slowstore 0.1.5

File json storage backend for your collections

Slowstore

This is a very simple single file single class key-value store written in Python. It is designed to be slow and inefficient, and is intended to be used for testing purposes only. The rules are simple: Every store has it's own directory, and every item is stored in a separate JSON file.

That's it.

It is easy to use and inspect the data being manipulated.

Installation

You can install Slowstore using pip:

pip install slowstore

Usage

You can create a new Slowstore instance by calling the constructor:

from slowstore import Slowstore

class SampleModel(BaseModel):
    name: str
    age: int = 0

# Create a new store and load the data 
store = Slowstore[SampleModel](SampleModel, "mydata")).load()

One feature that I use a lot is to commit on property change, so I can inspect exactly what is going on

store.save_on_change = True

you can also set this from the constructor

store = Slowstore[SampleModel](SampleModel, "mydata", save_on_change=True).load()

After this code is executed, every time a property is changed, the changes will be saved to disk immediately.

This is slow, but it is useful for debugging and testing.

Adding items to the store

s1 = store.upsert(SampleModel(name="Alice", age=30))
s2 = store.upsert(SampleModel(name="Bob", age=25))
s3 = store.upsert(SampleModel(name="Charlie", age=35))
store.commit_all()

s1.age = 32

Commit the changes to the store

store.commit(s1)
store.commit(s2)
# or just commit all changes
store.commit_all() 

Undo/Redo

every slowstore item is a proxy object around what you've created. This allows you to access the object's attributes and adds undo/redo/dirty functionality

s1.undo()
s1.redo()

Querying

# get all items, returns an iterator
all_items = store.all()

# yield all items that match a condition
filtered_items = store.filter(lambda x: x.age > 30)

# get the first item that matches a condition
first_item = store.first(lambda x: x.age > 30)

# Check if some object or it's key is in the store
if s2 in store:
    print("s2 is in store")
else:
    print("s2 is not in store")

Deleting items

Any of the following will delete the item from the store, along with the file that contains the data

store.delete(s1)

del store[s2]

key = "some_key"
store.delete(key)

Wish list

• Partial load of the store, to avoid loading all items at once - We should use some form of lazy loading to avoid loading all items at once - Include cache for the items that are already loaded

• Add support for indexes, so we dont need to look at all items to find the one we want

• Add support for transactions These should be human readable, so we can inspect the data in the store

License

This project is licensed under the MIT License - see the LICENSE file for details.