Metadata-Version: 2.1
Name: yedb
Version: 0.2.20
Summary: Rugged embedded and client/server key/value database
Home-page: https://github.com/alttch/yedb
Author: Altertech
Author-email: pr@altertech.com
License: Apache License 2.0
Description: # yedb - rugged embedded and client/server key-value database (Python implementation)
        
        <img src="https://img.shields.io/pypi/v/yedb.svg" /> <img src="https://img.shields.io/badge/license-Apache%202.0-green" /> <img src="https://img.shields.io/badge/python-3.6%20%7C%203.7%20%7C%203.8%20%7C%203.9-blue.svg" />
        
        ## Why YEDB?
        
        - Is it fast?
        - Fast to read, slow to write
        
        - Is it smart?
        - No
        
        - So what is YEDB for?
        - YEDB is ultra-reliable, thread-safe and very easy to use.
        
        - I don't like Python
        - There are other [implementations](https://yedb.bma.ai)
        
        [![Power loss data survive
        demo](https://img.youtube.com/vi/i3hSWjrNqLo/0.jpg)](https://www.youtube.com/watch?v=i3hSWjrNqLo)
        
        https://www.youtube.com/watch?v=i3hSWjrNqLo
        
        YEDB is absolutely reliable rugged key-value database, which can survive in any
        power loss, unless the OS file system die. Keys data is saved in the very
        reliable way and immediately flushed to disk (this can be disabled to speed
                up the engine but is not recommended - why then YEDB is used for).
        
        * YEDB database objects are absolutely thread-safe.
        
        * YEDB has built-in tools to automatically repair itself if any keys are broken.
        
        * If the tools failed to help, YEDB can be easily repaired by a system
        administrator, using standard Linux tools.
        
        * YEDB can automatically validate keys with JSON Schema
        (https://json-schema.org/)
        
        * YEDB has a cool CLI
        
        Practical usage:
        
        * Create a database and start writing continuously
        
        * Turn the power switch off
        
        * Boot the machine again. The typical result: the latest saved key isn't
        survived, but the database is still valid and working. In 99% of cases, the
        latest key can be automatically restored with built-in repair tools.
        
        We created YEDB to use in our embedded products as config registry trees and
        rugged key-value data storage. We use it a lot and hope you'll like it too.
        
        Note: YEDB is good on SSDs and SD cards. As it immediately syncs all the data
        written, it can work on classic HDDs really slowly.
        
        ## Performance
        
        Modern SSDs give about 200-300 keys/sec written with auto-flush enabled. The
        write speed can be 10-15 times faster without it, but we would not recommend
        turning auto-flush off, as it is the key feature of YEDB.
        
        Reading speed varies:
        
        * for embedded: 30-40k keys/second (70-100k keys/second when cached).
        
        * for UNIX/TCP socket: 7-15k keys/second
        
        * for HTTP: 700-800 keys/second. Transport via HTTP is mostly slow because YEDB
          client uses synchronous "requests" library (while the default server is
          async). To get better results, consider tuning the server manually and use
          a custom async client.
        
        ## Quick start
        
        ```shell
        # install YEDB
        pip3 install yedb
        
        # to use as embedded or client/server - go on. to use CLI - install additional
        # required libraries
        pip3 install "yedb[cli]"
        
        # create a new database and go interactive
        yedb /path/to/my/database
        
        # set a key
        yedb set key1 value1
        # get the key value
        yedb get key1
        ```
        
        ## Quick client-server setup
        
        ```
        # Install required system packages
        # Debian/Ubuntu: apt-get install -y --no-install-recommends python3 python3-dev gcc
        # RedHat/Fedora/CenOS: yum install -y python3 python3-devel gcc
        sudo mkdir /opt/yedbd
        cd /opt/yedbd && curl https://raw.githubusercontent.com/alttch/yedb-py/main/setup-server.sh | sudo sh
        ```
        
        Use env to specify extra options:
        
        * YEDBD\_BIND - override bind to (tcp://host:port, http://host:port or path to
          UNIX socket)
        * YEDBD\_SERVICE - system service name
        * YEDB\_PS - CLI prompt
        * PIP\_EXTRA\_OPTIONS - specify pip extra options
        * PYTHON - override Python path
        * PIP - override pip path
        
        ## Embedding
        
        ```python
        from yedb import YEDB
        
        with YEDB('/path/to/db', auto_repair=True) as db:
            # do some stuff
        
        # OR
        
        db = YEDB('/path/to/db')
        db.open()
        try:
            # do some stuff
        finally:
            db.close()
        ```
        
        ## Client/server
        
        * If socket transport requested, the built-in in server requires "msgpack"
          Python module
        * If HTTP transport requested, the built-in server requires "aiohttp" Python
          module
        
        ```shell
        # listen to tcp://localhost:8870 (default), to bind UNIX socket, specify the
        # full socket path, to use http transport, specify http://host:port to bind to
        python3 -m yedb.server /path/to/db
        ```
        
        ### Connect a client
        
        * If socket transport requested, the built-in in client requires "msgpack"
          Python module
        * If HTTP transport requested, the built-in client requires "requests" Python
          module
        
        ```python
        from yedb import YEDB
        
        with YEDB('tcp://localhost:8870') as db:
            # do some stuff, remember to send all parameters as kwargs
        ```
        
        YEDB creates thread-local objects. If the software is using permanent threads
        or a thread pool, it is recommended to use sessions to correctly drop these
        objects at the end of the statement:
        
        ```python
        from yedb import YEDB
        
        with YEDB('tcp://localhost:8870') as db:
            with db.session() as session:
                # do some stuff, remember to send all parameters as kwargs
                session.key_set(key='key1', value='val1')
                print(session.key_get(key='key1'))
        ```
        
        ### Building own client
        
        YEDB uses JSON RPC (https://www.jsonrpc.org/) as the API protocol. Any method,
        listed in yedb.server.METHODS can be called. Payloads can be packed either with
        JSON or with MessagePack.
        
        If working via UNIX or TCP socket:
        
        * only MessagePack payload encoding is supported
        
        * Request/response format: PROTO\_VER + DATA\_FMT + FRAME\_LEN(32-bit
          little-endian) + frame
        
        Where PROTO\_VER = protocol version (0x01) and DATA\_FMT = data encoding format
        (0x02 for MessagePack, which is the only protocol supported by the
        built-in server).
        
        ### Working with complicated data structures (embedded only)
        
        ```python
        from yedb import YEDB
        
        with YEDB('/path/to/db') as db:
            with db.key_as_dict('path/to/keydict) as key:
                key.set('field', 'value')
            # If modified, the key is automatically saved at the end of the statement.
        ```
        
        ## Data formats
        
        The default engine data format is JSON
        (https://github.com/python-rapidjson/python-rapidjson is detected and imported
         automatically if present)
        
        Other possible formats and their benefits:
        
        * YAML - (requires manually installing "pyyaml" Python module) slow, but key
        files are more human-readable and editable
        
        * msgpack - (requires manually installing "msgpack" Python module). Fast,
        reliable binary serialization format. If used, keys can hold binary values as
        well.
        
        * cbor - similar to msgpack (requires manually installing "cbor" Python module)
        
        * pickle - native Python pickle binary data serialization format. Is slower
        than msgpack/cbor, but keys can hold Python objects and functions as-is.
        
        Databases can be easily converted between formats using "yedb" CLI tool or
        "convert\_fmt" method, unless format-specific features are used (e.g. if keys
                have binary data, they can't be converted to JSON properly).
        
        ## YEDB Specifications and Data formats
        
        See https://github.com/alttch/yedb
        
        ## Schema validation
        
        As all keys are serialized values, they can be automatically schema-validated
        with JSON Schema (https://json-schema.org/).
        
        To create the validation schema for the chosen key, or key group, create a
        special key ".schema/path/to", which has to contain the valid JSON Schema.
        
        E.g. the schema, stored in the key ".schema/groups/group1" will be used for
        validating all keys in "groups/group1", including the group primary key. And
        the schema, stored in ".schema/groups/group1/key1" will be used for validating
        "groups/group1/key1" only (if key or subgroup schema is present, the parent
                schemas are omitted).
        
        YEDB also supports a non-standard scheme:
        
        ```json
        { "type" : "code.python" }
        ```
        
        which requires the key to have valid Python code, without syntax errors.
        
        If schema validation fails on set or structure "with" statement exit, an
        exception yedb.SchemaValidationError is raised.
        
        ## Backup/restore
        
        Full backup: simply backup the database directory with any preferred method.
        
        Partial/server backup:
        
        Use "dump\_keys" / "load\_keys" methods. If dump is created with CLI (requires
        "msgpack" Python module for that), it has the format:
        
            DUMP\_VER + DUMP\_FMT
        
            KEY_LEN(32-bit little-endian) + KEY
            KEY_LEN(32-bit little-endian) + KEY
            KEY_LEN(32-bit little-endian) + KEY
            KEY_LEN(32-bit little-endian) + KEY
            ....
            KEY_LEN(32-bit little-endian) + KEY
        
        ## Debugging
        
        Start client/server with DEBUG=1 env variable:
        
        ```shell
        DEBUG=1 yedb /path/to/db
        ```
        
        to debug when embedded, enable debug logging
        
        ```python
        import yedb
        
        yedb.debug = True
        ```
        
        After, lower the default logging level.
        
        ## Module documentation
        
        https://yedb-py.readthedocs.io/
        
Platform: UNKNOWN
Classifier: Programming Language :: Python :: 3
Classifier: License :: OSI Approved :: Apache Software License
Classifier: Topic :: Database
Classifier: Topic :: Database :: Database Engines/Servers
Description-Content-Type: text/markdown
Provides-Extra: cli
