Small improvements in the S3 put workflow

author: Alex Auvolat <alex@adnab.me> 2021-02-19 12:11:02 +0100
committer: Alex Auvolat <alex@adnab.me> 2021-02-19 12:11:02 +0100
commit: 76390085ef7cc0a8879e9edc039b536f90d5aa59 (patch)
tree: e4a9524dcf3d6613e1a881f938c6ad581e9d9e72 /src
parent: 3b023c0c3b985dc1c04c8545351b5ba20cf9189e (diff)
download: garage-76390085ef7cc0a8879e9edc039b536f90d5aa59.tar.gz
garage-76390085ef7cc0a8879e9edc039b536f90d5aa59.zip
1 files changed, 70 insertions, 39 deletions
diff --git a/src/api/s3_put.rs b/src/api/s3_put.rs
index c42309b2..656d84a9 100644
--- a/src/api/s3_put.rs
+++ b/src/api/s3_put.rs
@@ -27,24 +27,25 @@ pub async fn handle_put(
 	key: &str,
 	content_sha256: Option<Hash>,
 ) -> Result<Response<Body>, Error> {
+	// Generate identity of new version
 	let version_uuid = gen_uuid();
+	let version_timestamp = now_msec();
+
+	// Retrieve interesting headers from request
 	let headers = get_headers(&req)?;
 	let content_md5 = match req.headers().get("content-md5") {
 		Some(x) => Some(x.to_str()?.to_string()),
 		None => None,
 	};
 
+	// Parse body of uploaded file
 	let body = req.into_body();
 
 	let mut chunker = BodyChunker::new(body, garage.config.block_size);
 	let first_block = chunker.next().await?.unwrap_or(vec![]);
 
-	let mut object_version = ObjectVersion {
-		uuid: version_uuid,
-		timestamp: now_msec(),
-		state: ObjectVersionState::Uploading(headers.clone()),
-	};
-
+	// If body is small enough, store it directly in the object table
+	// as "inline data". We can then return immediately.
 	if first_block.len() < INLINE_THRESHOLD {
 		let mut md5sum = Md5::new();
 		md5sum.update(&first_block[..]);
@@ -60,27 +61,41 @@ pub async fn handle_put(
 			content_sha256,
 		)?;
 
-		object_version.state = ObjectVersionState::Complete(ObjectVersionData::Inline(
-			ObjectVersionMeta {
-				headers,
-				size: first_block.len() as u64,
-				etag: md5sum_hex.clone(),
-			},
-			first_block,
-		));
+		let object_version = ObjectVersion {
+			uuid: version_uuid,
+			timestamp: version_timestamp,
+			state: ObjectVersionState::Complete(ObjectVersionData::Inline(
+				ObjectVersionMeta {
+					headers,
+					size: first_block.len() as u64,
+					etag: md5sum_hex.clone(),
+				},
+				first_block,
+			)),
+		};
 
 		let object = Object::new(bucket.into(), key.into(), vec![object_version]);
 		garage.object_table.insert(&object).await?;
+
 		return Ok(put_response(version_uuid, md5sum_hex));
 	}
 
-	let version = Version::new(version_uuid, bucket.into(), key.into(), false, vec![]);
-
-	let first_block_hash = hash(&first_block[..]);
+	// Write version identifier in object table so that we have a trace
+	// that we are uploading something
+	let mut object_version = ObjectVersion {
+		uuid: version_uuid,
+		timestamp: now_msec(),
+		state: ObjectVersionState::Uploading(headers.clone()),
+	};
 	let object = Object::new(bucket.into(), key.into(), vec![object_version.clone()]);
 	garage.object_table.insert(&object).await?;
 
-	let (total_size, md5sum_arr, sha256sum) = read_and_put_blocks(
+	// Initialize corresponding entry in version table
+	let version = Version::new(version_uuid, bucket.into(), key.into(), false, vec![]);
+	let first_block_hash = hash(&first_block[..]);
+
+	// Transfer data and verify checksum
+	let tx_result = read_and_put_blocks(
 		&garage,
 		version,
 		1,
@@ -88,19 +103,31 @@ pub async fn handle_put(
 		first_block_hash,
 		&mut chunker,
 	)
-	.await?;
-
-	ensure_checksum_matches(
-		md5sum_arr.as_slice(),
-		sha256sum,
-		content_md5.as_deref(),
-		content_sha256,
-	)?;
-
-	// TODO: if at any step we have an error, we should undo everything we did
+	.await
+	.and_then(|(total_size, md5sum_arr, sha256sum)| {
+		ensure_checksum_matches(
+			md5sum_arr.as_slice(),
+			sha256sum,
+			content_md5.as_deref(),
+			content_sha256,
+		)
+		.map(|()| (total_size, md5sum_arr))
+	});
+
+	// If something went wrong, clean up
+	let (total_size, md5sum_arr) = match tx_result {
+		Ok(rv) => rv,
+		Err(e) => {
+			// Mark object as aborted, this will free the blocks further down
+			object_version.state = ObjectVersionState::Aborted;
+			let object = Object::new(bucket.into(), key.into(), vec![object_version.clone()]);
+			garage.object_table.insert(&object).await?;
+			return Err(e);
+		}
+	};
 
+	// Save final object state, marked as Complete
 	let md5sum_hex = hex::encode(md5sum_arr);
-
 	object_version.state = ObjectVersionState::Complete(ObjectVersionData::FirstBlock(
 		ObjectVersionMeta {
 			headers,
@@ -109,7 +136,6 @@ pub async fn handle_put(
 		},
 		first_block_hash,
 	));
-
 	let object = Object::new(bucket.into(), key.into(), vec![object_version]);
 	garage.object_table.insert(&object).await?;
 
@@ -340,13 +366,12 @@ pub async fn handle_put_part(
 	};
 
 	// Read first chuck, and at the same time try to get object to see if it exists
-	let mut chunker = BodyChunker::new(req.into_body(), garage.config.block_size);
-
 	let bucket = bucket.to_string();
 	let key = key.to_string();
-	let get_object_fut = garage.object_table.get(&bucket, &key);
-	let get_first_block_fut = chunker.next();
-	let (object, first_block) = futures::try_join!(get_object_fut, get_first_block_fut)?;
+	let mut chunker = BodyChunker::new(req.into_body(), garage.config.block_size);
+
+	let (object, first_block) =
+		futures::try_join!(garage.object_table.get(&bucket, &key), chunker.next(),)?;
 
 	// Check object is valid and multipart block can be accepted
 	let first_block = first_block.ok_or(Error::BadRequest(format!("Empty body")))?;
@@ -404,8 +429,8 @@ pub async fn handle_complete_multipart_upload(
 		garage.object_table.get(&bucket, &key),
 		garage.version_table.get(&version_uuid, &EmptyKey),
 	)?;
-	let object = object.ok_or(Error::BadRequest(format!("Object not found")))?;
 
+	let object = object.ok_or(Error::BadRequest(format!("Object not found")))?;
 	let object_version = object
 		.versions()
 		.iter()
@@ -418,11 +443,12 @@ pub async fn handle_complete_multipart_upload(
 		}
 		Some(x) => x.clone(),
 	};
-	let version = version.ok_or(Error::BadRequest(format!("Version not found")))?;
 
+	let version = version.ok_or(Error::BadRequest(format!("Version not found")))?;
 	if version.blocks().len() == 0 {
 		return Err(Error::BadRequest(format!("No data was uploaded")));
 	}
+
 	let headers = match object_version.state {
 		ObjectVersionState::Uploading(headers) => headers.clone(),
 		_ => unreachable!(),
@@ -540,8 +566,13 @@ fn get_headers(req: &Request<Body>) -> Result<ObjectVersionHeaders, Error> {
 	let mut other = BTreeMap::new();
 	for h in other_headers.iter() {
 		if let Some(v) = req.headers().get(h) {
-			if let Ok(v_str) = v.to_str() {
-				other.insert(h.to_string(), v_str.to_string());
+			match v.to_str() {
+				Ok(v_str) => {
+					other.insert(h.to_string(), v_str.to_string());
+				}
+				Err(e) => {
+					warn!("Discarding header {}, error in .to_str(): {}", h, e);
+				}
 			}
 		}
 	}
author	Alex Auvolat <alex@adnab.me>	2021-02-19 12:11:02 +0100
committer	Alex Auvolat <alex@adnab.me>	2021-02-19 12:11:02 +0100
commit	76390085ef7cc0a8879e9edc039b536f90d5aa59 (patch)
tree	e4a9524dcf3d6613e1a881f938c6ad581e9d9e72 /src
parent	3b023c0c3b985dc1c04c8545351b5ba20cf9189e (diff)
download	garage-76390085ef7cc0a8879e9edc039b536f90d5aa59.tar.gz garage-76390085ef7cc0a8879e9edc039b536f90d5aa59.zip