diff options
Diffstat (limited to 'vendor/github.com/json-iterator/go/iter_str.go')
-rw-r--r-- | vendor/github.com/json-iterator/go/iter_str.go | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/vendor/github.com/json-iterator/go/iter_str.go b/vendor/github.com/json-iterator/go/iter_str.go new file mode 100644 index 00000000..adc487ea --- /dev/null +++ b/vendor/github.com/json-iterator/go/iter_str.go @@ -0,0 +1,215 @@ +package jsoniter + +import ( + "fmt" + "unicode/utf16" +) + +// ReadString read string from iterator +func (iter *Iterator) ReadString() (ret string) { + c := iter.nextToken() + if c == '"' { + for i := iter.head; i < iter.tail; i++ { + c := iter.buf[i] + if c == '"' { + ret = string(iter.buf[iter.head:i]) + iter.head = i + 1 + return ret + } else if c == '\\' { + break + } else if c < ' ' { + iter.ReportError("ReadString", + fmt.Sprintf(`invalid control character found: %d`, c)) + return + } + } + return iter.readStringSlowPath() + } else if c == 'n' { + iter.skipThreeBytes('u', 'l', 'l') + return "" + } + iter.ReportError("ReadString", `expects " or n, but found `+string([]byte{c})) + return +} + +func (iter *Iterator) readStringSlowPath() (ret string) { + var str []byte + var c byte + for iter.Error == nil { + c = iter.readByte() + if c == '"' { + return string(str) + } + if c == '\\' { + c = iter.readByte() + str = iter.readEscapedChar(c, str) + } else { + str = append(str, c) + } + } + iter.ReportError("readStringSlowPath", "unexpected end of input") + return +} + +func (iter *Iterator) readEscapedChar(c byte, str []byte) []byte { + switch c { + case 'u': + r := iter.readU4() + if utf16.IsSurrogate(r) { + c = iter.readByte() + if iter.Error != nil { + return nil + } + if c != '\\' { + iter.unreadByte() + str = appendRune(str, r) + return str + } + c = iter.readByte() + if iter.Error != nil { + return nil + } + if c != 'u' { + str = appendRune(str, r) + return iter.readEscapedChar(c, str) + } + r2 := iter.readU4() + if iter.Error != nil { + return nil + } + combined := utf16.DecodeRune(r, r2) + if combined == '\uFFFD' { + str = appendRune(str, r) + str = appendRune(str, r2) + } else { + str = appendRune(str, combined) + } + } else { + str = appendRune(str, r) + } + case '"': + str = append(str, '"') + case '\\': + str = append(str, '\\') + case '/': + str = append(str, '/') + case 'b': + str = append(str, '\b') + case 'f': + str = append(str, '\f') + case 'n': + str = append(str, '\n') + case 'r': + str = append(str, '\r') + case 't': + str = append(str, '\t') + default: + iter.ReportError("readEscapedChar", + `invalid escape char after \`) + return nil + } + return str +} + +// ReadStringAsSlice read string from iterator without copying into string form. +// The []byte can not be kept, as it will change after next iterator call. +func (iter *Iterator) ReadStringAsSlice() (ret []byte) { + c := iter.nextToken() + if c == '"' { + for i := iter.head; i < iter.tail; i++ { + // require ascii string and no escape + // for: field name, base64, number + if iter.buf[i] == '"' { + // fast path: reuse the underlying buffer + ret = iter.buf[iter.head:i] + iter.head = i + 1 + return ret + } + } + readLen := iter.tail - iter.head + copied := make([]byte, readLen, readLen*2) + copy(copied, iter.buf[iter.head:iter.tail]) + iter.head = iter.tail + for iter.Error == nil { + c := iter.readByte() + if c == '"' { + return copied + } + copied = append(copied, c) + } + return copied + } + iter.ReportError("ReadStringAsSlice", `expects " or n, but found `+string([]byte{c})) + return +} + +func (iter *Iterator) readU4() (ret rune) { + for i := 0; i < 4; i++ { + c := iter.readByte() + if iter.Error != nil { + return + } + if c >= '0' && c <= '9' { + ret = ret*16 + rune(c-'0') + } else if c >= 'a' && c <= 'f' { + ret = ret*16 + rune(c-'a'+10) + } else if c >= 'A' && c <= 'F' { + ret = ret*16 + rune(c-'A'+10) + } else { + iter.ReportError("readU4", "expects 0~9 or a~f, but found "+string([]byte{c})) + return + } + } + return ret +} + +const ( + t1 = 0x00 // 0000 0000 + tx = 0x80 // 1000 0000 + t2 = 0xC0 // 1100 0000 + t3 = 0xE0 // 1110 0000 + t4 = 0xF0 // 1111 0000 + t5 = 0xF8 // 1111 1000 + + maskx = 0x3F // 0011 1111 + mask2 = 0x1F // 0001 1111 + mask3 = 0x0F // 0000 1111 + mask4 = 0x07 // 0000 0111 + + rune1Max = 1<<7 - 1 + rune2Max = 1<<11 - 1 + rune3Max = 1<<16 - 1 + + surrogateMin = 0xD800 + surrogateMax = 0xDFFF + + maxRune = '\U0010FFFF' // Maximum valid Unicode code point. + runeError = '\uFFFD' // the "error" Rune or "Unicode replacement character" +) + +func appendRune(p []byte, r rune) []byte { + // Negative values are erroneous. Making it unsigned addresses the problem. + switch i := uint32(r); { + case i <= rune1Max: + p = append(p, byte(r)) + return p + case i <= rune2Max: + p = append(p, t2|byte(r>>6)) + p = append(p, tx|byte(r)&maskx) + return p + case i > maxRune, surrogateMin <= i && i <= surrogateMax: + r = runeError + fallthrough + case i <= rune3Max: + p = append(p, t3|byte(r>>12)) + p = append(p, tx|byte(r>>6)&maskx) + p = append(p, tx|byte(r)&maskx) + return p + default: + p = append(p, t4|byte(r>>18)) + p = append(p, tx|byte(r>>12)&maskx) + p = append(p, tx|byte(r>>6)&maskx) + p = append(p, tx|byte(r)&maskx) + return p + } +} |