mirror of https://github.com/beego/bee.git
82 lines
1.3 KiB
Go
82 lines
1.3 KiB
Go
package util
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import "bytes"
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// DecodeULEB128 decodes an unsigned Little Endian Base 128
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// represented number.
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func DecodeULEB128(buf *bytes.Buffer) (uint64, uint32) {
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var (
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result uint64
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shift uint64
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length uint32
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)
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if buf.Len() == 0 {
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return 0, 0
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}
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for {
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b, err := buf.ReadByte()
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if err != nil {
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panic("Could not parse ULEB128 value")
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}
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length++
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result |= uint64((uint(b) & 0x7f) << shift)
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// If high order bit is 1.
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if b&0x80 == 0 {
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break
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}
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shift += 7
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}
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return result, length
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}
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// DecodeSLEB128 decodes a signed Little Endian Base 128
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// represented number.
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func DecodeSLEB128(buf *bytes.Buffer) (int64, uint32) {
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var (
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b byte
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err error
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result int64
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shift uint64
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length uint32
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)
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if buf.Len() == 0 {
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return 0, 0
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}
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for {
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b, err = buf.ReadByte()
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if err != nil {
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panic("Could not parse SLEB128 value")
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}
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length++
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result |= int64((int64(b) & 0x7f) << shift)
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shift += 7
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if b&0x80 == 0 {
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break
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}
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}
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if (shift < 8*uint64(length)) && (b&0x40 > 0) {
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result |= -(1 << shift)
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}
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return result, length
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}
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func ParseString(data *bytes.Buffer) (string, uint32) {
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str, err := data.ReadString(0x0)
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if err != nil {
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panic("Could not parse string")
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}
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return str[:len(str)-1], uint32(len(str))
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}
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