exceptions.py

from __future__ import absolute_import
from .packages.six.moves.http_client import IncompleteRead as httplib_IncompleteRead

# Base Exceptions


class HTTPError(Exception):
    "Base exception used by this module."
    pass


class HTTPWarning(Warning):
    "Base warning used by this module."
    pass


class PoolError(HTTPError):
    "Base exception for errors caused within a pool."

    def __init__(self, pool, message):
        self.pool = pool
        HTTPError.__init__(self, "%s: %s" % (pool, message))

    def __reduce__(self):
        # For pickling purposes.
        return self.__class__, (None, None)


class RequestError(PoolError):
    "Base exception for PoolErrors that have associated URLs."

    def __init__(self, pool, url, message):
        self.url = url
        PoolError.__init__(self, pool, message)

    def __reduce__(self):
        # For pickling purposes.
        return self.__class__, (None, self.url, None)


class SSLError(HTTPError):
    "Raised when SSL certificate fails in an HTTPS connection."
    pass


class ProxyError(HTTPError):
    "Raised when the connection to a proxy fails."

    def __init__(self, message, error, *args):
        super(ProxyError, self).__init__(message, error, *args)
        self.original_error = error


class DecodeError(HTTPError):
    "Raised when automatic decoding based on Content-Type fails."
    pass


class ProtocolError(HTTPError):
    "Raised when something unexpected happens mid-request/response."
    pass


#: Renamed to ProtocolError but aliased for backwards compatibility.
ConnectionError = ProtocolError


# Leaf Exceptions


class MaxRetryError(RequestError):
    """Raised when the maximum number of retries is exceeded.

    :param pool: The connection pool
    :type pool: :class:`~urllib3.connectionpool.HTTPConnectionPool`
    :param string url: The requested Url
    :param exceptions.Exception reason: The underlying error

    """

    def __init__(self, pool, url, reason=None):
        self.reason = reason

        message = "Max retries exceeded with url: %s (Caused by %r)" % (url, reason)

        RequestError.__init__(self, pool, url, message)


class HostChangedError(RequestError):
    "Raised when an existing pool gets a request for a foreign host."

    def __init__(self, pool, url, retries=3):
        message = "Tried to open a foreign host with url: %s" % url
        RequestError.__init__(self, pool, url, message)
        self.retries = retries


class TimeoutStateError(HTTPError):
    """ Raised when passing an invalid state to a timeout """

    pass


class TimeoutError(HTTPError):
    """ Raised when a socket timeout error occurs.

    Catching this error will catch both :exc:`ReadTimeoutErrors
    <ReadTimeoutError>` and :exc:`ConnectTimeoutErrors <ConnectTimeoutError>`.
    """

    pass


class ReadTimeoutError(TimeoutError, RequestError):
    "Raised when a socket timeout occurs while receiving data from a server"
    pass


# This timeout error does not have a URL attached and needs to inherit from the
# base HTTPError
class ConnectTimeoutError(TimeoutError):
    "Raised when a socket timeout occurs while connecting to a server"
    pass


class NewConnectionError(ConnectTimeoutError, PoolError):
    "Raised when we fail to establish a new connection. Usually ECONNREFUSED."
    pass


class EmptyPoolError(PoolError):
    "Raised when a pool runs out of connections and no more are allowed."
    pass


class ClosedPoolError(PoolError):
    "Raised when a request enters a pool after the pool has been closed."
    pass


class LocationValueError(ValueError, HTTPError):
    "Raised when there is something wrong with a given URL input."
    pass


class LocationParseError(LocationValueError):
    "Raised when get_host or similar fails to parse the URL input."

    def __init__(self, location):
        message = "Failed to parse: %s" % location
        HTTPError.__init__(self, message)

        self.location = location


class ResponseError(HTTPError):
    "Used as a container for an error reason supplied in a MaxRetryError."
    GENERIC_ERROR = "too many error responses"
    SPECIFIC_ERROR = "too many {status_code} error responses"


class SecurityWarning(HTTPWarning):
    "Warned when performing security reducing actions"
    pass


class SubjectAltNameWarning(SecurityWarning):
    "Warned when connecting to a host with a certificate missing a SAN."
    pass


class InsecureRequestWarning(SecurityWarning):
    "Warned when making an unverified HTTPS request."
    pass


class SystemTimeWarning(SecurityWarning):
    "Warned when system time is suspected to be wrong"
    pass


class InsecurePlatformWarning(SecurityWarning):
    "Warned when certain SSL configuration is not available on a platform."
    pass


class SNIMissingWarning(HTTPWarning):
    "Warned when making a HTTPS request without SNI available."
    pass


class DependencyWarning(HTTPWarning):
    """
    Warned when an attempt is made to import a module with missing optional
    dependencies.
    """

    pass


class InvalidProxyConfigurationWarning(HTTPWarning):
    """
    Warned when using an HTTPS proxy and an HTTPS URL. Currently
    urllib3 doesn't support HTTPS proxies and the proxy will be
    contacted via HTTP instead. This warning can be fixed by
    changing your HTTPS proxy URL into an HTTP proxy URL.

    If you encounter this warning read this:
    https://github.com/urllib3/urllib3/issues/1850
    """

    pass


class ResponseNotChunked(ProtocolError, ValueError):
    "Response needs to be chunked in order to read it as chunks."
    pass


class BodyNotHttplibCompatible(HTTPError):
    """
    Body should be httplib.HTTPResponse like (have an fp attribute which
    returns raw chunks) for read_chunked().
    """

    pass


class IncompleteRead(HTTPError, httplib_IncompleteRead):
    """
    Response length doesn't match expected Content-Length

    Subclass of http_client.IncompleteRead to allow int value
    for `partial` to avoid creating large objects on streamed
    reads.
    """

    def __init__(self, partial, expected):
        super(IncompleteRead, self).__init__(partial, expected)

    def __repr__(self):
        return "IncompleteRead(%i bytes read, %i more expected)" % (
            self.partial,
            self.expected,
        )


class InvalidHeader(HTTPError):
    "The header provided was somehow invalid."
    pass


class ProxySchemeUnknown(AssertionError, ValueError):
    "ProxyManager does not support the supplied scheme"
    # TODO(t-8ch): Stop inheriting from AssertionError in v2.0.

    def __init__(self, scheme):
        message = "Not supported proxy scheme %s" % scheme
        super(ProxySchemeUnknown, self).__init__(message)


class ProxySchemeUnsupported(ValueError):
    "Fetching HTTPS resources through HTTPS proxies is unsupported"
    pass


class HeaderParsingError(HTTPError):
    "Raised by assert_header_parsing, but we convert it to a log.warning statement."

    def __init__(self, defects, unparsed_data):
        message = "%s, unparsed data: %r" % (defects or "Unknown", unparsed_data)
        super(HeaderParsingError, self).__init__(message)


class UnrewindableBodyError(HTTPError):
    "urllib3 encountered an error when trying to rewind a body"
    pass