Synnefo » Pithos

from httplib import HTTPConnection, HTTP

from sys import stdin

import json

import types

import socket

import pithos.api.faults

ERROR_CODES = {304:'Not Modified',

               400:'Bad Request',

               401:'Unauthorized',

               404:'Not Found',

               409:'Conflict',

               411:'Length Required',

               412:'Precondition Failed',

               416:'Range Not Satisfiable',

               422:'Unprocessable Entity',

               503:'Service Unavailable'}

class Fault(Exception):

    def __init__(self, data='', status=None):

        if data == '' and status in ERROR_CODES.keys():

            data = ERROR_CODES[status]

        Exception.__init__(self, data)

        self.data = data

        self.status = status

class Client(object):

    def __init__(self, host, account, api='v1', verbose=False, debug=False):

        """`host` can also include a port, e.g '127.0.0.1:8000'."""

        self.host = host

        self.account = account

        self.api = api

        self.verbose = verbose or debug

        self.debug = debug

    def _chunked_transfer(self, path, method='PUT', f=stdin, headers=None,

                          blocksize=1024):

        http = HTTPConnection(self.host)

        # write header

        path = '/%s/%s%s' % (self.api, self.account, path)

        http.putrequest(method, path)

        http.putheader('Content-Type', 'application/octet-stream')

        http.putheader('Transfer-Encoding', 'chunked')

        if headers:

            for header,value in headers.items():

                http.putheader(header, value)

        http.endheaders()

        # write body

        data = ''

        while True:

            if f.closed:

                break

            block = f.read(blocksize)

            if block == '':

                break

            data = '%s\r\n%s\r\n' % (hex(len(block)), block)

            try:

                http.send(data)

            except:

                #retry

                http.send(data)

        data = '0x0\r\n'

        try:

            http.send(data)

        except:

            #retry

            http.send(data)

        # get response

        resp = http.getresponse()

        headers = dict(resp.getheaders())

        if self.verbose:

            print '%d %s' % (resp.status, resp.reason)

            for key, val in headers.items():

                print '%s: %s' % (key.capitalize(), val)

            print

        length = resp.getheader('Content-length', None)

        data = resp.read(length)

        if self.debug:

            print data

            print

        if int(resp.status) in ERROR_CODES.keys():

            raise Fault(data, int(resp.status))

        #print '*',  resp.status, headers, data

        return resp.status, headers, data

    def req(self, method, path, body=None, headers=None, format='text',

            params=None):

        full_path = '/%s/%s%s?format=%s' % (self.api, self.account, path,

                                            format)

        if params:

            for k,v in params.items():

                if v:

                    full_path = '%s&%s=%s' %(full_path, k, v)

        conn = HTTPConnection(self.host)

        #encode whitespace

        full_path = full_path.replace(' ', '%20')

        kwargs = {}

        kwargs['headers'] = headers or {}

        if not headers or \

        'Transfer-Encoding' not in headers \

        or headers['Transfer-Encoding'] != 'chunked':

            kwargs['headers']['Content-Length'] = len(body) if body else 0

        if body:

            kwargs['body'] = body

            kwargs['headers']['Content-Type'] = 'application/octet-stream'

        #print '****', method, full_path, kwargs

        try:

            conn.request(method, full_path, **kwargs)

        except socket.error, e:

            raise Fault(status=503)

        resp = conn.getresponse()

        headers = dict(resp.getheaders())

        if self.verbose:

            print '%d %s' % (resp.status, resp.reason)

            for key, val in headers.items():

                print '%s: %s' % (key.capitalize(), val)

            print

        length = resp.getheader('Content-length', None)

        data = resp.read(length)

        if self.debug:

            print data

            print

        if int(resp.status) in ERROR_CODES.keys():

            raise Fault(data, int(resp.status))

        #print '*',  resp.status, headers, data

        return resp.status, headers, data

    def delete(self, path, format='text'):

        return self.req('DELETE', path, format=format)

    def get(self, path, format='text', headers=None, params=None):

        return self.req('GET', path, headers=headers, format=format,

                        params=params)

    def head(self, path, format='text', params=None):

        return self.req('HEAD', path, format=format, params=params)

    def post(self, path, body=None, format='text', headers=None):

        return self.req('POST', path, body, headers=headers, format=format)

    def put(self, path, body=None, format='text', headers=None):

        return self.req('PUT', path, body, headers=headers, format=format)

    def _list(self, path, detail=False, params=None, headers=None):

        format = 'json' if detail else 'text'

        status, headers, data = self.get(path, format=format, headers=headers,

                                         params=params)

        if detail:

            data = json.loads(data)

        else:

            data = data.strip().split('\n')

        return data

    def _get_metadata(self, path, prefix=None, params=None):

        status, headers, data = self.head(path, params=params)

        prefixlen = len(prefix) if prefix else 0

        meta = {}

        for key, val in headers.items():

            if prefix and not key.startswith(prefix):

                continue

            elif prefix and key.startswith(prefix):

                key = key[prefixlen:]

            meta[key] = val

        return meta

    def _update_metadata(self, path, entity, **meta):

        """

         adds new and updates the values of previously set metadata

        """

        for key, val in meta.items():

            meta.pop(key)

            meta['X-%s-Meta-%s' %(entity.capitalize(), key.capitalize())] = val

        prev_meta = self._get_metadata(path)

        prev_meta.update(meta)

        headers = {}

        for key, val in prev_meta.items():

            headers[key.capitalize()] = val

        self.post(path, headers=headers)

    def _delete_metadata(self, path, entity, meta=[]):

        """

        delete previously set metadata

        """

        prev_meta = self._get_metadata(path)

        headers = {}

        for key, val in prev_meta.items():

            if key.split('-')[-1] in meta:

                continue

            http_key = key.capitalize()

            headers[http_key] = val

        self.post(path, headers=headers)

    # Storage Account Services

    def list_containers(self, detail=False, params=None, headers=None):

        return self._list('', detail, params, headers)

    def account_metadata(self, restricted=False, until=None):

        prefix = 'x-account-meta-' if restricted else None

        params = {'until':until} if until else None

        return self._get_metadata('', prefix, params=params)

    def update_account_metadata(self, **meta):

        self._update_metadata('', 'account', **meta)

    def delete_account_metadata(self, meta=[]):

        self._delete_metadata('', 'account', meta)

    # Storage Container Services

    def list_objects(self, container, detail=False, params=None, headers=None):

        return self._list('/' + container, detail, params, headers)

    def create_container(self, container, headers=None):

        status, header, data = self.put('/' + container, headers=headers)

        if status == 202:

            return False

        elif status != 201:

            raise Fault(data, int(status))

        return True

    def delete_container(self, container):

        self.delete('/' + container)

    def retrieve_container_metadata(self, container, restricted=False,

                                    until=None):

        prefix = 'x-container-meta-' if restricted else None

        params = {'until':until} if until else None

        return self._get_metadata('/%s' % container, prefix, params=params)

    def update_container_metadata(self, container, **meta):

        self._update_metadata('/' + container, 'container', **meta)

    def delete_container_metadata(self, container, meta=[]):

        path = '/%s' % (container)

        self._delete_metadata(path, 'container', meta)

    # Storage Object Services

    def retrieve_object(self, container, object, detail=False, headers=None,

                        version=None):

        path = '/%s/%s' % (container, object)

        format = 'json' if detail else 'text'

        params = {'version':version} if version else None 

        status, headers, data = self.get(path, format, headers, params)

        return data

    def create_directory_marker(self, container, object):

        if not object:

            raise Fault('Directory markers have to be nested in a container')

        h = {'Content-Type':'application/directory'}

        self.create_object(container, object, f=None, headers=h)

    def create_object(self, container, object, f=stdin, chunked=False,

                      blocksize=1024, headers=None):

        """

        creates an object

        if f is None then creates a zero length object

        if f is stdin or chunked is set then performs chunked transfer 

        """

        path = '/%s/%s' % (container, object)

        if not chunked and f != stdin:

            data = f.read() if f else None

            return self.put(path, data, headers=headers)

        else:

            return self._chunked_transfer(path, 'PUT', f, headers=headers,

                                   blocksize=1024)

    def update_object(self, container, object, f=stdin, chunked=False,

                      blocksize=1024, headers=None):

        if not f:

            return

        path = '/%s/%s' % (container, object)

        if not chunked and f != stdin:

            data = f.read()

            self.post(path, data, headers=headers)

        else:

            self._chunked_transfer(path, 'POST', f, headers=headers,

                                   blocksize=1024)

    def _change_obj_location(self, src_container, src_object, dst_container,

                             dst_object, remove=False, headers=None):

        path = '/%s/%s' % (dst_container, dst_object)

        if not headers:

            headers = {}

        if remove:

            headers['X-Move-From'] = '/%s/%s' % (src_container, src_object)

        else:

            headers['X-Copy-From'] = '/%s/%s' % (src_container, src_object)

        headers['Content-Length'] = 0

        self.put(path, headers=headers)

    def copy_object(self, src_container, src_object, dst_container,

                             dst_object, headers=None):

        self._change_obj_location(src_container, src_object,

                                   dst_container, dst_object,

                                   headers=headers)

    def move_object(self, src_container, src_object, dst_container,

                             dst_object, headers=None):

        self._change_obj_location(src_container, src_object,

                                   dst_container, dst_object, True, headers)

    def delete_object(self, container, object):

        self.delete('/%s/%s' % (container, object))

    def retrieve_object_metadata(self, container, object, restricted=False,

                                 version=None):

        path = '/%s/%s' % (container, object)

        prefix = 'x-object-meta-' if restricted else None

        params = {'version':version} if version else None

        return self._get_metadata(path, prefix, params=params)

    def update_object_metadata(self, container, object, **meta):

        path = '/%s/%s' % (container, object)

        self._update_metadata(path, 'object', **meta)

    def delete_object_metadata(self, container, object, meta=[]):

        path = '/%s/%s' % (container, object)

        self._delete_metadata(path, 'object', meta)

    def trash_object(self, container, object):

        """

        trashes an object

        actually resets all object metadata with trash = true 

        """

        path = '/%s/%s' % (container, object)

        meta = {'trash':'true'}

        self._update_metadata(path, 'object', **meta)

    def restore_object(self, container, object):

        """

        restores a trashed object

        actualy just resets all object metadata except trash

        """

        self.delete_object_metadata(container, object, ['trash'])