1 files changed, 100 insertions, 0 deletions
diff --git a/adenosine/src/car.rs b/adenosine/src/car.rs
new file mode 100644
index 0000000..22f83bc
--- /dev/null
+++ b/adenosine/src/car.rs
@@ -0,0 +1,100 @@
+use anyhow::Result;
+
+use crate::vendored::iroh_car::{CarHeader, CarReader, CarWriter};
+use futures::TryStreamExt;
+use ipfs_sqlite_block_store::BlockStore;
+use libipld::{Block, Cid};
+use std::path::PathBuf;
+use tokio::fs::File;
+use tokio::io::{AsyncRead, BufReader};
+
+/// Synchronous wrapper for loading in-memory CAR bytes (`&[u8]`) into a blockstore.
+///
+/// Does not do any pinning, even temporarily. Returns the root CID indicated in the CAR file
+/// header.
+pub fn load_car_bytes_to_blockstore(
+    db: &mut BlockStore<libipld::DefaultParams>,
+    car_bytes: &[u8],
+) -> Result<Cid> {
+    let rt = tokio::runtime::Builder::new_current_thread()
+        .enable_all()
+        .build()?;
+    rt.block_on(inner_car_bytes_loader(db, car_bytes))
+}
+
+/// Synchronous wrapper for loading on-disk CAR file (by path) into a blockstore.
+///
+/// Does not do any pinning, even temporarily. Returns the root CID indicated in the CAR file
+/// header.
+pub fn load_car_path_to_blockstore(
+    db: &mut BlockStore<libipld::DefaultParams>,
+    car_path: &PathBuf,
+) -> Result<Cid> {
+    let rt = tokio::runtime::Builder::new_current_thread()
+        .enable_all()
+        .build()?;
+    rt.block_on(inner_car_path_loader(db, car_path))
+}
+
+pub fn read_car_bytes_from_blockstore(
+    db: &mut BlockStore<libipld::DefaultParams>,
+    root: &Cid,
+) -> Result<Vec<u8>> {
+    let rt = tokio::runtime::Builder::new_current_thread()
+        .enable_all()
+        .build()?;
+    rt.block_on(inner_car_bytes_reader(db, root))
+}
+
+async fn inner_car_bytes_loader(
+    db: &mut BlockStore<libipld::DefaultParams>,
+    car_bytes: &[u8],
+) -> Result<Cid> {
+    let car_reader = CarReader::new(car_bytes).await?;
+    inner_car_loader(db, car_reader).await
+}
+
+async fn inner_car_path_loader(
+    db: &mut BlockStore<libipld::DefaultParams>,
+    car_path: &PathBuf,
+) -> Result<Cid> {
+    let car_reader = {
+        let file = File::open(car_path).await?;
+        let buf_reader = BufReader::new(file);
+        CarReader::new(buf_reader).await?
+    };
+    inner_car_loader(db, car_reader).await
+}
+
+async fn inner_car_loader<R: AsyncRead + Send + Unpin>(
+    db: &mut BlockStore<libipld::DefaultParams>,
+    car_reader: CarReader<R>,
+) -> Result<Cid> {
+    let car_header = car_reader.header().clone();
+    car_reader
+        .stream()
+        .try_for_each(|(cid, raw)| {
+            // TODO: error handling here instead of unwrap (?)
+            let block = Block::new(cid, raw).unwrap();
+            db.put_block(block, None).unwrap();
+            futures::future::ready(Ok(()))
+        })
+        .await?;
+    Ok(car_header.roots()[0])
+}
+
+async fn inner_car_bytes_reader(
+    db: &mut BlockStore<libipld::DefaultParams>,
+    root: &Cid,
+) -> Result<Vec<u8>> {
+    let car_header = CarHeader::new_v1(vec![*root]);
+    let buf: Vec<u8> = Default::default();
+    let mut car_writer = CarWriter::new(car_header, buf);
+
+    let cid_list = db.get_descendants::<Vec<_>>(root)?;
+    for cid in cid_list {
+        let block = db.get_block(&cid)?.expect("block content");
+        car_writer.write(cid, block).await?;
+    }
+    Ok(car_writer.finish().await?)
+}