remove treehouse-format crate and collapse everything into src

src/vfs/content_version_cache.rs

@@ -0,0 +1,68 @@
+use std::fmt::{self, Debug};
+
+use dashmap::DashMap;
+use tracing::{info_span, instrument};
+
+use super::{query, Content, ContentVersion, Dir, Query, VPath, VPathBuf};
+
+pub struct Blake3ContentVersionCache<T> {
+    salt: Vec<u8>,
+    inner: T,
+    cache: DashMap<VPathBuf, ContentVersion>,
+}
+
+impl<T> Blake3ContentVersionCache<T> {
+    pub fn new(salt: Vec<u8>, inner: T) -> Self {
+        Self {
+            salt,
+            inner,
+            cache: DashMap::new(),
+        }
+    }
+}
+
+impl<T> Blake3ContentVersionCache<T>
+where
+    T: Dir,
+{
+    #[instrument(name = "Blake3ContentVersionCache::content_version", skip(self))]
+    fn content_version(&self, path: &VPath) -> Option<ContentVersion> {
+        self.cache.get(path).map(|x| x.clone()).or_else(|| {
+            let _span = info_span!("cache_miss").entered();
+
+            let version = query::<Content>(&self.inner, path).map(|content| {
+                let mut hasher = blake3::Hasher::new();
+                hasher.update(&self.salt);
+                hasher.update(&content.bytes());
+                let hash = hasher.finalize().to_hex();
+                ContentVersion {
+                    string: format!("b3-{}", &hash[0..8]),
+                }
+            });
+            if let Some(version) = &version {
+                self.cache.insert(path.to_owned(), version.clone());
+            }
+            version
+        })
+    }
+}
+
+impl<T> Dir for Blake3ContentVersionCache<T>
+where
+    T: Dir,
+{
+    fn query(&self, path: &VPath, query: &mut Query) {
+        query.try_provide(|| self.content_version(path));
+
+        self.inner.query(path, query);
+    }
+}
+
+impl<T> fmt::Debug for Blake3ContentVersionCache<T>
+where
+    T: Debug,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "Blake3ContentVersionCache({:?})", self.inner)
+    }
+}