#integer #leb128 #encoding #variables #varint

yanked vint

vint.rs: simple and efficient variable-length integer encoding

3.1.0 Jan 30, 2020

#14 in #leb128

Apache-2.0

5KB

vint.rs: simple and efficient variable-length integer encoding

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vint.rs is an implementation of a variable-length encoding for 64-bit little endian integers which optimizes for simplicity and performance.

Documentation

About

This crate implements a variable-length encoding for 64-bit little endian integers which does not otherwise have a specific name but aims to provide a number of properties which make it superior in every way to other variable-length integer encodings like LEB128:

  • Capable of expressing the full 64-bit integer range with a maximum of 9-bytes
  • No loops involved in decoding: just (unaligned) loads, masks, and shifts
  • Total length of a "vint" can be determined via the first byte alone

Some precedent for this sort of encoding can be found in the Extensible Binary Meta Language (used by e.g. the Matroska media container format), however note that the specific type of "vint" used by this format still requires a loop to decode.

License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions.

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