feat(iroh-bytes): add more context to errors (#2196)

## Description

feat(iroh-bytes): add more context to errors

add hash and offset/range as context for LeafHashMismatch and
ParentHashMismatch errors

This is what the log looks like now:

```
2024-04-16T07:17:19.613913Z  WARN iroh_bytes::provider: error: Error {
    context: "hash 17c8e5a70f69d289105553dfa762064e8cc57ffb9355d76508f557e37ef051db offset 9994240",
    source: LeafHashMismatch(
        ChunkNum(0x2620),
    ),
}
2024-04-16T07:17:26.664680Z  INFO magicsock{me=34qdsunbluss4zny}:actor:disco{node=kqn3pxyufuskwsup}: iroh_net::magicsock::node_map::best_addr: clearing best_addr reason=PongTimeout has_relay=true old_addr=192.168.1.131:64604
2024-04-16T07:18:05.507191Z  INFO poll_recv{me=34qdsunbluss4zny}:disco_in{node=kkpbi4eb5h6jcdjz src=Udp(192.168.1.131:62647)}: iroh_net::magicsock::node_map: inserting new node endpoint in NodeMap node=kkpbi4eb5h6jcdjz relay_url=None
2024-04-16T07:18:05.507311Z  INFO poll_recv{me=34qdsunbluss4zny}:disco_in{node=kkpbi4eb5h6jcdjz src=Udp(192.168.1.131:62647)}: iroh_net::magicsock::node_map::endpoint: new direct addr for node addr=192.168.1.131:62647
2024-04-16T07:18:05.510362Z  INFO poll_recv{me=34qdsunbluss4zny}:disco_in{node=kkpbi4eb5h6jcdjz src=Udp(192.168.1.131:62647)}: iroh_net::magicsock::node_map::best_addr: selecting new direct path for endpoint addr=192.168.1.131:62647 latency=2.686417ms trust_for=6.499932542s
2024-04-16T07:18:07.994402Z  INFO iroh_bytes::provider: sent 100390814 bytes in 2.4763055s
2024-04-16T07:18:07.994461Z  WARN iroh_bytes::provider: error: Error {
    context: "hash 370e2b3002be3b38b120f7b3be53da4cf646810e26f8f4a5018247c8188af5b2 range 65536..98304",
    source: Error {
        context: "g4hcwmacxy5trmja66z34u62jt3enaioe34pjjibqjd4qgek6wza",
        source: ParentHashMismatch(
            TreeNode::Branch(79, level=4),
        ),
    },
}
```

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changes. -->

## Notes & open questions

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## Change checklist

- [ ] Self-review.
- [ ] Documentation updates if relevant.
- [ ] Tests if relevant.

iroh-bytes/src/provider.rs

@@ -4,6 +4,7 @@ use std::time::Duration;
 
 use anyhow::{Context, Result};
 use bao_tree::io::fsm::{encode_ranges_validated, Outboard};
+use bao_tree::io::EncodeError;
 use futures::future::BoxFuture;
 use iroh_base::rpc::RpcError;
 use iroh_io::stats::{
@@ -487,34 +488,50 @@ pub enum SentStatus {
     NotFound,
 }
 
-/// Send a
+/// Send a blob to the client.
 pub async fn send_blob<D: Map, W: AsyncStreamWriter>(
     db: &D,
-    name: Hash,
+    hash: Hash,
     ranges: &RangeSpec,
     mut writer: W,
 ) -> Result<(SentStatus, u64, SliceReaderStats)> {
-    match db.get(&name).await? {
+    match db.get(&hash).await? {
         Some(entry) => {
             let outboard = entry.outboard().await?;
             let size = outboard.tree().size();
             let mut file_reader = TrackingSliceReader::new(entry.data_reader().await?);
             writer.write(size.to_le_bytes().as_slice()).await?;
-            let res = encode_ranges_validated(
+            encode_ranges_validated(
                 &mut file_reader,
                 outboard,
                 &ranges.to_chunk_ranges(),
                 writer,
             )
-            .await;
-            debug!("done sending blob {} {:?}", name, res);
-            res?;
+            .await
+            .map_err(|e| encode_error_to_anyhow(e, &hash))?;
 
             Ok((SentStatus::Sent, size, file_reader.stats()))
         }
         _ => {
-            debug!("blob not found {}", hex::encode(name));
+            debug!("blob not found {}", hash.to_hex());
             Ok((SentStatus::NotFound, 0, SliceReaderStats::default()))
         }
     }
 }
+
+fn encode_error_to_anyhow(err: EncodeError, hash: &Hash) -> anyhow::Error {
+    match err {
+        EncodeError::LeafHashMismatch(x) => anyhow::Error::from(EncodeError::LeafHashMismatch(x))
+            .context(format!("hash {} offset {}", hash.to_hex(), x.to_bytes())),
+        EncodeError::ParentHashMismatch(n) => {
+            let r = n.chunk_range();
+            anyhow::Error::from(EncodeError::ParentHashMismatch(n)).context(format!(
+                "hash {} range {}..{}",
+                hash.to_hex(),
+                r.start.to_bytes(),
+                r.end.to_bytes()
+            ))
+        }
+        e => anyhow::Error::from(e).context(format!("hash {}", hash.to_hex())),
+    }
+}