$MODULE = "MLDBM::Sync"; $VERSION = .17; $DATE = '2001/10/11';

- Make EXISTS safe after explicity tied hash ReadLock()

- For loops in MLDBM::Sync::SDBM_File that are friendlier 
  to perl5.004_04

- Better Lock() return value, whether or not a lock has
  previously been acquired

$MODULE = "MLDBM::Sync"; $VERSION = .15; $DATE = '2001/09/21';

- API fixes for easier integration with Apache::ASP

- Made $sync_dbm->UnLock() repeatable, with the next
  $sync_dbm->Lock() still working.

$MODULE = "MLDBM::Sync"; $VERSION = .11; $DATE = '2001/09/12';

++ Taking module out of BETA.  Been using it in production 
   for 3 months, and in development for 6.

- Bug fix for undefined warning in MLDBM::Sync::SDBM_File

- MLDBM::Sync::SDBM_File STORE() now deletes prior key parts
  before storing the value, which will result in more correct
  behavior, there was a possible bug here.  Added a test
  in t/sdbm_rec_big.t testing for this possible error.

+ Deletion of lock file when calling CLEAR(), or %dbm = ()
  Do this after unlock, which _might_ have a race condition
  but haven't seen in in heavy load testing... MLDBM::Sync
  recreates the lock file every time if necessary, so this
  may not be an issue anyway.  Might be good to unlink before
  unlocking, but this might only work on *nix platformns,
  now Win32.

$MODULE = "MLDBM::Sync"; $VERSION = .09; $DATE = '2001/07/31';

- Bug fix for undefined warning in MLDBM::Sync::SDBM_File

$MODULE = "MLDBM::Sync"; $VERSION = .07; $DATE = '2001/03/18';

+ $dbm->SyncCacheSize() API activates 2nd layer RAM cache
  via Tie::Cache with MaxBytes set.

+ CACHE documentation, cache.t test, sample benchmarks
  with ./bench/bench_sync.pl -c

$MODULE = "MLDBM::Sync"; $VERSION = .05; $DATE = '2001/03/13';

+ Simpler use of locking.

- Read locking works on Solaris, had to open lock file in 
  read/write mode.  Linux/NT didn't care.

$MODULE = "MLDBM::Sync"; $VERSION = .03; $DATE = 'TBA';

+ $dbm_obj->SyncKeysChecksum(1) API documented.
  New internal format that does not store the original key
  with keys() & each() throwing errors now if used on this
  kind of database.

+ ReadLock() API added, that does a LOCK_SH internally.
  Also uses ReadLock() for FETCH and *KEY operations.
  ** WARNING: one may not ReadLock() and then write to the 
  dbm, or that will die in an error.  Must UnLock() first.
  Writes may only occur in a Lock() section, which does a 
  LOCK_EX internally.

+ Better backward compatibility with old SDBM_Files
  for MLDBM::Sync::SDBM_File, also new format not compatible
  with .01 format.

+ Better test for MLDBM::Sync::SDBM_File, using keys with
  odd characters.

$MODULE = "MLDBM::Sync"; $VERSION = .01; $DATE = '2001/02/07';

+ Initial release with flock concurrent access control to 
  MLDBM databases.  

+ Also MLDBM::Sync::SDBM_File wrapper for getting around the 
  1024 byte / record limitation for sDBM_File.  Writes data
  in segments of 128 bytes.  This was created because SDBM_File
  access is an order of magnitude faster than DB_File on Linux
  with tie/untie per write in the MLDBM::Sync model, which is 
  for i/o flushing do dbms don't get corrupt.  

  But, then one has to worry about exceeding the 1024 byte limit, 
  which can happen for serializing larger objects.  Well worry
  no more!


