Initial project setup

Pipfile

@@ -0,0 +1,15 @@
+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+redis = "*"
+pymemcache = "*"
+pytest = "*"
+pytest-cov = "*"
+
+[dev-packages]
+
+[requires]
+python_version = "3.7"

README.md

@@ -8,12 +8,13 @@ Install using pip: `$ pip install cache4py`
 
 ### Usage
 ```python
-from cache4py import cache, LRU, Backend
+from cache4py.decorators import cache
+from cache4py.storage.backends import RedisBackend
 
 # You can choose memcached, redis or default (python's dict) as a backend.
-redis_backend = Backend(variant=Backend.REDIS, url='', port='')
+redis_backend = RedisBackend(url='localhost', port='6379')
 
-@cache(eviction_policy=LRU, backend=redis_backend)
+@cache(backend=redis_backend)
 def my_function_one(*args, **kwargs):
     # do something awesome
     return
@@ -42,11 +43,15 @@ pip install -r requirements.txt
 ```
 ### Running the tests
 
-Run unit tests using the command: `TODO`
+Run unit tests using the command: 
+
+```
+pytest --cov=cache4py --cov-report html tests/
+```
 
 ## Issue tracking
 
-Create issues at [cache4pd/issues](https://github.com/nitinl/cache4py/issues).
+Create issues at [cache4py/issues](https://github.com/nitinl/cache4py/issues).
 
 ## Authors
 

cache4py/__init__.py

@@ -0,0 +1,5 @@
+"""
+Author: nitin
+Date: 18/7/17
+Description: 
+"""

cache4py/decorators.py

@@ -0,0 +1,44 @@
+"""
+Author: nitin
+Date: 18/7/17
+Description: 
+"""
+from functools import wraps
+
+from cache4py.exceptions import BackendException
+from cache4py.utils import args_to_key, hash_key
+from cache4py.storage.redis import RedisBackend
+
+
+def cache(backend=RedisBackend, keys=args_to_key):
+    """
+    Cache decorator. Backend can be a python dict, redis or memcached server.
+    """
+
+    def _decorator(func):
+        @wraps(func)
+        def wrapper(*args, **kwargs):
+            if backend is None:
+                backend_exception_message = 'Invalid input None provided for backend.'
+                raise BackendException(backend_exception_message)
+
+            key = keys(*args, **kwargs)
+            hashed_key = hash_key(key)
+
+            result = backend.get(hashed_key)
+
+            if result is not None:
+                # cache hit
+                return result
+
+            # cache miss
+            function_result = func(*args, **kwargs)
+
+            # store result in cache
+            backend.set(hashed_key, function_result)
+            return function_result
+
+        return wrapper
+
+    return _decorator
+

cache4py/exceptions.py

@@ -0,0 +1,21 @@
+"""
+Author: nitin
+Date: 18/7/17
+Description: 
+"""
+
+
+class Cache4PyException(Exception):
+    pass
+
+
+class BackendException(Cache4PyException):
+    pass
+
+
+class RedisBackendException(BackendException):
+    pass
+
+
+class MemcachedBackendException(BackendException):
+    pass

cache4py/storage/__init__.py

@@ -0,0 +1,5 @@
+"""
+Author: nitin
+Date: 19/10/18
+Description: 
+"""

cache4py/storage/base.py

@@ -0,0 +1,41 @@
+"""
+Author: nitin
+Date: 19/10/18
+Description: Base class for all storage interfaces
+"""
+import abc
+
+
+class BaseBackend(metaclass=abc.ABCMeta):
+    """
+    Abstract class defining Cache client interface. All implementations of cache clients
+    must extend this class.
+    """
+
+    @abc.abstractmethod
+    def get(self, key_name):
+        """
+        Return the value at key ``key_name``, or None if the key doesn't exist.
+        :param key_name: A key.
+        :return: Value at key ``key_name``, or None if the key doesn't exist.
+        """
+        raise NotImplementedError('Cache client must define a get method.')
+
+    @abc.abstractmethod
+    def set(self, key_name, value):
+        """
+        Set the value at key ``key_name`` to ``value``
+        :param key_name: A key object.
+        :param value: A value object.
+        :return: True if set successfully else False.
+        """
+        raise NotImplementedError('Cache client must define a set method.')
+
+    @abc.abstractmethod
+    def delete(self, key_name):
+        """
+        Deletes key specified by ``key_name``.
+        :param key_name: A key object.
+        :return: True if key is successfully deleted else False. Failure can mean connection issue or no value at given key in db.
+        """
+        raise NotImplementedError('Cache client must define a delete method.')