{
    "info": {
        "author": "Will Breaden Madden",
        "author_email": "wbm@protonmail.ch",
        "bugtrack_url": null,
        "classifiers": [],
        "description": "lock\n====\n\nThis is a module for enabling file locks. It uses ``fcntl`` to\naccomplish this.\n\nPOSIX operating systems implement advisory file locking. This enables\nconcurrent processes to interact with the same file without conflict,\nprovided they first check for the existence of a lock held by a\ndifferent process. Mandatory file locking can be enabled on POSIX\nsystems by mounting volumes using the ``mount`` ``-o mand`` option and\nmakes the operating system prevent editing of a locked file.\n\nThe ``fcntl`` functionality is implemented in Python by the ``fcntl``\nstandard library module. Using this, a lock can be acquired in a way\nlike the following:\n\n.. code:: python\n\n    lock_file = open(\"data.db\", \"a\")\n    fcntl.lockf(lock_file, fcntl.LOCK_EX | fcntl.LOCK_NB)\n\nIf the file is locked, the following exception is raised:\n\n.. code:: python\n\n    BlockingIOError: [Errno 11] Resource temporarily unavailable\n\nWith advisory locking, code should test for the existence of a a lock\nbefore editing a file. It is the responsibility of the code, not the\noperating system, to enforce locking correctly. Information about the\nlocks currently held on a file may be retrieved by passing a bytes\nobject as the third argument to the ``fcntl.fcntl`` function (which\ntakes the place of a pointer to the process ID in the fcntl header). The\nlock information can be accessed in a way like the following:\n\n.. code:: python\n\n    lock_data = struct.pack(\"hhllhh\", fcntl.F_WRLCK, 0, 0, 0, 0, 0)\n    fcntl.fcntl(lock_file, fcntl.F_GETLK, lock_data)\n\nThis returns ``lock_data`` unchanged if there is no lock on the file.\n\nexamples\n========\n\nThe following code saves a dictionary to a file in a loop using ``lock``\nto lock the file while the save is happening:\n\n.. code:: python\n\n    import random\n\n    import lock\n\n    while True:\n        config = {\"a\": 1, \"b\": random.randint(1, 2)}\n        lock.save_JSON(\"config.json\", config)\n\nThe following code loads a dictionary from a file in a loop using\n``lock`` to lock the file while the load is happening:\n\n.. code:: python\n\n    import lock\n\n    while True:\n        config = lock.load_JSON(\"config.json\")\n        if config: print(config)\n\nThese two pieces of code can be used concurrently.\n",
        "description_content_type": "",
        "docs_url": null,
        "download_url": "",
        "downloads": {
            "last_day": -1,
            "last_month": -1,
            "last_week": -1
        },
        "home_page": "https://github.com/wdbm/lock",
        "keywords": "",
        "license": "GPLv3",
        "maintainer": "",
        "maintainer_email": "",
        "name": "lock",
        "package_url": "https://pypi.org/project/lock/",
        "platform": "",
        "project_url": "https://pypi.org/project/lock/",
        "project_urls": {
            "Homepage": "https://github.com/wdbm/lock"
        },
        "release_url": "https://pypi.org/project/lock/2018.3.25.2110/",
        "requires_dist": null,
        "requires_python": "",
        "summary": "module for enabling file locks",
        "version": "2018.3.25.2110"
    },
    "last_serial": 3704331,
    "releases": {
        "2018.3.25.2110": [
            {
                "comment_text": "",
                "digests": {
                    "md5": "435db9197f018956cbdddb58af977858",
                    "sha256": "cc5ac770930493eed7a8cfd0cf2568a125faf112eb8aa6b6149b3e581523d0c7"
                },
                "downloads": -1,
                "filename": "lock-2018.3.25.2110.tar.gz",
                "has_sig": false,
                "md5_digest": "435db9197f018956cbdddb58af977858",
                "packagetype": "sdist",
                "python_version": "source",
                "requires_python": null,
                "size": 3049,
                "upload_time": "2018-03-25T21:12:37",
                "url": "https://files.pythonhosted.org/packages/ea/ee/4c7e9740d397abd62b48bfe82f77f57a8984da4f5ba0a3b64930b44ccd8f/lock-2018.3.25.2110.tar.gz"
            }
        ],
        "2018.3.8.1911": [
            {
                "comment_text": "",
                "digests": {
                    "md5": "18600d3f1f9611c3bd72f5c2725b83ec",
                    "sha256": "8b599a5165aa0df8b5348dfc091ab45d19a774ec0eb1720f00fffbf57c890922"
                },
                "downloads": -1,
                "filename": "lock-2018.3.8.1911.tar.gz",
                "has_sig": false,
                "md5_digest": "18600d3f1f9611c3bd72f5c2725b83ec",
                "packagetype": "sdist",
                "python_version": "source",
                "requires_python": null,
                "size": 3050,
                "upload_time": "2018-03-08T19:47:38",
                "url": "https://files.pythonhosted.org/packages/4e/c2/bddf8c5efe7a336c5ab0faea5e635e4e50755f2428f0f7b07d4f8aade57e/lock-2018.3.8.1911.tar.gz"
            }
        ]
    },
    "urls": [
        {
            "comment_text": "",
            "digests": {
                "md5": "435db9197f018956cbdddb58af977858",
                "sha256": "cc5ac770930493eed7a8cfd0cf2568a125faf112eb8aa6b6149b3e581523d0c7"
            },
            "downloads": -1,
            "filename": "lock-2018.3.25.2110.tar.gz",
            "has_sig": false,
            "md5_digest": "435db9197f018956cbdddb58af977858",
            "packagetype": "sdist",
            "python_version": "source",
            "requires_python": null,
            "size": 3049,
            "upload_time": "2018-03-25T21:12:37",
            "url": "https://files.pythonhosted.org/packages/ea/ee/4c7e9740d397abd62b48bfe82f77f57a8984da4f5ba0a3b64930b44ccd8f/lock-2018.3.25.2110.tar.gz"
        }
    ]
}