#!/usr/bin/python
#
# see LICENSE.txt for license information
#
# $Id: test.py 381 2008-06-19 22:40:22Z camrdale-guest $

"""Automated tests of the DebTorrent functionality.

This script runs several automatic tests of some of the functionality in
the DebTorrent programs.

@type tests: C{dictionary}
@var tests: all of the tests that can be run.
    The keys are the test names (strings) which are used on the command-line
    to identify the tests (can not be 'all' or 'help'). The values are tuples
    with four elements: a description of the test (C{string}), the trackers
    to start (C{dictionary}), the downloaders to start (C{dictionary}, and
    the apt-get commands to run (C{list}).
    
    The trackers keys are integers, which must be in the range 1-9. The values
    are the list of command-line options (strings) to start the tracker with.
    
    The downloaders keys are also integers in the range 1-9. The values are
    tuples with 3 elements: the number of the tracker to connect to, the list
    of command-line options to start the downloader with, and any other
    keyword arguments to specify to the L{start_downloader} function.
    
    The apt-get commands' list elements are tuples with 2 elements: the
    downloader to run the command on, and the list of command-line
    arguments to specify to the apt-get program.
    
@type CWD: C{string}
@var CWD: the working directory the script was run from
@type apt_conf_template: C{string}
@var apt_conf_template: the template to use for the apt.conf file

"""

from time import sleep, time
from DebTorrent.BT1.track import track
from DebTorrent.__init__ import resetPeerIDs
import sys, os, signal
from traceback import print_exc
from os.path import exists

DebTorrentClient = __import__('debtorrent-client', globals(), locals(), [])

tests = {'1': ('Start a single tracker and downloader, test updating and downloading ' +
             'using the HTTPDownloader.',
             {1: []},
             {1: (1, [], {})},
             [(1, ['update']), 
              (1, ['install', 'aspectj-doc']),
              (1, ['install', 'fop-doc']),
              (1, ['install', 'asis-doc']),
              (1, ['install', 'bison-doc']),
              (1, ['install', 'crash-whitepaper']),
              (1, ['install', 'aboot-base']),
              (1, ['install', 'aap-doc']),
              (1, ['install', 'ada-reference-manual']),
              ]),

         '2': ('Start a single tracker and 2 downloaders, disable HTTP downloading' +
               ' on the second one to test downloading from a peer.',
               {1: []},
               {1: (1, [], {}),
                2: (1, ['--disable_http_downloader', '1'], {})},
               [(1, ['update']),
                (1, ['install', 'fop-doc']),
                (1, ['install', 'bison-doc']),
                (1, ['install', 'crash-whitepaper']),
                (1, ['install', 'aboot-base']),
                (1, ['install', 'aap-doc']),
                (1, ['install', 'ada-reference-manual']),
                (2, ['update']),
                (2, ['install', 'fop-doc']),
                (2, ['install', 'bison-doc']),
                (2, ['install', 'crash-whitepaper']),
                (2, ['install', 'aboot-base']),
                (2, ['install', 'aap-doc']),
                (2, ['install', 'ada-reference-manual']),
                ]),
                
         '3': ('Start a single tracker and 6 downloaders, to test downloading' +
               ' speeds from each other.',
               {1: []},
               {1: (1, [], {}),
                2: (1, [], {}),
                3: (1, [], {}),
                4: (1, [], {}),
                5: (1, [], {}),
                6: (1, [], {})},
               [(1, ['update']),
                (1, ['install', 'fop-doc']),
                (1, ['install', 'aboot-base']),
                (1, ['install', 'ada-reference-manual']),
                (2, ['update']),
                (2, ['install', 'fop-doc']),
                (2, ['install', 'aboot-base']),
                (2, ['install', 'ada-reference-manual']),
                (3, ['update']),
                (3, ['install', 'fop-doc']),
                (3, ['install', 'aboot-base']),
                (3, ['install', 'ada-reference-manual']),
                (4, ['update']),
                (4, ['install', 'fop-doc']),
                (4, ['install', 'aboot-base']),
                (4, ['install', 'ada-reference-manual']),
                (5, ['update']),
                (5, ['install', 'fop-doc']),
                (5, ['install', 'aboot-base']),
                (5, ['install', 'ada-reference-manual']),
                (6, ['update']),
                (6, ['install', 'fop-doc']),
                (6, ['install', 'aboot-base']),
                (6, ['install', 'ada-reference-manual']),
                ]),

         '4': ('Start a single tracker and 1 downloader, requesting the same' +
               ' packages multiple times to test caching.',
               {1: []},
               {1: (1, [], {})},
               [(1, ['update']),
                (1, ['install', 'fop-doc']),
                (1, ['install', 'aboot-base']),
                (1, ['install', 'ada-reference-manual']),
                (1, ['update']),
                (1, ['install', 'fop-doc']),
                (1, ['install', 'aboot-base']),
                (1, ['install', 'ada-reference-manual']),
                (1, ['update']),
                (1, ['install', 'fop-doc']),
                (1, ['install', 'aboot-base']),
                (1, ['install', 'ada-reference-manual']),
                ]),
                
         '5': ('Start a single tracker and 6 downloaders, update all to test' +
               ' that they can all see each other.',
               {1: []},
               {1: (1, [], {'suites': 'contrib non-free'}),
                2: (1, [], {'suites': 'contrib non-free', 'mirror': 'debian.mirror.iweb.ca/debian'}),
                3: (1, [], {'suites': 'contrib non-free', 'mirror': 'debian.sth.sze.hu'}),
                4: (1, [], {'suites': 'contrib non-free', 'mirror': 'ftp.monash.edu.au/pub/linux/debian'}),
                5: (1, [], {'suites': 'contrib non-free', 'mirror': 'mmc.igeofcu.unam.mx/debian'}),
                6: (1, [], {'suites': 'contrib non-free', 'mirror': 'debian.revolsys.fr/debian'})},
               [(1, ['update']),
                (2, ['update']),
                (3, ['update']),
                (4, ['update']),
                (5, ['update']),
                (6, ['update']),
                ]),

        '6': ('Test caching with multiple apt-get updates.',
             {1: []},
             {1: (1, [], {})},
             [(1, ['update']), 
              (1, ['update']),
              (1, ['update']),
              (1, ['update']),
              ]),

        '7': ('Test pipelining of multiple simultaneous downloads.',
             {1: []},
             {1: (1, [], {})},
             [(1, ['update']), 
              (1, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
                   'aspectj-doc', 'fop-doc', 'asis-doc',
                   'bison-doc', 'crash-whitepaper',
                   'bash-doc', 'apt-howto-common', 'autotools-dev',
                   'aptitude-doc-en', 'asr-manpages',
                   'atomix-data', 'alcovebook-sgml-doc',
                   'aegis-doc', 'afbackup-common', 'airstrike-common',
                   ]),
              ]),

        '8': ('Test pipelining of multiple simultaneous downloads with many peers.',
             {1: []},
             {1: (1, [], {}),
              2: (1, [], {}),
              3: (1, [], {}),
              4: (1, [], {}),
              5: (1, [], {}),
              6: (1, [], {})},
             [(1, ['update']), 
              (1, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
                   'aspectj-doc', 'fop-doc', 'asis-doc',
                   'bison-doc', 'crash-whitepaper',
                   'bash-doc', 'apt-howto-common', 'autotools-dev',
                   'aptitude-doc-en', 'asr-manpages',
                   'atomix-data', 'alcovebook-sgml-doc',
                   'aegis-doc', 'afbackup-common', 'airstrike-common',
                   ]),
              (2, ['update']), 
              (2, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
                   'aspectj-doc', 'fop-doc', 'asis-doc',
                   'bison-doc', 'crash-whitepaper',
                   'bash-doc', 'apt-howto-common', 'autotools-dev',
                   'aptitude-doc-en', 'asr-manpages',
                   'atomix-data', 'alcovebook-sgml-doc',
                   'aegis-doc', 'afbackup-common', 'airstrike-common',
                   ]),
              (3, ['update']), 
              (3, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
                   'aspectj-doc', 'fop-doc', 'asis-doc',
                   'bison-doc', 'crash-whitepaper',
                   'bash-doc', 'apt-howto-common', 'autotools-dev',
                   'aptitude-doc-en', 'asr-manpages',
                   'atomix-data', 'alcovebook-sgml-doc',
                   'aegis-doc', 'afbackup-common', 'airstrike-common',
                   ]),
              (4, ['update']), 
              (4, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
                   'aspectj-doc', 'fop-doc', 'asis-doc',
                   'bison-doc', 'crash-whitepaper',
                   'bash-doc', 'apt-howto-common', 'autotools-dev',
                   'aptitude-doc-en', 'asr-manpages',
                   'atomix-data', 'alcovebook-sgml-doc',
                   'aegis-doc', 'afbackup-common', 'airstrike-common',
                   ]),
              (5, ['update']), 
              (5, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
                   'aspectj-doc', 'fop-doc', 'asis-doc',
                   'bison-doc', 'crash-whitepaper',
                   'bash-doc', 'apt-howto-common', 'autotools-dev',
                   'aptitude-doc-en', 'asr-manpages',
                   'atomix-data', 'alcovebook-sgml-doc',
                   'aegis-doc', 'afbackup-common', 'airstrike-common',
                   ]),
              (6, ['update']), 
              (6, ['install', 'aboot-base', 'aap-doc', 'ada-reference-manual',
                   'aspectj-doc', 'fop-doc', 'asis-doc',
                   'bison-doc', 'crash-whitepaper',
                   'bash-doc', 'apt-howto-common', 'autotools-dev',
                   'aptitude-doc-en', 'asr-manpages',
                   'atomix-data', 'alcovebook-sgml-doc',
                   'aegis-doc', 'afbackup-common', 'airstrike-common',
                   ]),
              ]),

        '9': ('Run this test multiple times to test restarting the downloader.',
             {1: []},
             {1: (1, [], {'clean': False})},
             [(1, ['update']), 
              (1, ['install', 'aspectj-doc']),
              (1, ['install', 'fop-doc']),
              (1, ['install', 'asis-doc']),
              (1, ['install', 'bison-doc']),
              (1, ['install', 'crash-whitepaper']),
              (1, ['install', 'libhypre1.6.0c2']),
              (1, ['install', 'rar']),
              (1, ['install', 'aboot-base']),
              (1, ['install', 'aap-doc']),
              (1, ['install', 'ada-reference-manual']),
              (1, ['install', '2vcard']),
              (1, ['install', 'avahi-dbg']),
              (1, ['install', 'chasen-cannadic']),
              ]),

         }

assert 'all' not in tests
assert 'help' not in tests

CWD = os.getcwd()
apt_conf_template = """
{
  // Location of the state dir
  State "var/lib/apt/"
  {
     Lists "lists/";
     xstatus "xstatus";
     userstatus "status.user";
     cdroms "cdroms.list";
  };

  // Location of the cache dir
  Cache "var/cache/apt/" {
     Archives "archives/";
     srcpkgcache "srcpkgcache.bin";
     pkgcache "pkgcache.bin";
  };

  // Config files
  Etc "etc/apt/" {
     SourceList "sources.list";
     Main "apt.conf";
     Preferences "preferences";
     Parts "apt.conf.d/";
  };

  // Locations of binaries
  Bin {
     methods "/usr/lib/apt/methods/";
     gzip "/bin/gzip";
     gpg  "/usr/bin/gpgv";
     dpkg "/usr/bin/dpkg --simulate";
     dpkg-source "/usr/bin/dpkg-source";
     dpkg-buildpackage "/usr/bin/dpkg-buildpackage";
     apt-get "/usr/bin/apt-get";
     apt-cache "/usr/bin/apt-cache";
  };
};

// Options for the downloading routines
Acquire
{
  // DEBTORRENT method configuration
  debtorrent
  {
    // The timeout delay before the method will close the connection
    Timeout "300";
    // Don't keep copies of the downloaded files in apt's cache
    NoCache "false";
  };
};

/* Options you can set to see some debugging text They correspond to names
   of classes in the source code */
Debug
{
  pkgProblemResolver "false";
  pkgDepCache::AutoInstall "false"; // what packages apt install to satify dependencies
  pkgAcquire "false";
  pkgAcquire::Worker "false";
  pkgAcquire::Auth "false";
  pkgDPkgPM "false";
  pkgDPkgProgressReporting "false";
  pkgOrderList "false";
  BuildDeps "false";

  pkgInitialize "false";   // This one will dump the configuration space
  NoLocking "false";
  Acquire::Ftp "false";    // Show ftp command traffic
  Acquire::Http "false";   // Show http command traffic
  Acquire::Debtorrent "false";   // Show http command traffic
  Acquire::gpgv "false";   // Show the gpgv traffic
  aptcdrom "false";        // Show found package files
  IdentCdrom "false";

}
"""

def rmrf(top):
    """Remove all the files and directories below a top-level one.
    
    @type top: C{string}
    @param top: the top-level directory to start at
    
    """
    
    if exists(top):
        for root, dirs, files in os.walk(top, topdown=False):
            for name in files:
                os.remove(os.path.join(root, name))
            for name in dirs:
                os.rmdir(os.path.join(root, name))

def join(dir):
    """Join together a list of directories into a path string.
    
    @type dir: C{list} of C{string}
    @param dir: the path to join together
    @rtype: C{string}
    @return: the joined together path
    
    """
    
    joined = ''
    for i in dir:
        joined = os.path.join(joined, i)
    return joined

def makedirs(dir):
    """Create all the directories to make a path.
    
    @type dir: C{list} of C{string}
    @param dir: the path to create
    
    """
    
    if not exists(join(dir)):
        os.makedirs(join(dir))

def touch(path):
    """Create an empty file.
    
    @type path: C{list} of C{string}
    @param path: the path to create
    
    """

    if not exists(join(path)):
        f = open(join(path), 'w')
        f.close()

def start(func, args, work_dir = None):
    """Fork and start a background process running.
    
    @type func: C{method}
    @param func: the function to call in the child
    @type args: C{list} of C{string}
    @param args: the argument to pass to the function
    @type work_dir: C{string}
    @param work_dir: the directory to change to to execute the child process in
        (optional, defaults to the current directory)
    @rtype: C{int}
    @return: the PID of the forked child (only returned to the parent)
    
    """
    
    pid = os.fork()
    if pid != 0:
        return pid
    if work_dir:
        os.chdir(work_dir)
    func(args)
    os._exit(0)

def stop(pid):
    """Stop a forked background process that is running.
    
    @type pid: C{int}
    @param pid: the PID of the process to stop
    @rtype: C{int}
    @return: the return status code from the child
    
    """

    # First try a keyboard interrupt
    os.kill(pid, signal.SIGINT)
    for i in xrange(5):
        sleep(1)
        (r_pid, r_value) = os.waitpid(pid, os.WNOHANG)
        if r_pid:
            return r_value
    
    # Try a keyboard interrupt again, just in case
    os.kill(pid, signal.SIGINT)
    for i in xrange(5):
        sleep(1)
        (r_pid, r_value) = os.waitpid(pid, os.WNOHANG)
        if r_pid:
            return r_value

    # Try a terminate
    os.kill(pid, signal.SIGTERM)
    for i in xrange(5):
        sleep(1)
        (r_pid, r_value) = os.waitpid(pid, os.WNOHANG)
        if r_pid:
            return r_value

    # Finally a kill, don't return until killed
    os.kill(pid, signal.SIGKILL)
    while not r_pid:
        sleep(1)
        (r_pid, r_value) = os.waitpid(pid, os.WNOHANG)

    return r_value

def apt_get(num_down, cmd):
    """Start an apt-get process in the background.

    The default argument specified to the apt-get invocation are
    'apt-get -d -q -c <conf_file>'. Any additional arguments (including
    the apt-get action to use) should be specified.
    
    @type num_down: C{int}
    @param num_down: the number of the downloader to use
    @type cmd: C{list} of C{string}
    @param cmd: the arguments to pass to the apt-get process
    @rtype: C{int}
    @return: the PID of the background process
    
    """
    
    print '************************** apt-get (' + str(num_down) + ') ' + ' '.join(cmd) + ' **************************'
    apt_conf = join([down_dir(num_down), 'etc', 'apt', 'apt.conf'])
    dpkg_status = join([down_dir(num_down), 'var', 'lib', 'dpkg', 'status'])
    new_cmd = ['apt-get', '-d', '-c', apt_conf, '-o', 'Dir::state::status='+dpkg_status] + cmd
    pid = os.spawnvp(os.P_NOWAIT, new_cmd[0], new_cmd)
    return pid

def tracker_address(num_track):
    """Determine the announce address to use for a tracker.
    
    @type num_track: C{int}
    @param num_track: the number of the tracker
    @rtype: C{string}
    @return: the tracker address to use
    
    """
    
    return 'http://localhost:' + str(num_track) + '969/announce'

def down_dir(num_down):
    """Determine the working directory to use for a downloader.
    
    @type num_down: C{int}
    @param num_down: the number of the downloader
    @rtype: C{string}
    @return: the downloader's directory
    
    """
    
    return os.path.join(CWD,'downloader' + str(num_down))

def track_dir(num_track):
    """Determine the working directory to use for a tracker.
    
    @type num_track: C{int}
    @param num_track: the number of the tracker
    @rtype: C{string}
    @return: the tracker's directory
    
    """
    
    return os.path.join(CWD,'tracker' + str(num_track))

def start_downloader(num_down, options = [], mirror = 'ftp.us.debian.org/debian', 
                     suites = 'main contrib non-free', clean = True):
    """Initialize a new downloader process.

    The default arguments specified to the downloader invocation are
    the configuration directory, apt port, minport, maxport and the
    maximum upload rate. 
    Any additional arguments needed should be specified by L{options}.
    
    @type num_down: C{int}
    @param num_down: the number of the downloader to use
    @type options: C{list} of C{string}
    @param options: the arguments to pass to the downloader
        (optional, defaults to only using the default arguments)
    @type mirror: C{string}
    @param mirror: the Debian mirror to use
        (optional, defaults to 'ftp.us.debian.org/debian')
    @type suites: C{string}
    @param suites: space separated list of suites to download
        (optional, defaults to 'main contrib non-free')
    @type clean: C{boolean}
    @param clean: whether to remove any previous downloader files
        (optional, defaults to removing them)
    @rtype: C{int}
    @return: the PID of the downloader process
    
    """
    
    assert num_down < 10
    
    print '************************** Starting Downloader ' + str(num_down) + ' **************************'

    downloader_dir = down_dir(num_down)
    
    if clean:
        try:
            rmrf(downloader_dir)
        except:
            pass
    
    # Create the directory structure needed by apt
    makedirs([downloader_dir, 'etc', 'apt', 'apt.conf.d'])
    makedirs([downloader_dir, 'var', 'lib', 'apt', 'lists', 'partial'])
    makedirs([downloader_dir, 'var', 'lib', 'dpkg'])
    rmrf(join([downloader_dir, 'var', 'cache', 'apt', 'archives']))
    makedirs([downloader_dir, 'var', 'cache', 'apt', 'archives', 'partial'])
    touch([downloader_dir, 'var', 'lib', 'apt', 'lists', 'lock'])
    touch([downloader_dir, 'var', 'lib', 'dpkg', 'lock'])
    touch([downloader_dir, 'var', 'lib', 'dpkg', 'status'])
    touch([downloader_dir, 'var', 'cache', 'apt', 'archives', 'lock'])

    if not exists(join([downloader_dir, 'etc', 'apt', 'sources.list'])):
        # Create apt's config files
        f = open(join([downloader_dir, 'etc', 'apt', 'sources.list']), 'w')
        if exists('/usr/lib/apt/methods/newdebtorrent'):
            f.write('deb newdebtorrent://localhost:' + str(num_down) + '988/' + mirror + '/ unstable ' + suites + '\n')
        elif exists('/usr/lib/apt/methods/debtorrent'):
            f.write('deb debtorrent://localhost:' + str(num_down) + '988/' + mirror + '/ unstable ' + suites + '\n')
        else:
            f.write('deb http://localhost:' + str(num_down) + '988/' + mirror + '/ unstable ' + suites + '\n')
        f.close()

    if not exists(join([downloader_dir, 'etc', 'apt', 'apt.conf'])):
        f = open(join([downloader_dir, 'etc', 'apt', 'apt.conf']), 'w')
        f.write('Dir "' + downloader_dir + '"')
        f.write(apt_conf_template)
        f.close()

    # Reset the peer ID so it will be different
    resetPeerIDs()

    pid = start(DebTorrentClient.run, ['--cache_dir', downloader_dir,
                                       '--download_dir', downloader_dir,
                                       '--log_level', '10',
                                       '--security', '0',
                                       '--apt_port', str(num_down) + '988', 
                                       '--max_upload_rate', '100',
                                       '--minport', '1' + str(num_down) + '000', 
                                       '--maxport', '1' + str(num_down) + '999'] + options,
                downloader_dir)
    return pid

def start_tracker(num_track, options = [], clean = True):
    """Initialize a new tracker process.

    The default arguments specified to the tracker invocation are
    the state file and port to use. Any additional arguments needed 
    should be specified by L{options}.
    
    @type num_track: C{int}
    @param num_track: the number of the tracker to use
    @type options: C{list} of C{string}
    @param options: the arguments to pass to the tracker
        (optional, defaults to only using the default arguments)
    @type clean: C{boolean}
    @param clean: whether to remove any previous tracker files
        (optional, defaults to removing them)
    @rtype: C{int}
    @return: the PID of the downloader process
    
    """
    
    assert num_track < 10

    print '************************** Starting Tracker ' + str(num_track) + ' **************************'

    tracker_dir = track_dir(num_track)
    
    if clean:
        try:
            rmrf(tracker_dir)
        except:
            pass

    pid = start(track, ['--cache_dir', tracker_dir,
                        '--log_level', '10',
                        '--port', str(num_track) + '969'] + options)
    return pid

def run_test(trackers, downloaders, apt_get_queue):
    """Run a single test.
    
    @type trackers: C{dictionary} of {C{int}: C{list} of C{string}}
    @param trackers: the trackers to start, keys are the tracker numbers and
        values are the list of options to invoke the tracker with
    @type downloaders: C{dictionary} of {C{int}: (C{int}, C{list} of C{string})}
    @param downloaders: the downloaders to start, keys are the downloader numbers and
        values are the tracker to ascossiate with and the list of options to invoke 
        the downloader with
    @type apt_get_queue: C{list} of (C{int}, C{list} of C{string})
    @param apt_get_queue: the apt-get downloader to use and commands to execute
    @rtype: C{list} of (C{float}, C{int})
    @return: the execution time and returned status code for each element of apt_get_queue
    
    """
    
    running_trackers = {}
    running_downloaders = {}
    running_apt_get = {}
    apt_get_results = []

    try:
        for k, v in trackers.items():
            running_trackers[k] = start_tracker(k, v)
        
        sleep(5)
        
        for k, v in downloaders.items():
            opts = v[1] + ['--force_tracker', tracker_address(v[0])]
            running_downloaders[k] = start_downloader(k, opts, **v[2])
    
        sleep(10)
        
        for (num_down, cmd) in apt_get_queue:
            running_apt_get[num_down] = apt_get(num_down, cmd)
            start_time = time()
            (pid, r_value) = os.waitpid(running_apt_get[num_down], 0)
            elapsed = time() - start_time
            del running_apt_get[num_down]
            r_value = r_value / 256
            apt_get_results.append((elapsed, r_value))

            if r_value == 0:
                print '********************** apt-get completed successfully in ' +  str(elapsed) + ' sec. **************************'
            else:
                print '********************** apt-get finished with status ' + str(r_value) + ' in ' +  str(elapsed) + ' sec. **************************'
        
            sleep(5)
            if 'update' in cmd:
                sleep(25)
            
    except:
        print '************************** Exception occurred **************************'
        print_exc()
        print '************************** will attempt to shut down *******************'
        
    print '*********************** shutting down the apt-gets *******************'
    for k, v in running_apt_get.items():
        try:
            print 'apt-get', k, stop(v)
        except:
            print '************************** Exception occurred **************************'
            print_exc()

    sleep(5)

    print '*********************** shutting down the downloaders *******************'
    for k, v in running_downloaders.items():
        try:
            print 'downloader', k, stop(v)
        except:
            print '************************** Exception occurred **************************'
            print_exc()

    sleep(5)

    print '************************** shutting down the trackers *******************'
    for k, v in running_trackers.items():
        try:
            print 'tracker', k, stop(v)
        except:
            print '************************** Exception occurred **************************'
            print_exc()

    print '************************** Test Results *******************'
    i = -1
    for (num_down, cmd) in apt_get_queue:
        i += 1
        s = str(num_down) + ': "apt-get ' + ' '.join(cmd) + '" '
        if len(apt_get_results) > i:
            (elapsed, r_value) = apt_get_results[i]
            s += 'took ' + str(elapsed) + ' secs (' + str(r_value) + ')'
        else:
            s += 'did not complete'
        print s
    
    return apt_get_results

def get_usage():
    """Get the usage information to display to the user.
    
    @rtype: C{string}
    @return: the usage information to display
    
    """
    
    s = 'Usage: ' + sys.argv[0] + ' (all|<test>|help)\n\n'
    s += '  all    - run all the tests\n'
    s += '  help   - display this usage information\n'
    s += '  <test> - run the <test> test (see list below for valid tests)\n\n'
    
    t = tests.items()
    t.sort()
    for k, v in t:
        s += 'test "' + str(k) + '" - ' + v[0] + '\n'
    
    return s

if __name__ == '__main__':
    if len(sys.argv) != 2:
        print get_usage()
    elif sys.argv[1] == 'all':
        for k, v in tests.items():
            run_test(v[1], v[2], v[3])
    elif sys.argv[1] in tests:
        v = tests[sys.argv[1]]
        run_test(v[1], v[2], v[3])
    elif sys.argv[1] == 'help':
        print get_usage()
    else:
        print 'Unknown test to run:', sys.argv[1], '\n'
        print get_usage()
        
