diff options
Diffstat (limited to 'vendor/gopkg.in/yaml.v2/readerc.go')
| -rw-r--r-- | vendor/gopkg.in/yaml.v2/readerc.go | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/vendor/gopkg.in/yaml.v2/readerc.go b/vendor/gopkg.in/yaml.v2/readerc.go new file mode 100644 index 00000000..f4507917 --- /dev/null +++ b/vendor/gopkg.in/yaml.v2/readerc.go @@ -0,0 +1,394 @@ +package yaml + +import ( + "io" +) + +// Set the reader error and return 0. +func yaml_parser_set_reader_error(parser *yaml_parser_t, problem string, offset int, value int) bool { + parser.error = yaml_READER_ERROR + parser.problem = problem + parser.problem_offset = offset + parser.problem_value = value + return false +} + +// Byte order marks. +const ( + bom_UTF8 = "\xef\xbb\xbf" + bom_UTF16LE = "\xff\xfe" + 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. +func yaml_parser_determine_encoding(parser *yaml_parser_t) bool { + // Ensure that we had enough bytes in the raw buffer. + for !parser.eof && len(parser.raw_buffer)-parser.raw_buffer_pos < 3 { + if !yaml_parser_update_raw_buffer(parser) { + return false + } + } + + // Determine the encoding. + buf := parser.raw_buffer + pos := parser.raw_buffer_pos + avail := len(buf) - pos + if avail >= 2 && buf[pos] == bom_UTF16LE[0] && buf[pos+1] == bom_UTF16LE[1] { + parser.encoding = yaml_UTF16LE_ENCODING + parser.raw_buffer_pos += 2 + parser.offset += 2 + } else if avail >= 2 && buf[pos] == bom_UTF16BE[0] && buf[pos+1] == bom_UTF16BE[1] { + parser.encoding = yaml_UTF16BE_ENCODING + parser.raw_buffer_pos += 2 + parser.offset += 2 + } else if avail >= 3 && buf[pos] == bom_UTF8[0] && buf[pos+1] == bom_UTF8[1] && buf[pos+2] == bom_UTF8[2] { + parser.encoding = yaml_UTF8_ENCODING + parser.raw_buffer_pos += 3 + parser.offset += 3 + } else { + parser.encoding = yaml_UTF8_ENCODING + } + return true +} + +// Update the raw buffer. +func yaml_parser_update_raw_buffer(parser *yaml_parser_t) bool { + size_read := 0 + + // Return if the raw buffer is full. + if parser.raw_buffer_pos == 0 && len(parser.raw_buffer) == cap(parser.raw_buffer) { + return true + } + + // Return on EOF. + if parser.eof { + return true + } + + // Move the remaining bytes in the raw buffer to the beginning. + if parser.raw_buffer_pos > 0 && parser.raw_buffer_pos < len(parser.raw_buffer) { + copy(parser.raw_buffer, parser.raw_buffer[parser.raw_buffer_pos:]) + } + parser.raw_buffer = parser.raw_buffer[:len(parser.raw_buffer)-parser.raw_buffer_pos] + parser.raw_buffer_pos = 0 + + // Call the read handler to fill the buffer. + size_read, err := parser.read_handler(parser, parser.raw_buffer[len(parser.raw_buffer):cap(parser.raw_buffer)]) + parser.raw_buffer = parser.raw_buffer[:len(parser.raw_buffer)+size_read] + if err == io.EOF { + parser.eof = true + } else if err != nil { + return yaml_parser_set_reader_error(parser, "input error: "+err.Error(), parser.offset, -1) + } + return true +} + +// Ensure that the buffer contains at least `length` characters. +// Return true on success, false on failure. +// +// The length is supposed to be significantly less that the buffer size. +func yaml_parser_update_buffer(parser *yaml_parser_t, length int) bool { + if parser.read_handler == nil { + panic("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_pos == len(parser.raw_buffer) { + return true + } + + // Return if the buffer contains enough characters. + if parser.unread >= length { + return true + } + + // Determine the input encoding if it is not known yet. + if parser.encoding == yaml_ANY_ENCODING { + if !yaml_parser_determine_encoding(parser) { + return false + } + } + + // Move the unread characters to the beginning of the buffer. + buffer_len := len(parser.buffer) + if parser.buffer_pos > 0 && parser.buffer_pos < buffer_len { + copy(parser.buffer, parser.buffer[parser.buffer_pos:]) + buffer_len -= parser.buffer_pos + parser.buffer_pos = 0 + } else if parser.buffer_pos == buffer_len { + buffer_len = 0 + parser.buffer_pos = 0 + } + + // Open the whole buffer for writing, and cut it before returning. + parser.buffer = parser.buffer[:cap(parser.buffer)] + + // Fill the buffer until it has enough characters. + first := true + for parser.unread < length { + + // Fill the raw buffer if necessary. + if !first || parser.raw_buffer_pos == len(parser.raw_buffer) { + if !yaml_parser_update_raw_buffer(parser) { + parser.buffer = parser.buffer[:buffer_len] + return false + } + } + first = false + + // Decode the raw buffer. + inner: + for parser.raw_buffer_pos != len(parser.raw_buffer) { + var value rune + var width int + + raw_unread := len(parser.raw_buffer) - parser.raw_buffer_pos + + // 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[parser.raw_buffer_pos] + switch { + case octet&0x80 == 0x00: + width = 1 + case octet&0xE0 == 0xC0: + width = 2 + case octet&0xF0 == 0xE0: + width = 3 + case octet&0xF8 == 0xF0: + width = 4 + default: + // The leading octet is invalid. + return yaml_parser_set_reader_error(parser, + "invalid leading UTF-8 octet", + parser.offset, int(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) + } + break inner + } + + // Decode the leading octet. + switch { + case octet&0x80 == 0x00: + value = rune(octet & 0x7F) + case octet&0xE0 == 0xC0: + value = rune(octet & 0x1F) + case octet&0xF0 == 0xE0: + value = rune(octet & 0x0F) + case octet&0xF8 == 0xF0: + value = rune(octet & 0x07) + default: + value = 0 + } + + // Check and decode the trailing octets. + for k := 1; k < width; k++ { + octet = parser.raw_buffer[parser.raw_buffer_pos+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, int(octet)) + } + + // Decode the octet. + value = (value << 6) + rune(octet&0x3F) + } + + // Check the length of the sequence against the value. + switch { + case width == 1: + case width == 2 && value >= 0x80: + case width == 3 && value >= 0x800: + case width == 4 && value >= 0x10000: + default: + 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, int(value)) + } + + case yaml_UTF16LE_ENCODING, yaml_UTF16BE_ENCODING: + var low, high int + if parser.encoding == yaml_UTF16LE_ENCODING { + low, high = 0, 1 + } else { + low, high = 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) + } + break inner + } + + // Get the character. + value = rune(parser.raw_buffer[parser.raw_buffer_pos+low]) + + (rune(parser.raw_buffer[parser.raw_buffer_pos+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, int(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) + } + break inner + } + + // Get the next character. + value2 := rune(parser.raw_buffer[parser.raw_buffer_pos+low+2]) + + (rune(parser.raw_buffer[parser.raw_buffer_pos+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, int(value2)) + } + + // Generate the value of the surrogate pair. + value = 0x10000 + ((value & 0x3FF) << 10) + (value2 & 0x3FF) + } else { + width = 2 + } + + default: + panic("impossible") + } + + // 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) + switch { + case value == 0x09: + case value == 0x0A: + case value == 0x0D: + case value >= 0x20 && value <= 0x7E: + case value == 0x85: + case value >= 0xA0 && value <= 0xD7FF: + case value >= 0xE000 && value <= 0xFFFD: + case value >= 0x10000 && value <= 0x10FFFF: + default: + return yaml_parser_set_reader_error(parser, + "control characters are not allowed", + parser.offset, int(value)) + } + + // Move the raw pointers. + parser.raw_buffer_pos += width + parser.offset += width + + // Finally put the character into the buffer. + if value <= 0x7F { + // 0000 0000-0000 007F . 0xxxxxxx + parser.buffer[buffer_len+0] = byte(value) + buffer_len += 1 + } else if value <= 0x7FF { + // 0000 0080-0000 07FF . 110xxxxx 10xxxxxx + parser.buffer[buffer_len+0] = byte(0xC0 + (value >> 6)) + parser.buffer[buffer_len+1] = byte(0x80 + (value & 0x3F)) + buffer_len += 2 + } else if value <= 0xFFFF { + // 0000 0800-0000 FFFF . 1110xxxx 10xxxxxx 10xxxxxx + parser.buffer[buffer_len+0] = byte(0xE0 + (value >> 12)) + parser.buffer[buffer_len+1] = byte(0x80 + ((value >> 6) & 0x3F)) + parser.buffer[buffer_len+2] = byte(0x80 + (value & 0x3F)) + buffer_len += 3 + } else { + // 0001 0000-0010 FFFF . 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx + parser.buffer[buffer_len+0] = byte(0xF0 + (value >> 18)) + parser.buffer[buffer_len+1] = byte(0x80 + ((value >> 12) & 0x3F)) + parser.buffer[buffer_len+2] = byte(0x80 + ((value >> 6) & 0x3F)) + parser.buffer[buffer_len+3] = byte(0x80 + (value & 0x3F)) + buffer_len += 4 + } + + parser.unread++ + } + + // On EOF, put NUL into the buffer and return. + if parser.eof { + parser.buffer[buffer_len] = 0 + buffer_len++ + parser.unread++ + break + } + } + parser.buffer = parser.buffer[:buffer_len] + return true +} |