docs

Dockerfile

@@ -0,0 +1,15 @@
+# syntax=docker/dockerfile:1
+FROM python:3.10
+WORKDIR /app/
+RUN apt-get update
+RUN apt-get install -y python3-sphinx node.js
+RUN apt-get install -y npm
+RUN npm install -g http-server
+RUN pip install pydata-sphinx-theme
+COPY docs/Makefile Makefile
+COPY setup.py setup.py
+COPY docs/source source
+COPY ptvp35 ptvp35
+RUN make html
+WORKDIR /app/build/html/
+CMD [ "http-server", "-p", "80" ]

docs/Makefile

@@ -0,0 +1,20 @@
+# Minimal makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line, and also
+# from the environment for the first two.
+SPHINXOPTS    ?=
+SPHINXBUILD   ?= sphinx-build
+SOURCEDIR     = source
+BUILDDIR      = build
+
+# Put it first so that "make" without argument is like "make help".
+help:
+	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+
+.PHONY: help Makefile
+
+# Catch-all target: route all unknown targets to Sphinx using the new
+# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
+%: Makefile
+	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)

docs/make.bat

@@ -0,0 +1,35 @@
+@ECHO OFF
+
+pushd %~dp0
+
+REM Command file for Sphinx documentation
+
+if "%SPHINXBUILD%" == "" (
+	set SPHINXBUILD=sphinx-build
+)
+set SOURCEDIR=source
+set BUILDDIR=build
+
+%SPHINXBUILD% >NUL 2>NUL
+if errorlevel 9009 (
+	echo.
+	echo.The 'sphinx-build' command was not found. Make sure you have Sphinx
+	echo.installed, then set the SPHINXBUILD environment variable to point
+	echo.to the full path of the 'sphinx-build' executable. Alternatively you
+	echo.may add the Sphinx directory to PATH.
+	echo.
+	echo.If you don't have Sphinx installed, grab it from
+	echo.https://www.sphinx-doc.org/
+	exit /b 1
+)
+
+if "%1" == "" goto help
+
+%SPHINXBUILD% -M %1 %SOURCEDIR% %BUILDDIR% %SPHINXOPTS% %O%
+goto end
+
+:help
+%SPHINXBUILD% -M help %SOURCEDIR% %BUILDDIR% %SPHINXOPTS% %O%
+
+:end
+popd

docs/source/conf.py

@@ -0,0 +1,36 @@
+# Configuration file for the Sphinx documentation builder.
+#
+# For the full list of built-in configuration values, see the documentation:
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
+
+# -- Project information -----------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
+
+project = 'ptvp35'
+copyright = '2022, PARRRATE TNV'
+author = 'PARRRATE TNV'
+release = '1.0rc2'
+
+# -- General configuration ---------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
+
+extensions = [
+    'sphinx.ext.autodoc',
+]
+
+templates_path = ['_templates']
+exclude_patterns = []
+
+
+
+# -- Options for HTML output -------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/configuration.html#options-for-html-output
+
+html_theme = 'pydata_sphinx_theme'
+html_static_path = ['_static']
+
+
+import sys
+import os.path
+
+sys.path.insert(0, os.path.abspath('..'))

docs/source/index.rst

@@ -0,0 +1,25 @@
+.. ptvp35 documentation master file, created by
+   sphinx-quickstart on Sat Nov 19 20:02:24 2022.
+   You can adapt this file completely to your liking, but it should at least
+   contain the root `toctree` directive.
+
+Welcome to ptvp35's documentation!
+==================================
+
+.. toctree::
+   :maxdepth: 2
+   :caption: Contents:
+   motivation
+   usage
+   modules
+
+
+
+Indices and tables
+==================
+
+* :doc:`motivation`
+* :doc:`usage`
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`

docs/source/modules.rst

@@ -0,0 +1,7 @@
+ptvp35
+======
+
+.. toctree::
+   :maxdepth: 4
+
+   ptvp35

docs/source/motivation.rst

@@ -0,0 +1,28 @@
+Motivation
+==========
+
+General structure
+-----------------
+
+* We're making a key-value database.
+* Keys and values are python objects.
+* While the DB is offline (after a correct shutdown), all its KVPs are stored as lines in one editable file.
+* DB should be able to survive powercut at any point (D in ACID).
+
+AP/LP get
+------
+
+The central idea for this database is the zero-latency (as far as python goes) reads. Therefore, the DB has all its data stored as a :code:`dict`.
+
+CAP/CLP set
+-------
+
+The database allows both availability-(zero)latency and consistency (note: it's not ACID consistency, it's CAP consistency and ACID durability) variants for its writes.
+All zero-latency writes are also consistent with respect to (zero-latency) reads.
+
+Consistent get
+------
+
+Later versions of the database will include remote connections, and thus also consistent reads.
+These will probably be implemented as requests (same as writes).
+Some connection variants may not even include availability reads/writes.

docs/source/ptvp35.rst

@@ -0,0 +1,10 @@
+ptvp35 package
+==============
+
+Module contents
+---------------
+
+.. automodule:: ptvp35
+   :members:
+   :undoc-members:
+   :show-inheritance:

docs/source/usage.rst

@@ -0,0 +1,54 @@
+Usage
+=====
+
+Installation
+------------
+
+Default installation option is to use pip+git
+
+.. code-block:: console
+
+    (.venv) $ pip install git+https://gitea.parrrate.ru/PTV/ptvp35.git
+
+Basic functionality
+-------------------
+
+.. autoclass:: ptvp35.DbFactory
+
+    :code:`DbFactory` class provides context management for database connections (:code:`DbConnection`) via :code:`async with` statement.
+    The connection isn't just a "connection", it's also the MMDB itself, so **using two connections to one database is an undefined behaviour**.
+    Also, that means that each connection start/shutdown is quite time expensive.
+    These two facts together tell that, if you intend on using the connection, you should probably wrap the main program in an :code:`async with` block.
+
+.. code-block:: python3
+
+    import pathlib
+    from ptvp35 import DbFactory, KVJson
+    
+    async def main():
+        async with DbFactory(pathlib.Path('example.db', kvfactory=KVJson())) as connection:
+            await _main(connection)
+
+.. autoclass:: ptvp35.DbConnection
+
+    .. automethod:: get
+
+        this method is instant.
+
+    .. automethod:: set
+
+        this method may take time to run.
+        ordering may not be guaranteed (depends on event loop implementation).
+
+    .. automethod:: set_nowait
+
+        this method is instant.
+        ordering is guaranteed.
+
+    .. automethod:: commit
+
+        this method may take time to run.
+        respects the ordering of previously called :code:`set_nowait` methods.
+        will, under most circumstances, also execute later changes.
+
+    .. automethod:: transaction

ptvp35/__init__.py

@@ -9,7 +9,15 @@ from io import StringIO, UnsupportedOperation
 from typing import Any, Optional, IO, Hashable
 
 
-__all__ = ('KVRequest', 'KVJson', 'DbConnection', 'DbFactory', 'Db',)
+__all__ = (
+    'KVFactory',
+    'KVJson',
+    'DbConnection',
+    'DbFactory',
+    'Db',
+    'Transaction',
+    'FallbackMapping',
+)
 
 
 class Request:
@@ -37,18 +45,27 @@ class Request:
 
 
 class KVFactory:
+    """note: unstable signature."""
+
     __slots__ = ()
 
     def line(self, key: Any, value: Any, /) -> str:
+        """line must contain exactly one '\\n' at exactly the end if the line is not empty."""
         raise NotImplementedError
 
     def fromline(self, line: str, /) -> 'KVRequest':
+        """inverse of line(). should use free() method to construct the request."""
         raise NotImplementedError
 
     def request(self, key: Any, value: Any, /, *, future: Optional[asyncio.Future]) -> 'KVRequest':
+        """form request with Future.
+low-level API.
+note: unstable signature."""
         return KVRequest(key, value, future=future, factory=self)
 
     def free(self, key: Any, value: Any, /) -> 'KVRequest':
+        """result free from Future.
+note: unstable signature."""
         return self.request(key, value, future=None)
 
 
@@ -81,6 +98,8 @@ class UnknownRequestType(TypeError):
 
 
 class KVJson(KVFactory):
+    """note: unstable signature."""
+
     __slots__ = ()
 
     def line(self, key: Any, value: Any, /) -> str:
@@ -118,6 +137,8 @@ class TransactionRequest(Request):
 
 
 class DbConnection:
+    """note: unstable constructor signature."""
+
     __slots__ = (
         '__factory',
         '__path',
@@ -182,7 +203,8 @@ class DbConnection:
         self._queue_error(line).result()
 
     def io2db(self, io: IO[str], db: dict, /) -> int:
-        """there are no guarantees about .error file if error occurs here"""
+        """there are no guarantees about .error file if an error occurs here.
+note: unstable signature."""
         size = 0
         for line in io:
             try:
@@ -196,6 +218,8 @@ class DbConnection:
         return size
 
     def db2io(self, db: dict, io: IO[str], /) -> int:
+        """does not handle any errors.
+note: unstable signature."""
         size = 0
         for key, value in db.items():
             size += io.write(self.__factory.kvfactory.free(key, value).line())
@@ -211,9 +235,11 @@ class DbConnection:
             return self.db2io(db, file)
 
     def get(self, key: Any, default: Any, /):
+        """dict-like get with mandatory default parametre."""
         return self.__mmdb.get(key, default)
 
     async def set(self, key: Any, value: Any, /) -> None:
+        """set the value and wait until it's written to disk."""
         self.__mmdb[key] = value
         future = self._create_future()
         self.__queue.put_nowait(
@@ -221,6 +247,7 @@ class DbConnection:
         await future
 
     def set_nowait(self, key: Any, value: Any, /) -> None:
+        """set value and add write-to-disk request to queue."""
         self.__mmdb[key] = value
         self.__queue.put_nowait(self.__factory.kvfactory.free(key, value))
 
@@ -448,11 +475,15 @@ intended for heavy tasks."""
 
     @classmethod
     async def create(cls, factory: 'DbFactory', /) -> 'DbConnection':
+        """connect to the factory.
+note: unstable signature."""
         dbconnection = DbConnection(factory)
         await dbconnection._initialize()
         return dbconnection
 
     async def aclose(self, /) -> None:
+        """close the connection.
+note: unstable signature."""
         if not self.__task.done():
             await self.__queue.join()
             self.__task.cancel()
@@ -473,6 +504,7 @@ intended for heavy tasks."""
         self.__not_running = True
 
     async def complete_transaction(self, delta: dict, /) -> None:
+        """hybrid of set() and dict.update()."""
         if not delta:
             return
         buffer = StringIO()
@@ -481,13 +513,20 @@ intended for heavy tasks."""
         future = self._create_future()
         self.__queue.put_nowait(TransactionRequest(buffer, future=future))
         await future
+    
+    def submit_transaction(self, delta: dict, /) -> asyncio.Future | None:
+        """not implemented.
+low-level API."""
+        raise NotImplementedError
 
     async def commit(self, /) -> None:
+        """wait until all requests queued before are completed."""
         future = self._create_future()
         self.__queue.put_nowait(DumpRequest(future))
         await future
 
     def transaction(self, /) -> 'Transaction':
+        """open new transaction."""
         return Transaction(self)
 
 
@@ -496,23 +535,28 @@ class DbFactory:
         'path',
         'kvfactory',
         'buffersize',
-        'db',
+        '__db',
     )
 
     def __init__(self, path: pathlib.Path, /, *, kvfactory: KVFactory, buffersize=1048576) -> None:
         self.path = path
+        """note: unstable signature."""
         self.kvfactory = kvfactory
+        """note: unstable signature."""
         self.buffersize = buffersize
+        """note: unstable signature."""
 
     async def __aenter__(self) -> DbConnection:
-        self.db = await DbConnection.create(self)
+        self.__db = await DbConnection.create(self)
-        return self.db
+        return self.__db
 
     async def __aexit__(self, exc_type, exc_val, exc_tb):
-        await self.db.aclose()
+        await self.__db.aclose()
 
 
 class Db(DbConnection):
+    """simplified usecase combining the factory and the connection in one class."""
+
     __slots__ = ()
 
     def __init__(self, path: str | pathlib.Path, /, *, kvfactory: KVFactory, buffersize=1048576):
@@ -532,6 +576,8 @@ class Db(DbConnection):
 
 
 class FallbackMapping:
+    """note: unstable constructor signature."""
+
     __slots__ = (
         '__delta',
         '__shadow',
@@ -554,13 +600,28 @@ class FallbackMapping:
         self.__delta[key] = value
 
     async def commit(self, /) -> None:
+        """bulk analog of DbConnection.set method."""
         delta = self.__delta.copy()
         self.__shadow |= delta
         self.__delta.clear()
         await self.__connection.complete_transaction(delta)
 
+    async def commit_submitted(self, /) -> None:
+        """not implemented.
+commit previously submitted changes."""
+        raise NotImplementedError
+
+    def submit(self, /) -> None:
+        """not implemented.
+submit changes.
+_nowait analog of commit.
+bulk analog of DbConnection.set_nowait method."""
+        raise NotImplementedError
+
 
 class Transaction:
+    """note: unstable signature."""
+
     __slots__ = (
         '__connection',
         '__delta',