The underlying Dag for a COB will use the Ord implementation of whatever is provided as the key. This means that the lexicographical ordering of the Oid SHA will be used, which in turn means that if the SHAs change in our tests, then the ordering will be broken for concurrent updates.

To prevent this from happening, a new key is used EntryKey, which is the combination of an Oid and a Timestamp – the commit timestamp. The key is used in place of EntryId as the Dag key.

This introduction meant that in some places it was necessary to have a way of getting the timestamp of an EntryId. The TimestampOf trait is used in these cases, which means that some infallible functions became fallible.

Changes:

• rebased
• changed commit message to use the terminology “chronlogical ordering” rather than “stable ordering”

Changes:

• Approach the problem from the Dag API, introducing a prune_by method which is used in place of prune, and allows us to dictate the ordering based on the key and value pairs.

Changes:

• Reverting some erroneuous changes

Changes:

• Add test for prune_by
• Do not take ordering by reference in prune_by