-#define RAW_BUFFER_SIZE 16384
-#define BUFFER_SIZE (RAW_BUFFER_SIZE*2) /* Should be enough for decoding
- the whole raw buffer. */
+#include "yaml_private.h"
/*
- * Ensure that the buffer contains at least length characters.
- * Return 1 on success, 0 on failure.
+ * Declarations.
+ */
+
+static int
+yaml_parser_set_reader_error(yaml_parser_t *parser, const char *problem,
+ size_t offset, int value);
+
+static int
+yaml_parser_update_raw_buffer(yaml_parser_t *parser);
+
+static int
+yaml_parser_determine_encoding(yaml_parser_t *parser);
+
+YAML_DECLARE(int)
+yaml_parser_update_buffer(yaml_parser_t *parser, size_t length);
+
+/*
+ * Set the reader error and return 0.
*/
-int
-yaml_parser_update_reader(yaml_parser_t *parser, size_t length)
+static int
+yaml_parser_set_reader_error(yaml_parser_t *parser, const char *problem,
+ size_t offset, int value)
{
- /* If the EOF flag is set, do nothing. */
+ parser->error = YAML_READER_ERROR;
+ parser->problem = problem;
+ parser->problem_offset = offset;
+ parser->problem_value = value;
- if (parser->eof)
- return 1;
+ return 0;
+}
+
+/*
+ * Byte order marks.
+ */
+
+#define BOM_UTF8 "\xef\xbb\xbf"
+#define BOM_UTF16LE "\xff\xfe"
+#define BOM_UTF16BE "\xfe\xff"
+
+/*
+ * Determine the input stream encoding by checking the BOM symbol. If no BOM is
+ * found, the UTF-8 encoding is assumed. Return 1 on success, 0 on failure.
+ */
- /* First, let us check that the buffers are allocated. */
+static int
+yaml_parser_determine_encoding(yaml_parser_t *parser)
+{
+ /* Ensure that we had enough bytes in the raw buffer. */
- if (!parser->buffer) {
- parser->buffer = yaml_malloc(BUFFER_SIZE);
- if (!parser->buffer) {
- parser->error = YAML_MEMORY_ERROR;
+ while (!parser->eof
+ && parser->raw_buffer.last - parser->raw_buffer.pointer < 3) {
+ if (!yaml_parser_update_raw_buffer(parser)) {
return 0;
}
- parser->buffer_size = BUFFER_SIZE;
- parser->buffer_pointer = parser->buffer;
- parser->buffer_length = 0;
}
- if (!parser->raw_buffer) {
- parser->raw_buffer = yaml_malloc(RAW_BUFFER_SIZE);
- if (!parser->raw_buffer) {
- parser->error = YAML_MEMORY_ERROR;
- return 0;
- }
- parser->raw_buffer_size = RAW_BUFFER_SIZE;
+ /* Determine the encoding. */
+
+ if (parser->raw_buffer.last - parser->raw_buffer.pointer >= 2
+ && !memcmp(parser->raw_buffer.pointer, BOM_UTF16LE, 2)) {
+ parser->encoding = YAML_UTF16LE_ENCODING;
+ parser->raw_buffer.pointer += 2;
+ parser->offset += 2;
+ }
+ else if (parser->raw_buffer.last - parser->raw_buffer.pointer >= 2
+ && !memcmp(parser->raw_buffer.pointer, BOM_UTF16BE, 2)) {
+ parser->encoding = YAML_UTF16BE_ENCODING;
+ parser->raw_buffer.pointer += 2;
+ parser->offset += 2;
+ }
+ else if (parser->raw_buffer.last - parser->raw_buffer.pointer >= 3
+ && !memcmp(parser->raw_buffer.pointer, BOM_UTF8, 3)) {
+ parser->encoding = YAML_UTF8_ENCODING;
+ parser->raw_buffer.pointer += 3;
+ parser->offset += 3;
+ }
+ else {
+ parser->encoding = YAML_UTF8_ENCODING;
+ }
+
+ return 1;
+}
+
+/*
+ * Update the raw buffer.
+ */
+
+static int
+yaml_parser_update_raw_buffer(yaml_parser_t *parser)
+{
+ size_t size_read = 0;
+
+ /* Return if the raw buffer is full. */
+
+ if (parser->raw_buffer.start == parser->raw_buffer.pointer
+ && parser->raw_buffer.last == parser->raw_buffer.end)
+ return 1;
+
+ /* Return on EOF. */
+
+ if (parser->eof) return 1;
+
+ /* Move the remaining bytes in the raw buffer to the beginning. */
+
+ if (parser->raw_buffer.start < parser->raw_buffer.pointer
+ && parser->raw_buffer.pointer < parser->raw_buffer.last) {
+ memmove(parser->raw_buffer.start, parser->raw_buffer.pointer,
+ parser->raw_buffer.last - parser->raw_buffer.pointer);
+ }
+ parser->raw_buffer.last -=
+ parser->raw_buffer.pointer - parser->raw_buffer.start;
+ parser->raw_buffer.pointer = parser->raw_buffer.start;
+
+ /* Call the read handler to fill the buffer. */
+
+ if (!parser->read_handler(parser->read_handler_data, parser->raw_buffer.last,
+ parser->raw_buffer.end - parser->raw_buffer.last, &size_read)) {
+ return yaml_parser_set_reader_error(parser, "input error",
+ parser->offset, -1);
}
+ parser->raw_buffer.last += size_read;
+ if (!size_read) {
+ parser->eof = 1;
+ }
+
+ return 1;
+}
+
+/*
+ * Ensure that the buffer contains at least `length` characters.
+ * Return 1 on success, 0 on failure.
+ *
+ * The length is supposed to be significantly less that the buffer size.
+ */
+
+YAML_DECLARE(int)
+yaml_parser_update_buffer(yaml_parser_t *parser, size_t length)
+{
+ int first = 1;
+
+ assert(parser->read_handler); /* Read handler must be set. */
+
+ /* If the EOF flag is set and the raw buffer is empty, do nothing. */
+
+ if (parser->eof && parser->raw_buffer.pointer == parser->raw_buffer.last)
+ return 1;
+
+ /* Return if the buffer contains enough characters. */
- /* Next, determine the input encoding. */
+ if (parser->unread >= length)
+ return 1;
+
+ /* Determine the input encoding if it is not known yet. */
if (!parser->encoding) {
if (!yaml_parser_determine_encoding(parser))
return 0;
}
- /* more... */
+ /* Move the unread characters to the beginning of the buffer. */
-}
+ if (parser->buffer.start < parser->buffer.pointer
+ && parser->buffer.pointer < parser->buffer.last) {
+ size_t size = parser->buffer.last - parser->buffer.pointer;
+ memmove(parser->buffer.start, parser->buffer.pointer, size);
+ parser->buffer.pointer = parser->buffer.start;
+ parser->buffer.last = parser->buffer.start + size;
+ }
+ else if (parser->buffer.pointer == parser->buffer.last) {
+ parser->buffer.pointer = parser->buffer.start;
+ parser->buffer.last = parser->buffer.start;
+ }
+
+ /* Fill the buffer until it has enough characters. */
+
+ while (parser->unread < length)
+ {
+ /* Fill the raw buffer if necessary. */
+
+ if (!first || parser->raw_buffer.pointer == parser->raw_buffer.last) {
+ if (!yaml_parser_update_raw_buffer(parser)) return 0;
+ }
+ first = 0;
+
+ /* Decode the raw buffer. */
+
+ while (parser->raw_buffer.pointer != parser->raw_buffer.last)
+ {
+ unsigned int value = 0, value2 = 0;
+ int incomplete = 0;
+ unsigned char octet;
+ unsigned int width = 0;
+ int low, high;
+ size_t k;
+ size_t raw_unread = parser->raw_buffer.last - parser->raw_buffer.pointer;
+
+ /* Decode the next character. */
+
+ switch (parser->encoding)
+ {
+ case YAML_UTF8_ENCODING:
+
+ /*
+ * Decode a UTF-8 character. Check RFC 3629
+ * (http://www.ietf.org/rfc/rfc3629.txt) for more details.
+ *
+ * The following table (taken from the RFC) is used for
+ * decoding.
+ *
+ * Char. number range | UTF-8 octet sequence
+ * (hexadecimal) | (binary)
+ * --------------------+------------------------------------
+ * 0000 0000-0000 007F | 0xxxxxxx
+ * 0000 0080-0000 07FF | 110xxxxx 10xxxxxx
+ * 0000 0800-0000 FFFF | 1110xxxx 10xxxxxx 10xxxxxx
+ * 0001 0000-0010 FFFF | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+ *
+ * Additionally, the characters in the range 0xD800-0xDFFF
+ * are prohibited as they are reserved for use with UTF-16
+ * surrogate pairs.
+ */
+
+ /* Determine the length of the UTF-8 sequence. */
+
+ octet = parser->raw_buffer.pointer[0];
+ width = (octet & 0x80) == 0x00 ? 1 :
+ (octet & 0xE0) == 0xC0 ? 2 :
+ (octet & 0xF0) == 0xE0 ? 3 :
+ (octet & 0xF8) == 0xF0 ? 4 : 0;
+
+ /* Check if the leading octet is valid. */
+
+ if (!width)
+ return yaml_parser_set_reader_error(parser,
+ "invalid leading UTF-8 octet",
+ parser->offset, octet);
+
+ /* Check if the raw buffer contains an incomplete character. */
+
+ if (width > raw_unread) {
+ if (parser->eof) {
+ return yaml_parser_set_reader_error(parser,
+ "incomplete UTF-8 octet sequence",
+ parser->offset, -1);
+ }
+ incomplete = 1;
+ break;
+ }
+
+ /* Decode the leading octet. */
+
+ value = (octet & 0x80) == 0x00 ? octet & 0x7F :
+ (octet & 0xE0) == 0xC0 ? octet & 0x1F :
+ (octet & 0xF0) == 0xE0 ? octet & 0x0F :
+ (octet & 0xF8) == 0xF0 ? octet & 0x07 : 0;
+
+ /* Check and decode the trailing octets. */
+
+ for (k = 1; k < width; k ++)
+ {
+ octet = parser->raw_buffer.pointer[k];
+
+ /* Check if the octet is valid. */
+
+ if ((octet & 0xC0) != 0x80)
+ return yaml_parser_set_reader_error(parser,
+ "invalid trailing UTF-8 octet",
+ parser->offset+k, octet);
+
+ /* Decode the octet. */
+
+ value = (value << 6) + (octet & 0x3F);
+ }
+
+ /* Check the length of the sequence against the value. */
+
+ if (!((width == 1) ||
+ (width == 2 && value >= 0x80) ||
+ (width == 3 && value >= 0x800) ||
+ (width == 4 && value >= 0x10000)))
+ return yaml_parser_set_reader_error(parser,
+ "invalid length of a UTF-8 sequence",
+ parser->offset, -1);
+
+ /* Check the range of the value. */
+
+ if ((value >= 0xD800 && value <= 0xDFFF) || value > 0x10FFFF)
+ return yaml_parser_set_reader_error(parser,
+ "invalid Unicode character",
+ parser->offset, value);
+
+ break;
+
+ case YAML_UTF16LE_ENCODING:
+ case YAML_UTF16BE_ENCODING:
+
+ low = (parser->encoding == YAML_UTF16LE_ENCODING ? 0 : 1);
+ high = (parser->encoding == YAML_UTF16LE_ENCODING ? 1 : 0);
+
+ /*
+ * The UTF-16 encoding is not as simple as one might
+ * naively think. Check RFC 2781
+ * (http://www.ietf.org/rfc/rfc2781.txt).
+ *
+ * Normally, two subsequent bytes describe a Unicode
+ * character. However a special technique (called a
+ * surrogate pair) is used for specifying character
+ * values larger than 0xFFFF.
+ *
+ * A surrogate pair consists of two pseudo-characters:
+ * high surrogate area (0xD800-0xDBFF)
+ * low surrogate area (0xDC00-0xDFFF)
+ *
+ * The following formulas are used for decoding
+ * and encoding characters using surrogate pairs:
+ *
+ * U = U' + 0x10000 (0x01 00 00 <= U <= 0x10 FF FF)
+ * U' = yyyyyyyyyyxxxxxxxxxx (0 <= U' <= 0x0F FF FF)
+ * W1 = 110110yyyyyyyyyy
+ * W2 = 110111xxxxxxxxxx
+ *
+ * where U is the character value, W1 is the high surrogate
+ * area, W2 is the low surrogate area.
+ */
+
+ /* Check for incomplete UTF-16 character. */
+
+ if (raw_unread < 2) {
+ if (parser->eof) {
+ return yaml_parser_set_reader_error(parser,
+ "incomplete UTF-16 character",
+ parser->offset, -1);
+ }
+ incomplete = 1;
+ break;
+ }
+
+ /* Get the character. */
+
+ value = parser->raw_buffer.pointer[low]
+ + (parser->raw_buffer.pointer[high] << 8);
+ /* Check for unexpected low surrogate area. */
+ if ((value & 0xFC00) == 0xDC00)
+ return yaml_parser_set_reader_error(parser,
+ "unexpected low surrogate area",
+ parser->offset, value);
+
+ /* Check for a high surrogate area. */
+
+ if ((value & 0xFC00) == 0xD800) {
+
+ width = 4;
+
+ /* Check for incomplete surrogate pair. */
+
+ if (raw_unread < 4) {
+ if (parser->eof) {
+ return yaml_parser_set_reader_error(parser,
+ "incomplete UTF-16 surrogate pair",
+ parser->offset, -1);
+ }
+ incomplete = 1;
+ break;
+ }
+
+ /* Get the next character. */
+
+ value2 = parser->raw_buffer.pointer[low+2]
+ + (parser->raw_buffer.pointer[high+2] << 8);
+
+ /* Check for a low surrogate area. */
+
+ if ((value2 & 0xFC00) != 0xDC00)
+ return yaml_parser_set_reader_error(parser,
+ "expected low surrogate area",
+ parser->offset+2, value2);
+
+ /* Generate the value of the surrogate pair. */
+
+ value = 0x10000 + ((value & 0x3FF) << 10) + (value2 & 0x3FF);
+ }
+
+ else {
+ width = 2;
+ }
+
+ break;
+
+ default:
+ assert(1); /* Impossible. */
+ }
+
+ /* Check if the raw buffer contains enough bytes to form a character. */
+
+ if (incomplete) break;
+
+ /*
+ * Check if the character is in the allowed range:
+ * #x9 | #xA | #xD | [#x20-#x7E] (8 bit)
+ * | #x85 | [#xA0-#xD7FF] | [#xE000-#xFFFD] (16 bit)
+ * | [#x10000-#x10FFFF] (32 bit)
+ */
+
+ if (! (value == 0x09 || value == 0x0A || value == 0x0D
+ || (value >= 0x20 && value <= 0x7E)
+ || (value == 0x85) || (value >= 0xA0 && value <= 0xD7FF)
+ || (value >= 0xE000 && value <= 0xFFFD)
+ || (value >= 0x10000 && value <= 0x10FFFF)))
+ return yaml_parser_set_reader_error(parser,
+ "control characters are not allowed",
+ parser->offset, value);
+
+ /* Move the raw pointers. */
+
+ parser->raw_buffer.pointer += width;
+ parser->offset += width;
+
+ /* Finally put the character into the buffer. */
+
+ /* 0000 0000-0000 007F -> 0xxxxxxx */
+ if (value <= 0x7F) {
+ *(parser->buffer.last++) = value;
+ }
+ /* 0000 0080-0000 07FF -> 110xxxxx 10xxxxxx */
+ else if (value <= 0x7FF) {
+ *(parser->buffer.last++) = 0xC0 + (value >> 6);
+ *(parser->buffer.last++) = 0x80 + (value & 0x3F);
+ }
+ /* 0000 0800-0000 FFFF -> 1110xxxx 10xxxxxx 10xxxxxx */
+ else if (value <= 0xFFFF) {
+ *(parser->buffer.last++) = 0xE0 + (value >> 12);
+ *(parser->buffer.last++) = 0x80 + ((value >> 6) & 0x3F);
+ *(parser->buffer.last++) = 0x80 + (value & 0x3F);
+ }
+ /* 0001 0000-0010 FFFF -> 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
+ else {
+ *(parser->buffer.last++) = 0xF0 + (value >> 18);
+ *(parser->buffer.last++) = 0x80 + ((value >> 12) & 0x3F);
+ *(parser->buffer.last++) = 0x80 + ((value >> 6) & 0x3F);
+ *(parser->buffer.last++) = 0x80 + (value & 0x3F);
+ }
+
+ parser->unread ++;
+ }
+
+ /* On EOF, put NUL into the buffer and return. */
+
+ if (parser->eof) {
+ *(parser->buffer.last++) = '\0';
+ parser->unread ++;
+ return 1;
+ }
+
+ }
+
+ if (parser->offset >= PTRDIFF_MAX)
+ return yaml_parser_set_reader_error(parser, "input is too long",
+ PTRDIFF_MAX, -1);
+
+ return 1;
+}
andersk / libyaml.git / blobdiff