1 files changed, 150 insertions, 0 deletions
diff --git a/tvix/castore/src/blobservice/sled.rs b/tvix/castore/src/blobservice/sled.rs
new file mode 100644
index 0000000000..3dd4bff7bc
--- /dev/null
+++ b/tvix/castore/src/blobservice/sled.rs
@@ -0,0 +1,150 @@
+use super::{BlobReader, BlobService, BlobWriter};
+use crate::{B3Digest, Error};
+use std::{
+    io::{self, Cursor, Write},
+    path::Path,
+    task::Poll,
+};
+use tonic::async_trait;
+use tracing::instrument;
+
+#[derive(Clone)]
+pub struct SledBlobService {
+    db: sled::Db,
+}
+
+impl SledBlobService {
+    pub fn new<P: AsRef<Path>>(p: P) -> Result<Self, sled::Error> {
+        let config = sled::Config::default()
+            .use_compression(false) // is a required parameter
+            .path(p);
+        let db = config.open()?;
+
+        Ok(Self { db })
+    }
+
+    pub fn new_temporary() -> Result<Self, sled::Error> {
+        let config = sled::Config::default().temporary(true);
+        let db = config.open()?;
+
+        Ok(Self { db })
+    }
+}
+
+#[async_trait]
+impl BlobService for SledBlobService {
+    #[instrument(skip(self), fields(blob.digest=%digest))]
+    async fn has(&self, digest: &B3Digest) -> io::Result<bool> {
+        match self.db.contains_key(digest.as_slice()) {
+            Ok(has) => Ok(has),
+            Err(e) => Err(io::Error::new(io::ErrorKind::Other, e.to_string())),
+        }
+    }
+
+    #[instrument(skip(self), fields(blob.digest=%digest))]
+    async fn open_read(&self, digest: &B3Digest) -> io::Result<Option<Box<dyn BlobReader>>> {
+        match self.db.get(digest.as_slice()) {
+            Ok(None) => Ok(None),
+            Ok(Some(data)) => Ok(Some(Box::new(Cursor::new(data[..].to_vec())))),
+            Err(e) => Err(io::Error::new(io::ErrorKind::Other, e.to_string())),
+        }
+    }
+
+    #[instrument(skip(self))]
+    async fn open_write(&self) -> Box<dyn BlobWriter> {
+        Box::new(SledBlobWriter::new(self.db.clone()))
+    }
+}
+
+pub struct SledBlobWriter {
+    db: sled::Db,
+
+    /// Contains the buffer Vec and hasher, or None if already closed
+    writers: Option<(Vec<u8>, blake3::Hasher)>,
+
+    /// The digest that has been returned, if we successfully closed.
+    digest: Option<B3Digest>,
+}
+
+impl SledBlobWriter {
+    pub fn new(db: sled::Db) -> Self {
+        Self {
+            db,
+            writers: Some((Vec::new(), blake3::Hasher::new())),
+            digest: None,
+        }
+    }
+}
+
+impl tokio::io::AsyncWrite for SledBlobWriter {
+    fn poll_write(
+        mut self: std::pin::Pin<&mut Self>,
+        _cx: &mut std::task::Context<'_>,
+        b: &[u8],
+    ) -> std::task::Poll<Result<usize, io::Error>> {
+        Poll::Ready(match &mut self.writers {
+            None => Err(io::Error::new(
+                io::ErrorKind::NotConnected,
+                "already closed",
+            )),
+            Some((ref mut buf, ref mut hasher)) => {
+                let bytes_written = buf.write(b)?;
+                hasher.write(&b[..bytes_written])
+            }
+        })
+    }
+
+    fn poll_flush(
+        mut self: std::pin::Pin<&mut Self>,
+        _cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Result<(), io::Error>> {
+        Poll::Ready(match &mut self.writers {
+            None => Err(io::Error::new(
+                io::ErrorKind::NotConnected,
+                "already closed",
+            )),
+            Some(_) => Ok(()),
+        })
+    }
+
+    fn poll_shutdown(
+        self: std::pin::Pin<&mut Self>,
+        _cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Result<(), io::Error>> {
+        // shutdown is "instantaneous", we only write to a Vec<u8> as buffer.
+        Poll::Ready(Ok(()))
+    }
+}
+
+#[async_trait]
+impl BlobWriter for SledBlobWriter {
+    async fn close(&mut self) -> io::Result<B3Digest> {
+        if self.writers.is_none() {
+            match &self.digest {
+                Some(digest) => Ok(digest.clone()),
+                None => Err(io::Error::new(
+                    io::ErrorKind::NotConnected,
+                    "already closed",
+                )),
+            }
+        } else {
+            let (buf, hasher) = self.writers.take().unwrap();
+
+            let digest: B3Digest = hasher.finalize().as_bytes().into();
+
+            // Only insert if the blob doesn't already exist.
+            if !self.db.contains_key(digest.as_slice()).map_err(|e| {
+                Error::StorageError(format!("Unable to check if we have blob {}: {}", digest, e))
+            })? {
+                // put buf in there. This will move buf out.
+                self.db
+                    .insert(digest.as_slice(), buf)
+                    .map_err(|e| Error::StorageError(format!("unable to insert blob: {}", e)))?;
+            }
+
+            self.digest = Some(digest.clone());
+
+            Ok(digest)
+        }
+    }
+}