add test abstractions and Freq test

Cargo.lock

@@ -2,6 +2,214 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "bitvec"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1bc2832c24239b0141d5674bb9174f9d68a8b5b3f2753311927c172ca46f7e9c"
+dependencies = [
+ "funty",
+ "radium",
+ "tap",
+ "wyz",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
+
+[[package]]
+name = "env_logger"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a19187fea3ac7e84da7dacf48de0c45d63c6a76f9490dae389aead16c243fce3"
+dependencies = [
+ "log",
+ "regex",
+]
+
+[[package]]
+name = "funty"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6d5a32815ae3f33302d95fdcb2ce17862f8c65363dcfd29360480ba1001fc9c"
+
+[[package]]
+name = "getrandom"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.176"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "58f929b4d672ea937a23a1ab494143d968337a5f47e56d0815df1e0890ddf174"
+
+[[package]]
+name = "log"
+version = "0.4.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34080505efa8e45a4b816c349525ebe327ceaa8559756f0356cba97ef3bf7432"
+
+[[package]]
+name = "memchr"
+version = "2.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.101"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89ae43fd86e4158d6db51ad8e2b80f313af9cc74f5c0e03ccb87de09998732de"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quickcheck"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "588f6378e4dd99458b60ec275b4477add41ce4fa9f64dcba6f15adccb19b50d6"
+dependencies = [
+ "env_logger",
+ "log",
+ "rand",
+]
+
+[[package]]
+name = "quickcheck_macros"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f71ee38b42f8459a88d3362be6f9b841ad2d5421844f61eb1c59c11bff3ac14a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.41"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce25767e7b499d1b604768e7cde645d14cc8584231ea6b295e9c9eb22c02e1d1"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "radium"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc33ff2d4973d518d823d61aa239014831e521c75da58e3df4840d3f47749d09"
+
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "regex"
+version = "1.11.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b5288124840bee7b386bc413c487869b360b2b4ec421ea56425128692f2a82c"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "833eb9ce86d40ef33cb1306d8accf7bc8ec2bfea4355cbdebb3df68b40925cad"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "caf4aa5b0f434c91fe5c7f1ecb6a5ece2130b02ad2a590589dda5146df959001"
+
+[[package]]
+name = "syn"
+version = "2.0.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ede7c438028d4436d71104916910f5bb611972c5cfd7f89b8300a8186e6fada6"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "tap"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
+
 [[package]]
 name = "text-compression"
 version = "0.1.0"
+dependencies = [
+ "bitvec",
+ "quickcheck",
+ "quickcheck_macros",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f63a545481291138910575129486daeaf8ac54aee4387fe7906919f7830c7d9d"
+
+[[package]]
+name = "wasi"
+version = "0.11.1+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
+
+[[package]]
+name = "wyz"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "05f360fc0b24296329c78fda852a1e9ae82de9cf7b27dae4b7f62f118f77b9ed"
+dependencies = [
+ "tap",
+]

Cargo.toml

@@ -4,3 +4,8 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+bitvec = "1.0.1"
+
+[dev-dependencies]
+quickcheck = "1"
+quickcheck_macros = "1"

src/compression_scheme.rs

@@ -0,0 +1,20 @@
+use bitvec::{slice::BitSlice, vec::BitVec};
+
+pub trait CompressionScheme {
+    type Header;
+
+    fn encode(src: &[u8], buf: &mut BitVec) -> Self::Header;
+    fn decode(src: &BitSlice, header: &Self::Header, buf: &mut Vec<u8>);
+
+    fn header_size(header: &Self::Header) -> usize;
+
+    fn idempotent_on(src: &[u8]) -> bool {
+        let mut buf_bits = BitVec::new();
+        let header = Self::encode(src, &mut buf_bits);
+
+        let mut buf_bytes = Vec::new();
+        Self::decode(&buf_bits, &header, &mut buf_bytes);
+
+        src == buf_bytes
+    }
+}

src/freq.rs

@@ -8,6 +8,39 @@
 
 use std::{array, fmt};
 
+use crate::CompressionScheme;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Freq;
+
+impl CompressionScheme for Freq {
+    type Header = [u8; 256];
+
+    fn encode(src: &[u8], buf: &mut bitvec::prelude::BitVec) -> Self::Header {
+        let encoder = Encoder::new(src);
+
+        for Bits { one_count } in encoder.clone() {
+            for _ in 0..one_count {
+                buf.push(true);
+            }
+            buf.push(false);
+        }
+
+        encoder.byte_ranking
+    }
+
+    fn decode(mut src: &bitvec::prelude::BitSlice, header: &Self::Header, buf: &mut Vec<u8>) {
+        while let Some(one_count) = src.first_zero() {
+            buf.push(*header.get(one_count).unwrap());
+            src = &src[(one_count + 1)..];
+        }
+    }
+
+    fn header_size(_header: &Self::Header) -> usize {
+        256
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Bits {
     pub one_count: u8,
@@ -23,8 +56,9 @@ impl fmt::Display for Bits {
 }
 
 #[derive(Debug, Clone)]
-pub struct Encoder<'src> {
+struct Encoder<'src> {
     src: &'src [u8],
+    byte_ranking: [u8; 256],
     byte_mapping: [u8; 256],
 }
 
@@ -40,27 +74,20 @@ impl<'src> Encoder<'src> {
             clippy::cast_possible_truncation,
             reason = "`i` is in the range `0..256`"
         )]
-        let mut ranking: [u8; 256] = array::from_fn(|i| i as u8);
+        let mut byte_ranking: [u8; 256] = array::from_fn(|i| i as u8);
-        ranking.sort_by_key(|&byte| -i64::from(byte_counts[byte as usize]));
+        byte_ranking.sort_by_key(|&byte| -i64::from(byte_counts[byte as usize]));
 
         #[allow(
             clippy::cast_possible_truncation,
             reason = "`i` is in the range `0..256`"
         )]
         let byte_mapping =
-            array::from_fn(|i| ranking.iter().position(|b| *b == (i as u8)).unwrap() as u8);
+            array::from_fn(|i| byte_ranking.iter().position(|b| *b == (i as u8)).unwrap() as u8);
 
-        Self { src, byte_mapping }
+        Self {
-    }
+            src,
-
+            byte_ranking,
-    pub fn print_mapping(&self) {
+            byte_mapping,
-        for (one_count, byte) in self.byte_mapping.iter().zip(0u8..) {
-            println!(
-                "0x{byte:02x}: {:3} bit{s} ({:?})",
-                one_count + 1,
-                (byte as char),
-                s = if *one_count == 0 { "s" } else { "" },
-            );
         }
     }
 }

src/main.rs

@@ -1,34 +1,25 @@
-use std::{
+use std::io::{self, Read};
-    env,
-    io::{self, Read},
-};
 
+mod compression_scheme;
 mod freq;
 mod rle;
+#[cfg(test)]
+mod test;
+
+pub use compression_scheme::CompressionScheme;
+pub use freq::Freq;
 
 fn main() -> Result<(), io::Error> {
-    let debug = env::args().any(|arg| arg == "--debug" || arg == "-d");
-
     let mut buf = Vec::new();
     let len_src = io::stdin().read_to_end(&mut buf)?;
 
     println!("Original: {len_src}");
 
-    let len_rle = rle::Encoder::new(&buf).count() * 2;
+    // let len_rle = rle::Encoder::new(&buf).count() * 2;
-    println!("   Rle'd: {len_rle}");
+    // println!("   Rle'd: {len_rle}");
 
-    let encoder_freq = freq::Encoder::new(&buf);
+    // let len_freq = len_freq_table + len_freq_bits;
-    if debug {
+    // println!("  Freq'd: {len_freq}");
-        encoder_freq.print_mapping();
-    }
-
-    let len_freq_table = 256;
-    let len_freq_bits = encoder_freq
-        .map(|freq::Bits { one_count }| one_count as usize + 1)
-        .sum::<usize>()
-        .div_ceil(8);
-    let len_freq = len_freq_table + len_freq_bits;
-    println!("  Freq'd: {len_freq}");
 
     Ok(())
 }

src/test.rs

@@ -0,0 +1,9 @@
+use quickcheck_macros::quickcheck;
+
+use crate::{CompressionScheme, Freq, Rle};
+
+#[allow(clippy::needless_pass_by_value)]
+#[quickcheck]
+fn freq_roundtrip(src: Vec<u8>) -> bool {
+    Freq::idempotent_on(&src)
+}