checksum_tapestry/
lib.rs

1//! crate for various checksum algorithms
2//!
3//! This crate provides an API and set of implementations that can be
4//! used to compute checksums for collections of bytes.
5#![warn(missing_docs)]
6#![warn(unsafe_code)]
7#![no_std]
8
9pub mod adler32;
10pub mod crc;
11pub mod crc_table;
12pub mod fletcher16;
13
14/// Checksum trait all checksum algorithms should implement
15/// This provides several compute operations
16///
17/// There are multiple uses of the term check or checksum.  The term
18/// in this context is a computation of a error-correcting code for a
19/// set of data.
20/// Sometimes a checksum is specifically used to refer to computation
21/// of a checksum value that should equal zero.  That's not the
22/// meaning here.  The Checksum trait provides an interface for
23/// algorithms that can calculate checksums.
24pub trait Checksum<T> {
25    /// Compute a checksum over a u8 byte slice
26    ///
27    /// The Checksum API doesn't provide a finalize method.
28    ///
29    /// Every call to compute resets the state of the CRC to an
30    /// initial state.  So calling it twice with the same parameters
31    /// should yield the same result.
32    ///
33    /// # Examples
34    ///
35    /// ```
36    /// use crate::checksum_tapestry::Checksum;
37    /// use checksum_tapestry::adler32::Adler32;
38    ///
39    /// let expected: u32 = 0xe4801a6a;
40    /// let string = "It's a tiny change to the code and not completely disgusting. - Bob Manchek";
41    /// let data = string.as_bytes();
42    /// let mut adler32 = Adler32::default();
43    /// let result = adler32.compute(data);
44    /// assert_eq!(result, expected);
45    /// ```
46    fn compute(&mut self, data: &[u8]) -> T;
47
48    /// Perform a rolling update on the checksum.
49    ///
50    /// Update the checksum with a new byte, computing and returning
51    /// the checksum.
52    ///
53    /// # Examples
54    ///
55    /// ```
56    /// use crate::checksum_tapestry::Checksum;
57    /// use checksum_tapestry::adler32::Adler32;
58    ///
59    /// let expected1: u32 = 0x004A004A;
60    /// let expected2: u32 = 0x010800BE;
61    /// let string = "It's a tiny change to the code and not completely disgusting. - Bob Manchek";
62    /// let data = string.as_bytes();
63    /// let mut adler32 = Adler32::default();
64    /// let result = adler32.update(data[0]);
65    /// assert_eq!(result, expected1);
66    /// let result = adler32.update(data[1]);
67    /// assert_eq!(result, expected2);
68    /// ```
69    fn update(&mut self, data: u8) -> T;
70
71    /// Reset the checksum to the original state.
72    /// This resets the checksum to the state it was in when it was
73    /// created.
74    /// If it was created with non-default parameters, those should be
75    /// preserved.
76    /// If an initial value was specified when originally creating the checksum,
77    /// it should be preserved and initialized to that value.
78    fn reset(&mut self);
79}
checksum_tapestry/lib.rs

checksum_tapestry/
lib.rs
