mirror of
https://github.com/42wim/matterbridge
synced 2024-11-07 09:20:23 +00:00
104 lines
2.2 KiB
Go
104 lines
2.2 KiB
Go
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
|
|
}
|