Merge pull request #59 from cccs-sadugas/streaming-decompressor-v4

Streaming Decompressor v4

Cargo.toml

@@ -19,6 +19,7 @@ env_logger = { version = "^0.7.1", optional = true }
 
 [features]
 enable_logging = ["env_logger", "log"]
+stream = []
 
 [badges]
 travis-ci = { repository = "gendx/lzma-rs", branch = "master" }

benches/lzma.rs

@@ -34,13 +34,31 @@ fn decompress_bench(compressed: &[u8], b: &mut Bencher) {
     });
 }
 
+#[cfg(feature = "stream")]
+fn decompress_stream_bench(compressed: &[u8], b: &mut Bencher) {
+    use std::io::Write;
+    b.iter(|| {
+        let mut stream = lzma_rs::decompress::Stream::new(Vec::new());
+        stream.write_all(compressed).unwrap();
+        stream.finish().unwrap()
+    });
+}
+
 fn decompress_bench_file(compfile: &str, b: &mut Bencher) {
     let mut f = std::fs::File::open(compfile).unwrap();
     let mut compressed = Vec::new();
     f.read_to_end(&mut compressed).unwrap();
     decompress_bench(&compressed, b);
 }
 
+#[cfg(feature = "stream")]
+fn decompress_stream_bench_file(compfile: &str, b: &mut Bencher) {
+    let mut f = std::fs::File::open(compfile).unwrap();
+    let mut compressed = Vec::new();
+    f.read_to_end(&mut compressed).unwrap();
+    decompress_stream_bench(&compressed, b);
+}
+
 #[bench]
 fn compress_empty(b: &mut Bencher) {
     #[cfg(feature = "enable_logging")]
@@ -90,6 +108,14 @@ fn decompress_big_file(b: &mut Bencher) {
     decompress_bench_file("tests/files/foo.txt.lzma", b);
 }
 
+#[cfg(feature = "stream")]
+#[bench]
+fn decompress_stream_big_file(b: &mut Bencher) {
+    #[cfg(feature = "enable_logging")]
+    let _ = env_logger::try_init();
+    decompress_stream_bench_file("tests/files/foo.txt.lzma", b);
+}
+
 #[bench]
 fn decompress_huge_dict(b: &mut Bencher) {
     #[cfg(feature = "enable_logging")]

src/decode/lzbuffer.rs

@@ -18,8 +18,10 @@ where
     fn get_output(&self) -> &W;
     // Get a mutable reference to the output sink
     fn get_output_mut(&mut self) -> &mut W;
-    // Flush the buffer to the output
+    // Consumes this buffer and flushes any data
     fn finish(self) -> io::Result<W>;
+    // Consumes this buffer without flushing any data
+    fn into_output(self) -> W;
 }
 
 // An accumulating buffer for LZ sequences
@@ -143,12 +145,17 @@ where
         &mut self.stream
     }
 
-    // Flush the buffer to the output
+    // Consumes this buffer and flushes any data
     fn finish(mut self) -> io::Result<W> {
         self.stream.write_all(self.buf.as_slice())?;
         self.stream.flush()?;
         Ok(self.stream)
     }
+
+    // Consumes this buffer without flushing any data
+    fn into_output(self) -> W {
+        self.stream
+    }
 }
 
 // A circular buffer for LZ sequences
@@ -291,12 +298,17 @@ where
         &mut self.stream
     }
 
-    // Flush the buffer to the output
+    // Consumes this buffer and flushes any data
     fn finish(mut self) -> io::Result<W> {
         if self.cursor > 0 {
             self.stream.write_all(&self.buf[0..self.cursor])?;
             self.stream.flush()?;
         }
         Ok(self.stream)
     }
+
+    // Consumes this buffer without flushing any data
+    fn into_output(self) -> W {
+        self.stream
+    }
 }