Mini Shell

#
# Client code for Update Agent
# Copyright (c) 1999--2016 Red Hat, Inc.  Distributed under GPLv2.
#
#         Adrian Likins <alikins@redhat.com
#
#
# a couple of classes wrapping up transactions so that we
#    can share transactions instead of creating new ones all over
#

import rpm

read_ts = None
ts = None

# ************* NOTE: ************#
# for the sake of clarity, the names "added/removed" as used here
# are indicative of what happened when the original transaction was
# ran. Aka, if you "up2date foobar" and it updates foobar-1-0 with
# foobar-2-0, you added foobar-2-0 and removed foobar-1-0
#
# The reason I mention this explicitly is the trouble of describing
# what happens when you rollback the transaction, which is basically
# the opposite, and leads to plenty of confusion
#


class TransactionData:
    # simple data structure designed to transport info
    # about rpm transactions around
    def __init__(self):
        self.data = {}
        # a list of tuples of pkg info, and mode ('e', 'i', 'u')
        # the pkgInfo is tuple of [name, version, release, epoch, arch]
        # size is never used directly for this, it's here as a place holder
        # arch is optional, if the server specifies it, go with what
        # removed packages only need [n,v,r,e,arch]
        self.data['packages'] = []
        # list of flags to set for the transaction
        self.data['flags'] = []
        self.data['vsflags'] = []
        self.data['probFilterFlags'] = []


    def display(self):
        out = ""
        removed = []
        installed = []
        updated = []
        misc = []
        for (pkgInfo, mode) in self.data['packages']:
            if mode == 'u':
                updated.append(pkgInfo)
            elif mode == 'i':
                installed.append(pkgInfo)
            elif mode == 'e':
                removed.append(pkgInfo)
            else:
                misc.append(pkgInfo)
        for pkgInfo in removed:
            out = out + "\t\t[e] %s-%s-%s:%s\n" % (pkgInfo[0], pkgInfo[1], pkgInfo[2], pkgInfo[3])
        for pkgInfo in installed:
            out = out + "\t\t[i] %s-%s-%s:%s\n" % (pkgInfo[0], pkgInfo[1], pkgInfo[2], pkgInfo[3])
        for pkgInfo in updated:
            out = out + "\t\t[u] %s-%s-%s:%s\n" % (pkgInfo[0], pkgInfo[1], pkgInfo[2], pkgInfo[3])
        for pkgInfo in misc:
            out = out + "\t\t[%s] %s-%s-%s:%s\n" % (pkgInfo[5], pkgInfo[0], pkgInfo[1],
                                                    pkgInfo[2], pkgInfo[3])
        return out


# wrapper/proxy class for rpm.Transaction so we can
# instrument it, etc easily
class Up2dateTransaction:
    def __init__(self):
        self.ts = rpm.TransactionSet()
        self._methods = ['dbMatch',
                         'check',
                         'order',
                         'addErase',
                         'addInstall',
                         'run',
                         'IDTXload',
                         'IDTXglob',
                         'rollback',
                         'pgpImportPubkey',
                         'pgpPrtPkts',
                         'Debug',
                         'setFlags',
                         'setVSFlags',
                         'setProbFilter',
                         'hdrFromFdno']
        self.tsflags = []

    def __getattr__(self, attr):
        if attr in self._methods:
            return self.getMethod(attr)
        else:
            raise AttributeError(attr)

    def getMethod(self, method):
        # in theory, we can override this with
        # profile/etc info
        return getattr(self.ts, method)

    # push/pop methods so we dont lose the previous
    # set value, and we can potentiall debug a bit
    # easier
    def pushVSFlags(self, flags):
        self.tsflags.append(flags)
        self.ts.setVSFlags(self.tsflags[-1])

    def popVSFlags(self):
        del self.tsflags[-1]
        self.ts.setVSFlags(self.tsflags[-1])

def initReadOnlyTransaction():
    global read_ts
    if read_ts == None:
        read_ts =  Up2dateTransaction()
        # FIXME: replace with macro defination
        read_ts.pushVSFlags(-1)
    return read_ts