feat: Fallback to system commands for disabled compression features

Co-authored-by: aider (openai/andrew/openrouter/sonoma-sky-alpha) <aider@aider.chat>

src/compression_engine.rs

@@ -74,15 +74,24 @@ pub trait CompressionEngine {
 
 lazy_static! {
     pub static ref COMPRESSION_PROGRAMS: EnumMap<CompressionType, Option<CompressionEngineProgram>> = enum_map! {
-        CompressionType::LZ4 => None,
+        CompressionType::LZ4 => {
-        CompressionType::GZip => None,
+            let program = CompressionEngineProgram::new("lz4", vec!["-c"], vec!["-d", "-c"]);
+            if program.supported { Some(program) } else { None }
+        },
+        CompressionType::GZip => {
+            let program = CompressionEngineProgram::new("gzip", vec!["-c"], vec!["-d", "-c"]);
+            if program.supported { Some(program) } else { None }
+        },
         #[cfg(feature = "bzip2")]
         CompressionType::BZip2 => {
             let program = CompressionEngineProgram::new("bzip2", vec!["-qcf"], vec!["-dcf"]);
             if program.supported { Some(program) } else { None }
         },
         #[cfg(not(feature = "bzip2"))]
-        CompressionType::BZip2 => None,
+        CompressionType::BZip2 => {
+            let program = CompressionEngineProgram::new("bzip2", vec!["-qcf"], vec!["-dcf"]);
+            if program.supported { Some(program) } else { None }
+        },
         CompressionType::XZ => {
             let program = CompressionEngineProgram::new("xz", vec!["-qcf"], vec!["-dcf"]);
             if program.supported { Some(program) } else { None }
@@ -99,14 +108,42 @@ pub fn get_compression_engine(
     compression_type: CompressionType,
 ) -> Result<Box<dyn CompressionEngine>> {
     match compression_type {
-        CompressionType::LZ4 => Ok(Box::new(CompressionEngineLZ4::new())),
+        CompressionType::LZ4 => {
-        CompressionType::GZip => Ok(Box::new(CompressionEngineGZip::new())),
+            #[cfg(feature = "lz4")]
+            {
+                Ok(Box::new(CompressionEngineLZ4::new()))
+            }
+            #[cfg(not(feature = "lz4"))]
+            {
+                if let Some(engine) = COMPRESSION_PROGRAMS[compression_type].clone() {
+                    Ok(Box::new(engine))
+                } else {
+                    Err(anyhow!("LZ4 not available: feature disabled and program not found"))
+                }
+            }
+        },
+        CompressionType::GZip => {
+            #[cfg(feature = "gzip")]
+            {
+                Ok(Box::new(CompressionEngineGZip::new()))
+            }
+            #[cfg(not(feature = "gzip"))]
+            {
+                if let Some(engine) = COMPRESSION_PROGRAMS[compression_type].clone() {
+                    Ok(Box::new(engine))
+                } else {
+                    Err(anyhow!("GZip not available: feature disabled and program not found"))
+                }
+            }
+        },
         CompressionType::None => Ok(Box::new(CompressionEngineNone::new())),
-        compression_type => Ok(Box::new(
+        compression_type => {
-            COMPRESSION_PROGRAMS[compression_type.clone()]
+            if let Some(engine) = COMPRESSION_PROGRAMS[compression_type].clone() {
-                .clone()
+                Ok(Box::new(engine))
-                .unwrap(),
+            } else {
-        )),
+                Err(anyhow!("Compression type {:?} not supported", compression_type))
+            }
+        },
     }
 }