Replica Format

       overview

        $URL
           /<db-uuid>/
               /replica-uuid
               /latest-sequence-no
               /replica-version
               /cas/records/<substr(sha1,0,1)>/substr(sha1,1,1)/<sha1>
               /cas/changesets/<substr(sha1,0,1)>/substr(sha1,1,1)/<sha1>
               /records (optional?)
                   /<record type> (for resolution is actually _prophet-resolution-<cas-key>)
                       /<record uuid> which is a file containing a list of 0 or more rows
                           last-changed-sequence-no : cas key

               /changesets.idx

                   index which has records:
                       each record is : local-replica-seq-no : original-uuid : original-seq-no : cas key
                   ...

               /resolutions/
                   /replica-uuid
                   /latest-sequence-no
                   /cas/<substr(sha1,0,1)>/substr(sha1,1,1)/<sha1>
                   /content (optional?)
                       /_prophet-resolution-<cas-key>   (cas-key == a hash the conflicting change)
                           /<record uuid>  (record uuid == the originating replica)
                               last-changed-sequence-no : <cas key to the content of the resolution>

                   /changesets.idx
                       index which has records:
                           each record is : local-replica-seq-no : original-uuid : original-seq-no : cas key
                       ...

       Inside the top level directory for the mirror, you'll find a directory named as a hex-encoded UUID.  This
       directory is the root of the published replica. The uuid uniquely identifes the database being
       replicated.  All replicas of this database will share the same UUID.

       Inside the <db-uuid> directory, are a set of files and directories that make up the actual content of the
       database replica:

       "replica-uuid"
         Contains the replica's hex-encoded UUID.

       "replica-version"
         Contains a single integer that defines the replica format.

         The current replica version is 1.

       "latest-sequence-no"
         Contains a single integer, the replica's most recent sequence number.

       "cas/records"
       "cas/changesets"
         The  "cas"  directory  holds  changesets  and  records,  each keyed by a hex-encoded hash of the item's
         content. Inside the "cas" directory, you'll find a two-level deep directory  tree  of  single-character
         hex      digits.       You'll      find       the      changeset      with      the     sha1     digest
         "f4b7489b21f8d107ad8df78750a410c028abbf6c"                                                       inside
         "cas/changesets/f/4/f4b7489b21f8d107ad8df78750a410c028abbf6c".

         You'll   find  the  record  with  the  sha1  digest  "dd6fb674de879a1a4762d690141cdfee138daf65"  inside
         "cas/records/d/d/dd6fb674de879a1a4762d690141cdfee138daf65".

         TODO: define the format for changesets and records

       "records"
         Files inside the "records" directory are index files which list off all published versions of a  record
         and the key necessary to retrieve the record from the content-addressed store.

         Inside  the "records" directory, you'll find directories named for each "type" in your database. Inside
         each "type" directory, you'll find a two-level directory tree of single hexadecimal digits. You'll find
         the record with the type <Foo> and the UUID "29A3CA16-03C5-11DD-9AE0-E25CFCEE7EC4" stored in

          records/Foo/2/9/29A3CA16-03C5-11DD-9AE0-E25CFCEE7EC4

         The format of record files is:

             <unsigned-long-int: last-changed-sequence-no><40 chars of hex: cas key>

         The file is sorted in asecnding order by revision id.

       "changesets.idx"
         The "changesets.idx" file lists each changeset in this replica and provides an index into the  content-
         addressed storage to fetch the content of the changeset.

         The format of record files is:

             <unsigned-long-int: sequence-no><16 bytes: changeset original source uuid><unsigned-long-int: changeset original source sequence no><16 bytes: cas key - sha1 sum of the changeset's content>

         The file is sorted in ascending order by revision id.

       "resolutions"
         TODO DOC RESOLUTIONS

   BUILD
       Open a connection to the prophet replica source identified by "$self-"url>.

   replica_version
       Returns this replica's version.

   set_replica_version
       Sets the replica's version to the given integer.

   uuid
       Return the replica's UUID

Internals of record handling

   changesets_for_record { uuid => $uuid, type => $type, limit => $int }
       Returns an ordered set of changeset objects for all changesets containing changes to this object.

       Note that changesets may include changes to other records

       If "limit" is specified, only returns that many changesets (starting from record creation).

   begin_edit
       Creates a new Prophet::ChangeSet, which new changes will be added to.

perl v5.14.2                                       2011-07-09                     Prophet::Replica::prophet(3pm)