Some movement of helper code and refactoring of error handling

src/model/helper/bucket.rs

@@ -0,0 +1,56 @@
+use garage_table::util::EmptyKey;
+use garage_util::data::*;
+
+use crate::bucket_table::Bucket;
+use crate::garage::Garage;
+use crate::helper::error::*;
+
+pub struct BucketHelper<'a>(pub(crate) &'a Garage);
+
+impl<'a> BucketHelper<'a> {
+	#[allow(clippy::ptr_arg)]
+	pub async fn resolve_global_bucket_name(
+		&self,
+		bucket_name: &String,
+	) -> Result<Option<Uuid>, Error> {
+		// Bucket names in Garage are aliases, true bucket identifiers
+		// are 32-byte UUIDs. This function resolves bucket names into
+		// their full identifier by looking up in the bucket_alias_table.
+		// This function also allows buckets to be identified by their
+		// full UUID (hex-encoded). Here, if the name to be resolved is a
+		// hex string of the correct length, it is directly parsed as a bucket
+		// identifier which is returned. There is no risk of this conflicting
+		// with an actual bucket name: bucket names are max 63 chars long by
+		// the AWS spec, and hex-encoded UUIDs are 64 chars long.
+		let hexbucket = hex::decode(bucket_name.as_str())
+			.ok()
+			.map(|by| Uuid::try_from(&by))
+			.flatten();
+		if let Some(bucket_id) = hexbucket {
+			Ok(self
+				.0
+				.bucket_table
+				.get(&bucket_id, &EmptyKey)
+				.await?
+				.filter(|x| !x.state.is_deleted())
+				.map(|_| bucket_id))
+		} else {
+			Ok(self
+				.0
+				.bucket_alias_table
+				.get(&EmptyKey, bucket_name)
+				.await?
+				.map(|x| x.state.get().as_option().map(|x| x.bucket_id))
+				.flatten())
+		}
+	}
+
+	pub async fn get_existing_bucket(&self, bucket_id: Uuid) -> Result<Bucket, Error> {
+		self.0
+			.bucket_table
+			.get(&bucket_id, &EmptyKey)
+			.await?
+			.filter(|b| !b.is_deleted())
+			.ok_or_bad_request(format!("Bucket {:?} does not exist", bucket_id))
+	}
+}