| // Copyright Mozilla Foundation. See the COPYRIGHT |
| // file at the top-level directory of this distribution. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // https://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use super::*; |
| use crate::handles::*; |
| use crate::variant::*; |
| |
| pub struct Utf16Decoder { |
| lead_surrogate: u16, // If non-zero and pending_bmp == false, a pending lead surrogate |
| lead_byte: Option<u8>, |
| be: bool, |
| pending_bmp: bool, // if true, lead_surrogate is actually pending BMP |
| } |
| |
| impl Utf16Decoder { |
| pub fn new(big_endian: bool) -> VariantDecoder { |
| VariantDecoder::Utf16(Utf16Decoder { |
| lead_surrogate: 0, |
| lead_byte: None, |
| be: big_endian, |
| pending_bmp: false, |
| }) |
| } |
| |
| pub fn additional_from_state(&self) -> usize { |
| 1 + if self.lead_byte.is_some() { 1 } else { 0 } |
| + if self.lead_surrogate == 0 { 0 } else { 2 } |
| } |
| |
| pub fn max_utf16_buffer_length(&self, byte_length: usize) -> Option<usize> { |
| checked_add( |
| 1, |
| checked_div(byte_length.checked_add(self.additional_from_state()), 2), |
| ) |
| } |
| |
| pub fn max_utf8_buffer_length_without_replacement(&self, byte_length: usize) -> Option<usize> { |
| checked_add( |
| 1, |
| checked_mul( |
| 3, |
| checked_div(byte_length.checked_add(self.additional_from_state()), 2), |
| ), |
| ) |
| } |
| |
| pub fn max_utf8_buffer_length(&self, byte_length: usize) -> Option<usize> { |
| checked_add( |
| 1, |
| checked_mul( |
| 3, |
| checked_div(byte_length.checked_add(self.additional_from_state()), 2), |
| ), |
| ) |
| } |
| |
| decoder_functions!( |
| { |
| if self.pending_bmp { |
| match dest.check_space_bmp() { |
| Space::Full(_) => { |
| return (DecoderResult::OutputFull, 0, 0); |
| } |
| Space::Available(destination_handle) => { |
| destination_handle.write_bmp(self.lead_surrogate); |
| self.pending_bmp = false; |
| self.lead_surrogate = 0; |
| } |
| } |
| } |
| }, |
| { |
| // This is the fast path. The rest runs only at the |
| // start and end for partial sequences. |
| if self.lead_byte.is_none() && self.lead_surrogate == 0 { |
| if let Some((read, written)) = if self.be { |
| dest.copy_utf16_from::<BigEndian>(&mut source) |
| } else { |
| dest.copy_utf16_from::<LittleEndian>(&mut source) |
| } { |
| return (DecoderResult::Malformed(2, 0), read, written); |
| } |
| } |
| }, |
| { |
| debug_assert!(!self.pending_bmp); |
| if self.lead_surrogate != 0 || self.lead_byte.is_some() { |
| // We need to check space without intent to write in order to |
| // make sure that there is space for the replacement character. |
| match dest.check_space_bmp() { |
| Space::Full(_) => { |
| return (DecoderResult::OutputFull, 0, 0); |
| } |
| Space::Available(_) => { |
| if self.lead_surrogate != 0 { |
| self.lead_surrogate = 0; |
| match self.lead_byte { |
| None => { |
| return ( |
| DecoderResult::Malformed(2, 0), |
| src_consumed, |
| dest.written(), |
| ); |
| } |
| Some(_) => { |
| self.lead_byte = None; |
| return ( |
| DecoderResult::Malformed(3, 0), |
| src_consumed, |
| dest.written(), |
| ); |
| } |
| } |
| } |
| debug_assert!(self.lead_byte.is_some()); |
| self.lead_byte = None; |
| return (DecoderResult::Malformed(1, 0), src_consumed, dest.written()); |
| } |
| } |
| } |
| }, |
| { |
| match self.lead_byte { |
| None => { |
| self.lead_byte = Some(b); |
| continue; |
| } |
| Some(lead) => { |
| self.lead_byte = None; |
| let code_unit = if self.be { |
| u16::from(lead) << 8 | u16::from(b) |
| } else { |
| u16::from(b) << 8 | u16::from(lead) |
| }; |
| let high_bits = code_unit & 0xFC00u16; |
| if high_bits == 0xD800u16 { |
| // high surrogate |
| if self.lead_surrogate != 0 { |
| // The previous high surrogate was in |
| // error and this one becomes the new |
| // pending one. |
| self.lead_surrogate = code_unit as u16; |
| return ( |
| DecoderResult::Malformed(2, 2), |
| unread_handle.consumed(), |
| destination_handle.written(), |
| ); |
| } |
| self.lead_surrogate = code_unit; |
| continue; |
| } |
| if high_bits == 0xDC00u16 { |
| // low surrogate |
| if self.lead_surrogate == 0 { |
| return ( |
| DecoderResult::Malformed(2, 0), |
| unread_handle.consumed(), |
| destination_handle.written(), |
| ); |
| } |
| destination_handle.write_surrogate_pair(self.lead_surrogate, code_unit); |
| self.lead_surrogate = 0; |
| continue; |
| } |
| // bmp |
| if self.lead_surrogate != 0 { |
| // The previous high surrogate was in |
| // error and this code unit becomes a |
| // pending BMP character. |
| self.lead_surrogate = code_unit; |
| self.pending_bmp = true; |
| return ( |
| DecoderResult::Malformed(2, 2), |
| unread_handle.consumed(), |
| destination_handle.written(), |
| ); |
| } |
| destination_handle.write_bmp(code_unit); |
| continue; |
| } |
| } |
| }, |
| self, |
| src_consumed, |
| dest, |
| source, |
| b, |
| destination_handle, |
| unread_handle, |
| check_space_astral |
| ); |
| } |
| |
| // Any copyright to the test code below this comment is dedicated to the |
| // Public Domain. http://creativecommons.org/publicdomain/zero/1.0/ |
| |
| #[cfg(test)] |
| mod tests { |
| use super::super::testing::*; |
| use super::super::*; |
| |
| fn decode_utf_16le(bytes: &[u8], expect: &str) { |
| decode_without_padding(UTF_16LE, bytes, expect); |
| } |
| |
| fn decode_utf_16be(bytes: &[u8], expect: &str) { |
| decode_without_padding(UTF_16BE, bytes, expect); |
| } |
| |
| fn encode_utf_16le(string: &str, expect: &[u8]) { |
| encode(UTF_16LE, string, expect); |
| } |
| |
| fn encode_utf_16be(string: &str, expect: &[u8]) { |
| encode(UTF_16BE, string, expect); |
| } |
| |
| #[test] |
| fn test_utf_16_decode() { |
| decode_utf_16le(b"", ""); |
| decode_utf_16be(b"", ""); |
| |
| decode_utf_16le(b"\x61\x00\x62\x00", "\u{0061}\u{0062}"); |
| decode_utf_16be(b"\x00\x61\x00\x62", "\u{0061}\u{0062}"); |
| |
| decode_utf_16le(b"\xFE\xFF\x00\x61\x00\x62", "\u{0061}\u{0062}"); |
| decode_utf_16be(b"\xFF\xFE\x61\x00\x62\x00", "\u{0061}\u{0062}"); |
| |
| decode_utf_16le(b"\x61\x00\x62", "\u{0061}\u{FFFD}"); |
| decode_utf_16be(b"\x00\x61\x00", "\u{0061}\u{FFFD}"); |
| |
| decode_utf_16le(b"\x3D\xD8\xA9", "\u{FFFD}"); |
| decode_utf_16be(b"\xD8\x3D\xDC", "\u{FFFD}"); |
| |
| decode_utf_16le(b"\x3D\xD8\xA9\xDC\x03\x26", "\u{1F4A9}\u{2603}"); |
| decode_utf_16be(b"\xD8\x3D\xDC\xA9\x26\x03", "\u{1F4A9}\u{2603}"); |
| |
| decode_utf_16le(b"\xA9\xDC\x03\x26", "\u{FFFD}\u{2603}"); |
| decode_utf_16be(b"\xDC\xA9\x26\x03", "\u{FFFD}\u{2603}"); |
| |
| decode_utf_16le(b"\x3D\xD8\x03\x26", "\u{FFFD}\u{2603}"); |
| decode_utf_16be(b"\xD8\x3D\x26\x03", "\u{FFFD}\u{2603}"); |
| |
| // The \xFF makes sure that the parts before and after have different alignment |
| let long_le = b"\x00\x00\x00\x00\x00\x00\x00\x00\x3D\xD8\xA9\xDC\x00\x00\x00\x00\x00\x00\x00\x00\x3D\xD8\x00\x00\x00\x00\x00\x00\x00\x00\xA9\xDC\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x3D\xD8\xFF\x00\x00\x00\x00\x00\x00\x00\x00\x3D\xD8\xA9\xDC\x00\x00\x00\x00\x00\x00\x00\x00\x3D\xD8\x00\x00\x00\x00\x00\x00\x00\x00\xA9\xDC\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x3D\xD8"; |
| let long_be = b"\x00\x00\x00\x00\x00\x00\x00\x00\xD8\x3D\xDC\xA9\x00\x00\x00\x00\x00\x00\x00\x00\xD8\x3D\x00\x00\x00\x00\x00\x00\x00\x00\xDC\xA9\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xD8\x3D\xFF\x00\x00\x00\x00\x00\x00\x00\x00\xD8\x3D\xDC\xA9\x00\x00\x00\x00\x00\x00\x00\x00\xD8\x3D\x00\x00\x00\x00\x00\x00\x00\x00\xDC\xA9\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xD8\x3D"; |
| let long_expect = "\x00\x00\x00\x00\u{1F4A9}\x00\x00\x00\x00\u{FFFD}\x00\x00\x00\x00\u{FFFD}\x00\x00\x00\x00\x00\x00\x00\x00\u{FFFD}"; |
| decode_utf_16le(&long_le[..long_le.len() / 2], long_expect); |
| decode_utf_16be(&long_be[..long_be.len() / 2], long_expect); |
| decode_utf_16le(&long_le[long_le.len() / 2 + 1..], long_expect); |
| decode_utf_16be(&long_be[long_be.len() / 2 + 1..], long_expect); |
| } |
| |
| #[test] |
| fn test_utf_16_encode() { |
| // Empty |
| encode_utf_16be("", b""); |
| encode_utf_16le("", b""); |
| |
| // Encodes as UTF-8 |
| assert_eq!(UTF_16LE.new_encoder().encoding(), UTF_8); |
| assert_eq!(UTF_16BE.new_encoder().encoding(), UTF_8); |
| encode_utf_16le("\u{1F4A9}\u{2603}", "\u{1F4A9}\u{2603}".as_bytes()); |
| encode_utf_16be("\u{1F4A9}\u{2603}", "\u{1F4A9}\u{2603}".as_bytes()); |
| } |
| |
| #[test] |
| fn test_utf_16be_decode_one_by_one() { |
| let input = b"\x00\x61\x00\xE4\x26\x03\xD8\x3D\xDC\xA9"; |
| let mut output = [0u16; 20]; |
| let mut decoder = UTF_16BE.new_decoder(); |
| for b in input.chunks(1) { |
| assert_eq!(b.len(), 1); |
| let needed = decoder.max_utf16_buffer_length(b.len()).unwrap(); |
| let (result, read, _, had_errors) = |
| decoder.decode_to_utf16(b, &mut output[..needed], false); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, 1); |
| assert!(!had_errors); |
| } |
| } |
| |
| #[test] |
| fn test_utf_16le_decode_one_by_one() { |
| let input = b"\x61\x00\xE4\x00\x03\x26\x3D\xD8\xA9\xDC"; |
| let mut output = [0u16; 20]; |
| let mut decoder = UTF_16LE.new_decoder(); |
| for b in input.chunks(1) { |
| assert_eq!(b.len(), 1); |
| let needed = decoder.max_utf16_buffer_length(b.len()).unwrap(); |
| let (result, read, _, had_errors) = |
| decoder.decode_to_utf16(b, &mut output[..needed], false); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, 1); |
| assert!(!had_errors); |
| } |
| } |
| |
| #[test] |
| fn test_utf_16be_decode_three_at_a_time() { |
| let input = b"\x00\xE4\x26\x03\xD8\x3D\xDC\xA9\x00\x61\x00\xE4"; |
| let mut output = [0u16; 20]; |
| let mut decoder = UTF_16BE.new_decoder(); |
| for b in input.chunks(3) { |
| assert_eq!(b.len(), 3); |
| let needed = decoder.max_utf16_buffer_length(b.len()).unwrap(); |
| let (result, read, _, had_errors) = |
| decoder.decode_to_utf16(b, &mut output[..needed], false); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, b.len()); |
| assert!(!had_errors); |
| } |
| } |
| |
| #[test] |
| fn test_utf_16le_decode_three_at_a_time() { |
| let input = b"\xE4\x00\x03\x26\x3D\xD8\xA9\xDC\x61\x00\xE4\x00"; |
| let mut output = [0u16; 20]; |
| let mut decoder = UTF_16LE.new_decoder(); |
| for b in input.chunks(3) { |
| assert_eq!(b.len(), 3); |
| let needed = decoder.max_utf16_buffer_length(b.len()).unwrap(); |
| let (result, read, _, had_errors) = |
| decoder.decode_to_utf16(b, &mut output[..needed], false); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, b.len()); |
| assert!(!had_errors); |
| } |
| } |
| |
| #[test] |
| fn test_utf_16le_decode_bom_prefixed_split_byte_pair() { |
| let mut output = [0u16; 20]; |
| let mut decoder = UTF_16LE.new_decoder(); |
| { |
| let needed = decoder.max_utf16_buffer_length(1).unwrap(); |
| let (result, read, written, had_errors) = |
| decoder.decode_to_utf16(b"\xFF", &mut output[..needed], false); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, 1); |
| assert_eq!(written, 0); |
| assert!(!had_errors); |
| } |
| { |
| let needed = decoder.max_utf16_buffer_length(1).unwrap(); |
| let (result, read, written, had_errors) = |
| decoder.decode_to_utf16(b"\xFD", &mut output[..needed], true); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, 1); |
| assert_eq!(written, 1); |
| assert!(!had_errors); |
| assert_eq!(output[0], 0xFDFF); |
| } |
| } |
| |
| #[test] |
| fn test_utf_16be_decode_bom_prefixed_split_byte_pair() { |
| let mut output = [0u16; 20]; |
| let mut decoder = UTF_16BE.new_decoder(); |
| { |
| let needed = decoder.max_utf16_buffer_length(1).unwrap(); |
| let (result, read, written, had_errors) = |
| decoder.decode_to_utf16(b"\xFE", &mut output[..needed], false); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, 1); |
| assert_eq!(written, 0); |
| assert!(!had_errors); |
| } |
| { |
| let needed = decoder.max_utf16_buffer_length(1).unwrap(); |
| let (result, read, written, had_errors) = |
| decoder.decode_to_utf16(b"\xFD", &mut output[..needed], true); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, 1); |
| assert_eq!(written, 1); |
| assert!(!had_errors); |
| assert_eq!(output[0], 0xFEFD); |
| } |
| } |
| |
| #[test] |
| fn test_utf_16le_decode_bom_prefix() { |
| let mut output = [0u16; 20]; |
| let mut decoder = UTF_16LE.new_decoder(); |
| { |
| let needed = decoder.max_utf16_buffer_length(1).unwrap(); |
| let (result, read, written, had_errors) = |
| decoder.decode_to_utf16(b"\xFF", &mut output[..needed], true); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, 1); |
| assert_eq!(written, 1); |
| assert!(had_errors); |
| assert_eq!(output[0], 0xFFFD); |
| } |
| } |
| |
| #[test] |
| fn test_utf_16be_decode_bom_prefix() { |
| let mut output = [0u16; 20]; |
| let mut decoder = UTF_16BE.new_decoder(); |
| { |
| let needed = decoder.max_utf16_buffer_length(1).unwrap(); |
| let (result, read, written, had_errors) = |
| decoder.decode_to_utf16(b"\xFE", &mut output[..needed], true); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, 1); |
| assert_eq!(written, 1); |
| assert!(had_errors); |
| assert_eq!(output[0], 0xFFFD); |
| } |
| } |
| |
| #[test] |
| fn test_utf_16le_decode_near_end() { |
| let mut output = [0u8; 4]; |
| let mut decoder = UTF_16LE.new_decoder(); |
| { |
| let (result, read, written, had_errors) = |
| decoder.decode_to_utf8(&[0x03], &mut output[..], false); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, 1); |
| assert_eq!(written, 0); |
| assert!(!had_errors); |
| assert_eq!(output[0], 0x0); |
| } |
| { |
| let (result, read, written, had_errors) = |
| decoder.decode_to_utf8(&[0x26, 0x03, 0x26], &mut output[..], false); |
| assert_eq!(result, CoderResult::OutputFull); |
| assert_eq!(read, 1); |
| assert_eq!(written, 3); |
| assert!(!had_errors); |
| assert_eq!(output[0], 0xE2); |
| assert_eq!(output[1], 0x98); |
| assert_eq!(output[2], 0x83); |
| assert_eq!(output[3], 0x00); |
| } |
| } |
| |
| #[test] |
| fn test_utf_16be_decode_near_end() { |
| let mut output = [0u8; 4]; |
| let mut decoder = UTF_16BE.new_decoder(); |
| { |
| let (result, read, written, had_errors) = |
| decoder.decode_to_utf8(&[0x26], &mut output[..], false); |
| assert_eq!(result, CoderResult::InputEmpty); |
| assert_eq!(read, 1); |
| assert_eq!(written, 0); |
| assert!(!had_errors); |
| assert_eq!(output[0], 0x0); |
| } |
| { |
| let (result, read, written, had_errors) = |
| decoder.decode_to_utf8(&[0x03, 0x26, 0x03], &mut output[..], false); |
| assert_eq!(result, CoderResult::OutputFull); |
| assert_eq!(read, 1); |
| assert_eq!(written, 3); |
| assert!(!had_errors); |
| assert_eq!(output[0], 0xE2); |
| assert_eq!(output[1], 0x98); |
| assert_eq!(output[2], 0x83); |
| assert_eq!(output[3], 0x00); |
| } |
| } |
| } |
