core: add support for other backends apart from sqlite, add file-based backend (basically jsonl)

README.md

@@ -128,7 +128,7 @@ Cachew gives the best of two worlds and makes it both **easy and efficient**. Th
 - first your objects get [converted](src/cachew/marshall/cachew.py#L34) into a simpler JSON-like representation 
 - after that, they are mapped into byte blobs via [`orjson`](https://github.com/ijl/orjson).
 
-When the function is called, cachew [computes the hash of your function's arguments ](src/cachew/__init__.py:#L504)
+When the function is called, cachew [computes the hash of your function's arguments ](src/cachew/__init__.py:#L466)
 and compares it against the previously stored hash value.
 
 - If they match, it would deserialize and yield whatever is stored in the cache database
@@ -140,18 +140,18 @@ and compares it against the previously stored hash value.
 
 
 
-* automatic schema inference: [1](src/cachew/tests/test_cachew.py#L350), [2](src/cachew/tests/test_cachew.py#L364)
+* automatic schema inference: [1](src/cachew/tests/test_cachew.py#L371), [2](src/cachew/tests/test_cachew.py#L385)
 * supported types:    
 
     * primitive: `str`, `int`, `float`, `bool`, `datetime`, `date`, `Exception`
 
-      See [tests.test_types](src/cachew/tests/test_cachew.py#L676), [tests.test_primitive](src/cachew/tests/test_cachew.py#L710), [tests.test_dates](src/cachew/tests/test_cachew.py#L630), [tests.test_exceptions](src/cachew/tests/test_cachew.py#L1037)
-    * [@dataclass and NamedTuple](src/cachew/tests/test_cachew.py#L592)
-    * [Optional](src/cachew/tests/test_cachew.py#L494) types
-    * [Union](src/cachew/tests/test_cachew.py#L788) types
-    * [nested datatypes](src/cachew/tests/test_cachew.py#L410)
+      See [tests.test_types](src/cachew/tests/test_cachew.py#L697), [tests.test_primitive](src/cachew/tests/test_cachew.py#L731), [tests.test_dates](src/cachew/tests/test_cachew.py#L651), [tests.test_exceptions](src/cachew/tests/test_cachew.py#L1073)
+    * [@dataclass and NamedTuple](src/cachew/tests/test_cachew.py#L613)
+    * [Optional](src/cachew/tests/test_cachew.py#L515) types
+    * [Union](src/cachew/tests/test_cachew.py#L809) types
+    * [nested datatypes](src/cachew/tests/test_cachew.py#L431)
 
-* detects [datatype schema changes](src/cachew/tests/test_cachew.py#L440) and discards old data automatically
+* detects [datatype schema changes](src/cachew/tests/test_cachew.py#L461) and discards old data automatically
 
 
 # Performance
@@ -165,20 +165,20 @@ You can find some of my performance tests in [benchmarks/](benchmarks) dir, and
 
 
 # Using
-See [docstring](src/cachew/__init__.py#L329) for up-to-date documentation on parameters and return types. 
+See [docstring](src/cachew/__init__.py#L281) for up-to-date documentation on parameters and return types. 
 You can also use [extensive unit tests](src/cachew/tests/test_cachew.py) as a reference.
 
 Some useful (but optional) arguments of `@cachew` decorator:
 
-* `cache_path` can be a directory, or a callable that [returns a path](src/cachew/tests/test_cachew.py#L387) and depends on function's arguments.
+* `cache_path` can be a directory, or a callable that [returns a path](src/cachew/tests/test_cachew.py#L408) and depends on function's arguments.
 
    By default, `settings.DEFAULT_CACHEW_DIR` is used.
 
 * `depends_on` is a function which determines whether your inputs have changed, and the cache needs to be invalidated.
 
    By default it just uses string representation of the arguments, you can also specify a custom callable.
 
-   For instance, it can be used to [discard cache](src/cachew/tests/test_cachew.py#L89) if the input file was modified.
+   For instance, it can be used to [discard cache](src/cachew/tests/test_cachew.py#L103) if the input file was modified.
 
 * `cls` is the type that would be serialized.
 
@@ -251,6 +251,7 @@ def mcachew(*args, **kwargs):
         import cachew
     except ModuleNotFoundError:
         import warnings
+
         warnings.warn('cachew library not found. You might want to install it to speed things up. See https://github.com/karlicoss/cachew')
         return lambda orig_func: orig_func
     else:
@@ -264,9 +265,9 @@ Now you can use `@mcachew` in place of `@cachew`, and be certain things don't br
 ## Settings
 
 
-[cachew.settings](src/cachew/__init__.py#L68) exposes some parameters that allow you to control `cachew` behaviour:
+[cachew.settings](src/cachew/__init__.py#L66) exposes some parameters that allow you to control `cachew` behaviour:
 - `ENABLE`: set to `False` if you want to disable caching for without removing the decorators (useful for testing and debugging).
-   You can also use [cachew.extra.disabled_cachew](src/cachew/extra.py#L18) context manager to do it temporarily.
+   You can also use [cachew.extra.disabled_cachew](src/cachew/extra.py#L21) context manager to do it temporarily.
 - `DEFAULT_CACHEW_DIR`: override to set a different base directory. The default is the "user cache directory" (see [appdirs docs](https://github.com/ActiveState/appdirs#some-example-output)).
 - `THROW_ON_ERROR`: by default, cachew is defensive and simply attemps to cause the original function on caching issues.
    Set to `True` to catch errors earlier.

benchmarks/20230917.org

@@ -0,0 +1,18 @@
+Running on @karlicoss desktop PC, =python3.10=
+
+Just a comparison of =sqlite= and =file= backends.
+
+#+begin_example
+$ pytest --pyargs -k 'test_many and gc_off and 3000000' -s
+src/cachew/tests/test_cachew.py::test_many[sqlite-gc_off-3000000] [INFO    2023-09-17 02:02:09,946 cachew __init__.py:657 ] cachew.tests.test_cachew:test_many.<locals>.iter_data: wrote   3000000 objects to   cachew (sqlite:/tmp/pytest-of-karlicos/pytest-129/test_many_sqlite_gc_off_3000000/test_many)
+test_many: initial write to cache took 13.6s
+test_many: cache size is 229.220352Mb
+[INFO    2023-09-17 02:02:10,780 cachew __init__.py:662 ] cachew.tests.test_cachew:test_many.<locals>.iter_data: loading 3000000 objects from cachew (sqlite:/tmp/pytest-of-karlicos/pytest-129/test_many_sqlite_gc_off_3000000/test_many)
+test_many: reading from cache took 7.0s
+PASSED
+src/cachew/tests/test_cachew.py::test_many[file-gc_off-3000000] [INFO    2023-09-17 02:02:23,944 cachew __init__.py:657 ] cachew.tests.test_cachew:test_many.<locals>.iter_data: wrote   3000000 objects to   cachew (file:/tmp/pytest-of-karlicos/pytest-129/test_many_file_gc_off_3000000_0/test_many)
+test_many: initial write to cache took 6.1s
+test_many: cache size is 202.555667Mb
+[INFO    2023-09-17 02:02:23,945 cachew __init__.py:662 ] cachew.tests.test_cachew:test_many.<locals>.iter_data: loading objects from cachew (file:/tmp/pytest-of-karlicos/pytest-129/test_many_file_gc_off_3000000_0/test_many)
+test_many: reading from cache took 5.4s
+#+end_example

setup.py

@@ -10,6 +10,7 @@
     'appdirs'        ,  # default cache dir
     'sqlalchemy>=1.0',  # cache DB interaction
     'orjson',           # fast json serialization
+    'pytz',             # used to properly marshall pytz datatimes
 ]