diff options
Diffstat (limited to 'vendor/github.com/gogs/chardet/unicode.go')
-rw-r--r-- | vendor/github.com/gogs/chardet/unicode.go | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/vendor/github.com/gogs/chardet/unicode.go b/vendor/github.com/gogs/chardet/unicode.go new file mode 100644 index 0000000000..6f9fa9e67f --- /dev/null +++ b/vendor/github.com/gogs/chardet/unicode.go @@ -0,0 +1,103 @@ +package chardet + +import ( + "bytes" +) + +var ( + utf16beBom = []byte{0xFE, 0xFF} + utf16leBom = []byte{0xFF, 0xFE} + utf32beBom = []byte{0x00, 0x00, 0xFE, 0xFF} + utf32leBom = []byte{0xFF, 0xFE, 0x00, 0x00} +) + +type recognizerUtf16be struct { +} + +func newRecognizer_utf16be() *recognizerUtf16be { + return &recognizerUtf16be{} +} + +func (*recognizerUtf16be) Match(input *recognizerInput) (output recognizerOutput) { + output = recognizerOutput{ + Charset: "UTF-16BE", + } + if bytes.HasPrefix(input.raw, utf16beBom) { + output.Confidence = 100 + } + return +} + +type recognizerUtf16le struct { +} + +func newRecognizer_utf16le() *recognizerUtf16le { + return &recognizerUtf16le{} +} + +func (*recognizerUtf16le) Match(input *recognizerInput) (output recognizerOutput) { + output = recognizerOutput{ + Charset: "UTF-16LE", + } + if bytes.HasPrefix(input.raw, utf16leBom) && !bytes.HasPrefix(input.raw, utf32leBom) { + output.Confidence = 100 + } + return +} + +type recognizerUtf32 struct { + name string + bom []byte + decodeChar func(input []byte) uint32 +} + +func decodeUtf32be(input []byte) uint32 { + return uint32(input[0])<<24 | uint32(input[1])<<16 | uint32(input[2])<<8 | uint32(input[3]) +} + +func decodeUtf32le(input []byte) uint32 { + return uint32(input[3])<<24 | uint32(input[2])<<16 | uint32(input[1])<<8 | uint32(input[0]) +} + +func newRecognizer_utf32be() *recognizerUtf32 { + return &recognizerUtf32{ + "UTF-32BE", + utf32beBom, + decodeUtf32be, + } +} + +func newRecognizer_utf32le() *recognizerUtf32 { + return &recognizerUtf32{ + "UTF-32LE", + utf32leBom, + decodeUtf32le, + } +} + +func (r *recognizerUtf32) Match(input *recognizerInput) (output recognizerOutput) { + output = recognizerOutput{ + Charset: r.name, + } + hasBom := bytes.HasPrefix(input.raw, r.bom) + var numValid, numInvalid uint32 + for b := input.raw; len(b) >= 4; b = b[4:] { + if c := r.decodeChar(b); c >= 0x10FFFF || (c >= 0xD800 && c <= 0xDFFF) { + numInvalid++ + } else { + numValid++ + } + } + if hasBom && numInvalid == 0 { + output.Confidence = 100 + } else if hasBom && numValid > numInvalid*10 { + output.Confidence = 80 + } else if numValid > 3 && numInvalid == 0 { + output.Confidence = 100 + } else if numValid > 0 && numInvalid == 0 { + output.Confidence = 80 + } else if numValid > numInvalid*10 { + output.Confidence = 25 + } + return +} |