#!/usr/bin/python2.4

#

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import errno

import os

import shutil

import sys

import xml.dom.minidom as xmini

import xml.parsers.expat as expat

import pkg

import pkg.misc as misc

import pkg.portable as portable

# Constants for the (outcome, reason) combination for operation result.

# Indicates that the user canceled the operation.

RESULT_CANCELED = ["Canceled"]

# Indicates that the operation had no work to perform or didn't need to make

# any changes to the image.

RESULT_NOTHING_TO_DO = ["Nothing to do"]

# Indicates that the operation failed due to package constraints or because of

# a restriction enforced by the client (e.g. SUNWipkg out of date).

RESULT_FAILED_CONSTRAINED = ["Failed", "Constrained"]

# Indicates that a search operation failed.

RESULT_FAILED_SEARCH = ["Failed", "Search"]

# Indicates that there was a problem writing a file or a permissions error.

RESULT_FAILED_STORAGE = ["Failed", "Storage"]

# Indicates that a transport error caused the operation to fail.

RESULT_FAILED_TRANSPORT = ["Failed", "Transport"]

# Operations that are discarded, not saved, when recorded by history.

DISCARDED_OPERATIONS = ["contents", "info", "list"]

class _HistoryException(Exception):

        """Private base exception class for all History exceptions."""

        def __init__(self, *args):

                Exception.__init__(self, *args)

                self.error = args[0]

        def __str__(self):

                return str(self.error)

class HistoryLoadException(_HistoryException):

        """Used to indicate that an unexpected error occurred while loading

        History operation information.

        The first argument should be an exception object related to the

        error encountered.

        """

        def __init__(self, *args):

                _HistoryException.__init__(self, *args)

                self.parse_failure = isinstance(self.error, expat.ExpatError)

class HistoryStoreException(_HistoryException):

        """Used to indicate that an unexpected error occurred while storing

        History operation information.

        The first argument should be an exception object related to the

        error encountered.

        """

        pass

class HistoryPurgeException(_HistoryException):

        """Used to indicate that an unexpected error occurred while purging

        History operation information.

        The first argument should be an exception object related to the

        error encountered.

        """

        pass

class _HistoryOperation(object):

        """A _HistoryOperation object is a representation of data about an

        operation that a pkg(5) client has performed.  This class is private

        and not intended for use by classes other than History.

        This class provides an abstraction layer between the stack of

        operations that History manages should these values need to be

        manipulated as they are set or retrieved.

        """

        def __setattr__(self, name, value):

                if name not in ("result", "errors"):

                        # Force all other attribute values to be a string

                        # to avoid issues with minidom.

                        value = str(value)

                return object.__setattr__(self, name, value)

        def __str__(self):

                return """\

Operation Name: %s

Operation Result: %s

Operation Start Time: %s

Operation End Time: %s

Operation Start State:

%s

Operation End State:

%s

Operation User: %s (%s)

""" % (self.name, self.result, self.start_time, self.end_time,

    self.start_state, self.end_state, self.username, self.userid)

        # All "time" values should be in UTC, using ISO 8601 as the format.

        # Name of the operation performed (e.g. install, image-update, etc.).

        name = None

        # When the operation started.

        start_time = None

        # When the operation ended.

        end_time = None

        # The starting state of the operation (e.g. image plan pre-evaluation).

        start_state = None

        # The ending state of the operation (e.g. image plan post-evaluation).

        end_state = None

        # Errors encountered during an operation.

        errors = None

        # username of the user that performed the operation.

        username = None

        # id of the user that performed the operation.

        userid = None

        # The result of the operation (must be a list indicating (outcome,

        # reason)).

        result = None

        def __init__(self):

                self.errors = []

class History(object):

        """A History object is a representation of data about a pkg(5) client

        and about operations that the client is executing or has executed.  It

        uses the _HistoryOperation class to represent the data about an

        operation.

        """

        # The directory where the history directory can be found (or

        # created if it doesn't exist).

        root_dir = None

        # The name of the client (e.g. pkg, packagemanager, etc.)

        client_name = None

        # The version of the client (e.g. 093ca22da67c).

        client_version = None

        # How the client was invoked (e.g. 'pkg install -n foo').

        client_args = None

        # A stack where operation data will actually be stored.

        __operations = None

        # These attributes exist to fake access to the operations stack.

        operation_name = None

        operation_username = None

        operation_userid = None

        operation_start_time = None

        operation_end_time = None

        operation_start_state = None

        operation_end_state = None

        operation_errors = None

        operation_result = None

        def __getattribute__(self, name):

                if name == "client_args":

                        return object.__getattribute__(self, name)[:]

                if not name.startswith("operation_"):

                        return object.__getattribute__(self, name)

                ops = object.__getattribute__(self, "_History__operations")

                if not ops:

                        return None

                return getattr(ops[-1]["operation"], name[len("operation_"):])

        def __setattr__(self, name, value):

                if name == "client_args":

                        raise AttributeError("'history' object attribute '%s' "

                            "is read-only." % name)

                if not name.startswith("operation_"):

                        return object.__setattr__(self, name, value)

                ops = object.__getattribute__(self, "_History__operations")

                if name == "operation_name":

                        if not ops:

                                ops = []

                                object.__setattr__(self,

                                    "_History__operations", ops)

                        ops.append({

                            "pathname": None,

                            "operation": _HistoryOperation()

                        })

                elif not ops:

                        raise AttributeError("'history' object attribute '%s' "

                            "cannot be set before 'operation_name'." % name)

                op = ops[-1]["operation"]

                setattr(op, name[len("operation_"):], value)

                # Access to the class attributes is done through object instead

                # of just referencing self to avoid any of the special logic in

                # place interfering with logic here.

                if name == "operation_name":

                        # Mark the operation as having started and record

                        # other, relevant information.

                        op.start_time = misc.time_to_timestamp(None)

                        op.username = portable.get_username()

                        op.userid = portable.get_userid()

                        ca = None

                        if sys.argv[0]:

                                ca = [sys.argv[0]]

                        else:

                                # Fallback for clients that provide no value.

                                ca = [self.client_name]

                        ca.extend(sys.argv[1:])

                        object.__setattr__(self, "client_args", ca)

                        object.__setattr__(self, "client_version", pkg.VERSION)

                elif name == "operation_result":

                        # Record when the operation ended.

                        op.end_time = misc.time_to_timestamp(None)

                        # Some operations shouldn't be saved -- they're merely

                        # included in the stack for completeness or to support

                        # client functionality.

                        if op.name not in DISCARDED_OPERATIONS:

                                # Write current history and last operation to a

                                # file.

                                self.__save()

                        # Discard it now that it is no longer needed.

                        del ops[-1]

        def __init__(self, root_dir=".", filename=None):

                """'root_dir' should be the path of the directory where the

                history directory can be found (or created if it doesn't

                exist).  'filename' should be the name of an XML file

                containing serialized history information to load.

                """

                # Since this is a read-only attribute normally, we have to

                # bypass our setattr override by calling object.

                object.__setattr__(self, "client_args", [])

                # Initialize client_name to what the client thinks it is.  This

                # will be overridden if we load history entries off disk.

                self.client_name = pkg.client.global_settings.client_name

                self.root_dir = root_dir

                if filename:

                        self.__load(filename)

        def __str__(self):

                ops = self.__operations

                return "\n".join([str(op["operation"]) for op in ops])

        @property

        def path(self):

                """The directory where history files will be written to or

                read from.

                """

                return os.path.join(self.root_dir, "history")

        @property

        def pathname(self):

                """Returns the pathname that the history information was read

                from or will attempted to be written to.  Returns None if no

                operation has started yet or if no operation has been loaded.

                """

                if not self.operation_start_time:

                        return None

                ops = self.__operations

                pathname = ops[-1]["pathname"]

                if not pathname:

                        return os.path.join(self.path,

                            "%s-01.xml" % ops[-1]["operation"].start_time)

                return pathname

        def clear(self):

                """Discards all information related to the current history

                object.

                """

                self.client_name = None

                self.client_version = None

                object.__setattr__(self, "client_args", [])

                self.__operations = []

        def __load_client_data(self, node):

                """Internal function to load the client data from the given XML

                'node' object.

                """

                self.client_name = node.getAttribute("name")

                self.client_version = node.getAttribute("version")

                try:

                        args = node.getElementsByTagName("args")[0]

                except IndexError:

                        # There might not be any.

                        pass

                else:

                        ca = object.__getattribute__(self, "client_args")

                        for cnode in args.getElementsByTagName("arg"):

                                ca.append(cnode.childNodes[0].wholeText)

        @staticmethod

        def __load_operation_data(node):

                """Internal function to load the operation data from the given

                XML 'node' object and return a _HistoryOperation object.

                """

                op = _HistoryOperation()

                op.name = node.getAttribute("name")

                op.start_time = node.getAttribute("start_time")

                op.end_time = node.getAttribute("end_time")

                op.username = node.getAttribute("username")

                op.userid = node.getAttribute("userid")

                op.result = node.getAttribute("result").split(", ")

                state = None

                try:

                        state = node.getElementsByTagName("start_state")[0]

                except IndexError:

                        # The element might not exist.

                        pass

                else:

                        op.start_state = state.childNodes[0].wholeText

                try:

                        state = node.getElementsByTagName("end_state")[0]

                except IndexError:

                        # The element might not exist.

                        pass

                else:

                        op.end_state = state.childNodes[0].wholeText

                errors = None

                try:

                        errors = node.getElementsByTagName("errors")[0]

                except IndexError:

                        # The element might not exist.

                        pass

                else:

                        for cnode in errors.getElementsByTagName("error"):

                                op.errors.append(

                                    cnode.childNodes[0].wholeText)

                return op

        def __load(self, filename):

                """Loads the history from a file located in self.path/history/

                {filename}.  The file should contain a serialized history

                object in XML format.

                """

                # Ensure all previous information is discarded.

                self.clear()

                try:

                        pathname = os.path.join(self.path, filename)

                        d = xmini.parse(pathname)

                        root = d.documentElement

                        for cnode in root.childNodes:

                                if cnode.nodeName == "client":

                                        self.__load_client_data(cnode)

                                elif cnode.nodeName == "operation":

                                        # Operations load differently due to

                                        # the stack.

                                        self.__operations.append({

                                            "pathname": pathname,

                                            "operation":

                                                self.__load_operation_data(

                                                cnode)

                                            })

                except KeyboardInterrupt:

                        raise

                except Exception, e:

                        raise HistoryLoadException(e)

        def __serialize_client_data(self, d):

                """Internal function used to serialize current client data

                using the supplied 'd' (xml.dom.minidom) object.

                """

                assert self.client_name is not None

                assert self.client_version is not None

                root = d.documentElement

                client = d.createElement("client")

                client.setAttribute("name", self.client_name)

                client.setAttribute("version", self.client_version)

                root.appendChild(client)

                if self.client_args:

                        args = d.createElement("args")

                        client.appendChild(args)

                        for entry in self.client_args:

                                arg = d.createElement("arg")

                                args.appendChild(arg)

                                arg.appendChild(

                                    d.createCDATASection(str(entry)))

        def __serialize_operation_data(self, d):

                """Internal function used to serialize current operation data

                using the supplied 'd' (xml.dom.minidom) object.

                """

                if self.operation_userid is None:

                        raise HistoryStoreException("Unable to determine the "

                            "id of the user that performed the current "

                            "operation; unable to store history information.")

                elif self.operation_username is None:

                        raise HistoryStoreException("Unable to determine the "

                            "username of the user that performed the current "

                            "operation; unable to store history information.")

                root = d.documentElement

                op = d.createElement("operation")

                op.setAttribute("name", self.operation_name)

                # Must explictly convert values to a string due to minidom bug

                # that causes a fatal whenever using types other than str.

                op.setAttribute("username", str(self.operation_username))

                op.setAttribute("userid", str(self.operation_userid))

                op.setAttribute("result", ", ".join(self.operation_result))

                op.setAttribute("start_time", self.operation_start_time)

                op.setAttribute("end_time", self.operation_end_time)

                root.appendChild(op)

                if self.operation_start_state:

                        state = d.createElement("start_state")

                        op.appendChild(state)

                        state.appendChild(d.createCDATASection(

                            str(self.operation_start_state)))

                if self.operation_end_state:

                        state = d.createElement("end_state")

                        op.appendChild(state)

                        state.appendChild(d.createCDATASection(

                            str(self.operation_end_state)))

                if self.operation_errors:

                        errors = d.createElement("errors")

                        op.appendChild(errors)

                        for entry in self.operation_errors:

                                error = d.createElement("error")

                                errors.appendChild(error)

                                error.appendChild(

                                    d.createCDATASection(str(entry)))

        def __save(self):

                """Serializes the current history information and writes it to

                a file in self.path/{operation_start_time}-{sequence}.xml.

                """

                d = xmini.Document()

                d.appendChild(d.createElement("history"))

                self.__serialize_client_data(d)

                self.__serialize_operation_data(d)

                if not os.path.exists(self.path):

                        try:

                                os.makedirs(self.path, mode=0755)

                        except EnvironmentError, e:

                                if e.errno not in (errno.EROFS,

                                    errno.EACCES):

                                        # Ignore read-only file system and

                                        # access errors as it isn't critical

                                        # to the image that this data is

                                        # written.

                                        raise HistoryStoreException(

                                            e)

                                # Return, since without the directory, the rest

                                # of this will fail.

                                return