Bug fix: need to implement Zlib format

Cargo.toml

@@ -29,6 +29,7 @@ required-features = ["zopfli"]
 [dependencies]
 zopfli = {git = "https://github.com/Pr0methean/zopfli.git", default-features = false, features = ["zlib"] }
 simd-adler32 = { version = "0.3.5", optional = true, default-features = false }
+simd-adler32 = { version = "0.3.5", optional = true, default-features = false }
 rgb = "0.8.36"
 indexmap = "2.0.0"
 libdeflater = "1.19.0"
@@ -73,6 +74,7 @@ version = "0.24.6"
 rustc_version = "0.4.0"
 
 [features]
+zopfli = ["zopfli/std", "zopfli/zlib", "simd-adler32"]
 binary = ["clap", "glob", "env_logger"]
 default = ["binary", "filetime", "parallel", "zopfli"]
 parallel = ["rayon", "indexmap/rayon", "crossbeam-channel"]

src/deflate/mod.rs

@@ -4,20 +4,21 @@ use crate::{PngError, PngResult};
 pub use deflater::crc32;
 pub use deflater::deflate;
 pub use deflater::inflate;
-use std::io::{copy, BufWriter, Cursor, Write};
+use std::io::{copy, BufWriter, copy, Cursor, Write};
 use std::{fmt, fmt::Display, io};
 
 #[cfg(feature = "zopfli")]
 use std::num::NonZeroU8;
 #[cfg(feature = "zopfli")]
 use zopfli::{DeflateEncoder, Options};
-
 #[cfg(feature = "zopfli")]
 mod zopfli_oxipng;
 #[cfg(feature = "zopfli")]
 use simd_adler32::Adler32;
 #[cfg(feature = "zopfli")]
 pub use zopfli_oxipng::deflate as zopfli_deflate;
+#[cfg(feature = "zopfli")]
+use simd_adler32::Adler32;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 /// DEFLATE algorithms supported by oxipng
@@ -102,28 +103,40 @@ impl Default for BufferedZopfliDeflater {
 
 #[cfg(feature = "zopfli")]
 impl Deflater for BufferedZopfliDeflater {
+
+    /// Fork of the zlib_compress function in Zopfli.
     fn deflate(&self, data: &[u8], max_size: &AtomicMin) -> PngResult<Vec<u8>> {
         #[allow(clippy::needless_update)]
         let options = Options {
             iteration_count: self.iterations,
             ..Default::default() // for forward compatibility
         };
-        let mut out = Vec::with_capacity(self.output_buffer_size);
-        let mut buffer = BufWriter::with_capacity(
-            self.buffer_size,
-            DeflateEncoder::new(
-                options,
-                Default::default(),
-                &mut out,
-            ),
-        );
-        let result = (|| -> io::Result<()> {
-            buffer.write_all(data)?;
+        let mut out = Cursor::new(Vec::with_capacity(self.output_buffer_size));
+        let cmf = 120; /* CM 8, CINFO 7. See zlib spec.*/
+        let flevel = 3;
+        let fdict = 0;
+        let mut cmfflg: u16 = 256 * cmf + fdict * 32 + flevel * 64;
+        let fcheck = 31 - cmfflg % 31;
+        cmfflg += fcheck;
+
+        let out = (|| -> io::Result<Vec<u8>> {
+            let mut rolling_adler = Adler32::new();
+            let mut in_data = zopfli_oxipng::HashingAndCountingRead::new(data, &mut rolling_adler, None);
+            out.write_all(&cmfflg.to_be_bytes())?;
+            let mut buffer = BufWriter::with_capacity(
+                self.buffer_size,
+                DeflateEncoder::new(
+                    options,
+                    Default::default(),
+                    &mut out,
+                ),
+            );
+            copy(&mut in_data, &mut buffer)?;
             buffer.into_inner()?.finish()?;
-            Ok(())
+            out.write_all(&rolling_adler.finish().to_be_bytes())?;
+            Ok(out.into_inner())
         })();
-        result.map_err(|e| PngError::new(&e.to_string()))?;
-        println!("Compressed {} -> {} bytes", data.len(), out.len());
+        let out = out.map_err(|e| PngError::new(&e.to_string()))?;
         if max_size.get().is_some_and(|max| max < out.len()) {
             Err(PngError::DeflatedDataTooLong(out.len()))
         } else {

src/deflate/zopfli_oxipng.rs

@@ -1,5 +1,7 @@
+use std::io::{Error, ErrorKind, Read};
 use crate::{PngError, PngResult};
 use std::num::NonZeroU8;
+use simd_adler32::Adler32;
 
 pub fn deflate(data: &[u8], iterations: NonZeroU8) -> PngResult<Vec<u8>> {
     let mut output = Vec::with_capacity(data.len());
@@ -14,3 +16,52 @@ pub fn deflate(data: &[u8], iterations: NonZeroU8) -> PngResult<Vec<u8>> {
     output.shrink_to_fit();
     Ok(output)
 }
+
+/// Forked from zopfli crate
+pub trait Hasher {
+    fn update(&mut self, data: &[u8]);
+}
+
+impl Hasher for &mut Adler32 {
+    fn update(&mut self, data: &[u8]) {
+        Adler32::write(self, data)
+    }
+}
+
+/// A reader that wraps another reader, a hasher and an optional counter,
+/// updating the hasher state and incrementing a counter of bytes read so
+/// far for each block of data read.
+pub struct HashingAndCountingRead<'counter, R: Read, H: Hasher> {
+    inner: R,
+    hasher: H,
+    bytes_read: Option<&'counter mut u32>,
+}
+
+impl<'counter, R: Read, H: Hasher> HashingAndCountingRead<'counter, R, H> {
+    pub fn new(inner: R, hasher: H, bytes_read: Option<&'counter mut u32>) -> Self {
+        Self {
+            inner,
+            hasher,
+            bytes_read,
+        }
+    }
+}
+
+impl<R: Read, H: Hasher> Read for HashingAndCountingRead<'_, R, H> {
+    fn read(&mut self, buf: &mut [u8]) -> Result<usize, Error> {
+        match self.inner.read(buf) {
+            Ok(bytes_read) => {
+                self.hasher.update(&buf[..bytes_read]);
+
+                if let Some(total_bytes_read) = &mut self.bytes_read {
+                    **total_bytes_read = total_bytes_read
+                        .checked_add(bytes_read.try_into().map_err(|_| ErrorKind::Other)?)
+                        .ok_or(ErrorKind::Other)?;
+                }
+
+                Ok(bytes_read)
+            }
+            Err(err) => Err(err),
+        }
+    }
+}