CouchDB
  1. CouchDB
  2. COUCHDB-1170

include attachment md5 sums in _attachments

    Details

    • Type: Bug Bug
    • Status: Resolved
    • Priority: Minor Minor
    • Resolution: Duplicate
    • Affects Version/s: 1.0.2
    • Fix Version/s: 1.1
    • Component/s: HTTP Interface
    • Labels:
      None

      Description

      Crucial to functioning replication is deterministic revisions. Attachment md5 sums are used in CouchDB's revision generation (see couch_db:new_revid/1).

      Alternative CouchDB implementations may find it impossible or impractical to support binary attachments yet still wish to track changes and replicate efficiently with Apache CouchDB. To this end, such implementations need an efficient way to fetch all metadata necessary for calculating compatible revisions in the event of locally executed future updates.

      As a bonus, exposing this metadata is particularly beneficial for filesystem sync tools (such as couchapp implementations), e.g. through eliminating the need for redundantly storing checksums as user data on synchronized documents.

      To this end I propose the following 5-line patch which applies cleanly to trunk, 1.1.x and 1.0.x.

        Issue Links

          Activity

          Hide
          Randall Leeds added a comment -

          Shoot. Just saw COUCHDB-687 and relevant discussion there about complications. Resolving this as a duplicate and moving my efforts there.

          Show
          Randall Leeds added a comment - Shoot. Just saw COUCHDB-687 and relevant discussion there about complications. Resolving this as a duplicate and moving my efforts there.
          Hide
          Paul Joseph Davis added a comment -

          I don't really have anything against show the checksum, though I might take md5 out of the name in case we ever decide to change the hash algorithm.

          As to replication, do we short circuit attachment updates based on md5 somewhere? I haven't spent the time reading through the new replicator yet but I would've thought I'd heard of that bit.

          Show
          Paul Joseph Davis added a comment - I don't really have anything against show the checksum, though I might take md5 out of the name in case we ever decide to change the hash algorithm. As to replication, do we short circuit attachment updates based on md5 somewhere? I haven't spent the time reading through the new replicator yet but I would've thought I'd heard of that bit.
          Hide
          Jason Smith added a comment -

          Paul, I will reply to you in COUCHDB-687.

          Show
          Jason Smith added a comment - Paul, I will reply to you in COUCHDB-687 .

            People

            • Assignee:
              Unassigned
              Reporter:
              Randall Leeds
            • Votes:
              0 Vote for this issue
              Watchers:
              0 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved:

                Development