Add put test for mem cache

src/cache/mem.rs

@@ -202,6 +202,7 @@ where
 
 #[cfg(test)]
 mod test_util {
+    use std::cell::RefCell;
     use std::collections::HashMap;
 
     use super::{CacheValue, InternalMemoryCache};
@@ -209,10 +210,14 @@ mod test_util {
         Cache, CacheEntry, CacheError, CacheKey, CacheStream, CallbackCache, ImageMetadata,
     };
     use async_trait::async_trait;
+    use parking_lot::Mutex;
+    use tokio::io::BufReader;
     use tokio::sync::mpsc::Sender;
+    use tokio_util::codec::{BytesCodec, FramedRead};
 
+    #[derive(Default)]
     pub struct TestDiskCache(
-        pub HashMap<CacheKey, Result<(CacheStream, ImageMetadata), CacheError>>,
+        pub Mutex<RefCell<HashMap<CacheKey, Result<(CacheStream, ImageMetadata), CacheError>>>>,
     );
 
     #[async_trait]
@@ -221,8 +226,7 @@ mod test_util {
             &self,
             key: &CacheKey,
         ) -> Option<Result<(CacheStream, ImageMetadata), CacheError>> {
-            // todo: Actually implement nontrivial code
-            None
+            self.0.lock().get_mut().remove(key)
         }
 
         async fn put(
@@ -231,7 +235,12 @@ mod test_util {
             image: bytes::Bytes,
             metadata: ImageMetadata,
         ) -> Result<(), CacheError> {
-            todo!()
+            let reader = Box::pin(BufReader::new(tokio_util::io::StreamReader::new(
+                tokio_stream::once(Ok::<_, std::io::Error>(image)),
+            )));
+            let stream = CacheStream::Completed(FramedRead::new(reader, BytesCodec::new()));
+            self.0.lock().get_mut().insert(key, Ok((stream, metadata)));
+            Ok(())
         }
     }
 
@@ -240,11 +249,22 @@ mod test_util {
         async fn put_with_on_completed_callback(
             &self,
             key: CacheKey,
-            image: bytes::Bytes,
+            data: bytes::Bytes,
             metadata: ImageMetadata,
             on_complete: Sender<CacheEntry>,
         ) -> Result<(), CacheError> {
-            todo!()
+            self.put(key.clone(), data.clone(), metadata.clone())
+                .await?;
+            let on_disk_size = data.len() as u64;
+            let _ = on_complete
+                .send(CacheEntry {
+                    key,
+                    data,
+                    metadata,
+                    on_disk_size,
+                })
+                .await;
+            Ok(())
         }
     }
 
@@ -272,14 +292,13 @@ mod test_util {
 
 #[cfg(test)]
 mod cache_ops {
-    use std::collections::HashMap;
     use std::error::Error;
 
     use bytes::Bytes;
-    use futures::FutureExt;
+    use futures::{FutureExt, StreamExt};
 
     use crate::cache::mem::InternalMemoryCache;
-    use crate::cache::{Cache, CacheKey, CacheStream, ImageMetadata, MemStream};
+    use crate::cache::{Cache, CacheEntry, CacheKey, CacheStream, ImageMetadata, MemStream};
 
     use super::test_util::{TestDiskCache, TestMemoryCache};
     use super::MemoryCache;
@@ -287,7 +306,7 @@ mod cache_ops {
     #[tokio::test]
     async fn get_mem_cached() -> Result<(), Box<dyn Error>> {
         let (cache, mut rx) = MemoryCache::<TestMemoryCache, _>::new_with_receiver(
-            TestDiskCache(HashMap::new()),
+            TestDiskCache::default(),
             crate::units::Bytes(10),
         );
 
@@ -320,11 +339,132 @@ mod cache_ops {
         Ok(())
     }
 
-    #[test]
-    fn get_disk_cached() {}
+    #[tokio::test]
+    async fn get_disk_cached() -> Result<(), Box<dyn Error>> {
+        let (mut cache, mut rx) = MemoryCache::<TestMemoryCache, _>::new_with_receiver(
+            TestDiskCache::default(),
+            crate::units::Bytes(10),
+        );
 
-    #[test]
-    fn get_miss() {}
+        let key = CacheKey("a".to_string(), "b".to_string(), false);
+        let metadata = ImageMetadata {
+            content_type: None,
+            content_length: Some(1),
+            last_modified: None,
+        };
+        let bytes = Bytes::from_static(b"abcd");
+
+        {
+            let cache = &mut cache.inner;
+            cache
+                .put(key.clone(), bytes.clone(), metadata.clone())
+                .await?;
+        }
+
+        let (mut stream, ret_metadata) = cache.get(&key).await.unwrap()?;
+        assert_eq!(metadata, ret_metadata);
+        assert!(matches!(stream, CacheStream::Completed(_)));
+        assert_eq!(stream.next().await, Some(Ok(bytes.clone())));
+
+        assert!(rx.recv().now_or_never().is_none());
+
+        Ok(())
+    }
+
+    // Identical to the get_disk_cached test but we hold a lock on the mem_cache
+    #[tokio::test]
+    async fn get_mem_locked() -> Result<(), Box<dyn Error>> {
+        let (mut cache, mut rx) = MemoryCache::<TestMemoryCache, _>::new_with_receiver(
+            TestDiskCache::default(),
+            crate::units::Bytes(10),
+        );
+
+        let key = CacheKey("a".to_string(), "b".to_string(), false);
+        let metadata = ImageMetadata {
+            content_type: None,
+            content_length: Some(1),
+            last_modified: None,
+        };
+        let bytes = Bytes::from_static(b"abcd");
+
+        {
+            let cache = &mut cache.inner;
+            cache
+                .put(key.clone(), bytes.clone(), metadata.clone())
+                .await?;
+        }
+
+        // intentionally not dropped
+        let _mem_cache = &mut cache.mem_cache.lock().await;
+
+        let (mut stream, ret_metadata) = cache.get(&key).await.unwrap()?;
+        assert_eq!(metadata, ret_metadata);
+        assert!(matches!(stream, CacheStream::Completed(_)));
+        assert_eq!(stream.next().await, Some(Ok(bytes.clone())));
+
+        assert!(rx.recv().now_or_never().is_none());
+
+        Ok(())
+    }
+
+    #[tokio::test]
+    async fn get_miss() {
+        let (cache, mut rx) = MemoryCache::<TestMemoryCache, _>::new_with_receiver(
+            TestDiskCache::default(),
+            crate::units::Bytes(10),
+        );
+
+        let key = CacheKey("a".to_string(), "b".to_string(), false);
+        assert!(cache.get(&key).await.is_none());
+        assert!(rx.recv().now_or_never().is_none());
+    }
+
+    #[tokio::test]
+    async fn put_puts_into_disk_and_hears_from_rx() -> Result<(), Box<dyn Error>> {
+        let (cache, mut rx) = MemoryCache::<TestMemoryCache, _>::new_with_receiver(
+            TestDiskCache::default(),
+            crate::units::Bytes(10),
+        );
+
+        let key = CacheKey("a".to_string(), "b".to_string(), false);
+        let metadata = ImageMetadata {
+            content_type: None,
+            content_length: Some(1),
+            last_modified: None,
+        };
+        let bytes = Bytes::from_static(b"abcd");
+        let bytes_len = bytes.len() as u64;
+
+        cache
+            .put(key.clone(), bytes.clone(), metadata.clone())
+            .await?;
+
+        // Because the callback is supposed to let the memory cache insert the
+        // entry into its cache, we can check that it properly stored it on the
+        // disk layer by checking if we can successfully fetch it.
+
+        let (mut stream, ret_metadata) = cache.get(&key).await.unwrap()?;
+        assert_eq!(metadata, ret_metadata);
+        assert!(matches!(stream, CacheStream::Completed(_)));
+        assert_eq!(stream.next().await, Some(Ok(bytes.clone())));
+
+        // Check that we heard back
+        let cache_entry = rx
+            .recv()
+            .now_or_never()
+            .flatten()
+            .ok_or("failed to hear back from cache")?;
+        assert_eq!(
+            cache_entry,
+            CacheEntry {
+                key,
+                data: bytes,
+                metadata,
+                on_disk_size: bytes_len,
+            }
+        );
+        Ok(())
+    }
 }
 
 #[cfg(test)]

src/cache/mod.rs

@@ -32,7 +32,7 @@ mod disk;
 mod fs;
 pub mod mem;
 
-#[derive(PartialEq, Eq, Hash, Clone)]
+#[derive(PartialEq, Eq, Hash, Clone, Debug)]
 pub struct CacheKey(pub String, pub String, pub bool);
 
 impl Display for CacheKey {
@@ -62,7 +62,7 @@ impl From<&CacheKey> for PathBuf {
 #[derive(Clone)]
 pub struct CachedImage(pub Bytes);
 
-#[derive(Copy, Clone, Serialize, Deserialize, Debug, PartialEq)]
+#[derive(Copy, Clone, Serialize, Deserialize, Debug, PartialEq, Eq)]
 pub struct ImageMetadata {
     pub content_type: Option<ImageContentType>,
     pub content_length: Option<u32>,
@@ -232,6 +232,7 @@ impl<T: CallbackCache> CallbackCache for Arc<T> {
     }
 }
 
+#[derive(PartialEq, Eq, Debug)]
 pub struct CacheEntry {
     key: CacheKey,
     data: Bytes,