summaryrefslogtreecommitdiff
path: root/ext/psych/yaml/writer.c
blob: b90019f5cb7ec584ea5625c6e5d849e8423003c3 (plain)
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

#include "yaml_private.h"

/*
 * Declarations.
 */

static int
yaml_emitter_set_writer_error(yaml_emitter_t *emitter, const char *problem);

YAML_DECLARE(int)
yaml_emitter_flush(yaml_emitter_t *emitter);

/*
 * Set the writer error and return 0.
 */

static int
yaml_emitter_set_writer_error(yaml_emitter_t *emitter, const char *problem)
{
    emitter->error = YAML_WRITER_ERROR;
    emitter->problem = problem;

    return 0;
}

/*
 * Flush the output buffer.
 */

YAML_DECLARE(int)
yaml_emitter_flush(yaml_emitter_t *emitter)
{
    int low, high;

    assert(emitter);    /* Non-NULL emitter object is expected. */
    assert(emitter->write_handler); /* Write handler must be set. */
    assert(emitter->encoding);  /* Output encoding must be set. */

    emitter->buffer.last = emitter->buffer.pointer;
    emitter->buffer.pointer = emitter->buffer.start;

    /* Check if the buffer is empty. */

    if (emitter->buffer.start == emitter->buffer.last) {
        return 1;
    }

    /* If the output encoding is UTF-8, we don't need to recode the buffer. */

    if (emitter->encoding == YAML_UTF8_ENCODING)
    {
        if (emitter->write_handler(emitter->write_handler_data,
                    emitter->buffer.start,
                    emitter->buffer.last - emitter->buffer.start)) {
            emitter->buffer.last = emitter->buffer.start;
            emitter->buffer.pointer = emitter->buffer.start;
            return 1;
        }
        else {
            return yaml_emitter_set_writer_error(emitter, "write error");
        }
    }

    /* Recode the buffer into the raw buffer. */

    low = (emitter->encoding == YAML_UTF16LE_ENCODING ? 0 : 1);
    high = (emitter->encoding == YAML_UTF16LE_ENCODING ? 1 : 0);

    while (emitter->buffer.pointer != emitter->buffer.last)
    {
        unsigned char octet;
        unsigned int width;
        unsigned int value;
        size_t k;

        /* 
         * See the "reader.c" code for more details on UTF-8 encoding.  Note
         * that we assume that the buffer contains a valid UTF-8 sequence.
         */

        /* Read the next UTF-8 character. */

        octet = emitter->buffer.pointer[0];

        width = (octet & 0x80) == 0x00 ? 1 :
                (octet & 0xE0) == 0xC0 ? 2 :
                (octet & 0xF0) == 0xE0 ? 3 :
                (octet & 0xF8) == 0xF0 ? 4 : 0;

        value = (octet & 0x80) == 0x00 ? octet & 0x7F :
                (octet & 0xE0) == 0xC0 ? octet & 0x1F :
                (octet & 0xF0) == 0xE0 ? octet & 0x0F :
                (octet & 0xF8) == 0xF0 ? octet & 0x07 : 0;

        for (k = 1; k < width; k ++) {
            octet = emitter->buffer.pointer[k];
            value = (value << 6) + (octet & 0x3F);
        }

        emitter->buffer.pointer += width;

        /* Write the character. */

        if (value < 0x10000)
        {
            emitter->raw_buffer.last[high] = value >> 8;
            emitter->raw_buffer.last[low] = value & 0xFF;

            emitter->raw_buffer.last += 2;
        }
        else
        {
            /* Write the character using a surrogate pair (check "reader.c"). */

            value -= 0x10000;
            emitter->raw_buffer.last[high] = 0xD8 + (value >> 18);
            emitter->raw_buffer.last[low] = (value >> 10) & 0xFF;
            emitter->raw_buffer.last[high+2] = 0xDC + ((value >> 8) & 0xFF);
            emitter->raw_buffer.last[low+2] = value & 0xFF;

            emitter->raw_buffer.last += 4;
        }
    }

    /* Write the raw buffer. */

    if (emitter->write_handler(emitter->write_handler_data,
                emitter->raw_buffer.start,
                emitter->raw_buffer.last - emitter->raw_buffer.start)) {
        emitter->buffer.last = emitter->buffer.start;
        emitter->buffer.pointer = emitter->buffer.start;
        emitter->raw_buffer.last = emitter->raw_buffer.start;
        emitter->raw_buffer.pointer = emitter->raw_buffer.start;
        return 1;
    }
    else {
        return yaml_emitter_set_writer_error(emitter, "write error");
    }
}