def style(self, id):

        """Serve Pylons' stock stylesheets"""

        return self._serve_file(os.path.join(media_path, 'style', id))

    def _serve_file(self, path):

        """Call Paste's FileApp (a WSGI application) to serve the file

        at the specified path

        """

        fapp = paste.fileapp.FileApp(path)

        return fapp(request.environ, self.start_response)

    def get_error_explanation(self, code):

        try:

            code = int(code)

        except Exception:

            code = 500

        if code == 400:

            return _('The request could not be understood by the server'

                     ' due to malformed syntax.')

        if code == 401:

            return _('Unauthorized access to resource')

        if code == 403:

            return _("You don't have permission to view this page")

        out = []

        if self.declarative:

            out.append(DECLARATIVE_HEADER)

        else:

            out.append(HEADER)

        out.append("")

        for table in self._get_tables(missingA=True):

            out.extend(self._getTableDefn(table))

        return '\n'.join(out)

    def genB2AMigration(self, indent='    '):

        Was: toUpgradeDowngradePython

        Assume model (A) is most current and database (B) is out-of-date.

        decls = ['from migrate.changeset import schema',

                 'pre_meta = MetaData()',

                 'post_meta = MetaData()',

                ]

        upgradeCommands = ['pre_meta.bind = migrate_engine',

                           'post_meta.bind = migrate_engine']

        downgradeCommands = list(upgradeCommands)

        for tn in self.diff.tables_missing_from_A:

            pre_table = self.diff.metadataB.tables[tn]

            decls.extend(self._getTableDefn(pre_table, metaName='pre_meta'))

                    )

                if cd:

                    td.columns_different[col_name]=cd

            # XXX - index and constraint differences should

            #       be checked for here

            if td:

                self.tables_different[table_name]=td

    def __str__(self):

        out = []

        column_template ='      %%%is: %%r' % self.label_width

        for names,label in (

            (self.tables_missing_from_A,self.labelA),

            (self.tables_missing_from_B,self.labelB),

            ):

            if names:

                out.append(

                    '  tables missing from %s: %s' % (

                        label,', '.join(sorted(names))

                        )

Module provides a class allowing to wrap communication over subprocess.Popen

input, output, error streams into a meaningfull, non-blocking, concurrent

stream processor exposing the output data as an iterator fitting to be a

return value passed by a WSGI applicaiton to a WSGI server per PEP 3333.

Copyright (c) 2011  Daniel Dotsenko <dotsa@hotmail.com>

This file is part of git_http_backend.py Project.

git_http_backend.py Project is free software: you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public License as

published by the Free Software Foundation, either version 2.1 of the License,

or (at your option) any later version.

git_http_backend.py Project is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License

along with git_http_backend.py Project.

If not, see <http://www.gnu.org/licenses/>.

import os

import subprocess

from rhodecode.lib.vcs.utils.compat import deque, Event, Thread, _bytes, _bytearray

class StreamFeeder(Thread):

    """

    Normal writing into pipe-like is blocking once the buffer is filled.

    This thread allows a thread to seep data from a file-like into a pipe

    without blocking the main thread.

    We close inpipe once the end of the source stream is reached.

    """

#                    raise Exception("Timed out while waiting for input to be read.")

                # instead we'll use this

                if len(t) > ccm + 3:

                    raise IOError("Timed out while waiting for input from subprocess.")

            t.append(b)

            da.set()

            b = s.read(cs)

        self.EOF.set()

        da.set()  # for cases when done but there was no input.

class BufferedGenerator():

    Class behaves as a non-blocking, buffered pipe reader.

    Reads chunks of data (through a thread)

    from a blocking pipe, and attaches these to an array (Deque) of chunks.

    Reading is halted in the thread when max chunks is internally buffered.

    The .next() may operate in blocking or non-blocking fashion by yielding

    '' if no data is ready

    to be sent or by not returning until there is some data to send

    When we get EOF from underlying source pipe we raise the marker to raise

    StopIteration after the last chunk of data is yielded.

    def __init__(self, source, buffer_size=65536, chunk_size=4096,

                 starting_values=[], bottomless=False):

        if bottomless:

            maxlen = int(buffer_size / chunk_size)

        else:

            maxlen = None

        self.data = deque(starting_values, maxlen)

        self.worker = InputStreamChunker(source, self.data, buffer_size,

        return self.worker.data_added

    @property

    def data_added(self):

        return self.worker.data_added.is_set()

    @property

    def reading_paused(self):

        return not self.worker.keep_reading.is_set()

    @property

    def done_reading_event(self):

        Done_reding does not mean that the iterator's buffer is empty.

        Iterator might have done reading from underlying source, but the read

        chunks might still be available for serving through .next() method.

        @return An Event class instance.

        return self.worker.EOF

    @property

    def done_reading(self):

        Done_reding does not mean that the iterator's buffer is empty.

        Iterator might have done reading from underlying source, but the read

        chunks might still be available for serving through .next() method.

        @return An Bool value.

        return self.worker.EOF.is_set()

    @property

    def length(self):

        returns int.

        This is the lenght of the que of chunks, not the length of

        the combined contents in those chunks.

        __len__() cannot be meaningfully implemented because this

        reader is just flying throuh a bottomless pit content and

        can only know the lenght of what it already saw.

        If __len__() on WSGI server per PEP 3333 returns a value,

        the responce's length will be set to that. In order not to

        confuse WSGI PEP3333 servers, we will not implement __len__

        at all.

        return len(self.data)

    def prepend(self, x):

        self.data.appendleft(x)

    def append(self, x):

        self.data.append(x)

    def extend(self, o):

        self.data.extend(o)

    def __getitem__(self, i):

        return self.data[i]

class SubprocessIOChunker(object):

    Processor class wrapping handling of subprocess IO.

    In a way, this is a "communicate()" replacement with a twist.

    - We are multithreaded. Writing in and reading out, err are all sep threads.

    - We support concurrent (in and out) stream processing.

    - The output is not a stream. It's a queue of read string (bytes, not unicode)

      chunks. The object behaves as an iterable. You can "for chunk in obj:" us.

    - We are non-blocking in more respects than communicate()

      (reading from subprocess out pauses when internal buffer is full, but

       does not block the parent calling code. On the flip side, reading from

       slow-yielding subprocess may block the iteration until data shows up. This

    #            cmd,

    #            input,

    #            buffer_size = 65536,

    #            chunk_size = 4096

    #            )

    #    except (EnvironmentError) as e:

    #        print str(e)

    #        raise e

    #

    #    return answer

    def __init__(self, cmd, inputstream=None, buffer_size=65536,

                 chunk_size=4096, starting_values=[], **kwargs):

        Initializes SubprocessIOChunker

        :param cmd: A Subprocess.Popen style "cmd". Can be string or array of strings

        :param inputstream: (Default: None) A file-like, string, or file pointer.

        :param buffer_size: (Default: 65536) A size of total buffer per stream in bytes.

        :param chunk_size: (Default: 4096) A max size of a chunk. Actual chunk may be smaller.

        :param starting_values: (Default: []) An array of strings to put in front of output que.

        if inputstream:

            input_streamer = StreamFeeder(inputstream)

            input_streamer.start()

            inputstream = input_streamer.output

        _shell = kwargs.get('shell', True)

        if isinstance(cmd, (list, tuple)):

            cmd = ' '.join(cmd)

        kwargs['shell'] = _shell

        _p = subprocess.Popen(cmd,

        root = chset.root

        docs = root.get_node('docs')

        self.assertTrue(docs is chset.get_node('docs'))

        api = docs.get_node('api')

        self.assertTrue(api is chset.get_node('docs/api'))

        index = api.get_node('index.rst')

        self.assertTrue(index is chset.get_node('docs/api/index.rst'))

        self.assertTrue(index is chset.get_node('docs')\

            .get_node('api')\

            .get_node('index.rst'))

    def test_branch_and_tags(self):

        rev0 = self.repo.revisions[0]

        chset0 = self.repo.get_changeset(rev0)

        self.assertEqual(chset0.branch, 'master')

        self.assertEqual(chset0.tags, [])

        rev10 = self.repo.revisions[10]

        chset10 = self.repo.get_changeset(rev10)

        self.assertEqual(chset10.branch, 'master')

        self.assertEqual(chset10.tags, [])

        rev44 = self.repo.revisions[44]

        chset44 = self.repo.get_changeset(rev44)

        self.assertEqual(chset44.branch, 'web-branch')

        tip = self.repo.get_changeset('tip')

        self.assertTrue('tip' in tip.tags)

        # Those tests would fail - branches are now going

        # to be changed at main API in order to support git backend

        pass

    def _test_slices(self, limit, offset):

        count = self.repo.count()

        changesets = self.repo.get_changesets(limit=limit, offset=offset)

        idx = 0

        for changeset in changesets:

            rev = offset + idx

            idx += 1

            rev_id = self.repo.revisions[rev]