Remote.py :  » Build » A-A-P » aap-1.091 » Python Open Source

Home
Python Open Source
1.3.1.2 Python
2.Ajax
3.Aspect Oriented
4.Blog
5.Build
6.Business Application
7.Chart Report
8.Content Management Systems
9.Cryptographic
10.Database
11.Development
12.Editor
13.Email
14.ERP
15.Game 2D 3D
16.GIS
17.GUI
18.IDE
19.Installer
20.IRC
21.Issue Tracker
22.Language Interface
23.Log
24.Math
25.Media Sound Audio
26.Mobile
27.Network
28.Parser
29.PDF
30.Project Management
31.RSS
32.Search
33.Security
34.Template Engines
35.Test
36.UML
37.USB Serial
38.Web Frameworks
39.Web Server
40.Web Services
41.Web Unit
42.Wiki
43.Windows
44.XML
Python Open Source » Build » A A P 
A A P » aap 1.091 » Remote.py
# Part of the A-A-P recipe executive: Access files which may be remote

# Copyright (C) 2002-2003 Stichting NLnet Labs
# Permission to copy and use this file is specified in the file COPYING.
# If this file is missing you can find it here: http://www.a-a-p.org/COPYING

#
# Access files by their URL.
# If they are remote, may download or upload the file.
# Uses the Cache to avoid up/downloading too often.
#

import os.path
import shutil
import time
from urlparse import urlparse
from urllib import urlretrieve,urlcleanup,urlopen

from Util import *
from Message import *

def is_url(name):
    """Return non-zero when "name" is a URL, zero when it's a local file."""
    # On MS-Windows c:/name is a file, not a URL.
    if len(name) > 2 and name[1] == ':':
        return 0
    scheme, mach, path, parm, query, frag = urlparse(name, '', 0)
    return scheme != ''


def url_split3(name):
    """Split a URL into scheme, machine and path."""
    # On MS-Windows c:/name is a file, not a URL.
    if len(name) > 2 and name[1] == ':':
        return '', '', name
    scheme, mach, path, parm, query, frag = urlparse(name, '', 0)
    path = path + parm + query + frag

    # Python 2.4 understands rsync, but includes an extra slash.
    if scheme == 'rsync' and mach != '':
        i = string.index(name, mach) + len(mach)
        if i < len(name) and name[i] == '/':
            path = name[i+1:]

    if scheme != '' and mach == '' and path[:2] == '//':
        # urlparse doesn't handle scp://machine/path correctly
        # Python 2.3 doesn't handle rsync either.
        mach = path[2:]
        path = ''
        i = string.find(mach, '/')
        if i > 0:
            path = mach[i + 1:]
            mach = mach[:i]

    if scheme == "file":
        scheme = ''     # A file is the same as no scheme.

    # For "ftp://mach/foobar" the file is "foobar", not "/foobar".
    if scheme == "ftp" and len(path) > 1 and path[0] == '/':
        path = path[1:]
    return scheme, mach, path


def url_time(recdict, name):
    """Obtain the timestamp in seconds (in GMT if possible) for the URL "name".
       Returns zero (very old) if the timestamp can't be obtained."""
    if is_url(name):
        from Cache import cache_lookup
        c = cache_lookup(recdict, name)
        if c:
            # use timestamp for cached file.
            t = c.timestamp()
        else:
            # obtain timestamp for remote files.
            t = remote_time(recdict, name)

    else:
        try:
            t = os.path.getmtime(name)
        except (IOError, OSError):
            t = 0
    return t


def remote_time(recdict, name):
    """Get the timestamp of a remote file."""
    try:
        msg_info(recdict, _('getting timestamp for "%s"') % name)
        up = urlopen(name)
        t = get_header_date(up.info())
        up.close()
        if t == 1:
            msg_info(recdict, _('"%s" can be found but has no timestamp') % name)
    except:
        msg_info(recdict, _('Could not obtain timestamp for "%s"') % name)
        t = 0
    return t


def get_header_date(headers):
    """Get the date from a MIME header.  Returns zero when not available."""
    from rfc822 import parsedate

    if headers.has_key("Last-Modified"):
        return time.mktime(parsedate(headers["Last-Modified"]))
    if headers.has_key("Date"):
        return time.mktime(parsedate(headers["Date"]))
    # When a file does exist but has no timestamp return 1, so that it's
    # different from a file that does not exist.
    return 1


def get_progname_rsync(recdict):
    """
    Use $RSYNC if defined, otherwise use "rsync -p --rsh=ssh --copy-links".
    """
    return get_progname(recdict, "RSYNC", "rsync", " -p --rsh=ssh --copy-links")

def get_progname_scp(recdict):
    """
    Use $SCP if defined, otherwise use "scp -C -p".
    """
    return get_progname(recdict, "SCP", "scp", " -C -p")

def get_progname_rcp(recdict):
    """
    Use $RCP if defined, otherwise use "rcp -p".
    """
    return get_progname(recdict, "RCP", "rcp", " -p")


def url_download(recdict, url, fname):
    """Attempt downloading file "url" to file "fname".
       Overwrite "fname" if it already exists.
       When "fname" is empty, use a temporary file.  The caller has to use
       "url_cleanup()" when done with it.
       Returns a tuple of the filename and the timestamp of the remote file
       when possible.
       Throws an IOError if downloading failed."""
    msg_info(recdict, _('Attempting download of "%s"' % url))
    rtime = 0

    fscheme, fmach, fpath = url_split3(url)

    # First try using a function the user specified, this overrules our own
    # stuff.
    scope = recdict.get("_no")
    if not scope is None:
        user_func = scope.get("fetch_" + fscheme)
    else:
        user_func = None

    if (user_func
            or fscheme == 'rcp'
            or fscheme == 'scp'
            or fscheme == 'rsync'
            or fscheme == 'ftp'):
        if fname == '':
            from RecPython import tempfname
            resfile = tempfname()
        else:
            resfile = fname

    if user_func:
        res = apply(user_func, (recdict, fmach, fpath, resfile))
        if not res:
            raise IOError, (_("fetch_%s() could not download %s")
                                                              % (fscheme, url))

    elif fscheme == 'rcp':
        # Install rcp when needed.
        from DoInstall import assert_pkg
        from Work import getrpstack
        assert_pkg(getrpstack(recdict), recdict, "rcp")

        cmd = '%s %s:%s %s' % (get_progname_rcp(recdict), fmach, fpath, resfile)
        logged_system(recdict, cmd)

    elif fscheme == 'scp':
        # Install scp when needed.
        from DoInstall import assert_pkg
        from Work import getrpstack
        assert_pkg(getrpstack(recdict), recdict, "scp")

        cmd = '%s %s:%s %s' % (get_progname_scp(recdict), fmach, fpath, resfile)
        if os.name != "posix":
            # Can't use "tee" and scp may prompt for a password.
            cmd = "{interactive} " + cmd

        logged_system(recdict, cmd)

    elif fscheme == 'rsync':
        # Install rsync when needed.
        from DoInstall import assert_pkg
        from Work import getrpstack
        assert_pkg(getrpstack(recdict), recdict, "rsync")

        cmd = '%s %s:%s %s' % (get_progname_rsync(recdict),
                                                         fmach, fpath, resfile)
        if os.name != "posix":
            # Can't use "tee" and ssh may prompt for a password.
            cmd = "{interactive} " + cmd

        logged_system(recdict, cmd)

    elif fscheme == 'ftp':
        # urlretrieve() doesn't work well for ftp in Python 1.5, use ftplib.
        # This also allows us to cache the connections.
        # And it avoids a bug in urllib that trying to download a file without
        # read permission results in a directory listing.
        from CopyMove import ftpConnect

        # Create the output file first (opening ftp connection may take time).
        msg = ''
        try:
            ftpfile = open(resfile, "wb")
        except StandardError, e:
            msg = _('Cannot open "%s" for writing: %s') % (resfile, e)

        if not msg:
            ftp, msg = ftpConnect(fmach)

            if not msg:
                # Invoke the ftp command.  Use a passive connection, this
                # appears to work best.
                import ftplib
                ftp.set_pasv(1)
                try:
                    ftp.retrbinary("RETR " + fpath, ftpfile.write, 8192)
                except ftplib.all_errors, e:
                    msg = e

            ftpfile.close()
            if msg:
                # Delete an empty or truncated result file.
                os.remove(resfile)

        if msg:
            raise IOError, msg

    else:
        if fname == '':
            # read to temporary file
            resfile, h = urlretrieve(url)
        else:
            resfile, h = urlretrieve(url, fname)
            if resfile != fname:
                # Using a cached file, need to make a copy.
                shutil.copy2(resfile, fname)
                resfile = fname
            urlcleanup()

        # When obtaining a file through http:// an non-existing page isn't
        # noticed.  Check for a 404 error by looking in the file.  Limit the
        # search to the first 1000 bytes, an error page should not be longer,
        # while an actual file can be very long.
        f = open(resfile)
        txt = f.read(1000)
        f.close()

        import re
        if re.search("<title>\\s*404\\s*not\\s*found", txt, re.IGNORECASE):
            try_delete(resfile)
            raise IOError, (_("fetch_%s() encountered a 404 error for %s")
                                                              % (fscheme, url))
        if h:
            rtime = get_header_date(h)

    if fname == '':
        msg_info(recdict, _('Downloaded "%s"' % url))
    else:
        msg_info(recdict, _('Downloaded "%s" to "%s"' % (url, fname)))

    return resfile, rtime


def url_cleanup(scheme):
    """Cleanup after using url_download with scheme "scheme"."""
    if not scheme in ['scp', 'rsync']:
        urlcleanup()    # remove any cached file from urlretrieve()


def download_file(recdict, url_dl, node, use_cache):
    """Download a file according to "url_dl" and copy it over "node.name".
       Use the cache when "use_cache" is non-zero, otherwise obtain a fresh
       copy.
       Can also be used for a local file, it is copied.
       Return non-zero for success."""
    from Cache import local_name
    from VersCont import separate_scheme

    # When copying a local file invoke local_name() and copy the file, the
    # cache isn't really used, even though "use_cache" is set.
    url = url_dl["name"]
    scheme, fname = separate_scheme(url)
    if scheme == "file" or not is_url(url):
        use_cache = 1

    # When not using the cache download directly to the destination file.
    # Avoids that the cache is filled with files that are never used again.
    if not use_cache:
        if skip_commands():
            msg_info(recdict, _('Skip download for "%s"') % node.short_name())
            return 1
        try:
            f, rtime = url_download(recdict, url, node.absname)
        except EnvironmentError, e:
            msg_note(recdict, _('Cannot download "%s" to "%s": %s')
                                        % (url, node.short_name(), str(e)))
            return 0
        return 1

    if url_dl.has_key("cache_update"):
        cu = url_dl["cache_update"]
    else:
        cu = None
    # This downloads the file when it's not in the cache already.
    # TODO: handle attributes (e.g., login and password)
    fname, used_cache = local_name(recdict, url, cu)

    if fname and os.path.exists(fname):
        if skip_commands():
            msg_info(recdict, _('Skip copy file: "%s"') % node.short_name())
        else:
            # copy the downloaded file over the original one.
            try:
                shutil.copyfile(fname, node.absname)
            except IOError, e:
                raise UserError, (_('Cannot copy "%s" to "%s": ')
                                                 % (fname, node.name) + str(e))
            if used_cache:
                msg_info(recdict, _('Copied file from cache: "%s"')
                                                           % node.short_name())
            else:
                msg_info(recdict, _('Copied file "%s" to "%s"')
                                                  % (fname, node.short_name()))
        return 1
    return 0


def upload_file(recdict, url_dl, nodelist):
    """Upload nodes in "nodelist" according to "url_dl".
       Return list of nodes that failed."""
    # TODO: use other attributes in url_dl, e.g. a login name.
    from CopyMove import remote_copy_move
    from VersCont import repl_file_name
    failed = []

    # Make a copy of the nodelist.  Remove items that have been done until none
    # are left.
    todolist = nodelist[:]
    while todolist:
        # Collect nodes that are in the same directory and where the source and
        # destination file names are identical.
        to_item = ''
        fromlist = []
        for node in todolist[:]:
            to_name = repl_file_name(url_dl["name"], node.name)
            if os.path.basename(node.absname) == os.path.basename(to_name):
                d = os.path.dirname(to_name)
                if not d:
                    d = "."
                if not to_item or d == to_item:
                    fromlist.append({"name" : node.absname})
                    todolist.remove(node)
                    to_item = d
            elif not to_item:
                # Source and target name are different, must copy this one by
                # itself.
                fromlist = [ {"name" : node.absname } ]
                todolist.remove(node)
                to_item = to_name
                break

        # When there is only one item include the file name in the to_item,
        # this avoids using the name of a directory for a file.
        if len(fromlist) == 1 and to_item != to_name:
            to_item = path_join(to_item, os.path.basename(fromlist[0]["name"]))

        msg_info(recdict, 'Uploading %s to %s' % (str(map(lambda x:
                             x["name"], shorten_dictlist(fromlist))), to_item))

        flist = remote_copy_move([], recdict, 1, fromlist,
                             { "name" : to_item }, {"mkdir": 1}, 0, errmsg = 0)

        # Find the nodes for the failed file names.
        for f in flist:
            for node in nodelist:
                if node.absname == f:
                    failed.append(node)

    return failed


def remote_remove(recdict, url_dl, node):
    """Delete remote file for node "node" according to "url_dl"."""
    msg_info(recdict, 'Removing "%s" NOT IMPLEMENTED YET' % url_dl["name"])
    return 1


# vim: set sw=4 et sts=4 tw=79 fo+=l:
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.