polystore 0.1.8

Framework-agnostic multi-backend storage abstraction for ML and scientific computing

polystore

Framework-agnostic multi-backend storage abstraction for ML and scientific computing

Features

• Pluggable Backends: Disk, memory, Zarr, and streaming backends with auto-registration
• Multi-Framework I/O: Seamless support for NumPy, PyTorch, JAX, TensorFlow, CuPy
• Atomic Operations: Cross-platform atomic file writes with automatic locking
• Batch Operations: Efficient batch loading and saving
• Format Detection: Automatic format detection and routing
• Type-Safe: Full type hints and mypy support
• Zero Dependencies: Core requires only NumPy (framework support is optional)

Quick Start

from polystore import FileManager, BackendRegistry

# Create registry and file manager
registry = BackendRegistry()
fm = FileManager(registry)

# Save data to disk
import numpy as np
data = np.array([[1, 2], [3, 4]])
fm.save(data, "output.npy", backend="disk")

# Load data back
loaded = fm.load("output.npy", backend="disk")

# Use memory backend for testing
fm.save(data, "test.npy", backend="memory")
cached = fm.load("test.npy", backend="memory")

Installation

# Base installation (NumPy only)
pip install polystore

# With specific frameworks
pip install polystore[zarr]
pip install polystore[torch]
pip install polystore[jax]
pip install polystore[tensorflow]
pip install polystore[cupy]

# With streaming support
pip install polystore[streaming]

# With all optional dependencies
pip install polystore[all]

Supported Backends

Backend	Description	Storage	Dependencies
disk	Local filesystem	Persistent	None
memory	In-memory cache	Volatile	None
zarr	Zarr/OME-Zarr arrays	Persistent	zarr, ome-zarr
streaming	ZeroMQ streaming	None	pyzmq

Supported Formats

Format	Extensions	Frameworks
NumPy	.npy, .npz	NumPy, PyTorch, JAX, TensorFlow, CuPy
TIFF	.tif, .tiff	NumPy, PyTorch, JAX, TensorFlow, CuPy
Zarr	.zarr	NumPy, PyTorch, JAX, TensorFlow, CuPy
PyTorch	.pt, .pth	PyTorch
CSV	.csv	NumPy, pandas
JSON	.json	Python dicts

Architecture

polystore/
├── base.py              # Abstract interfaces (DataSink, DataSource, StorageBackend)
├── backend_registry.py  # Auto-registration system
├── disk.py              # Disk storage backend
├── memory.py            # In-memory backend
├── zarr.py              # Zarr backend
├── streaming.py         # ZeroMQ streaming backend
├── filemanager.py       # High-level API
├── atomic.py            # Atomic file operations
└── exceptions.py        # Custom exceptions

Advanced Usage

Custom Backends

from polystore import StorageBackend

class MyBackend(StorageBackend):
    _backend_type = 'my_backend'  # Auto-registers
    
    def save(self, data, file_path, **kwargs):
        # Your save logic
        pass
    
    def load(self, file_path, **kwargs):
        # Your load logic
        pass

Batch Operations

# Save multiple files
data_list = [np.random.rand(100, 100) for _ in range(10)]
paths = [f"image_{i}.npy" for i in range(10)]
fm.save_batch(data_list, paths, backend="disk")

# Load multiple files
loaded_list = fm.load_batch(paths, backend="disk")

Atomic Writes

from polystore import atomic_write, atomic_write_json

# Atomic file write with automatic locking
with atomic_write("output.txt") as f:
    f.write("data")

# Atomic JSON write
atomic_write_json({"key": "value"}, "config.json")

Why polystore?

Before (Manual backend management):

if backend == 'disk':
    np.save(path, data)
elif backend == 'memory':
    cache[path] = data
elif backend == 'zarr':
    zarr.save(path, data)
# ... 50 more lines of if/elif ...

After (polystore):

fm.save(data, path, backend=backend)

Documentation

Full documentation available at polystore.readthedocs.io

Addons

Extend polystore with additional backends:

• polystore-napari: Napari viewer streaming backend
• polystore-fiji: Fiji/ImageJ streaming backend
• polystore-omero: OMERO server backend

Performance

• Zero-copy conversions between frameworks via DLPack (when possible)
• Lazy loading for optional dependencies
• Batch operations for efficient I/O
• Atomic writes with minimal overhead

License

MIT License - see LICENSE file for details

Contributing

Contributions welcome! Please see CONTRIBUTING.md for guidelines.

Credits

Developed by Tristan Simas.