https://github.com/tspurway/pymdb-lightning

Python interface to OpenLDAP MDB (aka. lightning db) key/value store.
https://github.com/tspurway/pymdb-lightning

Last synced: 11 days ago
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Python interface to OpenLDAP MDB (aka. lightning db) key/value store.

• Host: GitHub
• URL: https://github.com/tspurway/pymdb-lightning
• Owner: tspurway
• License: other
• Created: 2012-12-13T17:05:49.000Z (almost 12 years ago)
• Default Branch: master
• Last Pushed: 2014-03-09T20:49:44.000Z (over 10 years ago)
• Last Synced: 2024-08-02T14:12:21.231Z (4 months ago)
• Language: Python
• Size: 263 KB
• Stars: 22
• Watchers: 5
• Forks: 5
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.txt

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README

        
pymdb-lightning

===============

**NOTE: **

==========

A much more up-to-date, bug freer, featureful version of this API is over on the Hustle project: https://github.com/chango/hustle.

===

Python interface to OpenLDAP MDB (aka. lightning db) key/value store.

Official Symas MDB Site:  http://www.symas.com/mdb/

MDB git repo:

The MDB database is a memory mapped (mmap) based b+ tree key/value store.

It uses MVCC, which allows for lockless read/writes - which is very useful in a process heavy Python system.

It is fully ACID compliant, and allows for nested transactions.

It allows for mutliple database instances per mmap, which is a nice touch.

It's got an excellent and very rich API (duplicate key b+ trees, read/write/del cursors, burst writes, etc).

It is fast.  I compares very favourably to kyotocabinet (faster than KCH in my application).

It's tiny.  It compiles to a library < 32K in size.

Requires:

=======

 - mdb

 - Python 2.7 (that is all I have tested with)

 - compatibly versioned Cython

Install

=======

    (in your src directory)

    git clone https://github.com/tspurway/pymdb-lightning.git

    git clone https://git.gitorious.org/mdb/mdb.git

    

    cd mdb/libraries/liblmdb/

    make

    sudo make install

    

    cd ../../../pymdb-lightning

    python setup.py build_ext --inplace

    (bravely install to your system with: sudo python setup.py install)

Usage

=====

Using Writer and Reader

-----------------------

    >>> import mdb

    >>> writer = mdb.Writer('/tmp/mdbtest')

    >>> writer.put('foo', 'bar')

    >>> writer.mput({"key": "value", "egg": "spam"})

    >>> writer.close()

    >>> reader = mdb.Reader('/tmp/mdbtest')

    >>> reader.get('foo')

    >>> for key, value in reader.iteritems():

    ...   print key, value

    >>> reader.close()

Using Integer Key

-----------------

    >>> writer = mdb.Writer('/tmp/mdbtest', dup=True, int_key=True)

    >>> writer = writer.put(1, 'foo')

    >>> writer = writer.put(1, 'bar')  # append a duplicate key

    >>> writer.close()

    >>> reader = mdb.DupReader('/tmp/mdbtest', int_key=True)

    >>> for v in reader.get(1):

    ...   print v

    >>> reader.close()

    

Using Low-level MDB

-------------------

    >>> env = mdb.Env('/tmp/mdbtest')

    >>> txn = env.begin_txn()

    >>> db = env.open_db(txn)

    >>> db.put(txn, 'hi', 'assinine')

    >>> txn.commit()

    >>> txn = env.begin_txn()

    >>> print '"%s"' % db.get(txn, 'hi')  # --> assinine

    >>> txn.close()

    >>> db.close()

    >>> env.close()

RELEASE NOTES:

0.2.6

    * Added integer values

    * Improved overall performance