add documentation, make pbr optional as well

Cargo.lock

@@ -308,7 +308,7 @@ checksum = "dcc811dc4066ac62f84f11307873c4850cb653bfa9b1719cee2bd2204a4bc5dd"
 
 [[package]]
 name = "upkr"
-version = "0.2.0"
+version = "0.2.1"
 dependencies = [
  "anyhow",
  "cdivsufsort",

Cargo.toml

@@ -1,15 +1,18 @@
 [package]
 name = "upkr"
-version = "0.2.0"
+version = "0.2.1"
 edition = "2021"
 
 [profile.release]
 strip = "debuginfo"
 
+[features]
+terminal = ["crossterm", "pbr"]
+
 [dependencies]
 cdivsufsort = "2"
 lexopt = "0.2.1"
 anyhow = "1"
 thiserror = "1.0.36"
-pbr = "1"
+pbr = { version = "1", optional = true }
 crossterm = { version = "0.25.0", default-features = false, optional = true }

release/Makefile

@@ -23,12 +23,12 @@ upkr-windows-$(VERSION).zip: upkr-windows/upkr.exe PHONY
 	zip -r -9 $@ upkr-windows
 
 upkr-linux/upkr:
-	cargo build --target x86_64-unknown-linux-musl --release -F crossterm
+	cargo build --target x86_64-unknown-linux-musl --release -F terminal
 	mkdir -p upkr-linux
 	cp ../target/x86_64-unknown-linux-musl/release/upkr upkr-linux/
 
 upkr-windows/upkr.exe:
-	cargo build --target x86_64-pc-windows-gnu --release -F crossterm
+	cargo build --target x86_64-pc-windows-gnu --release -F terminal
 	mkdir -p upkr-windows
 	cp ../target/x86_64-pc-windows-gnu/release/upkr.exe upkr-windows/
 	

src/heatmap.rs

@@ -1,3 +1,14 @@
+/// Heatmap information about a compressed block of data.
+///
+/// For each byte in the uncompressed data, the heatmap provides two pieces of intormation:
+/// 1. whether this byte was encoded as a literal or as part of a match
+/// 2. how many (fractional) bits where spend on encoding this byte
+///
+/// For the sake of the heatmap, the cost of literals are spread out across all matches
+/// that reference the literal.
+///
+/// If the `terminal` feature is enabled, there is a function to write out the
+/// heatmap as a colored hexdump.
 pub struct Heatmap {
     data: Vec<u8>,
     cost: Vec<f32>,
@@ -5,7 +16,7 @@ pub struct Heatmap {
 }
 
 impl Heatmap {
-    pub fn new() -> Heatmap {
+    pub(crate) fn new() -> Heatmap {
         Heatmap {
             data: Vec::new(),
             cost: Vec::new(),
@@ -13,13 +24,13 @@ impl Heatmap {
         }
     }
 
-    pub fn add_literal(&mut self, byte: u8, cost: f32) {
+    pub(crate) fn add_literal(&mut self, byte: u8, cost: f32) {
         self.data.push(byte);
         self.cost.push(cost);
         self.literal_index.push(self.literal_index.len());
     }
 
-    pub fn add_match(&mut self, offset: usize, length: usize, mut cost: f32) {
+    pub(crate) fn add_match(&mut self, offset: usize, length: usize, mut cost: f32) {
         cost /= length as f32;
         for _ in 0..length {
             self.data.push(self.data[self.data.len() - offset]);
@@ -29,7 +40,7 @@ impl Heatmap {
         }
     }
 
-    pub fn finish(&mut self) {
+    pub(crate) fn finish(&mut self) {
         let mut ref_count = vec![0usize; self.literal_index.len()];
         for &index in &self.literal_index {
             ref_count[index] += 1;
@@ -47,6 +58,7 @@ impl Heatmap {
         }
     }
 
+    /// Reverses the heatmap
     pub fn reverse(&mut self) {
         self.data.reverse();
         self.cost.reverse();
@@ -56,23 +68,28 @@ impl Heatmap {
         }
     }
 
+    /// The number of (uncompressed) bytes of data in this heatmap
     pub fn len(&self) -> usize {
         self.cost.len()
     }
 
+    /// Returns whether the byte at `index` was encoded as a literal
     pub fn is_literal(&self, index: usize) -> bool {
         self.literal_index[index] == index
     }
 
+    /// Returns the cost of encoding the byte at `index` in (fractional) bits
     pub fn cost(&self, index: usize) -> f32 {
         self.cost[index]
     }
 
+    /// Returns the uncompressed data byte at `index`
     pub fn byte(&self, index: usize) -> u8 {
         self.data[index]
     }
 
     #[cfg(feature = "crossterm")]
+    /// Print the heatmap as a colored hexdump
     pub fn print_as_hex(&self) -> std::io::Result<()> {
         use crossterm::{
             style::{Attribute, Color, Print, SetAttribute, SetBackgroundColor},

src/lz.rs

@@ -133,21 +133,47 @@ impl CoderState {
     }
 }
 
+/// The error type for the uncompressing related functions
 #[derive(Error, Debug)]
 pub enum UnpackError {
+    /// a match offset pointing beyond the start of the unpacked data was encountered
     #[error("match offset out of range: {offset} > {position}")]
-    OffsetOutOfRange { offset: usize, position: usize },
+    OffsetOutOfRange {
+        /// the match offset
+        offset: usize,
+        /// the current position in the uncompressed stream
+        position: usize,
+    },
+    /// The passed size limit was exceeded
     #[error("Unpacked data over size limit: {size} > {limit}")]
-    OverSize { size: usize, limit: usize },
+    OverSize {
+        /// the size of the uncompressed data
+        size: usize,
+        /// the size limit passed into the function
+        limit: usize,
+    },
+    /// The end of the packed data was reached without an encoded EOF marker
     #[error("Unexpected end of input data")]
     UnexpectedEOF {
         #[from]
+        /// the underlying EOF error in the rANS decoder
         source: crate::rans::UnexpectedEOF,
     },
+    /// An offset or length value was found that exceeded 32bit
     #[error("Overflow while reading value")]
     ValueOverflow,
 }
 
+/// Uncompress a piece of compressed data
+///
+/// Returns either the uncompressed data, or an `UnpackError`
+///
+/// # Parameters
+///
+/// - `packed_data`: the compressed data
+/// - `config`: the exact compression format config used to compress the data
+/// - `max_size`: the maximum size of uncompressed data to return. When this is exceeded,
+///   `UnpackError::OverSize` is returned
 pub fn unpack(
     packed_data: &[u8],
     config: &Config,
@@ -158,10 +184,22 @@ pub fn unpack(
     Ok(result)
 }
 
+/// Calculates the minimum margin when overlapping buffers.
+///
+/// Returns the minimum margin needed between the end of the compressed data and the
+/// end of the uncompressed data when overlapping the two buffers to save on RAM.
 pub fn calculate_margin(packed_data: &[u8], config: &Config) -> Result<isize, UnpackError> {
     unpack_internal(None, None, packed_data, config, usize::MAX)
 }
 
+/// Calculates a `Heatmap` from compressed data.
+///
+/// # Parameters
+///
+/// - `packed_data`: the compressed data
+/// - `config`: the exact compression format config used to compress the data
+/// - `max_size`: the maximum size of the heatmap to return. When this is exceeded,
+///   `UnpackError::OverSize` is returned
 pub fn create_heatmap(
     packed_data: &[u8],
     config: &Config,

src/main.rs

@@ -123,9 +123,11 @@ fn main() -> Result<()> {
             data.reverse();
         }
 
+        #[cfg(feature = "terminal")]
+        let mut packed_data = {
             let mut pb = pbr::ProgressBar::new(data.len() as u64);
             pb.set_units(pbr::Units::Bytes);
-        let mut packed_data = upkr::pack(
+            let packed_data = upkr::pack(
                 &data,
                 level,
                 &config,
@@ -134,6 +136,10 @@ fn main() -> Result<()> {
                 }),
             );
             pb.finish();
+            packed_data
+        };
+        #[cfg(not(feature = "terminal"))]
+        let mut packed_data = upkr::pack(&data, level, &config, None);
 
         if reverse {
             packed_data.reverse();