1. 06 Mar, 2019 6 commits
    • Kirill Smelkov's avatar
      go/zodb/*: Cosmetics, typos, ... · 60682993
      Kirill Smelkov authored
      60682993
    • Kirill Smelkov's avatar
      go/zodb: Connection.Resync · bae8fda6
      Kirill Smelkov authored
      Add low-level option to resync Connection to another database state with
      preserving its live cache.
      
      Wendelin.core needs this for its main ZODB connection because it needs
      to carefully propagate ZODB invalidations into file invalidations and
      semantically relies on objects staying in ZODB live cache for this to
      work correctly:
      
      https://lab.nexedi.com/kirr/wendelin.core/blob/455a54425c/wcfs/wcfs.go#L245
      bae8fda6
    • Kirill Smelkov's avatar
      go/zodb: DB: handle invalidations · 918455e7
      Kirill Smelkov authored
      Implement invalidation handling to teach DB to reuse Connections from
      connection pool: after connection is returned to the pool on transaction
      completion, we can use this connection for next DB.Open(at) request, by
      seeing which objects we changed in conn.at..at range and invalidating
      those objects in connection live cache.
      
      To know which objects were changed, DB adds watch on its storage and
      maintains some history tail (using ΔTail - see previous commit).
      
      Finally add test for both DB and Connection, and also for Persistent,
      LiveCache, ... - as all those application-level components are tightly
      inter-related.
      918455e7
    • Kirill Smelkov's avatar
      go/zodb: ΔTail · d8e9d7a9
      Kirill Smelkov authored
      Add ΔTail - utility class to keep track of history tail of revisional
      changes. This will be needed for both DB (to handle invalidations) and
      for raw Cache(*). It also might be useful in places outside of zodb/go -
      for example WCFS from Wendelin.core uses ΔTail to keep track of which
      ZODB revision changed which block of file(+).
      
      Please see ΔTail comments for details.
      
      (*) to check a bit ahead on load to see whether loaded serial is
      actually the latest one for ≤ Cache.head, and, if yes, mark
      corresponding cache entry as having .head="current" so that the entry
      coverage could be extended when Cache.head is extended to cover more
      database state instead of loading the same data from the database again.
      
      (+) that's why we have δtail.go.cat-generic, so that third-party
      packages could adapt ΔTail to needed types.
      d8e9d7a9
    • Kirill Smelkov's avatar
      go/zodb: ↑ SNR for ConnOptions · 030b0c42
      Kirill Smelkov authored
      We are going to add more options. Adopt "!" prefix as "no" for
      something. Make the code flow in ConnOptions more suitable for further
      additions without changing formatter for previous option.
      030b0c42
    • Kirill Smelkov's avatar
      go/zodb: Require DB to be closed · 2f5e3606
      Kirill Smelkov authored
      DB is a "handle to database". It has to be closed to release its
      resources when no longer needed. We don't have to release anything
      currently, but that will soon change in a followup patch.
      2f5e3606
  2. 20 Feb, 2019 9 commits
  3. 19 Feb, 2019 4 commits
  4. 18 Feb, 2019 5 commits
  5. 05 Feb, 2019 3 commits
  6. 01 Feb, 2019 3 commits
    • Kirill Smelkov's avatar
      go/zodb: tests: Provide way to commit IPersistent objects · 42118074
      Kirill Smelkov authored
      Add a way for tests to serialize and commit IPersistent objects. The
      commit, for now, is implemented via calling external zodbtools/py to
      commit raw data (see 7f14e2cb "go/zodb/fs1: tests: Factor-out commiting
      a transaction via ZODB/py into common place). The data to commit is what
      object serialization (see previous patch) gives.
      
      For now there is no tracking of dirtiness. A test must explicitly list
      objects it wants to save into database.
      
      This functionality will soon be used to implement Persistent/DB/...
      tests.
      42118074
    • Kirill Smelkov's avatar
      go/zodb: Teach Persistent to serialize itself · a16c9e06
      Kirill Smelkov authored
      This will be used in the future to commit object changes back into
      database. No test, since this functionality will be used at first to
      implement tests themselves (see next patch). Hopefully after
      bootstrapping we'll have full tests.
      a16c9e06
    • Kirill Smelkov's avatar
      go/zodb: Complete (Py)Stateful & Ghostable · e020026a
      Kirill Smelkov authored
      - require (Py)GetState and make it clear that it is called by
        persistency machinery only on non-ghost objects.
      - make it clear that (Py)SetState is called by persistency machinery
        only on ghost objects.
      - make it clear that DropState is called by persistency machinery only
        on non-ghost objects.
      
      For btree PyGetState is marked as TODO which we'll fill incrementally
      (the code is draftly ready, but there is no test for now).
      e020026a
  7. 30 Jan, 2019 3 commits
    • Kirill Smelkov's avatar
      go/zodb/fs1: tests: Factor-out commiting a transaction via ZODB/py into common place · 7f14e2cb
      Kirill Smelkov authored
      We will soon need to be able to commit in tests for ZODB itself.
      7f14e2cb
    • Kirill Smelkov's avatar
      go/zodb: Require drivers to provide at₀ on open · a6580062
      Kirill Smelkov authored
      and to deliver to watchq only and all events in (at₀, +∞] range.
      
      This continues 4d2c8b1d (go/zodb: Require drivers to provide
      notifications for database change events) and makes initialization
      semantics to process invalidations easier for both application-level ZODB
      layer, and for low-level users that work with drivers directly:
      
      - there is no possibility that an event will come from watchq with tid <
        current user head.
      
      - there is no possibility that watcher will start delivering events
        after at₀, but not immediately after it, i.e. users can rely that they
        won't loose an event.
      
      This correctness invariants should be easy to provide in drivers.
      a6580062
    • Kirill Smelkov's avatar
      go/zodb: DB.connv -> DB.pool · 2799f995
      Kirill Smelkov authored
      pool is a better name for "pool of unused connections" compared to connv.
      2799f995
  8. 29 Jan, 2019 2 commits
    • Kirill Smelkov's avatar
      go/zodb: Connection -= .stor · 0806740d
      Kirill Smelkov authored
      Connection has .db and db has .stor - there is no need to keep separate
      .stor on the Connection. This thinko was there from Connection beginning
      (533f0c73 "go/zodb: DB - application-level handle to database (very draft)")
      0806740d
    • Kirill Smelkov's avatar
      go/transaction: Fix Abort to wait for synchronizers completion · 7e0c944f
      Kirill Smelkov authored
      There was a thinko in transaction.Abort - it was spawning synchronizers
      under a waitgroup, but wg.Wait() call was forgotten. This way, e.g. in
      ZODB if a transaction was aborted, corresponding connection could be not
      yet returned back into DB pool.
      
      Fix it.
      
      Test is TODO for the time when, hopefully, tracetest is generally ready.
      7e0c944f
  9. 28 Jan, 2019 1 commit
    • Kirill Smelkov's avatar
      go/zodb += TidFromTime · a9e2badf
      Kirill Smelkov authored
      In ZODB transaction ID is connected with time. We already have
      functionality to convert tid to time (see bac6c953 "go/zodb: Tid
      connection with time"), but the functionality for converting in another
      way - time -> tid - was missing.
      
      Fix it.
      a9e2badf
  10. 18 Jan, 2019 4 commits
    • Kirill Smelkov's avatar
      go/zodb: Expose retrieving ZODB class name of a Go object as public API · 2f061c0c
      Kirill Smelkov authored
      It is useful in situations where one need to print potentially Broken
      objects properly, because %T does not print that detail and using %#v
      creates too much noise.
      2f061c0c
    • Kirill Smelkov's avatar
      go/zodb: Allow to set live cache control policy · cab4dd52
      Kirill Smelkov authored
      This allows for applications to tune eviction strategy for their needs.
      The interface to do so (LiveCacheControl) was defined previously in
      c67ff9ea (go/zodb: Connection: Allow applications to tune live-cache
      eviction policy), but so far there was no way to install cache
      controller. Fix it.
      cab4dd52
    • Kirill Smelkov's avatar
      go/zodb: Expose access to connection's live cache as public API · e2d902b0
      Kirill Smelkov authored
      Wendelin.core (wcfs) needs to check whether an object is currently
      cached or not.
      e2d902b0
    • Kirill Smelkov's avatar
      go/zodb/fs1: Teach it to support notifications on database change · db852511
      Kirill Smelkov authored
      Following-up on 4d2c8b1d (go/zodb: Require drivers to provide
      notifications for database change events) let's teach FileStorage to
      support watching for database changes:
      
      - add watcher who observes changes to data file via fsnotify.
      
      - when we see that the file was updated - there is a tricky case to distinguish
        in-progress writes from just some garbage added at tail. See comments in
        _watcher for details.
      
      - if the watcher sees there is indeed new transactions, the watcher
        updates index & txnh{Min,Max} and sends corresponding event to watchq.
      
      - since index / txnh{Min,Max} can now be changed (by watcher) -> they
        are now protected by mu.
      
      - consequently operations like LastTid, LastOid, Load, ... are all taught to
        observe index / txnh{Min,Max} state in read-snapshot way.
      
      - add down & friends to indicate that the storage is no longer
        operational, if watcher sees there is a problem with data file.
      
      - Open is reworked to start from loading/rebuilding index first, and then tail
        to watcher to detect whether what's after found topPos is garbage or another
        in-progress transaction. Consequently it is now possible to correctly open
        filestorage that is being currently written to and has in-progress transaction
        at tail.
      
      The patch is a bit big, but the changes here are all tightly
      interrelated.
      db852511