Synnefo

import os

import time

import sqlite3

import logging

import types

import hashlib

import shutil

from base import BaseBackend

logger = logging.getLogger(__name__)

class SimpleBackend(BaseBackend):

    def __init__(self, basepath):

        self.basepath = basepath

        if not os.path.exists(basepath):

            os.makedirs(basepath)

        db = os.path.join(basepath, 'db')

        self.con = sqlite3.connect(db)

        # Create tables

        sql = 'create table if not exists objects (name TEXT)'

        self.con.execute(sql)

        sql = '''create table if not exists metadata (

                    object_id int, key text, value text, primary key (object_id, key))'''

        self.con.execute(sql)

        self.con.commit()

    def get_account_meta(self, account):

        """Return a dictionary with the account metadata."""

        logger.debug("get_account_meta: %s", account)

        try:

            fullname = self._get_accountinfo(account)

        except NameError:

            return {'name': account, 'count': 0, 'bytes': 0}

        contents = os.listdir(fullname)

        count = len(contents)

        size = 0

        for y in (os.path.join(fullname, z) for z in contents):

            size += sum((os.path.getsize(os.path.join(y, x)) for x in os.listdir(y)))

        meta = self._get_metadata(account)

        meta.update({'name': account, 'count': count, 'bytes': size})

        return meta

    def update_account_meta(self, account, meta):

        """Update the metadata associated with the account."""

        logger.debug("update_account_meta: %s %s", account, meta)

        fullname = os.path.join(self.basepath, account)

        if not os.path.exists(fullname):

            os.makedirs(fullname)

        self._update_metadata(account, None, None, meta)

    def create_container(self, account, name):

        """Create a new container with the given name."""

        logger.debug("create_container: %s %s", account, name)

        fullname = os.path.join(self.basepath, account, name)

        if not os.path.exists(fullname):

            os.makedirs(fullname)

        else:

            raise NameError('Container already exists')

        self._update_metadata(account, name, None, None)

    def delete_container(self, account, name):

        """Delete the container with the given name."""

        logger.debug("delete_container: %s %s", account, name)

        fullname = self._get_containerinfo(account, name)

        if os.listdir(fullname):

            raise IndexError('Container is not empty')

        os.rmdir(fullname)

        self._del_dbpath(os.path.join(account, name))

        self._update_metadata(account, None, None, None)

    def get_container_meta(self, account, name):

        """Return a dictionary with the container metadata."""

        logger.debug("get_container_meta: %s %s", account, name)

        fullname = self._get_containerinfo(account, name)

        contents = os.listdir(fullname)

        count = len(contents)

        size = sum((os.path.getsize(os.path.join(fullname, x)) for x in contents))

        meta = self._get_metadata(os.path.join(account, name))

        meta.update({'name': name, 'count': count, 'bytes': size})

        return meta

    def update_container_meta(self, account, name, meta):

        """Update the metadata associated with the container."""

        logger.debug("update_container_meta: %s %s %s", account, name, meta)

        fullname = self._get_containerinfo(account, name)

        self._update_metadata(account, name, None, meta)

    def list_containers(self, account, marker=None, limit=10000):

        """Return a list of containers existing under an account."""

        logger.debug("list_containers: %s %s %s", account, marker, limit)

        try:

            fullname = self._get_accountinfo(account)

        except NameError:

            containers = []

        containers = os.listdir(fullname)

        containers.sort()

        start = 0

        if marker:

            try:

                start = containers.index(marker) + 1

            except ValueError:

                pass

        if not limit or limit > 10000:

            limit = 10000

        return containers[start:start + limit]

    def list_objects(self, account, container, prefix='', delimiter=None, marker=None, limit=10000, virtual=True):

        """Return a list of objects existing under a container."""

        logger.debug("list_objects: %s %s %s %s %s %s", account, container, prefix, delimiter, marker, limit)

        fullname = self._get_containerinfo(account, container)

        cont_prefix = os.path.join(account, container) + '/'

        sql = 'select * from objects where name like ? order by name'

        c = self.con.execute(sql, (cont_prefix + prefix + '%',))

        objects = [x[0][len(cont_prefix):] for x in c.fetchall()]

        if delimiter:

            pseudo_objects = []

            for x in objects:

                pseudo_name = x

                i = pseudo_name.find(delimiter, len(prefix))

                if not virtual:

                    # If the delimiter is not found, or the name ends

                    # with the delimiter's first occurence.

                    if i == -1 or len(pseudo_name) == i + len(delimiter):

                        pseudo_objects.append(pseudo_name)

                else:

                    # If the delimiter is found, keep up to (and including) the delimiter.

                    if i != -1:

                        pseudo_name = pseudo_name[:i + len(delimiter)]

                    if pseudo_name not in pseudo_objects:

                        pseudo_objects.append(pseudo_name)

            objects = pseudo_objects

        start = 0

        if marker:

            try:

                start = objects.index(marker) + 1

            except ValueError:

                pass

        if not limit or limit > 10000:

            limit = 10000

        return objects[start:start + limit]

    def get_object_meta(self, account, container, name):

        """Return a dictionary with the object metadata."""

        logger.debug("get_object_meta: %s %s %s", account, container, name)

        fullname = self._get_containerinfo(account, container)

        link = self._get_linkinfo(os.path.join(account, container, name))

        location = os.path.join(self.basepath, account, container, link)

        size = os.path.getsize(location)

        meta = self._get_metadata(os.path.join(account, container, name))

        meta.update({'name': name, 'bytes': size})

        return meta

    def update_object_meta(self, account, container, name, meta):

        """Update the metadata associated with the object."""

        logger.debug("update_object_meta: %s %s %s %s", account, container, name, meta)

        fullname = self._get_containerinfo(account, container)

        link = self._get_linkinfo(os.path.join(account, container, name))

        self._update_metadata(account, container, name, meta)

    def get_object(self, account, container, name, offset=0, length=-1):

        """Return the object data."""

        logger.debug("get_object: %s %s %s %s %s", account, container, name, offset, length)

        fullname = self._get_containerinfo(account, container)       

        link = self._get_linkinfo(os.path.join(account, container, name))

        location = os.path.join(self.basepath, account, container, link)

        f = open(location, 'r')

        if offset:

            f.seek(offset)

        data = f.read(length)

        f.close()

        return data

    def update_object(self, account, container, name, data, offset=0):

        """Create/update an object with the specified data."""

        logger.debug("put_object: %s %s %s %s %s", account, container, name, data, offset)

        fullname = self._get_containerinfo(account, container)

        try:

            link = self._get_linkinfo(os.path.join(account, container, name))

        except NameError:

            # new object

            link = self._put_linkinfo(os.path.join(account, container, name))

        location = os.path.join(self.basepath, account, container, link)

        f = open(location, 'w')

        if offset:

            f.seek(offset)

        f.write(data)

        f.close()

        self._update_metadata(account, container, name, None)

    def copy_object(self, account, src_container, src_name, dest_container, dest_name, dest_meta={}):

        """Copy an object's data and metadata."""

        logger.debug("copy_object: %s %s %s %s %s %s",

                        account, src_container, src_name, dest_container, dest_name, dest_meta)

        link = self._get_linkinfo(os.path.join(account, src_container, src_name))

        src_location = os.path.join(self.basepath, account, src_container, link)

        dest_fullname = self._get_containerinfo(account, dest_container)       

        try:

            link = self._get_linkinfo(os.path.join(account, dest_container, dest_name))

        except NameError:

            # new object

            link = self._put_linkinfo(os.path.join(account, dest_container, dest_name))

        dest_location = os.path.join(self.basepath, account, dest_container, link)

        shutil.copyfile(src_location, dest_location)

        meta = self._get_metadata(os.path.join(account, src_container, src_name))

        meta.update(dest_meta)

        self._update_metadata(account, dest_container, dest_name, meta)

        return

    def move_object(self, account, src_container, src_name, dest_container, dest_name, dest_meta={}):

        """Move an object's data and metadata."""

        logger.debug("move_object: %s %s %s %s %s %s",

                        account, src_container, src_name, dest_container, dest_name, dest_meta)

        self.copy_object(account, src_container, src_name, dest_container, dest_name, dest_meta)

        self.delete_object(account, src_container, src_name)

    def delete_object(self, account, container, name):

        """Delete an object."""

        logger.debug("delete_object: %s %s %s", account, container, name)

        fullname = self._get_containerinfo(account, container)       

        # delete object data

        link = self._get_linkinfo(os.path.join(account, container, name))

        location = os.path.join(self.basepath, account, container, link)

        try:

            os.remove(location)

        except:

            pass

        # delete object metadata

        self._del_dbpath(os.path.join(account, container, name))

        self._update_metadata(account, container, None, None)

    def _get_accountinfo(self, account):

        path = os.path.join(self.basepath, account)

        if not os.path.exists(path):

            raise NameError('Account does not exist')

        return path

    def _get_containerinfo(self, account, container):

        path = os.path.join(self.basepath, account, container)

        if not os.path.exists(path):

            raise NameError('Container does not exist')

        return path

    def _get_linkinfo(self, path):

        c = self.con.execute('select rowid from objects where name=?', (path,))

        row = c.fetchone()

        if row:

            return str(row[0])

        else:

            raise NameError('Object does not exist')

    def _put_linkinfo(self, path):

        id = self.con.execute('insert into objects (name) values (?)', (path,)).lastrowid

        self.con.commit()

        return str(id)

    def _get_metadata(self, path):

        sql = 'select m.key, m.value from metadata m, objects o where o.rowid = m.object_id and o.name = ?'

        c = self.con.execute(sql, (path,))

        return dict(c.fetchall())

    def _put_metadata(self, path, meta):

        c = self.con.execute('select rowid from objects where name=?', (path,))

        row = c.fetchone()

        if row:

            link = str(row[0])

        else:

            link = self.con.execute('insert into objects (name) values (?)', (path,)).lastrowid      

        for k, v in meta.iteritems():

            sql = 'insert or replace into metadata (object_id, key, value) values (?, ?, ?)'

            self.con.execute(sql, (link, k, v))

        self.con.commit()

    def _update_metadata(self, account, container, name, meta):

        """Recursively update metadata and set modification time."""

        modified = {'modified': int(time.time())}

        if not meta:

            meta = {}

        meta.update(modified)

        path = (account, container, name)

        for x in reversed(range(3)):

            if not path[x]:

                continue

            self._put_metadata(os.path.join(*path[:x+1]), meta)

            break

        for y in reversed(range(x)):

            self._put_metadata(os.path.join(*path[:y+1]), modified)

    def _del_dbpath(self, path):

        sql = 'delete from metadata where object_id in (select rowid from objects where name = ?)'

        self.con.execute(sql, (path,))

        self.con.execute('delete from objects where name = ?', (path,))

        self.con.commit()

        return