X-Git-Url: https://vcs.fsf.org/?a=blobdiff_plain;f=mediagoblin%2Fstorage.py;h=7ada95e1165c3d177a37993066f715bdb4449ff9;hb=7dc3a66f924c734cbee68677e84f5b656eefe280;hp=ad8f8829dce562da22c63eb16260b4ef30fea5ce;hpb=2d1a60739ecfb64c16e35940b7cee1eb018eb448;p=mediagoblin.git

diff --git a/mediagoblin/storage.py b/mediagoblin/storage.py
index ad8f8829..7ada95e1 100644
--- a/mediagoblin/storage.py
+++ b/mediagoblin/storage.py
@@ -1,4 +1,4 @@
-# GNU Mediagoblin -- federated, autonomous media hosting
+# GNU MediaGoblin -- federated, autonomous media hosting
 # Copyright (C) 2011 Free Software Foundation, Inc
 #
 # This program is free software: you can redistribute it and/or modify
@@ -15,42 +15,39 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
+import shutil
+import urlparse
+import uuid
+import cloudfiles
 
 from werkzeug.utils import secure_filename
 
+from mediagoblin import util
 
-class Error(Exception): pass
-class InvalidFilepath(Error): pass
+########
+# Errors
+########
 
-class NotImplementedError(Error): pass
 
+class Error(Exception):
+    pass
 
-def clean_listy_filepath(listy_filepath):
-    """
-    Take a listy filepath (like ['dir1', 'dir2', 'filename.jpg']) and
-    clean out any nastiness from it.
 
-    For example:
-    >>> clean_listy_filepath([u'/dir1/', u'foo/../nasty', u'linooks.jpg'])
-    [u'dir1', u'foo_.._nasty', u'linooks.jpg']
+class InvalidFilepath(Error):
+    pass
 
-    Args:
-    - listy_filepath: a list of filepath components, mediagoblin
-      storage API style.
 
-    Returns:
-      A cleaned list of unicode objects.
-    """
-    cleaned_filepath = [
-        unicode(secure_filename(filepath))
-        for filepath in listy_filepath]
+class NoWebServing(Error):
+    pass
 
-    if u'' in cleaned_filepath:
-        raise InvalidFilepath(
-            "A filename component could not be resolved into a usable name.")
 
-    return cleaned_filepath
+class NotImplementedError(Error):
+    pass
+
 
+###############################################
+# Storage interface & basic file implementation
+###############################################
 
 class StorageInterface(object):
     """
@@ -62,9 +59,20 @@ class StorageInterface(object):
     It is important to note that the storage API idea of a "filepath"
     is actually like ['dir1', 'dir2', 'file.jpg'], so keep that in
     mind while reading method documentation.
+
+    You should set up your __init__ method with whatever keyword
+    arguments are appropriate to your storage system, but you should
+    also passively accept all extraneous keyword arguments like:
+
+      def __init__(self, **kwargs):
+          pass
+
+    See BasicFileStorage as a simple implementation of the
+    StorageInterface.
     """
-    # def __init__(self, *args, **kwargs):
-    #     pass
+
+    # Whether this file store is on the local filesystem.
+    local_storage = False
 
     def __raise_not_implemented(self):
         """
@@ -85,7 +93,7 @@ class StorageInterface(object):
         # Subclasses should override this method.
         self.__raise_not_implemented()
 
-    def get_file(self, filepath, mode):
+    def get_file(self, filepath, mode='r'):
         """
         Return a file-like object for reading/writing from this filepath.
 
@@ -104,7 +112,7 @@ class StorageInterface(object):
         # Subclasses should override this method.
         self.__raise_not_implemented()
 
-    def url_for_file(self, filepath):
+    def file_url(self, filepath):
         """
         Get the URL for this file.  This assumes our storage has been
         mounted with some kind of URL which makes this possible.
@@ -119,31 +127,66 @@ class StorageInterface(object):
         Eg, if the filename doesn't exist:
         >>> storage_handler.get_unique_filename(['dir1', 'dir2', 'fname.jpg'])
         [u'dir1', u'dir2', u'fname.jpg']
-        
+
         But if a file does exist, let's get one back with at uuid tacked on:
         >>> storage_handler.get_unique_filename(['dir1', 'dir2', 'fname.jpg'])
         [u'dir1', u'dir2', u'd02c3571-dd62-4479-9d62-9e3012dada29-fname.jpg']
         """
+        # Make sure we have a clean filepath to start with, since
+        # we'll be possibly tacking on stuff to the filename.
+        filepath = clean_listy_filepath(filepath)
+
         if self.file_exists(filepath):
             return filepath[:-1] + ["%s-%s" % (uuid.uuid4(), filepath[-1])]
         else:
             return filepath
 
+    def get_local_path(self, filepath):
+        """
+        If this is a local_storage implementation, give us a link to
+        the local filesystem reference to this file.
+
+        >>> storage_handler.get_local_path(['foo', 'bar', 'baz.jpg'])
+        u'/path/to/mounting/foo/bar/baz.jpg'
+        """
+        # Subclasses should override this method, if applicable.
+        self.__raise_not_implemented()
+
+    def copy_locally(self, filepath, dest_path):
+        """
+        Copy this file locally.
+
+        A basic working method for this is provided that should
+        function both for local_storage systems and remote storge
+        systems, but if more efficient systems for copying locally
+        apply to your system, override this method with something more
+        appropriate.
+        """
+        if self.local_storage:
+            shutil.copy(
+                self.get_local_path(filepath), dest_path)
+        else:
+            with self.get_file(filepath, 'rb') as source_file:
+                with file(dest_path, 'wb') as dest_file:
+                    dest_file.write(source_file.read())
+
 
 class BasicFileStorage(StorageInterface):
     """
     Basic local filesystem implementation of storage API
     """
 
-    def __init__(self, base_dir, serve_url=None):
+    local_storage = True
+
+    def __init__(self, base_dir, base_url=None, **kwargs):
         """
         Keyword arguments:
         - base_dir: Base directory things will be served out of.  MUST
           be an absolute path.
-        - serve_url: URL files will be served from
+        - base_url: URL files will be served from
         """
         self.base_dir = base_dir
-        self.serve_url = serve_url
+        self.base_url = base_url
 
     def _resolve_filepath(self, filepath):
         """
@@ -151,15 +194,305 @@ class BasicFileStorage(StorageInterface):
         """
         return os.path.join(
             self.base_dir, *clean_listy_filepath(filepath))
-        
+
     def file_exists(self, filepath):
         return os.path.exists(self._resolve_filepath(filepath))
 
-    def get_file(self, filepath, mode):
-        pass
+    def get_file(self, filepath, mode='r'):
+        # Make directories if necessary
+        if len(filepath) > 1:
+            directory = self._resolve_filepath(filepath[:-1])
+            if not os.path.exists(directory):
+                os.makedirs(directory)
+
+        # Grab and return the file in the mode specified
+        return open(self._resolve_filepath(filepath), mode)
+
+    def delete_file(self, filepath):
+        # TODO: Also delete unused directories if empty (safely, with
+        # checks to avoid race conditions).
+        os.remove(self._resolve_filepath(filepath))
+
+    def file_url(self, filepath):
+        if not self.base_url:
+            raise NoWebServing(
+                "base_url not set, cannot provide file urls")
+
+        return urlparse.urljoin(
+            self.base_url,
+            '/'.join(clean_listy_filepath(filepath)))
+
+    def get_local_path(self, filepath):
+        return self._resolve_filepath(filepath)
+
+
+class CloudFilesStorage(StorageInterface):
+    def __init__(self, **kwargs):
+        self.param_container = kwargs.get('cloudfiles_container')
+        self.param_user = kwargs.get('cloudfiles_user')
+        self.param_api_key = kwargs.get('cloudfiles_api_key')
+        self.param_host = kwargs.get('cloudfiles_host')
+        self.param_use_servicenet = kwargs.get('cloudfiles_use_servicenet')
+
+        if not self.param_host:
+            print('No CloudFiles host URL specified, '
+                  'defaulting to Rackspace US')
+
+        self.connection = cloudfiles.get_connection(
+            username=self.param_user,
+            api_key=self.param_api_key,
+            servicenet=True if self.param_use_servicenet == 'true' or \
+                self.param_use_servicenet == True else False)
+
+        if not self.param_container == \
+                self.connection.get_container(self.param_container):
+            self.container = self.connection.create_container(
+                self.param_container)
+            self.container.make_public(
+                ttl=60 * 60 * 2)
+        else:
+            self.container = self.connection.get_container(
+                self.param_container)
+
+        self.container_uri = self.container.public_uri()
+
+    def _resolve_filepath(self, filepath):
+        return '/'.join(
+            clean_listy_filepath(filepath))
+
+    def file_exists(self, filepath):
+        try:
+            object = self.container.get_object(
+                self._resolve_filepath(filepath))
+            return True
+        except cloudfiles.errors.NoSuchObject:
+            return False
+
+    def get_file(self, filepath, mode='r'):
+        try:
+            obj = self.container.get_object(
+                self._resolve_filepath(filepath))
+        except cloudfiles.errors.NoSuchObject:
+            obj = self.container.create_object(
+                self._resolve_filepath(filepath))
+
+        return obj
+
+    def delete_file(self, filepath):
+        # TODO: Also delete unused directories if empty (safely, with
+        # checks to avoid race conditions).
+        self.container.delete_object(filepath)
+
+    def file_url(self, filepath):
+        return '/'.join([
+                self.container_uri,
+                self._resolve_filepath(filepath)])
+
+
+class MountStorage(StorageInterface):
+    """
+    Experimental "Mount" virtual Storage Interface
+    
+    This isn't an interface to some real storage, instead it's a
+    redirecting interface, that redirects requests to other
+    "StorageInterface"s.
+
+    For example, say you have the paths:
+
+     1. ['user_data', 'cwebber', 'avatar.jpg']
+     2. ['user_data', 'elrond', 'avatar.jpg']
+     3. ['media_entries', '34352f304c3f4d0ad8ad0f043522b6f2', 'thumb.jpg']
+
+    You could mount media_entries under CloudFileStorage and user_data
+    under BasicFileStorage.  Then 1 would be passed to
+    BasicFileStorage under the path ['cwebber', 'avatar.jpg'] and 3
+    would be passed to CloudFileStorage under
+    ['34352f304c3f4d0ad8ad0f043522b6f2', 'thumb.jpg'].
+
+    In other words, this is kind of like mounting /home/ and /etc/
+    under different filesystems on your operating system... but with
+    mediagoblin filestorages :)
+    
+    To set this up, you currently need to call the mount() method with
+    the target path and a backend, that shall be available under that
+    target path.  You have to mount things in a sensible order,
+    especially you can't mount ["a", "b"] before ["a"].
+    """
+    def __init__(self, **kwargs):
+        self.mounttab = {}
+
+    def mount(self, dirpath, backend):
+        """
+        Mount a new backend under dirpath
+        """
+        new_ent = clean_listy_filepath(dirpath)
+
+        print "Mounting:", repr(new_ent)
+        already, rem_1, table, rem_2 = self._resolve_to_backend(new_ent, True)
+        print "===", repr(already), repr(rem_1), repr(rem_2), len(table)
+
+        assert (len(rem_2) > 0) or (None not in table), \
+            "That path is already mounted"
+        assert (len(rem_2) > 0) or (len(table)==0), \
+            "A longer path is already mounted here"
+
+        for part in rem_2:
+            table[part] = {}
+            table = table[part]
+        table[None] = backend
+
+    def _resolve_to_backend(self, filepath, extra_info = False):
+        """
+        extra_info = True is for internal use!
+
+        Normally, returns the backend and the filepath inside that backend.
+
+        With extra_info = True it returns the last directory node and the
+        remaining filepath from there in addition.
+        """
+        table = self.mounttab
+        filepath = filepath[:]
+        res_fp = None
+        while True:
+            new_be = table.get(None)
+            if (new_be is not None) or res_fp is None:
+                res_be = new_be
+                res_fp = filepath[:]
+                res_extra = (table, filepath[:])
+                # print "... New res: %r, %r, %r" % (res_be, res_fp, res_extra)
+            if len(filepath) == 0:
+                break
+            query = filepath.pop(0)
+            entry = table.get(query)
+            if entry is not None:
+                table = entry
+                res_extra = (table, filepath[:])
+            else:
+                break
+        if extra_info:
+            return (res_be, res_fp) + res_extra
+        else:
+            return (res_be, res_fp)
+
+    def resolve_to_backend(self, filepath):
+        backend, filepath = self._resolve_to_backend(filepath)
+        if backend is None:
+            raise Error("Path not mounted")
+        return backend, filepath
+
+    def __repr__(self, table = None, indent = []):
+        res = []
+        if table is None:
+            res.append("MountStorage<")
+            table = self.mounttab
+        v = table.get(None)
+        if v:
+            res.append("  " * len(indent) + repr(indent) + ": " + repr(v))
+        for k, v in table.iteritems():
+            if k == None:
+                continue
+            res.append("  " * len(indent) + repr(k) + ":")
+            res += self.__repr__(v, indent + [k])
+        if table is self.mounttab:
+            res.append(">")
+            return "\n".join(res)
+        else:
+            return res
+
+    def file_exists(self, filepath):
+        backend, filepath = self.resolve_to_backend(filepath)
+        return backend.file_exists(filepath)
+
+    def get_file(self, filepath, mode='r'):
+        backend, filepath = self.resolve_to_backend(filepath)
+        return backend.get_file(filepath, mode)
 
     def delete_file(self, filepath):
-        pass
+        backend, filepath = self.resolve_to_backend(filepath)
+        return backend.delete_file(filepath)
+
+    def file_url(self, filepath):
+        backend, filepath = self.resolve_to_backend(filepath)
+        return backend.file_url(filepath)
+
+    def get_local_path(self, filepath):
+        backend, filepath = self.resolve_to_backend(filepath)
+        return backend.get_local_path(filepath)
+
+    def copy_locally(self, filepath, dest_path):
+        """
+        Need to override copy_locally, because the local_storage
+        attribute is not correct.
+        """
+        backend, filepath = self.resolve_to_backend(filepath)
+        backend.copy_locally(filepath, dest_path)
+
+
+###########
+# Utilities
+###########
+
+def clean_listy_filepath(listy_filepath):
+    """
+    Take a listy filepath (like ['dir1', 'dir2', 'filename.jpg']) and
+    clean out any nastiness from it.
+
+
+    >>> clean_listy_filepath([u'/dir1/', u'foo/../nasty', u'linooks.jpg'])
+    [u'dir1', u'foo_.._nasty', u'linooks.jpg']
+
+    Args:
+    - listy_filepath: a list of filepath components, mediagoblin
+      storage API style.
+
+    Returns:
+      A cleaned list of unicode objects.
+    """
+    cleaned_filepath = [
+        unicode(secure_filename(filepath))
+        for filepath in listy_filepath]
+
+    if u'' in cleaned_filepath:
+        raise InvalidFilepath(
+            "A filename component could not be resolved into a usable name.")
+
+    return cleaned_filepath
+
+
+def storage_system_from_config(config_section):
+    """
+    Utility for setting up a storage system from a config section.
+
+    Note that a special argument may be passed in to
+    the config_section which is "storage_class" which will provide an
+    import path to a storage system.  This defaults to
+    "mediagoblin.storage:BasicFileStorage" if otherwise undefined.
 
-    def url_for_file(self, filepath):
-        pass
+    Arguments:
+     - config_section: dictionary of config parameters
+
+    Returns:
+      An instantiated storage system.
+
+    Example:
+      storage_system_from_config(
+        {'base_url': '/media/',
+         'base_dir': '/var/whatever/media/'})
+
+       Will return:
+         BasicFileStorage(
+           base_url='/media/',
+           base_dir='/var/whatever/media')
+    """
+    # This construct is needed, because dict(config) does
+    # not replace the variables in the config items.
+    config_params = dict(config_section.iteritems())
+
+    if 'storage_class' in config_params:
+        storage_class = config_params['storage_class']
+        config_params.pop('storage_class')
+    else:
+        storage_class = "mediagoblin.storage:BasicFileStorage"
+
+    storage_class = util.import_component(storage_class)
+    return storage_class(**config_params)