dummy backend

backends/dummy.py

-
-def create_container(name):
-    return
-
-def delete_container(name):
-    return
-
-def get_container_meta(name):
-    return {'name': name, 'count': 0, 'bytes': 0}
-
-def list_containers():
-    return []
-
-def list_objects(container, prefix='', delimiter='/'):
-    return []
-
-def get_object_meta(container, name):
-    return {'name': name, 'hash': '', 'bytes': 0}
-
-def get_object_data(container, name, offset=0, length=0):
-    return ''
-
-def update_object(container, name, meta, data):
-    return
-
-def update_object_meta(container, name, meta):
-    return
-
-def copy_object(container, name, new_name):
-    return
-
-def delete_object(container, name):
-    return
+import os
+import sqlite3
+import json
+
+basepath = '/Users/butters/src/pithos/backends/content' #full path
+if not os.path.exists(basepath):
+    os.makedirs(basepath)
+db = '/'.join([basepath, 'db'])
+con = sqlite3.connect(db)
+# Create tables
+print 'Creating tables....'
+sql = '''create table if not exists objects(name varchar(2560))'''
+print sql
+con.execute(sql)
+# Save (commit) the changes
+con.commit()
+    
+def create_container(name):
+    """ creates a new container with the given name
+    if it doesn't exists under the basepath """
+    fullname = '/'.join([basepath, name])    
+    if not os.path.exists(fullname):
+        os.chdir(basepath)
+        os.mkdir(name)
+    else:
+        raise NameError('Container already exists')
+    return
+
+def delete_container(name):
+    """ deletes the container with the given name
+        if it exists under the basepath """
+    fullname = '/'.join([basepath, name])    
+    if not os.path.exists(fullname):
+        raise NameError('Container does not exist')
+    if not list_objects(name):
+        raise Error('Container is not empty')
+    else:
+        os.chdir(basepath)
+        os.rmdir(name)
+    return
+
+def get_container_meta(name):
+    """ returns a dictionary with the container metadata """
+    fullname = '/'.join([basepath, name])
+    if not os.path.exists(fullname):
+        raise NameError('Container does not exist')
+    contents = os.listdir(fullname) 
+    count = len(contents)
+    size = sum(os.path.getsize('/'.join([basepath, name, objectname])) for objectname in contents)
+    return {'name': name, 'count': count, 'bytes': size}
+
+def list_containers():
+    return os.listdir(basepath) 
+
+def list_objects(container, prefix='', delimiter=None):
+    dir = '/'.join([basepath, container])
+    if not os.path.exists(dir):
+        raise NameError('Container does not exist')
+    search_str = ''
+    if prefix:
+        search_str = '/'.join([search_str, prefix])
+    #if delimiter:
+    if None:
+        search_str = ''.join(['%', search_str, '%', delimiter])
+        print search_str
+        c = con.execute('select * from objects where name like ''?'' order by name', (search_str,))
+    else:
+        search_str = ''.join(['%', search_str, '%'])
+        print search_str
+        c = con.execute('select * from objects where name like ''?'' order by name', (search_str,))
+    l = []
+    for row in c.fetchall():
+        s = ''
+        print row[0]
+        rest = str(row[0]).split(prefix)[1]
+        print rest
+        #if delimiter:
+        #    rest = rest.partition(delimiter)[0]
+        #print rest
+        folders = rest.split('/')[:-1]
+        for folder in folders:
+            path = ''.join([s, folder, '/'])
+            if path not in l:
+                l.append(path)
+            s = ''.join([s, folder, '/'])
+        l.append(rest)
+    return l
+
+def get_object_meta(container, name):
+    dir = '/'.join([basepath, container])
+    if not os.path.exists(dir):
+        raise NameError('Container does not exist')
+    else:
+        os.chdir(dir)
+    location = __get_object_linkinfo('/'.join([container, name]))
+    location = '.'.join([location, 'meta'])
+    f = open(location, 'r')
+    data = json.load(f)
+    f.close()
+    return data
+
+def get_object_data(container, name, offset=0, length=-1):
+    dir = '/'.join([basepath, container])
+    if not os.path.exists(dir):
+        raise NameError('Container does not exist')
+    else:
+        os.chdir(dir)
+    location = __get_object_linkinfo('/'.join([container, name]))
+    f = open(location, 'r')
+    if offset:
+        f.seek(offset)
+    data = f.read(length)
+    f.close()
+    return data
+
+def update_object(container, name, data):
+    dir = '/'.join([basepath, container])
+    if not os.path.exists(dir):
+        raise NameError('Container does not exist')
+    try:
+        location = __get_object_linkinfo('/'.join([container, name]))
+    except NameError:
+        # new object
+        location = str(__save_linkinfo('/'.join([container, name])))
+        print ':'.join(['Creating new location', location])
+    __store_data(location, container, data)
+    return
+
+def update_object_meta(container, name, meta):
+    dir = '/'.join([basepath, container])
+    if not os.path.exists(dir):
+        raise NameError('Container does not exist')
+    try:
+        location = __get_object_linkinfo('/'.join([container, name]))
+    except NameError:
+        # new object
+        location = str(__save_linkinfo('/'.join([container, name])))
+        print ':'.join(['Creating new location', location])
+    __store_metadata(location, container, meta)
+    return
+
+def copy_object(src_container, src_name, dest_container, dest_name, meta):
+    fullname = '/'.join([basepath, dest_container])    
+    if not os.path.exists(fullname):
+        raise NameError('Destination container does not exist')
+    update_object(dest_container, dest_name, get_object_data(src_container, src_name))
+    src_object_meta = get_object_meta(src_container, src_name)
+    if (type(src_object_meta) == types.DictType):
+        distinct_keys = [k for k in src_object_meta.keys() if k not in meta.keys()]
+        for k in distinct_keys:
+            meta[k] = src_object_meta[k]
+            update_object_meta(dest_container, dest_name, meta)
+    else:
+        update_object_meta(dest_container, dest_name, meta)
+    return
+
+def delete_object(container, name):
+    return
+
+def __store_metadata(location, container, meta):
+    dir = '/'.join([basepath, container])
+    if not os.path.exists(dir):
+        raise NameError('Container does not exist')
+    else:
+        os.chdir(dir)
+    location = '.'.join([location, 'meta'])
+    f = open(location, 'w')
+    data = json.dumps(meta)
+    f.write(data)
+    f.close()
+
+def __store_data(location, container, data):
+    dir = '/'.join([basepath, container])
+    if not os.path.exists(dir):
+        raise NameError('Container does not exist')
+    else:
+        os.chdir(dir)
+    f = open(location, 'w')
+    f.write(data)
+    f.close()
+    
+def __get_object_linkinfo(name):
+    c = con.execute('select rowid from objects where name=''?''', (name,))
+    row = c.fetchone()
+    if row:
+        return str(row[0])
+    else:
+        raise NameError('Object not found')
+
+def __save_linkinfo(name):
+    id = con.execute('insert into objects(name) values(?)', (name,)).lastrowid
+    con.commit()
+    return id
+    
+if __name__ == '__main__':
+    dirname = 'papagian'
+    #create_container(dirname)
+    #assert os.path.exists(dirname)
+    #assert os.path.isdir(dirname)
+    
+    #print get_container_meta(dirname)
+    
+    #update_object_meta(dirname, 'photos/animals/dog.jpg', {'name':'dog.jpg'})
+    #update_object_meta(dirname, 'photos/animals/dog.jpg', {'name':'dog.jpg', 'type':'image', 'size':400})
+    #print get_object_meta(dirname, 'photos/animals/dog.jpg')
+    
+    #f = open('dummy.py')
+    #data  = f.read()
+    #update_object(dirname, 'photos/animals/dog.jpg', data)
+    #update_object(dirname, 'photos/animals/cat.jpg', data)
+    #update_object(dirname, 'photos/animals/thumbs/cat.jpg', data)
+    #update_object(dirname, 'photos/fruits/banana.jpg', data)
+    
+    #print list_objects(dirname, 'photos/animals');
+    
+    copy_object(dirname, 'photos/animals/dog.jpg', 'photos/animals/dog2.jpg')
+    copy_object(dirname, 'photos/animals/dg.jpg', 'photos/animals/dog2.jpg')
+