contrib/libyaml/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     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