Key/value

Functions for the key/value store include: set, get, delete, has, and keys. The k/v store can also be used in a dict-like fashion with s[k], del s[k], k in s, and len(s).

with Store('file.name', frozen=False) as kv:
    kv.set('some_key', value)
    value = kv.get('some_key')
    del kv['some_key']

Time series

Time series are key/value pairs where the value changes over time. Each value change (or data point) is recorded with a timestamp. The timestamp is an arbitrary int value and its meaning must be determined by the application. An even frequency between the timestamps is optional.

Functions for time series include: range, first, last, missing, iscomplete, extend, remove, and timeseries.

with Store('file.name', frozen=False) as ts:
    ts.extend('some_series', (timestamp1, value1), ...)
    timestamp, value = ts.last('some_series')
    ts.remove('some_series')

Event sequences

Event sequences are key/dict pairs where each change to the dict is recorded as an event. Events are stored as tuple (timestamp, item, op, value) where:

• timestamp is the POSIX timestamp in milliseconds when the event was recorded (type int)

• item is the name of the dict member (type str)

• op is the operator to apply to the dict member (operator.setitem, operator.delitem, operator.add, …)

• value is the value to apply to the dict member (or None for unary operators such as operator.delitem)

Functions for event sequences include: current, past, apply, prune, events, and eventsources.

with Store('file.name', frozen=False) as es:
    es.apply('some_dict', {'item': 1})       # op defaults to operator.setitem
    es.apply('some_dict', {'item': (operator.add, 1)})
    es.events('some_dict') == [(timestamp, 'item', operator.setitem, 1), (timestamp, 'item', operator.add, 1)]
    es.current('some_dict') == {'item': 2}
    es.prune('some_dict', remove=True)

Installation

$ pip install rlib-store

Getting Started

from rstore import Store

Check the doc strings and unit tests for examples.

License

“MIT”. See LICENSE for details. Copyright t5w5h5@gmail.com, 2018.