[pbs-devel] [PATCH proxmox v3 4/5] compression: deflate: add test module

[Maximiliano Sandoval <m.sandoval@proxmox.com>]

We test the deflate encoder against the deflate decoder using (or not)
zlib and with different small buffer sizes. We also test compression and
decompression against the flate2 crate.

Signed-off-by: Maximiliano Sandoval <m.sandoval@proxmox.com>
---
 proxmox-compression/Cargo.toml         |   3 +-
 proxmox-compression/src/deflate/mod.rs | 160 +++++++++++++++++++++++++
 2 files changed, 161 insertions(+), 2 deletions(-)

diff --git a/proxmox-compression/Cargo.toml b/proxmox-compression/Cargo.toml
index 49735cbe..3879ed16 100644
--- a/proxmox-compression/Cargo.toml
+++ b/proxmox-compression/Cargo.toml
@@ -27,5 +27,4 @@ proxmox-io = { workspace = true, features = [ "tokio" ] }
 proxmox-lang.workspace = true
 
 [dev-dependencies]
-tokio = { workspace = true, features = [ "macros" ] }
-
+tokio = { workspace = true, features = [ "macros", "rt-multi-thread" ] }
diff --git a/proxmox-compression/src/deflate/mod.rs b/proxmox-compression/src/deflate/mod.rs
index 6867176c..94faabb3 100644
--- a/proxmox-compression/src/deflate/mod.rs
+++ b/proxmox-compression/src/deflate/mod.rs
@@ -5,3 +5,163 @@ pub use compression::{DeflateEncoder, Level};
 pub use decompression::DeflateDecoder;
 
 const BUFFER_SIZE: usize = 8192;
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    use std::io::Write;
+
+    use flate2::Compression;
+    use futures::StreamExt;
+
+    const BUFFER_SIZE: usize = 25;
+    const BODY: &str = r#"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do
+eiusmod tempor incididunt ut labore et dolore magnam aliquam quaerat voluptatem. Ut
+enim aeque doleamus animo, cum corpore dolemus, fieri tamen permagna accessio potest,
+si aliquod aeternum et infinitum impendere."#;
+
+    fn chunker(content: &[u8]) -> Vec<Result<Vec<u8>, std::io::Error>> {
+        vec![
+            Ok(content[..10].to_vec()),
+            Ok(content[10..20].to_vec()),
+            Ok(content[20..30].to_vec()),
+            Ok(content[30..40].to_vec()),
+            Ok(content[40..].to_vec()),
+        ]
+    }
+
+    #[tokio::test]
+    async fn test_encoder_against_decoder() {
+        // We use mixed sizes for the buffers, on the next test we invert the
+        // sizes.
+        let stream = futures::stream::iter(chunker(BODY.as_bytes()));
+        let encoder = DeflateEncoder::builder(stream)
+            .buffer_size(BUFFER_SIZE * 2)
+            .build();
+        let mut decoder = DeflateDecoder::builder(encoder)
+            .buffer_size(BUFFER_SIZE)
+            .build();
+
+        let mut buf = Vec::with_capacity(BODY.len());
+        while let Some(Ok(res)) = decoder.next().await {
+            buf.write_all(&res).unwrap();
+        }
+
+        assert_eq!(buf, BODY.as_bytes());
+    }
+
+    #[tokio::test]
+    async fn test_zlib_encoder_against_decoder() {
+        let stream = futures::stream::iter(chunker(BODY.as_bytes()));
+        let encoder = DeflateEncoder::builder(stream)
+            .zlib(true)
+            .buffer_size(BUFFER_SIZE)
+            .build();
+        let mut decoder = DeflateDecoder::builder(encoder)
+            .zlib(true)
+            .buffer_size(BUFFER_SIZE * 2)
+            .build();
+
+        let mut buf = Vec::with_capacity(BODY.len());
+        while let Some(Ok(res)) = decoder.next().await {
+            buf.write_all(&res).unwrap();
+        }
+
+        assert_eq!(buf, BODY.as_bytes());
+    }
+
+    #[tokio::test]
+    async fn test_deflate_decompression_against_flate2() {
+        let encoded = flate2_encode(BODY.as_bytes(), false).unwrap();
+        let decoded = decode(&encoded, false, 7).await.unwrap();
+
+        assert_eq!(decoded, BODY.as_bytes());
+    }
+
+    #[tokio::test]
+    async fn test_zlib_decompression_against_flate2() {
+        let encoded = flate2_encode(BODY.as_bytes(), true).unwrap();
+        let decoded = decode(&encoded, true, 4).await.unwrap();
+
+        assert_eq!(decoded, BODY.as_bytes());
+    }
+
+    #[tokio::test]
+    async fn test_deflate_compression_against_flate2() {
+        let encoded = encode(BODY.as_bytes(), false, 5).await.unwrap();
+        let decoded = flate2_decode(&encoded, false).unwrap();
+
+        assert_eq!(decoded, BODY.as_bytes());
+    }
+
+    #[tokio::test]
+    async fn test_zlib_compression_against_flate2() {
+        let encoded = encode(BODY.as_bytes(), true, 3).await.unwrap();
+        let decoded = flate2_decode(&encoded, true).unwrap();
+
+        assert_eq!(decoded, BODY.as_bytes());
+    }
+
+    fn flate2_encode(bytes: &[u8], is_zlib: bool) -> Result<Vec<u8>, std::io::Error> {
+        if is_zlib {
+            let mut e = flate2::write::ZlibEncoder::new(Vec::new(), Compression::default());
+            e.write_all(bytes).unwrap();
+            e.finish()
+        } else {
+            let mut e = flate2::write::DeflateEncoder::new(Vec::new(), Compression::default());
+            e.write_all(bytes).unwrap();
+            e.finish()
+        }
+    }
+
+    fn flate2_decode(bytes: &[u8], is_zlib: bool) -> Result<Vec<u8>, std::io::Error> {
+        if is_zlib {
+            let mut e = flate2::write::ZlibDecoder::new(Vec::new());
+            e.write_all(bytes).unwrap();
+            e.finish()
+        } else {
+            let mut e = flate2::write::DeflateDecoder::new(Vec::new());
+            e.write_all(bytes).unwrap();
+            e.finish()
+        }
+    }
+
+    async fn decode(
+        content: &[u8],
+        is_zlib: bool,
+        buffer_size: usize,
+    ) -> Result<Vec<u8>, std::io::Error> {
+        let stream = futures::stream::iter(chunker(content));
+        let mut decoder = DeflateDecoder::builder(stream)
+            .zlib(is_zlib)
+            .buffer_size(buffer_size)
+            .build();
+        let mut buf = Vec::new();
+
+        while let Some(Ok(res)) = decoder.next().await {
+            buf.write_all(&res)?;
+        }
+
+        Ok(buf)
+    }
+
+    async fn encode(
+        content: &[u8],
+        is_zlib: bool,
+        buffer_size: usize,
+    ) -> Result<Vec<u8>, std::io::Error> {
+        let stream = futures::stream::iter(chunker(content));
+        let mut encoder = DeflateEncoder::builder(stream)
+            .zlib(is_zlib)
+            .buffer_size(buffer_size)
+            .build();
+        let mut buf = Vec::with_capacity(BODY.len());
+
+        while let Some(Ok(res)) = encoder.next().await {
+            buf.write_all(&res)?;
+        }
+
+        Ok(buf)
+    }
+}
-- 
2.39.2