Flask-HashFS 0.3.0

Flask extension for HashFS, a content-addressable file management system.

Flask extension for HashFS, a content-addressable file management system.

What is HashFS?

HashFS is a content-addressable file management system. What does that mean? Simply, that HashFS manages a directory where files are saved based on the file’s hash.

Typical use cases for this kind of system are ones where:

• Files are written once and never change (e.g. image storage).

• It’s desirable to have no duplicate files (e.g. user uploads).

• File metadata is stored elsewhere (e.g. in a database).

What is Flask-HashFS?

Flask-HashFS is a Flask extension that integrates HashFS into the Flask ecosystem.

Links

• Project: https://github.com/dgilland/flask-hashfs

• Documentation: http://flask-hashfs.readthedocs.org

• PyPI: https://pypi.python.org/pypi/flask-hashfs/

• TravisCI: https://travis-ci.org/dgilland/flask-hashfs

Quickstart

Install using pip:

pip install Flask-HashFS

Initialization

from flask import Flask
from flask_hashfs import FlaskHashFS

app = Flask(__name__)
fs = FlaskHashFS()

Configure Flask-HashFS to store files in /var/www/data/uploads and give them a route prefix at /uploads.

app.config.update({
    'HASHFS_HOST': None,
    'HASHFS_PATH_PREFIX': '/uploads',
    'HASHFS_ROOT_FOLDER': '/var/www/data/uploads',
    'HASHFS_DEPTH': 4,
    'HASHFS_WIDTH': 1,
    'HASHFS_ALGORITHM': 'sha256'
})

fs.init_app(app)

Usage

Use Flask-HashFS to manage files using HashFS.

with app.app_context():
    # Store readable objects or file paths
    address = fs.put(io_obj, extension='.jpg')


    # Get a file's hash address
    assert fs.get(address.id) == address
    assert fs.get(address.relpath) == address
    assert fs.get(address.abspath) == address
    assert fs.get('invalid') is None


    # Get a BufferedReader handler
    fileio = fs.open(address.id)

    # Or using the full path...
    fileio = fs.open(address.abspath)

    # Or using a path relative to fs.root
    fileio = fs.open(address.relpath)


    # Delete a file by address ID or path
    fs.delete(address.id)
    fs.delete(address.abspath)
    fs.delete(address.relpath)

For direct access to the HashFS instance, use the client attribute.

fs.client
assert isinstance(fs.client, flask_hashfs.HashFS)

Generate URLs for HashFS content.

with app.test_request_context():
    fs.url_for('relative/file/path')

For more details, please see the full documentation at http://flask-hashfs.readthedocs.org and http://hashfs.readthedocs.org.

Changelog

v0.3.0 (2015-06-03)

• Replace manual proxy access of HashFS methods with single __getattr__ method.

v0.2.0 (2015-06-02)

• Pin hashfs dependency to >=0.3.0. (breaking change)

• Rename config key HASHFS_LENGTH to HASHFS_WIDTH to be in alignment with hashfs>=0.3.0. (breaking change)

v0.1.0 (2015-06-02)

• First release.

• Add FlaskHashFS.put.

• Add FlaskHashFS.get.

• Add FlaskHashFS.open.

• Add FlaskHashFS.delete.

• Add FlaskHashFS.url_for.