-
Notifications
You must be signed in to change notification settings - Fork 0
/
buffer.c
143 lines (111 loc) · 3.13 KB
/
buffer.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
#include "codes.h"
#include "buffer.h"
byte_buffer *new_buffer(int size) {
byte_buffer *b = (byte_buffer *) malloc(sizeof(byte_buffer));
b->buffer = (uchar *) malloc(sizeof(uchar) * size);
memset(b->buffer, 0, size*sizeof(uchar));
b->capacity = size;
b->current_byte = b->current_bit = 0;
return b;
}
void resize(byte_buffer *b) {
if (b->current_byte >= b->capacity) {
int i, num_elems=b->capacity;
uchar temp[num_elems];
for (i = 0; i < num_elems; ++i) {
temp[i] = b->buffer[i];
}
free(b->buffer);
b->capacity *= MEM_COEFF;
b->buffer = (uchar *) malloc(sizeof(uchar) * b->capacity);
memset(b->buffer, 0, b->capacity);
for (i = 0; i < num_elems; ++i) {
b->buffer[i] = temp[i];
}
}
}
void append_bit_to_buffer(byte_buffer *b, uchar bit) {
if (b->current_bit > 7) {
b->current_byte++;
resize(b);
b->current_bit = 0;
}
if (bit) {
set_bit(b->buffer + b->current_byte, b->current_bit);
}
b->current_bit++;
}
void append_byte_to_buffer(byte_buffer *b, uchar byte) {
int i;
for (i = 0; i < 8; ++i) {
append_bit_to_buffer(b, is_bit_set(byte, i));
}
}
void append_to_buffer(byte_buffer *b, code *c) {
int i, byte, pos;
for (i = 0; i < c->num_bits; ++i) {
byte = i / 8;
pos = i % 8;
append_bit_to_buffer(b, is_bit_set(c->memory[byte], pos));
}
}
uchar get_next_bit(byte_buffer *b) {
if (b->current_byte > b->capacity) return -1;
uchar bit = is_bit_set(b->buffer[b->current_byte], b->current_bit);
b->current_bit++;
if (b->current_bit > 7) {
b->current_byte++;
b->current_bit = 0;
}
return bit;
}
uchar get_next_byte(byte_buffer *b) {
if (b->current_byte > b->capacity) return -1;
int i;
uchar byte = 0;
for (i = 0; i < 8; ++i) {
if (get_next_bit(b) == 1) {
set_bit(&byte, i);
}
}
return byte;
}
void print_buffer(byte_buffer *b) {
int i, k;
for (i = 0; i <= b->current_byte; ++i) {
if (i == b->current_byte) {
for (k = 0; k < b->current_bit; ++k) {
printf("%d", is_bit_set(b->buffer[i], k));
}
} else {
for (k = 0; k < 8; ++k) {
printf("%d", is_bit_set(b->buffer[i], k));
}
if ((i+1)%4 == 0) {
printf("\n");
} else {
printf(" ");
}
}
}
printf("\n");
}
void save(byte_buffer *b, const char *filename) {
int fd = open(filename, O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
int num_bytes = b->current_byte;
num_bytes += (b->current_bit == 0)? 0 : 1;
if (fd == -1) {
printf("Error opening file '%s'\n", filename);
return;
}
if (write(fd, b->buffer, num_bytes) == -1) {
printf("Error writing buffer to file '%s'\n", filename);
}
if (close(fd) == -1) {
printf("Error closing file '%s'\n", filename);
}
}
void free_buffer(byte_buffer *b) {
free(b->buffer);
free(b);
}