/src/libyaml/writer.c

  1
  2#include "yaml_private.h"
  3
  4/*
  5 * Declarations.
  6 */
  7
  8static int
  9yaml_emitter_set_writer_error(yaml_emitter_t *emitter, const char *problem);
 10
 11YAML_DECLARE(int)
 12yaml_emitter_flush(yaml_emitter_t *emitter);
 13
 14/*
 15 * Set the writer error and return 0.
 16 */
 17
 18static int
 19yaml_emitter_set_writer_error(yaml_emitter_t *emitter, const char *problem)
 20{
 21    emitter->error = YAML_WRITER_ERROR;
 22    emitter->problem = problem;
 23
 24    return 0;
 25}
 26
 27/*
 28 * Flush the output buffer.
 29 */
 30
 31YAML_DECLARE(int)
 32yaml_emitter_flush(yaml_emitter_t *emitter)
 33{
 34    int low, high;
 35
 36    assert(emitter);    /* Non-NULL emitter object is expected. */
 37    assert(emitter->write_handler); /* Write handler must be set. */
 38    assert(emitter->encoding);  /* Output encoding must be set. */
 39
 40    emitter->buffer.last = emitter->buffer.pointer;
 41    emitter->buffer.pointer = emitter->buffer.start;
 42
 43    /* Check if the buffer is empty. */
 44
 45    if (emitter->buffer.start == emitter->buffer.last) {
 46        return 1;
 47    }
 48
 49    /* If the output encoding is UTF-8, we don't need to recode the buffer. */
 50
 51    if (emitter->encoding == YAML_UTF8_ENCODING)
 52    {
 53        if (emitter->write_handler(emitter->write_handler_data,
 54                    emitter->buffer.start,
 55                    emitter->buffer.last - emitter->buffer.start)) {
 56            emitter->buffer.last = emitter->buffer.start;
 57            emitter->buffer.pointer = emitter->buffer.start;
 58            return 1;
 59        }
 60        else {
 61            return yaml_emitter_set_writer_error(emitter, "write error");
 62        }
 63    }
 64
 65    /* Recode the buffer into the raw buffer. */
 66
 67    low = (emitter->encoding == YAML_UTF16LE_ENCODING ? 0 : 1);
 68    high = (emitter->encoding == YAML_UTF16LE_ENCODING ? 1 : 0);
 69
 70    while (emitter->buffer.pointer != emitter->buffer.last)
 71    {
 72        unsigned char octet;
 73        unsigned int width;
 74        unsigned int value;
 75        size_t k;
 76
 77        /* 
 78         * See the "reader.c" code for more details on UTF-8 encoding.  Note
 79         * that we assume that the buffer contains a valid UTF-8 sequence.
 80         */
 81
 82        /* Read the next UTF-8 character. */
 83
 84        octet = emitter->buffer.pointer[0];
 85
 86        width = (octet & 0x80) == 0x00 ? 1 :
 87                (octet & 0xE0) == 0xC0 ? 2 :
 88                (octet & 0xF0) == 0xE0 ? 3 :
 89                (octet & 0xF8) == 0xF0 ? 4 : 0;
 90
 91        value = (octet & 0x80) == 0x00 ? octet & 0x7F :
 92                (octet & 0xE0) == 0xC0 ? octet & 0x1F :
 93                (octet & 0xF0) == 0xE0 ? octet & 0x0F :
 94                (octet & 0xF8) == 0xF0 ? octet & 0x07 : 0;
 95
 96        for (k = 1; k < width; k ++) {
 97            octet = emitter->buffer.pointer[k];
 98            value = (value << 6) + (octet & 0x3F);
 99        }
100
101        emitter->buffer.pointer += width;
102
103        /* Write the character. */
104
105        if (value < 0x10000)
106        {
107            emitter->raw_buffer.last[high] = value >> 8;
108            emitter->raw_buffer.last[low] = value & 0xFF;
109
110            emitter->raw_buffer.last += 2;
111        }
112        else
113        {
114            /* Write the character using a surrogate pair (check "reader.c"). */
115
116            value -= 0x10000;
117            emitter->raw_buffer.last[high] = 0xD8 + (value >> 18);
118            emitter->raw_buffer.last[low] = (value >> 10) & 0xFF;
119            emitter->raw_buffer.last[high+2] = 0xDC + ((value >> 8) & 0xFF);
120            emitter->raw_buffer.last[low+2] = value & 0xFF;
121
122            emitter->raw_buffer.last += 4;
123        }
124    }
125
126    /* Write the raw buffer. */
127
128    if (emitter->write_handler(emitter->write_handler_data,
129                emitter->raw_buffer.start,
130                emitter->raw_buffer.last - emitter->raw_buffer.start)) {
131        emitter->buffer.last = emitter->buffer.start;
132        emitter->buffer.pointer = emitter->buffer.start;
133        emitter->raw_buffer.last = emitter->raw_buffer.start;
134        emitter->raw_buffer.pointer = emitter->raw_buffer.start;
135        return 1;
136    }
137    else {
138        return yaml_emitter_set_writer_error(emitter, "write error");
139    }
140}
141