review/api.py @ 36b37712c670 webpy-sucks

Get a bare Cherrypy server up and running.
author Steve Losh <steve@stevelosh.com>
date Tue, 02 Mar 2010 20:23:36 -0500
parents 1133505b5b04
children 538a3dada709
from __future__ import with_statement

"""The API for interacting with code review data."""

import datetime, operator, os
import file_templates, messages
from mercurial import cmdutil, error, hg, patch, util
from mercurial.node import hex
from mercurial import ui as _ui


try:
    from os.path import relpath
except ImportError: # python < 2.6
    from os.path import curdir, abspath, sep, commonprefix, pardir, join
    def relpath(path, start=curdir):
        """Return a relative version of a path"""
        
        if not path:
            raise ValueError("no path specified")
        
        start_list = abspath(start).split(sep)
        path_list = abspath(path).split(sep)
        
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))
        
        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    

DEFAULT_DATASTORE_DIRNAME = os.path.join('.hg', 'review')

class PreexistingDatastore(Exception):
    """Raised when trying to initialize a datastore when one seems to exist."""
    def __init__(self, committed):
        super(PreexistingDatastore, self).__init__()
        self.committed = committed
    

class UninitializedDatastore(Exception):
    """Raised when trying to access a datastore that does not exist.
    
    The committed attribute will be True if someone else has already
    initialized code review for the target (i.e. the .hgreview file is present
    in the target repository), or False otherwise.
    
    """
    def __init__(self, committed):
        super(UninitializedDatastore, self).__init__()
        self.committed = committed
    

class DatastoreRequiresRemotePath(Exception):
    """Raised when initializing a fresh datastore without a remote path."""
    pass

class RelativeRemotePath(Exception):
    """Raised when trying to use a relative remote path (for now)."""
    pass


class SignoffExists(Exception):
    """Raised when trying to signoff twice without forcing."""
    pass

class CannotDeleteObject(Exception):
    """Raised when trying to delete an object that does not support deletion."""
    pass

class FileNotInChangeset(Exception):
    """Raised when trying to add a comment on a file not in the changeset."""
    def __init__(self, filename):
        super(FileNotInChangeset, self).__init__()
        self.filename = filename
    


def _split_path_dammit(p):
    """Take a file path (from the current platform) and split it.  Really.
    
    os.path doesn't seem to have an easy way to say "Split this path into a
    list of pieces."
    
    >>> _split_path_dammit('')
    []
    >>> _split_path_dammit('one')
    ['one']
    >>> _split_path_dammit('one/two/three')
    ['one', 'two', 'three']
    >>> _split_path_dammit('one/two/three/')
    ['one', 'two', 'three']
    >>> _split_path_dammit('one/two/three.py')
    ['one', 'two', 'three.py']
    
    """
    def _spd(p):
        p, i = os.path.split(p)
        while i or p:
            yield i
            p, i = os.path.split(p)
    
    return filter(None, list(_spd(p)))[::-1]

def _parse_hgrf(repo):
    """Parse the .hgreview file and return the data inside.
    
    The .hgreview file will be pulled from the tip revision of the given
    repository.  If it is not committed it will not be found!
    
    """
    data = {}
    hgrd = repo['tip']['.hgreview'].data().split('\n')
    lines = [line for line in hgrd if line.strip()]
    for line in lines:
        label, _, path = [i.strip() for i in line.partition('=')]
        if label == 'remote':
            data['rpath'] = path
    
    return data

def _commitfunc(ui, repo, message, match, opts):
    """A function used by the guts of Mercurial.
    
    Mercurial needs a "commit function" parameter when using cmdutil.commit.
    This is a simple function for *only* that purpose.
    
    """
    return repo.commit(message, opts.get('user'), opts.get('date'), match)

def _parse_data(data):
    """Parse the data (string) of a stored _ReviewObject and return a dict."""
    meta, _, message = data.partition('\n\n')
    
    data = {}
    for m in meta.split('\n'):
        label, _, val = m.partition(':')
        data[label] = val
    data['message'] = message
    return data

def _datetime_from_hgdate(hgdate):
    """Return a datetime.datetime for the given Mecurial-style date tuple.
    
    It will have NO timezone information -- the date and time are what a clock
    next to the current computer would have read at the instant represented
    by the Mercurial-style date!
    
    """
    offset = abs(hgdate[1] - util.makedate()[1])
    later = offset < 0
    offset = datetime.timedelta(seconds=offset)
    
    conversion_format = '%Y-%m-%d %H:%M:%S'
    bare = util.datestr(hgdate, format=conversion_format)
    bare_datetime = datetime.datetime.strptime(bare, conversion_format)
    if later:
        return bare_datetime + offset
    else:
        return bare_datetime - offset


def sanitize_path(p, repo=None):
    """Sanitize a (platform-specific) path.
    
    If no repository is given, the path's separators will be replaced with
    forward slashes (the form Mercurial uses internally).
    
    If a repository is given, the result will be relative to the root of the
    repository.  This is useful for turning relative paths into normalized
    paths that can be used to look up files from a changectx.
    
    This function is idempotent.  If you sanitize a path multiple times
    against the same repository the result will not change.
    
    """
    if repo:
        p = relpath(os.path.realpath(p), start=repo.root)
    return '/'.join(_split_path_dammit(p))


class ReviewDatastore(object):
    """The code review data for a particular repository."""
    def __init__(self, ui, repo, lpath=None, rpath=None, create=False):
        """Initialize a ReviewDatastore for a Mercurial repository.
        
        To get a ReviewDatastore for a repository that has already been
        initialized for code reviewing:
        
            review_data = ReviewDatastore(ui, repo)
        
        To set up a repository to support code review:
        
            review_data = ReviewDatastore(ui, repo, create=True)
        
        If you want to specify your own path to the code review repository for
        this repo, pass the FULL path to the repository as the lpath parameter.
        
        Error handling is a bit tricky at the moment.  I need to refactor
        and/or document this.
        
        """
        self.ui = ui
        self.target = repo
        self.lpath = lpath or os.path.join(
            self.target.root, DEFAULT_DATASTORE_DIRNAME
        )
        
        if not create:
            if not '.hgreview' in repo['tip']:
                raise UninitializedDatastore(False)
            
            data = _parse_hgrf(repo)
            self.rpath = data['rpath']
            
            try:
                self.repo = hg.repository(_ui.ui(), self.lpath)
            except error.RepoError:
                raise UninitializedDatastore(True)
        elif '.hgreview' in repo['tip']:
            data = _parse_hgrf(self.target)
            self.rpath = data['rpath']
            
            if self.rpath.startswith('.'):
                raise RelativeRemotePath
            
            try:
                hg.repository(ui, self.lpath)
            except error.RepoError:
                hg.clone(cmdutil.remoteui(self.ui, {}), self.rpath, self.lpath)
            else:
                raise PreexistingDatastore(True)
        elif os.path.exists(os.path.join(self.target.root, '.hgreview')):
            raise PreexistingDatastore(False)
        else:
            if not rpath:
                raise DatastoreRequiresRemotePath
            elif rpath.startswith('.'):
                raise RelativeRemotePath
            else:
                self.rpath = rpath
            
            with open(os.path.join(self.target.root, '.hgreview'), 'w') as hgrf:
                hgrf.write('remote = %s\n' % self.rpath)
            self.target.add(['.hgreview'])
            
            self.repo = hg.repository(ui, self.lpath, create)
    
    def __getitem__(self, rev):
        """Return a ReviewChangeset for the given revision."""
        node = hex(self.target[rev].node())
        return ReviewChangeset(self.ui, self.repo, self.target, node)
    

class ReviewChangeset(object):
    """The review data about one changeset in the target repository.
    
    Individual changesets can be retrieved from a ReviewDatastore.
    
    Each ReviewChangeset stores a list of ReviewComment objects and a list
    of ReviewSignoff objects:
    
        rcset = rd['tip']
        rcset.comments
        rcset.signoffs
    
    Comments and signoffs should be added to a changeset by using the
    add_comment and add_signoff methods:
    
        rcset = rd['tip']
        rcset.add_comment(...)
        rcset.add_signoff(...)
    
    Diffs for files modified in a changeset can be retrived with the diffs
    and full_diffs methods.  See the docs of those methods for more info.
    
    """
    def __init__(self, ui, repo, target, node):
        """Initialize a ReviewChangeset.
        
        You shouldn't need to create these directly -- use a ReviewDatastore
        object to get them:
        
            review_data = ReviewDatastore(ui, repo)
            tip_review_data = review_data['tip']
        
        """
        self.repo = repo
        self.target = target
        self.ui = ui
        self.node = node
        
        if '%s/.exists' % self.node in self.repo['tip']:
            _match = lambda p: lambda fn: fn.startswith(p)
            
            relevant = filter(_match(node), self.repo['tip'])
            commentfns = filter(_match('%s/comments' % node), relevant)
            signofffns = filter(_match('%s/signoffs' % node), relevant)
            
            self.comments = []
            for fn in commentfns:
                data = _parse_data(self.repo['tip'][fn].data())
                data['lines'] = data['lines'].split(',')
                data['lines'] = map(int, filter(None, data['lines']))
                data['hgdate'] = util.parsedate(data['hgdate'])
                self.comments.append(ReviewComment(**data))
            self.comments.sort(key=operator.attrgetter('local_datetime'))
            
            self.signoffs = []
            for fn in signofffns:
                data = _parse_data(self.repo['tip'][fn].data())
                data['hgdate'] = util.parsedate(data['hgdate'])
                self.signoffs.append(ReviewSignoff(**data))
            self.signoffs.sort(key=operator.attrgetter('local_datetime'))
        else:
            self.comments = []
            self.signoffs = []
            
            path = os.path.join(self.repo.root, self.node)
            os.mkdir(path)
            with open(os.path.join(path, '.exists'), 'w') as e:
                pass
            
            cmdutil.commit(ui, self.repo, _commitfunc,
                [os.path.join(path, '.exists')],
                { 'message': 'Initialize review data for changeset %s' % self.node,
                  'addremove': True, })
    
    def add_signoff(self, message, opinion='', force=False):
        """Add (and commit) a signoff for the given revision.
        
        The opinion argument should be 'yes', 'no', or ''.
        
        If a signoff from the user already exists, a SignoffExists exception
        will be raised unless the force argument is used.
        
        """
        existing = filter(lambda s: s.author == self.ui.username(), self.signoffs)
        
        if existing:
            if not force:
                raise SignoffExists
            existing[0]._delete(self.ui, self.repo)
        
        signoff = ReviewSignoff(self.ui.username(), util.makedate(),
            self.node, opinion, message)
        signoff._commit(self.ui, self.repo)
    
    def add_comment(self, message, filename='', lines=[]):
        """Add (and commit) a comment for the given file and lines.
        
        The filename should be normalized to the format Mercurial expects,
        that is: relative to the root of the repository and using forward
        slashes as the separator.  Paths can be converted with the
        sanitize_path function in this module.
        
        If the comment is on one or more lines, a filename *must* be given.
        
        Line numbers should be passed as a list, even if there is only one.
        See the full_diffs function for how to refer to line numbers.
        
        """
        if filename and filename not in self.target[self.node].files():
            raise FileNotInChangeset(filename)
        
        comment = ReviewComment(self.ui.username(), util.makedate(),
            self.node, filename, lines, message)
        comment._commit(self.ui, self.repo)
    
    def full_diffs(self, filenames=None, opts={}):
        """Return full diffs of the given files (or all files).
        
        If the filenames argument is not used, diffs for every file in the
        changeset will be returned.
        
        The diffs are returned as a dictionary in the form:
        
            { 'filename': 'string of the diff' }
        
        All headers are stripped, so the an entire diff looks like this:
        
             unchanged line
             unchanged line
            -removed line
            -removed line
            +added line
             unchanged line
            -removed line
            -removed line
             unchanged line
             unchanged line
        
        When adding a comment, the line number given should be the line
        number from this diff (starting at 0).  To comment on the first two
        removed lines in the above example you would pass [2, 3].
        
        """
        
        target_files = self.target[self.node].files()
        if not filenames:
            filenames = target_files
        else:
            filenames = filter(lambda f: f in target_files, filenames)
        
        opts['unified'] = '100000'
        node2 = self.node
        node1 = self.target[node2].parents()[0].node()
        
        diffs = {}
        for filename in filenames:
            m = cmdutil.matchfiles(self.target, [filename])
            d = patch.diff(self.target, node1, node2, match=m,
                opts=patch.diffopts(self.ui, opts))
            
            # patch.diff will give us back a generator with two items
            # the first is the diff --git header, which we don't care about
            d.next()
            
            # the second is the diff's contents, which is what we want,
            # minus the header
            diffs[filename] = '\n'.join(d.next().splitlines()[3:])
        
        return diffs
    
    def diffs(self, filenames=None, context=5):
        """Return a mapping of diff lines for the given files (or all).
        
        If the filenames argument is not used, diffs for every file in the
        changeset will be returned.
        
        The diffs are returned in a dictionary of the form:
        
        { 
            'filename': {
                # the line number of the last line of the FULL diff
                'max': 90,
                
                # A sorted list of tuples of (line_number, line_content)
                'content': [
                    (10, ' context line'),
                    (11, ' context line'),
                    (12, '-removed line'),
                    (13, '+added line'),
                    (14, ' context line'),
                    (15, ' context line'),
                    (39, ' context line'),
                    (40, ' context line'),
                    (41, '-removed line'),
                    (42, '+added line'),
                    (43, ' context line'),
                    (44, ' context line'),
                ],
            },
        }
        
        There's a lot of structure there, but it will provide everything you
        need to display contextualized diffs.
        
        """
        ds = self.full_diffs(filenames, {})
        
        def _filter_diff(d):
            for n, line in enumerate(d):
                start = n - context if n > context else 0
                end = n + context + 1
                if any(filter(lambda l: l[0] in '+-', d[start:end])):
                    yield (n, line)
        
        for filename, content in ds.iteritems():
            content = content.splitlines()
            ds[filename] = {
                'max': len(content) - 1,
                'content': list(_filter_diff(content)),
            }
        
        return ds
    
    
    def review_level_comments(self):
        """Comments on this changeset which aren't on a particular file."""
        return filter(lambda c: not c.filename, self.comments)
    
    def file_level_comments(self, filename=None):
        """Comments on this changeset that are on a file, but not a line.
        
        If a file is given only comments for that file will be returned.
        """
        
        if filename:
            return filter(
                lambda c: filename == c.filename and not c.lines, self.comments
            )
        else:
            return filter(
                lambda c: filename and not c.lines, self.comments
            )
    
    def line_level_comments(self, filename=None):
        """Comments on this changeset that are on a line of file.
        
        If a file is given only comments for that file will be returned.
        """
        
        if filename:
            return filter(
                lambda c: filename == c.filename and c.lines, self.comments
            )
        else:
            return filter(
                lambda c: filename and c.lines, self.comments
            )
    

class _ReviewObject(object):
    """A base object for some kind of review data (a signoff or comment)."""
    def __init__(self, container, commit_message, delete_message=None):
        self.container = container
        self.commit_message = commit_message
        self.delete_message = delete_message
    
    def _commit(self, ui, repo):
        """Write and commit this object to the given repo."""
        
        path = os.path.join(repo.root, self.node, self.container)
        if not os.path.exists(path):
            os.mkdir(path)
        
        data = self._render_data()
        filename = util.sha1(data).hexdigest()
        objectpath = os.path.join(path, filename)
        
        with open(objectpath, 'w') as objectfile:
            objectfile.write(data)
        
        cmdutil.commit(ui, repo, _commitfunc, [objectpath],
            { 'message': self.commit_message % self.node, 'addremove': True, })
    
    def _delete(self, ui, repo):
        """Delete and commit this object in the given repo."""
        
        if not self.delete_message:
            raise CannotDeleteObject
        
        data = self._render_data()
        filename = util.sha1(data).hexdigest()
        objectpath = os.path.join(repo.root, self.node, self.container, filename)
        
        os.remove(objectpath)
        
        cmdutil.commit(ui, repo, _commitfunc, [objectpath],
            { 'message': self.delete_message % self.node, 'addremove': True, })
    
    
    @property
    def local_datetime(self):
        return _datetime_from_hgdate(self.hgdate)
    

class ReviewComment(_ReviewObject):
    """A single review comment.
    
    A list of comments can be retrieved from a ReviewChangeset.
    
    The following pieces of information are stored for comments:
    
        comment = rcset.comments[0]
        comment.author
        comment.hgdate
        comment.node
        comment.filename
        comment.lines
        comment.message
        comment.local_datetime
    
    Each item is a string, except for lines, hgdate, and local_datetime.
    
    lines is a list of ints.
    
    hgdate is a tuple of (seconds from the epoch, seconds offset from UTC),
    which is the format Mercurial itself uses internally.
    
    local_datetime is a datetime object representing what a clock on the wall
    next to the current computer would have read at the instant the comment
    was added.
    
    """
    def __init__(self, author, hgdate, node, filename, lines, message, **extra):
        """Initialize a ReviewComment.
        
        You shouldn't need to create these directly -- use a ReviewChangeset
        to add comments and retrieve existing ones:
        
            review_data = ReviewDatastore(ui, repo)
            tip_review = review_data['tip']
            tip_review.add_comment(...)
            tip_comments = tip_review.comments
        
        """
        super(ReviewComment, self).__init__(
            container='comments', commit_message=messages.COMMIT_COMMENT,
        )
        self.author = author
        self.hgdate = hgdate
        self.node = node
        self.filename = filename
        self.lines = lines
        self.message = message
    
    def _render_data(self):
        """Render the data of this comment into a string for writing to disk.
        
        You probably don't need to call this directly, the add_comment method
        of a ReviewChangeset will handle it for you.
        
        """
        rendered_date = util.datestr(self.hgdate)
        lines = ','.join(self.lines)
        return file_templates.COMMENT_FILE_TEMPLATE % ( self.author, rendered_date,
            self.node, self.filename, lines, self.message )
    
    def __str__(self):
        """Stringify this comment for easy printing (for debugging)."""
        
        return '\n'.join(map(str, [
            self.author,
            self.hgdate,
            self.node,
            self.filename,
            self.lines,
            self.message,
            '\n',
        ]))
    

class ReviewSignoff(_ReviewObject):
    """A single review signoff.
    
    A list of signoffs can be retrieved from a ReviewChangeset.
    
    The following pieces of information are stored for signoffs:
    
        signoff = rcset.comments[0]
        signoff.author
        signoff.hgdate
        signoff.node
        signoff.opinion
        signoff.message
    
    Each item is a string, except for hgdate and local_datetime.
    
    hgdate is a tuple of (seconds from the epoch, seconds offset from UTC),
    which is the format Mercurial itself uses internally.
    
    local_datetime is a datetime object representing what a clock on the wall
    next to the current computer would have read at the instant the signoff
    was added.
    
    """
    def __init__(self, author, hgdate, node, opinion, message, **extra):
        """Initialize a ReviewSignoff.
        
        You shouldn't need to create these directly -- use a ReviewChangeset
        to add signoffs and retrieve existing ones:
        
            review_data = ReviewDatastore(ui, repo)
            tip_review = review_data['tip']
            tip_review.add_signoff(...)
            tip_signoffs = tip_review.signoffs
        
        """
        super(ReviewSignoff, self).__init__(
            container='signoffs', commit_message=messages.COMMIT_SIGNOFF,
            delete_message=messages.DELETE_SIGNOFF,
        )
        self.author = author
        self.hgdate = hgdate
        self.node = node
        self.opinion = opinion
        self.message = message
    
    def _render_data(self):
        """Render the data of this signoff into a string for writing to disk.
        
        You probably don't need to call this directly, the add_signoff method
        of a ReviewChangeset will handle it for you.
        
        """
        rendered_date = util.datestr(self.hgdate)
        return file_templates.SIGNOFF_FILE_TEMPLATE % ( self.author, rendered_date,
            self.node, self.opinion, self.message )