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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
#include "fitz-internal.h"
fz_buffer *
fz_new_buffer(fz_context *ctx, int size)
{
fz_buffer *b;
size = size > 1 ? size : 16;
b = fz_malloc_struct(ctx, fz_buffer);
b->refs = 1;
fz_try(ctx)
{
b->data = fz_malloc(ctx, size);
}
fz_catch(ctx)
{
fz_free(ctx, b);
fz_rethrow(ctx);
}
b->cap = size;
b->len = 0;
b->unused_bits = 0;
return b;
}
fz_buffer *
fz_keep_buffer(fz_context *ctx, fz_buffer *buf)
{
if (buf)
{
if (buf->refs == 1 && buf->cap > buf->len+1)
fz_resize_buffer(ctx, buf, buf->len);
buf->refs ++;
}
return buf;
}
void
fz_drop_buffer(fz_context *ctx, fz_buffer *buf)
{
if (!buf)
return;
if (--buf->refs == 0)
{
fz_free(ctx, buf->data);
fz_free(ctx, buf);
}
}
void
fz_resize_buffer(fz_context *ctx, fz_buffer *buf, int size)
{
buf->data = fz_resize_array(ctx, buf->data, size, 1);
buf->cap = size;
if (buf->len > buf->cap)
buf->len = buf->cap;
}
void
fz_grow_buffer(fz_context *ctx, fz_buffer *buf)
{
fz_resize_buffer(ctx, buf, (buf->cap * 3) / 2);
}
static void
fz_ensure_buffer(fz_context *ctx, fz_buffer *buf, int min)
{
int newsize = buf->cap;
while (newsize < min)
{
newsize = (newsize * 3) / 2;
}
fz_resize_buffer(ctx, buf, newsize);
}
void
fz_trim_buffer(fz_context *ctx, fz_buffer *buf)
{
if (buf->cap > buf->len+1)
fz_resize_buffer(ctx, buf, buf->len);
}
int
fz_buffer_storage(fz_context *ctx, fz_buffer *buf, unsigned char **datap)
{
if (datap)
*datap = (buf ? buf->data : NULL);
return (buf ? buf->len : 0);
}
void fz_write_buffer(fz_context *ctx, fz_buffer *buf, unsigned char *data, int len)
{
if (buf->len + len > buf->cap)
fz_ensure_buffer(ctx, buf, buf->len + len);
memcpy(buf->data + buf->len, data, len);
buf->len += len;
buf->unused_bits = 0;
}
void fz_write_buffer_byte(fz_context *ctx, fz_buffer *buf, int val)
{
if (buf->len > buf->cap)
fz_grow_buffer(ctx, buf);
buf->data[buf->len++] = val;
buf->unused_bits = 0;
}
void fz_write_buffer_bits(fz_context *ctx, fz_buffer *buf, int val, int bits)
{
int extra;
int shift;
if (bits == 0)
return;
/* buf->len always covers all the bits in the buffer, including
* any unused ones in the last byte, which will always be 0.
* buf->unused_bits = the number of unused bits in the last byte.
*/
/* Extend the buffer as required before we start; that way we never
* fail part way during writing. */
shift = (buf->unused_bits - bits);
if (shift < 0)
{
extra = (7-buf->unused_bits)>>3;
fz_ensure_buffer(ctx, buf, buf->len + extra);
}
/* Write any bits that will fit into the existing byte */
if (buf->unused_bits)
{
buf->data[buf->len-1] |= (shift >= 0 ? (((unsigned int)val)<<shift) : (((unsigned int)val)>>-shift));
if (shift >= 0)
return;
bits += shift;
}
/* Write any whole bytes */
while (bits >= 8)
{
bits -= 8;
buf->data[buf->len++] = val>>bits;
}
/* Write trailing bits (with 0's in unused bits) */
if (bits > 0)
{
bits += 8;
buf->data[buf->len++] = val<<bits;
}
buf->unused_bits = bits;
}
void fz_write_buffer_pad(fz_context *ctx, fz_buffer *buf)
{
buf->unused_bits = 0;
}
void
fz_buffer_printf(fz_context *ctx, fz_buffer *buffer, char *fmt, ...)
{
va_list args;
va_start(args, fmt);
/* Caller guarantees not to generate more than 256 bytes per call */
while(buffer->cap - buffer->len < 256)
fz_grow_buffer(ctx, buffer);
buffer->len += vsprintf((char *)buffer->data + buffer->len, fmt, args);
va_end(args);
}
|
