diff options
Diffstat (limited to 'entity/entity.go')
| -rw-r--r-- | entity/entity.go | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/entity/entity.go b/entity/entity.go index 9ba536d6..a1e8e57e 100644 --- a/entity/entity.go +++ b/entity/entity.go @@ -21,9 +21,7 @@ type Operation interface { Validate() error } -type OperationIterator struct { -} - +// Definition hold the details defining one specialization of an Entity. type Definition struct { // the name of the entity (bug, pull-request, ...) typename string @@ -59,6 +57,11 @@ func Read(def Definition, repo repository.ClockedRepo, id Id) (*Entity, error) { ref := fmt.Sprintf("refs/%s/%s", def.namespace, id.String()) + return read(def, repo, ref) +} + +// read fetch from git and decode an Entity at an arbitrary git reference. +func read(def Definition, repo repository.ClockedRepo, ref string) (*Entity, error) { rootHash, err := repo.ResolveRef(ref) if err != nil { return nil, err @@ -180,9 +183,22 @@ func Read(def Definition, repo repository.ClockedRepo, id Id) (*Entity, error) { oppSlice = append(oppSlice, pack) } sort.Slice(oppSlice, func(i, j int) bool { - // TODO: no secondary ordering? - // might be useful for stable ordering - return oppSlice[i].PackTime < oppSlice[i].PackTime + // Primary ordering with the dedicated "pack" Lamport time that encode causality + // within the entity + if oppSlice[i].PackTime != oppSlice[j].PackTime { + return oppSlice[i].PackTime < oppSlice[i].PackTime + } + // We have equal PackTime, which means we had a concurrent edition. We can't tell which exactly + // came first. As a secondary arbitrary ordering, we can use the EditTime. It's unlikely to be + // enough but it can give us an edge to approach what really happened. + if oppSlice[i].EditTime != oppSlice[j].EditTime { + return oppSlice[i].EditTime < oppSlice[j].EditTime + } + // Well, what now? We still need a total ordering, the most stable possible. + // As a last resort, we can order based on a hash of the serialized Operations in the + // operationPack. It doesn't carry much meaning but it's unbiased and hard to abuse. + // This is a lexicographic ordering. + return oppSlice[i].Id < oppSlice[j].Id }) // Now that we ordered the operationPacks, we have the order of the Operations @@ -270,6 +286,7 @@ func (e *Entity) CommitAdNeeded(repo repository.ClockedRepo) error { return nil } +// TODO: support commit signature func (e *Entity) Commit(repo repository.ClockedRepo) error { if !e.NeedCommit() { return fmt.Errorf("can't commit an entity with no pending operation") |