src/writer.c

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