Further perf improv attempts

Reuse the buffer when decompressing the frames

src/frame.rs

@@ -39,6 +39,25 @@ impl<'b> Frame<'b> {
         Some(self.inner.as_ref())
     }
 
+    pub fn decompress_with_buf<'s, 'buf>(&'s self, buf: &'b mut Vec<u8>) -> Result<&'buf [u8], ()> where 's: 'buf {
+        if !self.compressed {
+            return Ok(&self.inner);
+        }
+
+        let uncompressed_len = snap::raw::decompress_len(&self.inner).map_err(|e| {
+            println!("Getting decompress len");
+            ()
+        })?;
+        buf.resize(uncompressed_len, 0);
+
+        snap::raw::Decoder::new().decompress(&self.inner, buf.as_mut_slice()).map_err(|e| {
+            println!("Decompressing");
+            ()
+        })?;
+
+        Ok(buf.as_slice())
+    }
+
     pub fn decompress(&mut self) -> Result<(), ()> {
         if !self.compressed {
             return Ok(());

src/parser.rs

@@ -107,11 +107,9 @@ where
 
     let mut entity_states = Vec::new();
 
-    for mut frame in frames.into_iter() {
+    let mut buffer = Vec::new();
-        frame
+    for frame in frames.into_iter() {
-            .decompress()
+        let data = frame.decompress_with_buf(&mut buffer).map_err(|e| FirstPassError::DecompressFrame)?;
-            .map_err(|e| FirstPassError::DecompressFrame)?;
-        let data = frame.data().ok_or(FirstPassError::NoDataFrame)?;
 
         match frame.cmd {
             DemoCommand::FileHeader => {