pds: implement CAR import/export at repo level

1 files changed, 61 insertions, 25 deletions

diff --git a/adenosine-pds/src/car.rs b/adenosine-pds/src/car.rs
index 43b4e1f..832c87e 100644
--- a/adenosine-pds/src/car.rs
+++ b/adenosine-pds/src/car.rs
@@ -1,50 +1,76 @@
 use anyhow::Result;
 
-use crate::vendored::iroh_car::CarReader;
+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::BufReader;
+use tokio::io::{AsyncRead, BufReader};
 
-pub fn load_car_to_sqlite(db_path: &PathBuf, car_path: &PathBuf, alias: &str) -> Result<()> {
-    let mut db: BlockStore<libipld::DefaultParams> =
-        { BlockStore::open(db_path, Default::default())? };
-
-    load_car_to_blockstore(&mut db, car_path, alias)?;
-    Ok(())
+/// 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))
 }
 
-pub fn load_car_to_blockstore(
+/// 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,
-    alias: &str,
 ) -> Result<Cid> {
     let rt = tokio::runtime::Builder::new_current_thread()
         .enable_all()
         .build()?;
-    rt.block_on(inner_car_loader(db, car_path, alias))
+    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))
 }
 
-// this async function is wrapped in the sync version above
-async fn inner_car_loader(
+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,
-    alias: &str,
 ) -> Result<Cid> {
-    println!(
-        "{} - {}",
-        std::env::current_dir()?.display(),
-        car_path.display()
-    );
     let car_reader = {
         let file = File::open(car_path).await?;
         let buf_reader = BufReader::new(file);
         CarReader::new(buf_reader).await?
     };
-    let car_header = car_reader.header().clone();
+    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)| {
@@ -54,11 +80,21 @@ async fn inner_car_loader(
             futures::future::ready(Ok(()))
         })
         .await?;
+    Ok(car_header.roots()[0])
+}
 
-    // pin the header (?)
-    if !car_header.roots().is_empty() {
-        db.alias(alias.as_bytes(), Some(&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.clone()]);
+    let buf: Vec<u8> = Default::default();
+    let mut car_writer = CarWriter::new(car_header, buf);
 
-    Ok(car_header.roots()[0])
+    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?)
 }