nardl: unpack

rust/nardl/src/main.rs

@@ -4,11 +4,12 @@ use ed25519_dalek::{Signature, VerifyingKey};
 use sha2::Digest;
 use std::{
     collections::{HashMap, HashSet},
+    io::{BufReader, Read, Seek},
     os::unix::fs::MetadataExt,
     path::Path,
     pin::Pin,
 };
-use tokio::io::{AsyncRead, AsyncReadExt, AsyncSeekExt};
+use tokio::io::AsyncRead;
 use tokio_stream::StreamExt;
 use tokio_util::io::StreamReader;
 
@@ -22,7 +23,7 @@ const KEYS: [&str; 2] = [
 
 const OUTPUT: &str = "/nix/store/n50jk09x9hshwx1lh6k3qaiygc7yxbv9-lix-2.90.0-rc1";
 
-const TEST_PREFIX: &str = "/tmp/nardl";
+const TEST_PREFIX: &str = "/tmp/nardl/out";
 
 #[tokio::main]
 async fn main() -> eyre::Result<()> {
@@ -63,7 +64,8 @@ async fn main() -> eyre::Result<()> {
         })
         .collect::<eyre::Result<HashMap<&str, VerifyingKey>>>()?;
 
-    let temp_dir = async_tempfile::TempDir::new().await?;
+    // let temp_dir = async_tempfile::TempDir::new().await?;
+    let temp_dir = Path::new("/tmp/nardl");
 
     let client = reqwest::Client::new();
 
@@ -102,7 +104,12 @@ async fn main() -> eyre::Result<()> {
         let Some(output) = outputs_remaining.pop() else {
             break;
         };
-        outputs_done.insert(output.clone());
+
+        // If two outputs refer to the same reference before that reference is done
+        // then we can end up with it in the list twice, even with outputs_done filtering
+        if !outputs_done.insert(output.clone()) {
+            continue;
+        }
 
         log::debug!("Requesting output {}", output);
 
@@ -115,13 +122,16 @@ async fn main() -> eyre::Result<()> {
             get_narinfo(client.clone(), cache_base_urls.as_slice(), fingerprint)
                 .await
                 .wrap_err_with(|| format!("While processing {}", output))?;
-        let narinfo_parsed = narinfo::NarInfo::parse(&narinfo_text).unwrap();
+        // fuck it, i'm too tired to do it properly
+        let narinfo_parsed =
+            narinfo::NarInfo::parse(Box::leak(narinfo_text.into_boxed_str())).unwrap();
 
         verify_signature(&narinfo_parsed, &trusted_keys, store_dir, &output)
             .wrap_err_with(|| format!("While processing {}", output))?;
 
         for reference in narinfo_parsed.references.iter() {
             if reference.is_empty() || outputs_done.contains(reference.as_ref()) {
+                log::trace!("skipping reference from {} to {}", output, reference);
                 continue;
             }
             outputs_remaining.push(reference.to_string());
@@ -129,7 +139,6 @@ async fn main() -> eyre::Result<()> {
 
         // Download nar
         let nar_url = cache_base_url.join(narinfo_parsed.url)?;
-        log::trace!("Found nar url {}", nar_url);
 
         let response = client_no_compression
             .get(nar_url)
@@ -165,41 +174,52 @@ async fn main() -> eyre::Result<()> {
             .await?;
         tokio::io::copy(&mut decompressed_stream, &mut out_file).await?;
 
-        out_file.seek(std::io::SeekFrom::Start(0)).await?;
+        let mut out_file_blocking = out_file.into_std().await;
 
-        // Verify nar
-        let found_size = out_file.metadata().await?.size();
-        if found_size != narinfo_parsed.nar_size as u64 {
-            eyre::bail!("Wrong nar size for {}", output);
-        }
-
-        let (hash_algorithm, hash_expected) = narinfo_parsed
-            .nar_hash
-            .as_ref()
-            .split_once(':')
-            .ok_or_eyre("Invalid hash in nar")?;
-
-        if hash_algorithm != "sha256" {
-            eyre::bail!("who is using hashes other than sha256????");
-        }
-
-        log::trace!("expected hash: {}", hash_expected);
-
-        let mut buf = [0u8; 1024];
-        let mut hasher = sha2::Sha256::new();
-        loop {
-            let num_read = out_file.read(&mut buf).await?;
-            if num_read == 0 {
-                break;
+        tokio::task::spawn_blocking(move || {
+            // Verify nar
+            let found_size = out_file_blocking.metadata()?.size();
+            if found_size != narinfo_parsed.nar_size as u64 {
+                eyre::bail!("Wrong nar size for {}", output);
             }
-            hasher.update(&buf[0..num_read]);
-        }
 
-        let hash_found = hasher.finalize();
+            let (hash_algorithm, hash_expected) = narinfo_parsed
+                .nar_hash
+                .as_ref()
+                .split_once(':')
+                .ok_or_eyre("Invalid hash in nar")?;
 
-        if nix_base32::to_nix_base32(hash_found.as_ref()) != hash_expected {
-            eyre::bail!("Incorrect hash when downloading {}", output)
-        }
+            if hash_algorithm != "sha256" {
+                eyre::bail!("who is using hashes other than sha256????");
+            }
+
+            out_file_blocking.seek(std::io::SeekFrom::Start(0))?;
+            let mut buf = [0u8; 1024];
+            let mut hasher = sha2::Sha256::new();
+            loop {
+                let num_read = out_file_blocking.read(&mut buf)?;
+                if num_read == 0 {
+                    break;
+                }
+                hasher.update(&buf[0..num_read]);
+            }
+
+            let hash_found = hasher.finalize();
+
+            if nix_base32::to_nix_base32(hash_found.as_ref()) != hash_expected {
+                eyre::bail!("Incorrect hash when downloading {}", output)
+            }
+
+            // Unpack nar
+            out_file_blocking.seek(std::io::SeekFrom::Start(0))?;
+            let reader = BufReader::new(out_file_blocking);
+            let decoder = nix_nar::Decoder::new(reader)?;
+
+            decoder.unpack(Path::new(TEST_PREFIX).join(output))?;
+
+            Ok(())
+        })
+        .await??;
     }
 
     Ok(())
@@ -279,7 +299,6 @@ fn verify_signature(
                 .collect::<Vec<String>>()
                 .join(",")
         );
-        log::trace!("narinfo fingerprint: `{}`", fingerprint);
 
         key.verify_strict(fingerprint.as_bytes(), &signature)
             .wrap_err("Invalid signature")?;