Initial implementation.

Work in progress.

tornado_gallery/gallery.py

@@ -0,0 +1,98 @@
+#!/usr/bin/env python
+
+from weakref import WeakValueDictionary
+from collections import OrderedDict
+
+import os.path
+from time import time
+
+from .metadata import parse_meta
+from .photo import Photo
+
+
+class Gallery(object):
+    """
+    Representation of a photo gallery.
+    """
+
+    _INSTANCE = WeakValueDictionary()
+
+    def __init__(self, fs_cache, meta_cache, dir):
+        dir = os.path.realpath(dir)
+
+        self._dir = dir
+        self._title = None
+        self._desc = None
+        self._meta_cache = meta_cache
+        self._meta_mtime = 0
+        self._fs_cache = fs_cache
+
+        self._content = None
+        self._content_mtime = 0
+
+        assert self.name not in self._INSTANCE
+        self._INSTANCE[self.name] = self
+
+    @property
+    def fs_cache(self):
+        return self._fs_cache
+
+    @property
+    def meta_cache(self):
+        return self._meta_cache
+
+    @property
+    def dir(self):
+        return self._dir
+
+    @property
+    def name(self):
+        return os.path.basename(self.dir)
+
+    @property
+    def title(self):
+        self._parse_metadata()
+        return self._title
+
+    @property
+    def desc(self):
+        self._parse_metadata()
+        return self._desc
+
+    @property
+    def content(self):
+        content_mtime_now = self._content_mtime_now
+        if self._content_mtime < content_mtime_now:
+            content = {}
+            for name in self._fs_cache[self.dir]:
+                # Grab the file extension and analyse
+                (_, ext) = name.rsplit('.',1)
+                if ext.lower() not in ('jpg', 'jpe', 'jpeg', 'gif',
+                                        'png', 'tif', 'tiff'):
+                    continue
+                # This is a photo.
+                content[name] = Photo(self, name)
+            self._content = OrderedDict(sorted(content.items(),
+                key=lambda i : i[0]))
+            self._content_mtime = content_mtime_now
+        return self._content.copy()
+
+    @property
+    def _meta_file(self):
+        return os.path.join(self.dir, 'info.txt')
+
+    @property
+    def _meta_mtime_now(self):
+        return self._fs_cache[self._meta_file].stat.st_mtime
+
+    @property
+    def _dir_mtime_now(self):
+        return self._fs_cache[self.dir].stat.st_mtime
+
+    def _parse_metadata(self):
+        meta_mtime_now = self._meta_mtime_now
+        if meta_mtime_now > self._meta_mtime:
+            data = self._meta_cache[meta_file]
+            self._title = data.get('.title', self.name)
+            self._desc = data.get('.desc', 'No description given')
+            self._meta_mtime = meta_mtime_now

tornado_gallery/metadata.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+
+from os.path import realpath
+from time import time
+
+
+def parse_meta(filename):
+    """
+    Parse a raw metadata file and return the output.
+    """
+    return dict([
+        line.split('\t',1)
+        for line in open(filename, mode='rt')
+    ])
+
+
+class MetadataCache(object):
+    """
+    Store the metadata for lots of files and keep them cached.
+    """
+
+    def __init__(self, cache_duration=300.0, fs_cache=None):
+        self._cache_duration = float(cache_duration)
+        self._file = {}
+        self._fs_cache = None
+
+    def __getitem__(self, filename):
+        """
+        Retrieve the content of the given metadata file.
+        """
+        filename = realpath(filename)
+
+        # Retrieve the modification time of the file
+        if self._fs_cache is not None:
+            mtime_now = self._fs_cache[filename].stat.st_mtime
+        else:
+            mtime_now = 0
+
+        try:
+            (_, mtime_last, data) = self._file[filename]
+
+            if mtime_last == mtime_now:
+                # File is still being used, refresh expiry.
+                self._store_file(filename, mtime_last, data)
+                return data
+        except KeyError:
+            pass
+
+        # Not in cache, try to read it in.
+        data = parse_meta(filename)
+        self._store_file(filename, mtime_now, data)
+        return data
+
+    def _store_file(self, filename, mtime, data):
+        self._file[filename] = (time() + self._cache_duration, mtime, data)
+
+    def purge(self):
+        """
+        Purge the cache of expired content.
+        """
+        for filename, (expiry, _, _) in list(self._file.items()):
+            if expiry < time():
+                self._file.pop(filename, None)

tornado_gallery/photo.py

@@ -0,0 +1,95 @@
+#!/usr/bin/env python
+
+from weakref import ref
+
+import os.path
+from time import time
+
+from .metadata import parse_meta
+from .photo import Photo
+
+
+class Photo(object):
+    """
+    Representation of a photo in a gallery.
+    """
+
+    def __init__(self, gallery, name):
+        self._gallery = ref(gallery)
+        self._name = name
+
+        self._title = None
+        self._desc = None
+        self._meta_cache = meta_cache
+        self._meta_mtime = 0
+        self._fs_cache = fs_cache
+
+        self._content = None
+        self._content_mtime = 0
+
+        assert self.name not in self._INSTANCE
+        self._INSTANCE[self.name] = self
+
+    @property
+    def fs_cache(self):
+        return self._fs_cache
+
+    @property
+    def meta_cache(self):
+        return self._meta_cache
+
+    @property
+    def dir(self):
+        return self._dir
+
+    @property
+    def name(self):
+        return os.path.basename(self.dir)
+
+    @property
+    def title(self):
+        self._parse_metadata()
+        return self._title
+
+    @property
+    def desc(self):
+        self._parse_metadata()
+        return self._desc
+
+    @property
+    def content(self):
+        content_mtime_now = self._content_mtime_now
+        if self._content_mtime < content_mtime_now:
+            content = {}
+            for name in self._fs_cache[self.dir]:
+                # Grab the file extension and analyse
+                (_, ext) = name.rsplit('.',1)
+                if ext.lower() not in ('jpg', 'jpe', 'jpeg', 'gif',
+                                        'png', 'tif', 'tiff'):
+                    continue
+                # This is a photo.
+                content[name] = Photo(self, name)
+            self._content = OrderedDict(sorted(content.items(),
+                key=lambda i : i[0]))
+            self._content_mtime = content_mtime_now
+        return self._content.copy()
+
+    @property
+    def _meta_file(self):
+        return os.path.join(self.dir, 'info.txt')
+
+    @property
+    def _meta_mtime_now(self):
+        return self._fs_cache[self._meta_file].stat.st_mtime
+
+    @property
+    def _dir_mtime_now(self):
+        return self._fs_cache[self.dir].stat.st_mtime
+
+    def _parse_metadata(self):
+        meta_mtime_now = self._meta_mtime_now
+        if meta_mtime_now > self._meta_mtime:
+            data = self._meta_cache[meta_file]
+            self._title = data.get('.title', self.name)
+            self._desc = data.get('.desc', 'No description given')
+            self._meta_mtime = meta_mtime_now