Fix building without zopfli

src/deflate/mod.rs

@@ -1,31 +1,16 @@
-use crate::error::PngError;
-use crate::PngResult;
 use indexmap::IndexSet;
 
-#[cfg(feature = "zopfli")]
-use std::num::NonZeroU8;
-
 mod deflater;
 pub use deflater::crc32;
 pub use deflater::deflate;
 pub use deflater::inflate;
 
 #[cfg(feature = "zopfli")]
-pub fn zopfli_deflate(data: &[u8], iterations: NonZeroU8) -> PngResult<Vec<u8>> {
-    use std::cmp::max;
-
-    let mut output = Vec::with_capacity(max(1024, data.len() / 20));
-    let options = zopfli::Options {
-        iteration_count: iterations,
-        ..Default::default()
-    };
-    match zopfli::compress(&options, &zopfli::Format::Zlib, data, &mut output) {
-        Ok(_) => (),
-        Err(_) => return Err(PngError::new("Failed to compress in zopfli")),
-    };
-    output.shrink_to_fit();
-    Ok(output)
-}
+use std::num::NonZeroU8;
+#[cfg(feature = "zopfli")]
+mod zopfli_oxipng;
+#[cfg(feature = "zopfli")]
+pub use zopfli_oxipng::deflate as zopfli_deflate;
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 /// DEFLATE algorithms supported by oxipng

src/deflate/zopfli_oxipng.rs

@@ -0,0 +1,18 @@
+use crate::{PngError, PngResult};
+use std::num::NonZeroU8;
+
+pub fn deflate(data: &[u8], iterations: NonZeroU8) -> PngResult<Vec<u8>> {
+    use std::cmp::max;
+
+    let mut output = Vec::with_capacity(max(1024, data.len() / 20));
+    let options = zopfli::Options {
+        iteration_count: iterations,
+        ..Default::default()
+    };
+    match zopfli::compress(&options, &zopfli::Format::Zlib, data, &mut output) {
+        Ok(_) => (),
+        Err(_) => return Err(PngError::new("Failed to compress in zopfli")),
+    };
+    output.shrink_to_fit();
+    Ok(output)
+}

src/main.rs

@@ -22,6 +22,7 @@ use oxipng::Headers;
 use oxipng::Options;
 use oxipng::{InFile, OutFile};
 use std::fs::DirBuilder;
+#[cfg(feature = "zopfli")]
 use std::num::NonZeroU8;
 use std::path::PathBuf;
 use std::process::exit;
@@ -513,24 +514,20 @@ fn parse_opts_into_struct(
     }
 
     if matches.is_present("zopfli") {
-        opts.deflate = Deflaters::Zopfli {
-            iterations: NonZeroU8::new(15).unwrap(),
-        };
+        if explicit_level > Some(3) {
+            warn!("Level 4 and above are equivalent to level 3 for zopfli");
+        }
+        #[cfg(feature = "zopfli")]
+        if let Some(iterations) = NonZeroU8::new(15) {
+            opts.deflate = Deflaters::Zopfli { iterations };
+        }
     } else if let Deflaters::Libdeflater { compression } = &mut opts.deflate {
         if let Some(x) = matches.value_of("compression") {
             *compression = parse_numeric_range_opts(x, 1, 12).unwrap();
         }
     }
 
-    if explicit_level > Some(3) {
-        match opts.deflate {
-            Deflaters::Libdeflater { .. } => {}
-            _ => {
-                warn!("Level 4 and above are equivalent to level 3 for zopfli");
-            }
-        }
-    }
-
+    #[cfg(feature = "parallel")]
     if let Some(x) = matches.value_of("threads") {
         let threads = x.parse::<usize>().unwrap();