Files in Target Directory

cargo-maelstrom stores a number of files in the workspace’s target directory, under the maelstrom subdirectory. This chapter lists them and explains what they’re for.

It is safe to remove this directory whenever cargo-maelstrom isn’t running.

Except in the case of the local worker, cargo-maelstrom doesn’t currently make any effort to clean up these files. However, the total space consumed by these files should be pretty small.

cargo-maelstrom also uses the container-images cache. That cache is not stored in the target directory, as it can be shared by different Maelstrom clients.

Local Worker

The local worker stores its cache in maelstrom/cache/local-worker/ in the target directory. The cache-size configuration value indicates the target size of this cache directory.

Manifest Files

cargo-maelstrom uses “manifest files” for non-tar layers. These are like tar files, but without the actual data contents. These files are stored in maelstrom/cache/manifests/ in the target directory.

File Digests

Files uploaded to the broker are identified by a hash of their file contents. Calculating these hashes can be time consuming so cargo-maelstrom caches this information. This cache is stored in maelstrom/cache/cached-digests.toml in the target directory.

Test Listing

When cargo-maelstrom finishes, it updates a list of all of the tests in the workspace, and how long they took to run. This is used to predict the number of tests that will be run in subsequent invocations, as well as how long they will take. This is stored in the — maelstrom/state/test-listing.toml — file in the target directory.