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    "info": {
        "author": "Huang Junwen",
        "author_email": "kassarar@gmail.com",
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        "classifiers": [
            "Programming Language :: Python :: 2",
            "Programming Language :: Python :: 2.7",
            "Topic :: Software Development :: Libraries"
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        "description": "# TagCache\n\n## Support platform\n\n- linux\n- macos\n\n## How to install\n\n```base\n$ pip install tagcache\n```\n\n## Example usage\n\nSuppose you have a blog. And want to cache blog pages (e.g. home page).\n\n- First you need to create and configure a `Cache` object.\n\n```python\nfrom tagcache import Cache, NotCache\n\ncache = Cache()\n\n# configure the main directory to store cache files\ncache.configure('/tmp/blog_cache')\n\n```\n\n- Decorate the content function with the `Cache` object. In the following example\n  - `blog-home` is the key name of the cache\n  - `expire` specify the expiration in seconds of the cache (7 days), never expire if omitted\n  - `blog-new` and `bio` are the tags of the cache\n  - finally call the decorated function to get content, the function will use cache or call the original function to generate new content when cache miss\n\n```python\n\n@cache('blog-home', expire=3600*24*7, tags=('blog-new', 'bio'))\ndef home_page_content(cache_param):\n\n    ...\n    # sometimes content is not available and you don't want\n    # to cache the return value.\n    cache_param.disable()\n\n    # sometimes tags are only known at runtime\n    cache_param.tags.add('some-more-tag')\n\n    # sometimes you want to change expire\n    cache_param.expire = 3600*24\n\n    # generate home page content ...\n    ...\n    return {\"bio\": {...}, \"recent_blogs\": [...]}\n\ncontent = home_page_content()\n```\n\n- Later, you make changes to your bio (which is displayed on home page), then you can invalidate all caches containing the bio\n\n```python\ncache.invalidate_tag(\"bio\")\n```\n\n- Periodically, you need to clean up those expired or invalid files.\n\n```python\ncache.cleanup()\n```\n\n## How it works\n\nThe cache directory looks like:\n\n```bash\n.\n\u251c\u2500\u2500 data\n\u2502\u00a0\u00a0 \u251c\u2500\u2500 18\n\u2502\u00a0\u00a0 \u2502\u00a0\u00a0 \u2514\u2500\u2500 ae\n\u2502\u00a0\u00a0 \u2502\u00a0\u00a0     \u2514\u2500\u2500 tag:62696f                  <-- tag directory: hexlify('bio')\n\u2502\u00a0\u00a0 \u2502\u00a0\u00a0         \u2514\u2500\u2500 85\n\u2502\u00a0\u00a0 \u2502\u00a0\u00a0             \u2514\u2500\u2500 3:110235185         <-- hardlink of 'key:626c6f672d686f6d65'\n\u2502\u00a0\u00a0 \u251c\u2500\u2500 37\n\u2502\u00a0\u00a0 \u2502\u00a0\u00a0 \u2514\u2500\u2500 64\n\u2502\u00a0\u00a0 \u2502\u00a0\u00a0     \u2514\u2500\u2500 tag:626c6f672d6e6577        <-- tag directory: hexlify('blog-new')\n\u2502\u00a0\u00a0 \u2502\u00a0\u00a0         \u2514\u2500\u2500 85\n\u2502\u00a0\u00a0 \u2502\u00a0\u00a0             \u2514\u2500\u2500 3:110235185         <-- hardlink of 'key:626c6f672d686f6d65'\n\u2502\u00a0\u00a0 \u2514\u2500\u2500 ae\n\u2502\u00a0\u00a0     \u2514\u2500\u2500 08\n\u2502\u00a0\u00a0         \u2514\u2500\u2500 key:626c6f672d686f6d65      <-- cache file: hexlify('blog-home')\n\u2514\u2500\u2500 tmp\n```\n\nLoad process:\n\n1. Try to open exists cache file: `\"key:\" + hexlify(key)`\n1. If not found, generate content (see below)\n1. If found, check expiration (`st_mtime` as expire time) and tags validation (`st_nlink`)\n    1. If all checks were passed, return the cache directly\n    1. Try to flock the cache file in non-blocking mode, generate content if success, return cache otherwise\n\n\nGenerate content process:\n\n1. Create a temporary file under tmp and save serialized content (with tags info as well)\n1. Hardlink the temporary file into tag directories (`nlinks + inode number` as link name)\n1. Change the `mtime` of the temporary file to the expire time\n1. Atomic move (rename) the temporary file to the final destination: `\"key:\" + hexlify(key)`\n\nInvalidate tag process: just remove the tag directory\n\n## Author\n\nHuang junwen (email: <kassarar@gmail.com>)\n\n## Licence\n\nMIT\n\n\n",
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        "license": "MIT",
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        "name": "TagCache",
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