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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::mem;
use neqo_common::{qdebug, qtrace};
use crate::{
prefix::{
ENCODER_CAPACITY, ENCODER_DUPLICATE, ENCODER_INSERT_WITH_NAME_LITERAL,
ENCODER_INSERT_WITH_NAME_REF_DYNAMIC, ENCODER_INSERT_WITH_NAME_REF_STATIC, NO_PREFIX,
},
qpack_send_buf::QpackData,
reader::{IntReader, LiteralReader, ReadByte, Reader},
Res,
};
// The encoder only uses InsertWithNameLiteral, therefore clippy is complaining about dead_code.
// We may decide to use othe instruction in the future.
// All instructions are used for testing, therefore they are defined.
#[allow(dead_code)]
#[derive(Debug, PartialEq, Eq)]
pub enum EncoderInstruction<'a> {
Capacity { value: u64 },
InsertWithNameRefStatic { index: u64, value: &'a [u8] },
InsertWithNameRefDynamic { index: u64, value: &'a [u8] },
InsertWithNameLiteral { name: &'a [u8], value: &'a [u8] },
Duplicate { index: u64 },
NoInstruction,
}
impl<'a> EncoderInstruction<'a> {
pub(crate) fn marshal(&self, enc: &mut QpackData, use_huffman: bool) {
match self {
Self::Capacity { value } => {
enc.encode_prefixed_encoded_int(ENCODER_CAPACITY, *value);
}
Self::InsertWithNameRefStatic { index, value } => {
enc.encode_prefixed_encoded_int(ENCODER_INSERT_WITH_NAME_REF_STATIC, *index);
enc.encode_literal(use_huffman, NO_PREFIX, value);
}
Self::InsertWithNameRefDynamic { index, value } => {
enc.encode_prefixed_encoded_int(ENCODER_INSERT_WITH_NAME_REF_DYNAMIC, *index);
enc.encode_literal(use_huffman, NO_PREFIX, value);
}
Self::InsertWithNameLiteral { name, value } => {
enc.encode_literal(use_huffman, ENCODER_INSERT_WITH_NAME_LITERAL, name);
enc.encode_literal(use_huffman, NO_PREFIX, value);
}
Self::Duplicate { index } => {
enc.encode_prefixed_encoded_int(ENCODER_DUPLICATE, *index);
}
Self::NoInstruction => {}
}
}
}
#[derive(Debug)]
enum EncoderInstructionReaderState {
ReadInstruction,
ReadFirstInt { reader: IntReader },
ReadFirstLiteral { reader: LiteralReader },
ReadSecondLiteral { reader: LiteralReader },
Done,
}
#[derive(Debug, PartialEq, Eq)]
pub enum DecodedEncoderInstruction {
Capacity { value: u64 },
InsertWithNameRefStatic { index: u64, value: Vec<u8> },
InsertWithNameRefDynamic { index: u64, value: Vec<u8> },
InsertWithNameLiteral { name: Vec<u8>, value: Vec<u8> },
Duplicate { index: u64 },
NoInstruction,
}
impl<'a> From<&'a EncoderInstruction<'a>> for DecodedEncoderInstruction {
fn from(inst: &'a EncoderInstruction) -> Self {
match inst {
EncoderInstruction::Capacity { value } => Self::Capacity { value: *value },
EncoderInstruction::InsertWithNameRefStatic { index, value } => {
Self::InsertWithNameRefStatic {
index: *index,
value: value.to_vec(),
}
}
EncoderInstruction::InsertWithNameRefDynamic { index, value } => {
Self::InsertWithNameRefDynamic {
index: *index,
value: value.to_vec(),
}
}
EncoderInstruction::InsertWithNameLiteral { name, value } => {
Self::InsertWithNameLiteral {
name: name.to_vec(),
value: value.to_vec(),
}
}
EncoderInstruction::Duplicate { index } => Self::Duplicate { index: *index },
EncoderInstruction::NoInstruction => Self::NoInstruction,
}
}
}
#[derive(Debug)]
pub struct EncoderInstructionReader {
state: EncoderInstructionReaderState,
instruction: DecodedEncoderInstruction,
}
impl ::std::fmt::Display for EncoderInstructionReader {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
write!(
f,
"EncoderInstructionReader state={:?} instruction:{:?}",
self.state, self.instruction
)
}
}
impl EncoderInstructionReader {
pub fn new() -> Self {
Self {
state: EncoderInstructionReaderState::ReadInstruction,
instruction: DecodedEncoderInstruction::NoInstruction,
}
}
fn decode_instruction_from_byte(&mut self, b: u8) {
self.instruction = if ENCODER_INSERT_WITH_NAME_REF_STATIC.cmp_prefix(b) {
DecodedEncoderInstruction::InsertWithNameRefStatic {
index: 0,
value: Vec::new(),
}
} else if ENCODER_INSERT_WITH_NAME_REF_DYNAMIC.cmp_prefix(b) {
DecodedEncoderInstruction::InsertWithNameRefDynamic {
index: 0,
value: Vec::new(),
}
} else if ENCODER_INSERT_WITH_NAME_LITERAL.cmp_prefix(b) {
DecodedEncoderInstruction::InsertWithNameLiteral {
name: Vec::new(),
value: Vec::new(),
}
} else if ENCODER_CAPACITY.cmp_prefix(b) {
DecodedEncoderInstruction::Capacity { value: 0 }
} else if ENCODER_DUPLICATE.cmp_prefix(b) {
DecodedEncoderInstruction::Duplicate { index: 0 }
} else {
unreachable!("The above patterns match everything.");
};
qdebug!([self], "instruction decoded");
}
fn decode_instruction_type<T: ReadByte + Reader>(&mut self, recv: &mut T) -> Res<()> {
let b = recv.read_byte()?;
self.decode_instruction_from_byte(b);
match self.instruction {
DecodedEncoderInstruction::Capacity { .. }
| DecodedEncoderInstruction::Duplicate { .. } => {
self.state = EncoderInstructionReaderState::ReadFirstInt {
reader: IntReader::new(b, ENCODER_CAPACITY.len()),
}
}
DecodedEncoderInstruction::InsertWithNameRefStatic { .. }
| DecodedEncoderInstruction::InsertWithNameRefDynamic { .. } => {
self.state = EncoderInstructionReaderState::ReadFirstInt {
reader: IntReader::new(b, ENCODER_INSERT_WITH_NAME_REF_STATIC.len()),
}
}
DecodedEncoderInstruction::InsertWithNameLiteral { .. } => {
self.state = EncoderInstructionReaderState::ReadFirstLiteral {
reader: LiteralReader::new_with_first_byte(
b,
ENCODER_INSERT_WITH_NAME_LITERAL.len(),
),
}
}
DecodedEncoderInstruction::NoInstruction => {
unreachable!("We must have instruction at this point.");
}
}
Ok(())
}
/// # Errors
///
/// 1) `NeedMoreData` if the reader needs more data
/// 2) `ClosedCriticalStream`
/// 3) other errors will be translated to `EncoderStream` by the caller of this function.
pub fn read_instructions<T: ReadByte + Reader>(
&mut self,
recv: &mut T,
) -> Res<DecodedEncoderInstruction> {
qdebug!([self], "reading instructions");
loop {
match &mut self.state {
EncoderInstructionReaderState::ReadInstruction => {
self.decode_instruction_type(recv)?;
}
EncoderInstructionReaderState::ReadFirstInt { reader } => {
let val = reader.read(recv)?;
qtrace!([self], "First varint read {}", val);
match &mut self.instruction {
DecodedEncoderInstruction::Capacity { value: v, .. }
| DecodedEncoderInstruction::Duplicate { index: v } => {
*v = val;
self.state = EncoderInstructionReaderState::Done;
}
DecodedEncoderInstruction::InsertWithNameRefStatic { index, .. }
| DecodedEncoderInstruction::InsertWithNameRefDynamic { index, .. } => {
*index = val;
self.state = EncoderInstructionReaderState::ReadFirstLiteral {
reader: LiteralReader::default(),
};
}
_ => unreachable!("This instruction cannot be in this state."),
}
}
EncoderInstructionReaderState::ReadFirstLiteral { reader } => {
let val = reader.read(recv)?;
qtrace!([self], "first literal read {:?}", val);
match &mut self.instruction {
DecodedEncoderInstruction::InsertWithNameRefStatic { value, .. }
| DecodedEncoderInstruction::InsertWithNameRefDynamic { value, .. } => {
*value = val;
self.state = EncoderInstructionReaderState::Done;
}
DecodedEncoderInstruction::InsertWithNameLiteral { name, .. } => {
*name = val;
self.state = EncoderInstructionReaderState::ReadSecondLiteral {
reader: LiteralReader::default(),
};
}
_ => unreachable!("This instruction cannot be in this state."),
}
}
EncoderInstructionReaderState::ReadSecondLiteral { reader } => {
let val = reader.read(recv)?;
qtrace!([self], "second literal read {:?}", val);
match &mut self.instruction {
DecodedEncoderInstruction::InsertWithNameLiteral { value, .. } => {
*value = val;
self.state = EncoderInstructionReaderState::Done;
}
_ => unreachable!("This instruction cannot be in this state."),
}
}
EncoderInstructionReaderState::Done => {}
}
if matches!(self.state, EncoderInstructionReaderState::Done) {
self.state = EncoderInstructionReaderState::ReadInstruction;
break Ok(mem::replace(
&mut self.instruction,
DecodedEncoderInstruction::NoInstruction,
));
}
}
}
}
#[cfg(test)]
mod test {
use super::{EncoderInstruction, EncoderInstructionReader, QpackData};
use crate::{reader::test_receiver::TestReceiver, Error};
fn test_encoding_decoding(instruction: &EncoderInstruction, use_huffman: bool) {
let mut buf = QpackData::default();
instruction.marshal(&mut buf, use_huffman);
let mut test_receiver: TestReceiver = TestReceiver::default();
test_receiver.write(&buf);
let mut reader = EncoderInstructionReader::new();
assert_eq!(
reader.read_instructions(&mut test_receiver).unwrap(),
instruction.into()
);
}
#[test]
fn test_encoding_decoding_instructions() {
test_encoding_decoding(&EncoderInstruction::Capacity { value: 1 }, false);
test_encoding_decoding(&EncoderInstruction::Capacity { value: 10_000 }, false);
test_encoding_decoding(
&EncoderInstruction::InsertWithNameRefStatic {
index: 1,
value: &[0x62, 0x64, 0x65],
},
false,
);
test_encoding_decoding(
&EncoderInstruction::InsertWithNameRefStatic {
index: 1,
value: &[0x62, 0x64, 0x65],
},
true,
);
test_encoding_decoding(
&EncoderInstruction::InsertWithNameRefStatic {
index: 10_000,
value: &[0x62, 0x64, 0x65],
},
false,
);
test_encoding_decoding(
&EncoderInstruction::InsertWithNameRefStatic {
index: 10_000,
value: &[0x62, 0x64, 0x65],
},
true,
);
test_encoding_decoding(
&EncoderInstruction::InsertWithNameRefDynamic {
index: 1,
value: &[0x62, 0x64, 0x65],
},
false,
);
test_encoding_decoding(
&EncoderInstruction::InsertWithNameRefDynamic {
index: 1,
value: &[0x62, 0x64, 0x65],
},
true,
);
test_encoding_decoding(
&EncoderInstruction::InsertWithNameRefDynamic {
index: 10_000,
value: &[0x62, 0x64, 0x65],
},
false,
);
test_encoding_decoding(
&EncoderInstruction::InsertWithNameRefDynamic {
index: 10_000,
value: &[0x62, 0x64, 0x65],
},
true,
);
test_encoding_decoding(
&EncoderInstruction::InsertWithNameLiteral {
name: &[0x62, 0x64, 0x65],
value: &[0x62, 0x64, 0x65],
},
false,
);
test_encoding_decoding(
&EncoderInstruction::InsertWithNameLiteral {
name: &[0x62, 0x64, 0x65],
value: &[0x62, 0x64, 0x65],
},
true,
);
test_encoding_decoding(&EncoderInstruction::Duplicate { index: 1 }, false);
test_encoding_decoding(&EncoderInstruction::Duplicate { index: 10_000 }, false);
}
fn test_encoding_decoding_slow_reader(instruction: &EncoderInstruction, use_huffman: bool) {
let mut buf = QpackData::default();
instruction.marshal(&mut buf, use_huffman);
let mut test_receiver: TestReceiver = TestReceiver::default();
let mut decoder = EncoderInstructionReader::new();
for i in 0..buf.len() - 1 {
test_receiver.write(&buf[i..=i]);
assert_eq!(
decoder.read_instructions(&mut test_receiver),
Err(Error::NeedMoreData)
);
}
test_receiver.write(&buf[buf.len() - 1..buf.len()]);
assert_eq!(
decoder.read_instructions(&mut test_receiver).unwrap(),
instruction.into()
);
}
#[test]
fn test_encoding_decoding_instructions_slow_reader() {
test_encoding_decoding_slow_reader(&EncoderInstruction::Capacity { value: 1 }, false);
test_encoding_decoding_slow_reader(&EncoderInstruction::Capacity { value: 10_000 }, false);
test_encoding_decoding_slow_reader(
&EncoderInstruction::InsertWithNameRefStatic {
index: 1,
value: &[0x62, 0x64, 0x65],
},
false,
);
test_encoding_decoding_slow_reader(
&EncoderInstruction::InsertWithNameRefStatic {
index: 1,
value: &[0x62, 0x64, 0x65],
},
true,
);
test_encoding_decoding_slow_reader(
&EncoderInstruction::InsertWithNameRefStatic {
index: 10_000,
value: &[0x62, 0x64, 0x65],
},
false,
);
test_encoding_decoding_slow_reader(
&EncoderInstruction::InsertWithNameRefStatic {
index: 10_000,
value: &[0x62, 0x64, 0x65],
},
true,
);
test_encoding_decoding_slow_reader(
&EncoderInstruction::InsertWithNameRefDynamic {
index: 1,
value: &[0x62, 0x64, 0x65],
},
false,
);
test_encoding_decoding_slow_reader(
&EncoderInstruction::InsertWithNameRefDynamic {
index: 1,
value: &[0x62, 0x64, 0x65],
},
true,
);
test_encoding_decoding_slow_reader(
&EncoderInstruction::InsertWithNameRefDynamic {
index: 10_000,
value: &[0x62, 0x64, 0x65],
},
false,
);
test_encoding_decoding_slow_reader(
&EncoderInstruction::InsertWithNameRefDynamic {
index: 10_000,
value: &[0x62, 0x64, 0x65],
},
true,
);
test_encoding_decoding_slow_reader(
&EncoderInstruction::InsertWithNameLiteral {
name: &[0x62, 0x64, 0x65],
value: &[0x62, 0x64, 0x65],
},
false,
);
test_encoding_decoding_slow_reader(
&EncoderInstruction::InsertWithNameLiteral {
name: &[0x62, 0x64, 0x65],
value: &[0x62, 0x64, 0x65],
},
true,
);
test_encoding_decoding_slow_reader(&EncoderInstruction::Duplicate { index: 1 }, false);
test_encoding_decoding_slow_reader(&EncoderInstruction::Duplicate { index: 10_000 }, false);
}
#[test]
fn test_decoding_error() {
let mut test_receiver: TestReceiver = TestReceiver::default();
// EncoderInstruction::Capacity with overflow
test_receiver.write(&[
0x3f, 0xc1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xff, 0x02,
]);
let mut decoder = EncoderInstructionReader::new();
assert_eq!(
decoder.read_instructions(&mut test_receiver),
Err(Error::IntegerOverflow)
);
let mut test_receiver: TestReceiver = TestReceiver::default();
// EncoderInstruction::InsertWithNameRefStatic with overflow of index value.
test_receiver.write(&[
0xff, 0xc1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xff, 0x02, 0x00, 0x00,
]);
let mut decoder = EncoderInstructionReader::new();
assert_eq!(
decoder.read_instructions(&mut test_receiver),
Err(Error::IntegerOverflow)
);
let mut test_receiver: TestReceiver = TestReceiver::default();
// EncoderInstruction::InsertWithNameRefStatic with a garbage value.
test_receiver.write(&[0xc1, 0x81, 0x00]);
let mut decoder = EncoderInstructionReader::new();
assert_eq!(
decoder.read_instructions(&mut test_receiver),
Err(Error::HuffmanDecompressionFailed)
);
}
}