  See the LICENSE.txt file for details.
      13             : 
      14             : *******************************************************************************/
      15             : 
      16             : #include <string.h>
      17             : #include <assert.h>
      18             : 
      19             : #include "libstephen/base.h"
      20             : #include "libstephen/bf.h"
      21             : 
      22           5 : void bf_init(unsigned char *data, int num_bools) {
      23           5 :   int size = SMB_BITFIELD_SIZE(num_bools);
      24           5 :   memset(data, 0, size);
      25           5 : }
      26             : 
      27           1 : unsigned char *bf_create(int num_bools) {
      28             :   unsigned char *data;
      29           1 :   int size = SMB_BITFIELD_SIZE(num_bools);
      30             : 
      31           1 :   data = smb_new(unsigned char, size);
      32             : 
      33           1 :   bf_init(data, num_bools);
      34           1 :   return data;
      35             : }
      36             : 
      37           1 : void bf_delete(unsigned char *data, int num_bools) {
      38             :   (void) num_bools; // unused
      39           1 :   smb_free(data);
      40           1 : }
      41             : 
      42         416 : int bf_check(unsigned char *data, int index) {
      43         416 :   int byte_index = (int)(index / BIT_PER_CHAR);
      44         416 :   unsigned char bit_mask = 0x01 << (index % BIT_PER_CHAR);
      45             : 
      46         416 :   return data[byte_index] & bit_mask;
      47             : }
      48             : 
      49         160 : void bf_set(unsigned char *data, int index) {
      50         160 :   int byte_index = (int)(index / BIT_PER_CHAR);
      51         160 :   unsigned char bit_mask = 0x01 << (index % BIT_PER_CHAR);
      52             : 
      53         160 :   data[byte_index] |= bit_mask;
      54         160 : }
      55             : 
      56          40 : void bf_clear(unsigned char *data, int index) {
      57          40 :   int byte_index = (int)(index / BIT_PER_CHAR);
      58          40 :   unsigned char bit_mask = ~(0x01 << (index % BIT_PER_CHAR));
      59             : 
      60          40 :   data[byte_index] &= bit_mask;
      61          40 : }
      62             : 
      63          80 : void bf_flip(unsigned char *data, int index) {
      64          80 :   int byte_index = (int)(index / BIT_PER_CHAR);
      65          80 :   unsigned char bit_mask = 0x01 << (index % BIT_PER_CHAR);
      66             : 
      67          80 :   unsigned char value = ~(data[byte_index] & bit_mask) & bit_mask;
      68          80 :   data[byte_index] = (data[byte_index] & ~bit_mask) | value;
      69          80 : }