132 lines
2.6 KiB
Go
132 lines
2.6 KiB
Go
package rfc3986
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import (
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"io"
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"github.com/reiver/go-erorr"
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)
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const pctencodedprefix = '%'
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func IsPctEncodedPrefix(r rune) bool {
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return pctencodedprefix == r
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}
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func ReadPctEncodedByte(reader io.Reader) (byte, error) {
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if nil == reader {
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return 0, errNilReader
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}
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var buffer [1]byte
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var p []byte = buffer[:]
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{
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n, err := reader.Read(p)
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if nil != err {
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return 0, erorr.Errorf("rfc3986: could not read the 1st byte in pct-encoded string because: %w", err)
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}
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if 1 != n {
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return 0, erorr.Errorf("rfc3986: problem reading the 1st byte in pct-encoded string — expected to have read 1 byte but actually read %d bytes.", n)
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}
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b0 := buffer[0]
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if !IsPctEncodedPrefix(rune(b0)) {
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return 0, erorr.Errorf("rfc3986:the 1st byte in pct-encoded string is not a percent-sign (%U) (%q) is actually %U (%q)", pctencodedprefix, pctencodedprefix, b0, b0)
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}
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}
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var result byte = 0
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{
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n, err := reader.Read(p)
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if nil != err {
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return 0, erorr.Errorf("rfc3986: could not read the 2nd byte in pct-encoded string because: %w", err)
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}
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if 1 != n {
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return 0, erorr.Errorf("rfc3986: problem reading the 2nd byte in pct-encoded string — expected to have read 1 byte but actually read %d bytes.", n)
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}
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b0 := buffer[0]
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switch {
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case '0' <= b0 && b0 <= '9':
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b0 -= '0'
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case 'A' <= b0 && b0 <= 'F':
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b0 -= 'A'
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b0 += 10
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case 'a' <= b0 && b0 <= 'f':
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b0 -= 'a'
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b0 += 10
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default:
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return 0, erorr.Errorf("rfc3986: the 2nd byte in the pct-encoded string is not an IETF RFC-2234 'HEXDIG'")
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}
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result |= (b0 << 4)
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}
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{
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n, err := reader.Read(p)
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if nil != err {
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return 0, erorr.Errorf("rfc3986: could not read the 3rd byte in pct-encoded string because: %w", err)
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}
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if 1 != n {
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return 0, erorr.Errorf("rfc3986: problem reading the 3rd byte in pct-encoded string — expected to have read 1 byte but actually read %d bytes.", n)
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}
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b0 := buffer[0]
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switch {
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case '0' <= b0 && b0 <= '9':
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b0 -= '0'
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case 'A' <= b0 && b0 <= 'F':
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b0 -= 'A'
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b0 += 10
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case 'a' <= b0 && b0 <= 'f':
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b0 -= 'a'
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b0 += 10
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default:
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return 0, erorr.Errorf("rfc3986: the 2nd byte in the pct-encoded string is not an IETF RFC-2234 'HEXDIG'")
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}
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result |= b0
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}
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return result, nil
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}
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func WritePctEncodedByte(writer io.Writer, b byte) error {
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if nil == writer {
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return errNilWriter
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}
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var buffer [3]byte = [3]byte{'%','.','.'}
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{
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var x byte = ((b>>4) % 16)
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if x < 10 {
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x += '0'
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} else {
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x += ('A' - 10)
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}
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buffer[1] = x
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}
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{
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var x byte = (b & 0x0f)
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if x < 10 {
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x += '0'
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} else {
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x += ('A' - 10)
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}
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buffer[2] = x
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}
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_, err := writer.Write(buffer[:])
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return err
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}
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