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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/neqo-qpack/src/prefix.rs | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/neqo-qpack/src/prefix.rs')
-rw-r--r-- | third_party/rust/neqo-qpack/src/prefix.rs | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/third_party/rust/neqo-qpack/src/prefix.rs b/third_party/rust/neqo-qpack/src/prefix.rs new file mode 100644 index 0000000000..ee0826850d --- /dev/null +++ b/third_party/rust/neqo-qpack/src/prefix.rs @@ -0,0 +1,139 @@ +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#[derive(Copy, Clone, Debug)] +pub struct Prefix { + prefix: u8, + len: u8, + mask: u8, +} + +impl Prefix { + pub fn new(prefix: u8, len: u8) -> Self { + // len should never be larger than 7. + // Most of Prefixes are instantiated as consts bellow. The only place where this construcrtor is used + // is in tests and when literals are encoded and the Huffman bit is added to one of the consts bellow. + // create_prefix guaranty that all const have len < 7 so we can safely assert that len is <=7. + assert!(len <= 7); + assert!((len == 0) || (prefix & ((1 << (8 - len)) - 1) == 0)); + Self { + prefix, + len, + mask: if len == 0 { + 0xFF + } else { + ((1 << len) - 1) << (8 - len) + }, + } + } + + pub fn len(self) -> u8 { + self.len + } + + pub fn prefix(self) -> u8 { + self.prefix + } + + pub fn cmp_prefix(self, b: u8) -> bool { + (b & self.mask) == self.prefix + } +} + +#[macro_export] +macro_rules! create_prefix { + ($n:ident) => { + pub const $n: Prefix = Prefix { + prefix: 0x0, + len: 0, + mask: 0xFF, + }; + }; + ($n:ident, $v:expr, $l:expr) => { + static_assertions::const_assert!($l < 7); + static_assertions::const_assert!($v & ((1 << (8 - $l)) - 1) == 0); + pub const $n: Prefix = Prefix { + prefix: $v, + len: $l, + mask: ((1 << $l) - 1) << (8 - $l), + }; + }; + ($n:ident, $v:expr, $l:expr, $m:expr) => { + static_assertions::const_assert!($l < 7); + static_assertions::const_assert!($v & ((1 << (8 - $l)) - 1) == 0); + static_assertions::const_assert!((((1 << $l) - 1) << (8 - $l)) >= $m); + pub const $n: Prefix = Prefix { + prefix: $v, + len: $l, + mask: $m, + }; + }; +} + +create_prefix!(NO_PREFIX); +//===================================================================== +// Decoder instructions prefix +//===================================================================== + +// | 1 | Stream ID (7+) | +create_prefix!(DECODER_HEADER_ACK, 0x80, 1); + +// | 0 | 1 | Stream ID (6+) | +create_prefix!(DECODER_STREAM_CANCELLATION, 0x40, 2); + +// | 0 | 0 | Increment (6+) | +create_prefix!(DECODER_INSERT_COUNT_INCREMENT, 0x00, 2); + +//===================================================================== +// Encoder instructions prefix +//===================================================================== + +// | 0 | 0 | 1 | Capacity (5+) | +create_prefix!(ENCODER_CAPACITY, 0x20, 3); + +// | 1 | T | Name Index (6+) | +// T == 1 static +// T == 0 dynamic +create_prefix!(ENCODER_INSERT_WITH_NAME_REF_STATIC, 0xC0, 2); +create_prefix!(ENCODER_INSERT_WITH_NAME_REF_DYNAMIC, 0x80, 2); + +// | 0 | 1 | H | Name Length (5+) | +// H is not relevant for decoding this prefix, therefore the mask is 1100 0000 = 0xC0 +create_prefix!(ENCODER_INSERT_WITH_NAME_LITERAL, 0x40, 2); + +// | 0 | 0 | 0 | Index (5+) | +create_prefix!(ENCODER_DUPLICATE, 0x00, 3); + +//===================================================================== +//Header block encoding prefixes +//===================================================================== + +create_prefix!(BASE_PREFIX_POSITIVE, 0x00, 1); +create_prefix!(BASE_PREFIX_NEGATIVE, 0x80, 1); + +// | 1 | T | index(6+) | +// T == 1 static +// T == 0 dynamic +create_prefix!(HEADER_FIELD_INDEX_STATIC, 0xC0, 2); +create_prefix!(HEADER_FIELD_INDEX_DYNAMIC, 0x80, 2); + +// | 0 | 0 | 0 | 1 | Index(4+) | +create_prefix!(HEADER_FIELD_INDEX_DYNAMIC_POST, 0x10, 4); + +// | 0 | 1 | N | T | Index(4+) | +// T == 1 static +// T == 0 dynamic +// N is ignored, therefore the mask is 1101 0000 = 0xD0 +create_prefix!(HEADER_FIELD_LITERAL_NAME_REF_STATIC, 0x50, 4, 0xD0); +create_prefix!(HEADER_FIELD_LITERAL_NAME_REF_DYNAMIC, 0x40, 4, 0xD0); + +// | 0 | 0 | 0 | 0 | N | Index(3+) | +// N is ignored, therefore the mask is 1111 0000 = 0xF0 +create_prefix!(HEADER_FIELD_LITERAL_NAME_REF_DYNAMIC_POST, 0x00, 5, 0xF0); + +// | 0 | 0 | 1 | N | H | Index(3+) | +// N is ignored and H is not relevant for decoding this prefix, therefore the mask is 1110 0000 = 0xE0 +create_prefix!(HEADER_FIELD_LITERAL_NAME_LITERAL, 0x20, 4, 0xE0); |