Open a Multispool.t. This function will fail by default if the spool directory does not exist, does not look like a spool, or does not contain the set of directories named after the strings returned by Spoolable.Queue.to_dir. Pass ~create_if_missing:() to create the necessary directories.

Note that, even if ~create_if_missing:() is specified, this function will still fail if the supplied directory is non-empty and not already a spool.

Open a Multispool.t with no spool directory validation.

Open a Multispool.t and create the spool directory if necessary. This is functionally identical to load ?create_if_missing:().

Provide access to a Spoolable.Data.t. Data_file.t functions as a "handle" to the underlying data so the user can choose when to read a Spoolable.Data.t.

An Entry is associated with a particular queue

Add a Spoolable to a queue. An Entry.t is returned, but it may make sense to ignore it.

Do something with the contents of an entry within f. Use with_entry if you expect to be the only user of an Entry.t and it is an error if the Entry.t is grabbed by another process (or otherwise disappears). See checkout for a lower-level interface.

Like with_entry, but use with_entry' if you expect that another process might race to grab an Entry.t and want straightforward handling. See checkout' for a lower-level interface.

Interface for iteration and waiting on queue activity. Multiple processes will not interfere with one another.