Synnefo » ./kamaki

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#      disclaimer in the documentation and/or other materials

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from urllib2 import quote, unquote

from urlparse import urlparse

from threading import Thread

from json import dumps, loads

from time import time

from httplib import ResponseNotReady, HTTPException

from time import sleep

from random import random

from logging import getLogger

from objpool.http import PooledHTTPConnection

TIMEOUT = 60.0   # seconds

HTTP_METHODS = ['GET', 'POST', 'PUT', 'HEAD', 'DELETE', 'COPY', 'MOVE']

log = getLogger(__name__)

sendlog = getLogger('%s.send' % __name__)

recvlog = getLogger('%s.recv' % __name__)

def _encode(v):

    if v and isinstance(v, unicode):

        return quote(v.encode('utf-8'))

    return v

class ClientError(Exception):

    def __init__(self, message, status=0, details=None):

        log.debug('ClientError: msg[%s], sts[%s], dtl[%s]' % (

            message,

            status,

            details))

        try:

            message += '' if message and message[-1] == '\n' else '\n'

            serv_stat, sep, new_msg = message.partition('{')

            new_msg = sep + new_msg[:-1 if new_msg.endswith('\n') else 0]

            json_msg = loads(new_msg)

            key = json_msg.keys()[0]

            serv_stat = serv_stat.strip()

            json_msg = json_msg[key]

            message = '%s %s (%s)\n' % (

                serv_stat,

                key,

                json_msg['message']) if (

                    'message' in json_msg) else '%s %s' % (serv_stat, key)

            status = json_msg.get('code', status)

            if 'details' in json_msg:

                if not details:

                    details = []

                if not isinstance(details, list):

                    details = [details]

                if json_msg['details']:

                    details.append(json_msg['details'])

        except Exception:

            pass

        finally:

            while message.endswith('\n\n'):

                message = message[:-1]

            super(ClientError, self).__init__(message)

            self.status = status if isinstance(status, int) else 0

            self.details = details if details else []

class Logged(object):

    LOG_TOKEN = False

    LOG_DATA = False

    LOG_PID = False

    _token = None

class RequestManager(Logged):

    """Handle http request information"""

    def _connection_info(self, url, path, params={}):

        """ Set self.url to scheme://netloc/?params

        :param url: (str or unicode) The service url

        :param path: (str or unicode) The service path (url/path)

        :param params: (dict) Parameters to add to final url

        :returns: (scheme, netloc)

        """

        url = _encode(str(url)) if url else 'http://127.0.0.1/'

        url += '' if url.endswith('/') else '/'

        if path:

            url += _encode(path[1:] if path.startswith('/') else path)

        delim = '?'

        for key, val in params.items():

            val = quote('' if val in (None, False) else _encode('%s' % val))

            url += '%s%s%s' % (delim, key, ('=%s' % val) if val else '')

            delim = '&'

        parsed = urlparse(url)

        self.url = url

        self.path = parsed.path or '/'

        if parsed.query:

            self.path += '?%s' % parsed.query

        return (parsed.scheme, parsed.netloc)

    def __init__(

            self, method, url, path,

            data=None, headers={}, params={}):

        method = method.upper()

        assert method in HTTP_METHODS, 'Invalid http method %s' % method

        if headers:

            assert isinstance(headers, dict)

        self.headers = dict(headers)

        self.method, self.data = method, data

        self.scheme, self.netloc = self._connection_info(url, path, params)

    def dump_log(self):

        plog = ('\t[%s]' % self) if self.LOG_PID else ''

        sendlog.info('- -  -   -     -        -             -')

        sendlog.info('%s %s://%s%s%s' % (

            self.method, self.scheme, self.netloc, self.path, plog))

        for key, val in self.headers.items():

            if key.lower() in ('x-auth-token', ) and not self.LOG_TOKEN:

                self._token, val = val, '...'

            sendlog.info('  %s: %s%s' % (key, val, plog))

        if self.data:

            sendlog.info('data size: %s%s' % (len(self.data), plog))

            if self.LOG_DATA:

                sendlog.info(self.data.replace(self._token, '...') if (

                    self._token) else self.data)

        else:

            sendlog.info('data size: 0%s' % plog)

    def perform(self, conn):

        """

        :param conn: (httplib connection object)

        :returns: (HTTPResponse)

        """

        self.dump_log()

        conn.request(

            method=str(self.method.upper()),

            url=str(self.path),

            headers=self.headers,

            body=self.data)

        sendlog.info('')

        keep_trying = TIMEOUT

        while keep_trying > 0:

            try:

                return conn.getresponse()

            except ResponseNotReady:

                wait = 0.03 * random()

                sleep(wait)

                keep_trying -= wait

        plog = ('\t[%s]' % self) if self.LOG_PID else ''

        logmsg = 'Kamaki Timeout %s %s%s' % (self.method, self.path, plog)

        recvlog.debug(logmsg)

        raise ClientError('HTTPResponse takes too long - kamaki timeout')

class ResponseManager(Logged):

    """Manage the http request and handle the response data, headers, etc."""

    def __init__(self, request, poolsize=None, connection_retry_limit=0):

        """

        :param request: (RequestManager)

        :param poolsize: (int) the size of the connection pool

        :param connection_retry_limit: (int)

        """

        self.CONNECTION_TRY_LIMIT = 1 + connection_retry_limit

        self.request = request

        self._request_performed = False

        self.poolsize = poolsize

    def _get_response(self):

        if self._request_performed:

            return

        pool_kw = dict(size=self.poolsize) if self.poolsize else dict()

        for retries in range(1, self.CONNECTION_TRY_LIMIT + 1):

            try:

                with PooledHTTPConnection(

                        self.request.netloc, self.request.scheme,

                        **pool_kw) as connection:

                    self.request.LOG_TOKEN = self.LOG_TOKEN

                    self.request.LOG_DATA = self.LOG_DATA

                    self.request.LOG_PID = self.LOG_PID

                    r = self.request.perform(connection)

                    plog = ''

                    if self.LOG_PID:

                        recvlog.info('\n%s <-- %s <-- [req: %s]\n' % (

                            self, r, self.request))

                        plog = '\t[%s]' % self

                    self._request_performed = True

                    self._status_code, self._status = r.status, unquote(

                        r.reason)

                    recvlog.info(

                        '%d %s%s' % (

                            self.status_code, self.status, plog))

                    self._headers = dict()

                    for k, v in r.getheaders():

                        if k.lower in ('x-auth-token', ) and (

                                not self.LOG_TOKEN):

                            self._token, v = v, '...'

                        v = unquote(v)

                        self._headers[k] = v

                        recvlog.info('  %s: %s%s' % (k, v, plog))

                    self._content = r.read()

                    recvlog.info('data size: %s%s' % (

                        len(self._content) if self._content else 0, plog))

                    if self.LOG_DATA and self._content:

                        data = '%s%s' % (self._content, plog)

                        if self._token:

                            data = data.replace(self._token, '...')

                        recvlog.info(data)

                    recvlog.info('-             -        -     -   -  - -')

                break

            except Exception as err:

                if isinstance(err, HTTPException):

                    if retries >= self.CONNECTION_TRY_LIMIT:

                        raise ClientError(

                            'Connection to %s failed %s times (%s: %s )' % (

                                self.request.url, retries, type(err), err))

                else:

                    from traceback import format_stack

                    recvlog.debug(

                        '\n'.join(['%s' % type(err)] + format_stack()))

                    raise

                    raise ClientError(

                        'Failed while http-connecting to %s (%s)' % (

                            self.request.url, err))

    @property

    def status_code(self):

        self._get_response()

        return self._status_code

    @property

    def status(self):

        self._get_response()

        return self._status

    @property

    def headers(self):

        self._get_response()

        return self._headers

    @property

    def content(self):

        self._get_response()

        return self._content

    @property

    def text(self):

        """

        :returns: (str) content

        """

        self._get_response()

        return '%s' % self._content

    @property

    def json(self):

        """

        :returns: (dict) squeezed from json-formated content

        """

        self._get_response()

        try:

            return loads(self._content)

        except ValueError as err:

            raise ClientError('Response not formated in JSON - %s' % err)

class SilentEvent(Thread):

    """Thread-run method(*args, **kwargs)"""

    def __init__(self, method, *args, **kwargs):

        super(self.__class__, self).__init__()

        self.method = method

        self.args = args

        self.kwargs = kwargs

    @property

    def exception(self):

        return getattr(self, '_exception', False)

    @property

    def value(self):

        return getattr(self, '_value', None)

    def run(self):

        try:

            self._value = self.method(*(self.args), **(self.kwargs))

        except Exception as e:

            recvlog.debug('Thread %s got exception %s\n<%s %s' % (

                self,

                type(e),

                e.status if isinstance(e, ClientError) else '',

                e))

            self._exception = e

class Client(Logged):

    MAX_THREADS = 1

    DATE_FORMATS = ['%a %b %d %H:%M:%S %Y', ]

    CONNECTION_RETRY_LIMIT = 0

    def __init__(self, base_url, token):

        assert base_url, 'No base_url for client %s' % self

        self.base_url = base_url

        self.token = token

        self.headers, self.params = dict(), dict()

        self.poolsize = None

    def _init_thread_limit(self, limit=1):

        assert isinstance(limit, int) and limit > 0, 'Thread limit not a +int'

        self._thread_limit = limit

        self._elapsed_old = 0.0

        self._elapsed_new = 0.0

    def _watch_thread_limit(self, threadlist):

        self._thread_limit = getattr(self, '_thread_limit', 1)

        self._elapsed_new = getattr(self, '_elapsed_new', 0.0)

        self._elapsed_old = getattr(self, '_elapsed_old', 0.0)

        recvlog.debug('# running threads: %s' % len(threadlist))

        if self._elapsed_old and self._elapsed_old >= self._elapsed_new and (

                self._thread_limit < self.MAX_THREADS):

            self._thread_limit += 1

        elif self._elapsed_old <= self._elapsed_new and self._thread_limit > 1:

            self._thread_limit -= 1

        self._elapsed_old = self._elapsed_new

        if len(threadlist) >= self._thread_limit:

            self._elapsed_new = 0.0

            for thread in threadlist:

                begin_time = time()

                thread.join()

                self._elapsed_new += time() - begin_time

            self._elapsed_new = self._elapsed_new / len(threadlist)

            return []

        return threadlist

    def async_run(self, method, kwarg_list):

        """Fire threads of operations

        :param method: the method to run in each thread

        :param kwarg_list: (list of dicts) the arguments to pass in each method

            call

        :returns: (list) the results of each method call w.r. to the order of

            kwarg_list

        """

        flying, results = {}, {}

        self._init_thread_limit()

        for index, kwargs in enumerate(kwarg_list):

            self._watch_thread_limit(flying.values())

            flying[index] = SilentEvent(method=method, **kwargs)

            flying[index].start()

            unfinished = {}

            for key, thread in flying.items():

                if thread.isAlive():

                    unfinished[key] = thread

                elif thread.exception:

                    raise thread.exception

                else:

                    results[key] = thread.value

            flying = unfinished

        sendlog.info('- - - wait for threads to finish')

        for key, thread in flying.items():

            if thread.isAlive():

                thread.join()

            if thread.exception:

                raise thread.exception

            results[key] = thread.value

        return results.values()

    def _raise_for_status(self, r):

        log.debug('raise err from [%s] of type[%s]' % (r, type(r)))

        status_msg = getattr(r, 'status', None) or ''

        try:

            message = '%s %s\n' % (status_msg, r.text)

        except:

            message = '%s %s\n' % (status_msg, r)

        status = getattr(r, 'status_code', getattr(r, 'status', 0))

        raise ClientError(message, status=status)

    def set_header(self, name, value, iff=True):

        """Set a header 'name':'value'"""

        if value is not None and iff:

            self.headers['%s' % name] = '%s' % value

    def set_param(self, name, value=None, iff=True):

        if iff:

            self.params[name] = '%s' % value

    def request(

            self, method, path,

            async_headers=dict(), async_params=dict(),

            **kwargs):

        """Commit an HTTP request to base_url/path

        Requests are commited to and performed by Request/ResponseManager

        These classes perform a lazy http request. Present method, by default,

        enforces them to perform the http call. Hint: call present method with

        success=None to get a non-performed ResponseManager object.

        """

        assert isinstance(method, str) or isinstance(method, unicode)

        assert method

        assert isinstance(path, str) or isinstance(path, unicode)

        try:

            headers = dict(self.headers)

            headers.update(async_headers)

            params = dict(self.params)

            params.update(async_params)

            success = kwargs.pop('success', 200)

            data = kwargs.pop('data', None)

            headers.setdefault('X-Auth-Token', self.token)

            if 'json' in kwargs:

                data = dumps(kwargs.pop('json'))

                headers.setdefault('Content-Type', 'application/json')

            if data:

                headers.setdefault('Content-Length', '%s' % len(data))

            plog = ('\t[%s]' % self) if self.LOG_PID else ''

            sendlog.debug('\n\nCMT %s@%s%s', method, self.base_url, plog)

            req = RequestManager(

                method, self.base_url, path,

                data=data, headers=headers, params=params)

            #  req.log()

            r = ResponseManager(

                req,

                poolsize=self.poolsize,

                connection_retry_limit=self.CONNECTION_RETRY_LIMIT)

            r.LOG_TOKEN, r.LOG_DATA, r.LOG_PID = (

                self.LOG_TOKEN, self.LOG_DATA, self.LOG_PID)

            r._token = headers['X-Auth-Token']

        finally:

            self.headers = dict()

            self.params = dict()

        if success is not None:

            # Success can either be an int or a collection

            success = (success,) if isinstance(success, int) else success

            if r.status_code not in success:

                self._raise_for_status(r)

        return r

    def delete(self, path, **kwargs):

        return self.request('delete', path, **kwargs)

    def get(self, path, **kwargs):

        return self.request('get', path, **kwargs)

    def head(self, path, **kwargs):

        return self.request('head', path, **kwargs)

    def post(self, path, **kwargs):

        return self.request('post', path, **kwargs)

    def put(self, path, **kwargs):

        return self.request('put', path, **kwargs)

    def copy(self, path, **kwargs):

        return self.request('copy', path, **kwargs)

    def move(self, path, **kwargs):

        return self.request('move', path, **kwargs)

class Waiter(object):

    def _wait(

            self, item_id, wait_status, get_status,

            delay=1, max_wait=100, wait_cb=None, wait_for_status=False):

        """Wait while the item is still in wait_status or to reach it

        :param server_id: integer (str or int)

        :param wait_status: (str)

        :param get_status: (method(self, item_id)) if called, returns

            (status, progress %) If no way to tell progress, return None

        :param delay: time interval between retries

        :param wait_cb: (method(total steps)) returns a generator for

            reporting progress or timeouts i.e., for a progress bar

        :param wait_for_status: (bool) wait FOR (True) or wait WHILE (False)

        :returns: (str) the new mode if successful, (bool) False if timed out

        """

        status, progress = get_status(self, item_id)

        if wait_cb:

            wait_gen = wait_cb(max_wait // delay)

            wait_gen.next()

        if wait_for_status ^ (status != wait_status):

            # if wait_cb:

            #     try:

            #         wait_gen.next()

            #     except Exception:

            #         pass

            return status

        old_wait = total_wait = 0

        while (wait_for_status ^ (status == wait_status)) and (

                total_wait <= max_wait):

            if wait_cb:

                try:

                    for i in range(total_wait - old_wait):

                        wait_gen.next()

                except Exception:

                    break

            old_wait = total_wait

            total_wait = progress or total_wait + 1

            sleep(delay)

            status, progress = get_status(self, item_id)

        if total_wait < max_wait:

            if wait_cb:

                try:

                    for i in range(max_wait):

                        wait_gen.next()

                except:

                    pass

        return status if (wait_for_status ^ (status != wait_status)) else False

    def wait_for(

            self, item_id, target_status, get_status,

            delay=1, max_wait=100, wait_cb=None):

        self._wait(

            item_id, target_status, get_status, delay, max_wait, wait_cb,

            wait_for_status=True)

    def wait_while(

            self, item_id, target_status, get_status,

            delay=1, max_wait=100, wait_cb=None):

        self._wait(

            item_id, target_status, get_status, delay, max_wait, wait_cb,

            wait_for_status=False)