~bzr-pqm/bzr/bzr.dev

# (C) 2005 Canonical Ltd

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# This program 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 General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""Inventories map files to their name in a revision."""

# TODO: Maybe store inventory_id in the file?  Not really needed.

__author__ = "Martin Pool <mbp@canonical.com>"


# This should really be an id randomly assigned when the tree is
# created, but it's not for now.
ROOT_ID = "TREE_ROOT"


import sys, os.path, types, re
from sets import Set

try:
    from cElementTree import Element, ElementTree, SubElement
except ImportError:
    from elementtree.ElementTree import Element, ElementTree, SubElement

from xml import XMLMixin
from errors import bailout, BzrError

import bzrlib
from bzrlib.osutils import uuid, quotefn, splitpath, joinpath, appendpath
from bzrlib.trace import mutter

class InventoryEntry(XMLMixin):
    """Description of a versioned file.

    An InventoryEntry has the following fields, which are also
    present in the XML inventory-entry element:

    * *file_id*
    * *name*: (only the basename within the directory, must not
      contain slashes)
    * *kind*: "directory" or "file"
    * *directory_id*: (if absent/null means the branch root directory)
    * *text_sha1*: only for files
    * *text_size*: in bytes, only for files 
    * *text_id*: identifier for the text version, only for files

    InventoryEntries can also exist inside a WorkingTree
    inventory, in which case they are not yet bound to a
    particular revision of the file.  In that case the text_sha1,
    text_size and text_id are absent.


    >>> i = Inventory()
    >>> i.path2id('')
    'TREE_ROOT'
    >>> i.add(InventoryEntry('123', 'src', 'directory', ROOT_ID))
    >>> i.add(InventoryEntry('2323', 'hello.c', 'file', parent_id='123'))
    >>> for j in i.iter_entries():
    ...   print j
    ... 
    ('src', InventoryEntry('123', 'src', kind='directory', parent_id='TREE_ROOT'))
    ('src/hello.c', InventoryEntry('2323', 'hello.c', kind='file', parent_id='123'))
    >>> i.add(InventoryEntry('2323', 'bye.c', 'file', '123'))
    Traceback (most recent call last):
    ...
    BzrError: ('inventory already contains entry with id {2323}', [])
    >>> i.add(InventoryEntry('2324', 'bye.c', 'file', '123'))
    >>> i.add(InventoryEntry('2325', 'wibble', 'directory', '123'))
    >>> i.path2id('src/wibble')
    '2325'
    >>> '2325' in i
    True
    >>> i.add(InventoryEntry('2326', 'wibble.c', 'file', '2325'))
    >>> i['2326']
    InventoryEntry('2326', 'wibble.c', kind='file', parent_id='2325')
    >>> for j in i.iter_entries():
    ...     print j[0]
    ...     assert i.path2id(j[0])
    ... 
    src
    src/bye.c
    src/hello.c
    src/wibble
    src/wibble/wibble.c
    >>> i.id2path('2326')
    'src/wibble/wibble.c'

    :todo: Maybe also keep the full path of the entry, and the children?
           But those depend on its position within a particular inventory, and
           it would be nice not to need to hold the backpointer here.
    """

    # TODO: split InventoryEntry into subclasses for files,
    # directories, etc etc.
    
    def __init__(self, file_id, name, kind, parent_id, text_id=None):
        """Create an InventoryEntry
        
        The filename must be a single component, relative to the
        parent directory; it cannot be a whole path or relative name.

        >>> e = InventoryEntry('123', 'hello.c', 'file', ROOT_ID)
        >>> e.name
        'hello.c'
        >>> e.file_id
        '123'
        >>> e = InventoryEntry('123', 'src/hello.c', 'file', ROOT_ID)
        Traceback (most recent call last):
        BzrError: ("InventoryEntry name is not a simple filename: 'src/hello.c'", [])
        """
        
        if len(splitpath(name)) != 1:
            bailout('InventoryEntry name is not a simple filename: %r'
                    % name)
        
        self.file_id = file_id
        self.name = name
        assert kind in ['file', 'directory']
        self.kind = kind
        self.text_id = text_id
        self.parent_id = parent_id
        self.text_sha1 = None
        self.text_size = None
        if kind == 'directory':
            self.children = {}
        else:
            assert kind == 'file'


    def sorted_children(self):
        l = self.children.items()
        l.sort()
        return l


    def copy(self):
        other = InventoryEntry(self.file_id, self.name, self.kind,
                               self.parent_id, text_id=self.text_id)
        other.text_sha1 = self.text_sha1
        other.text_size = self.text_size
        return other


    def __repr__(self):
        return ("%s(%r, %r, kind=%r, parent_id=%r)"
                % (self.__class__.__name__,
                   self.file_id,
                   self.name,
                   self.kind,
                   self.parent_id))

    
    def to_element(self):
        """Convert to XML element"""
        e = Element('entry')

        e.set('name', self.name)
        e.set('file_id', self.file_id)
        e.set('kind', self.kind)

        if self.text_size != None:
            e.set('text_size', '%d' % self.text_size)
            
        for f in ['text_id', 'text_sha1']:
            v = getattr(self, f)
            if v != None:
                e.set(f, v)

        # to be conservative, we don't externalize the root pointers
        # for now, leaving them as null in the xml form.  in a future
        # version it will be implied by nested elements.
        if self.parent_id != ROOT_ID:
            assert isinstance(self.parent_id, basestring)
            e.set('parent_id', self.parent_id)

        e.tail = '\n'
            
        return e


    def from_element(cls, elt):
        assert elt.tag == 'entry'

        ## original format inventories don't have a parent_id for
        ## nodes in the root directory, but it's cleaner to use one
        ## internally.
        parent_id = elt.get('parent_id')
        if parent_id == None:
            parent_id = ROOT_ID

        self = cls(elt.get('file_id'), elt.get('name'), elt.get('kind'), parent_id)
        self.text_id = elt.get('text_id')
        self.text_sha1 = elt.get('text_sha1')
        
        ## mutter("read inventoryentry: %r" % (elt.attrib))

        v = elt.get('text_size')
        self.text_size = v and int(v)

        return self
            

    from_element = classmethod(from_element)

    def __cmp__(self, other):
        if self is other:
            return 0
        if not isinstance(other, InventoryEntry):
            return NotImplemented

        return cmp(self.file_id, other.file_id) \
               or cmp(self.name, other.name) \
               or cmp(self.text_sha1, other.text_sha1) \
               or cmp(self.text_size, other.text_size) \
               or cmp(self.text_id, other.text_id) \
               or cmp(self.parent_id, other.parent_id) \
               or cmp(self.kind, other.kind)



class RootEntry(InventoryEntry):
    def __init__(self, file_id):
        self.file_id = file_id
        self.children = {}
        self.kind = 'root_directory'
        self.parent_id = None
        self.name = ''

    def __cmp__(self, other):
        if self is other:
            return 0
        if not isinstance(other, RootEntry):
            return NotImplemented
        return cmp(self.file_id, other.file_id) \
               or cmp(self.children, other.children)



class Inventory(XMLMixin):
    """Inventory of versioned files in a tree.

    An Inventory acts like a set of InventoryEntry items.  You can
    also look files up by their file_id or name.
    
    May be read from and written to a metadata file in a tree.  To
    manipulate the inventory (for example to add a file), it is read
    in, modified, and then written back out.

    The inventory represents a typical unix file tree, with
    directories containing files and subdirectories.  We never store
    the full path to a file, because renaming a directory implicitly
    moves all of its contents.  This class internally maintains a
    lookup tree that allows the children under a directory to be
    returned quickly.

    InventoryEntry objects must not be modified after they are
    inserted, other than through the Inventory API.

    >>> inv = Inventory()
    >>> inv.write_xml(sys.stdout)
    <inventory>
    </inventory>
    >>> inv.add(InventoryEntry('123-123', 'hello.c', 'file', ROOT_ID))
    >>> inv['123-123'].name
    'hello.c'

    May be treated as an iterator or set to look up file ids:
    
    >>> bool(inv.path2id('hello.c'))
    True
    >>> '123-123' in inv
    True

    May also look up by name:

    >>> [x[0] for x in inv.iter_entries()]
    ['hello.c']
    
    >>> inv.write_xml(sys.stdout)
    <inventory>
    <entry file_id="123-123" kind="file" name="hello.c" />
    </inventory>

    """

    ## TODO: Make sure only canonical filenames are stored.

    ## TODO: Do something sensible about the possible collisions on
    ## case-losing filesystems.  Perhaps we should just always forbid
    ## such collisions.

    ## TODO: No special cases for root, rather just give it a file id
    ## like everything else.

    ## TODO: Probably change XML serialization to use nesting

    def __init__(self):
        """Create or read an inventory.

        If a working directory is specified, the inventory is read
        from there.  If the file is specified, read from that. If not,
        the inventory is created empty.

        The inventory is created with a default root directory, with
        an id of None.
        """
        self.root = RootEntry(ROOT_ID)
        self._byid = {self.root.file_id: self.root}


    def __iter__(self):
        return iter(self._byid)


    def __len__(self):
        """Returns number of entries."""
        return len(self._byid)


    def iter_entries(self, from_dir=None):
        """Return (path, entry) pairs, in order by name."""
        if from_dir == None:
            assert self.root
            from_dir = self.root
        elif isinstance(from_dir, basestring):
            from_dir = self._byid[from_dir]
            
        kids = from_dir.children.items()
        kids.sort()
        for name, ie in kids:
            yield name, ie
            if ie.kind == 'directory':
                for cn, cie in self.iter_entries(from_dir=ie.file_id):
                    yield '/'.join((name, cn)), cie
                    


    def directories(self):
        """Return (path, entry) pairs for all directories.
        """
        def descend(parent_ie):
            parent_name = parent_ie.name
            yield parent_name, parent_ie

            # directory children in sorted order
            dn = []
            for ie in parent_ie.children.itervalues():
                if ie.kind == 'directory':
                    dn.append((ie.name, ie))
            dn.sort()
            
            for name, child_ie in dn:
                for sub_name, sub_ie in descend(child_ie):
                    yield appendpath(parent_name, sub_name), sub_ie

        for name, ie in descend(self.root):
            yield name, ie
        


    def __contains__(self, file_id):
        """True if this entry contains a file with given id.

        >>> inv = Inventory()
        >>> inv.add(InventoryEntry('123', 'foo.c', 'file', ROOT_ID))
        >>> '123' in inv
        True
        >>> '456' in inv
        False
        """
        return file_id in self._byid


    def __getitem__(self, file_id):
        """Return the entry for given file_id.

        >>> inv = Inventory()
        >>> inv.add(InventoryEntry('123123', 'hello.c', 'file', ROOT_ID))
        >>> inv['123123'].name
        'hello.c'
        """
        if file_id == None:
            raise BzrError("can't look up file_id None")
            
        try:
            return self._byid[file_id]
        except KeyError:
            raise BzrError("file_id {%s} not in inventory" % file_id)


    def get_child(self, parent_id, filename):
        return self[parent_id].children.get(filename)


    def add(self, entry):
        """Add entry to inventory.

        To add  a file to a branch ready to be committed, use Branch.add,
        which calls this."""
        if entry.file_id in self._byid:
            bailout("inventory already contains entry with id {%s}" % entry.file_id)

        try:
            parent = self._byid[entry.parent_id]
        except KeyError:
            bailout("parent_id {%s} not in inventory" % entry.parent_id)

        if parent.children.has_key(entry.name):
            bailout("%s is already versioned" %
                    appendpath(self.id2path(parent.file_id), entry.name))

        self._byid[entry.file_id] = entry
        parent.children[entry.name] = entry


    def add_path(self, relpath, kind, file_id=None):
        """Add entry from a path.

        The immediate parent must already be versioned"""
        parts = bzrlib.osutils.splitpath(relpath)
        if len(parts) == 0:
            bailout("cannot re-add root of inventory")

        if file_id == None:
            file_id = bzrlib.branch.gen_file_id(relpath)

        parent_id = self.path2id(parts[:-1])
        assert parent_id != None
        ie = InventoryEntry(file_id, parts[-1],
                            kind=kind, parent_id=parent_id)
        return self.add(ie)


    def __delitem__(self, file_id):
        """Remove entry by id.

        >>> inv = Inventory()
        >>> inv.add(InventoryEntry('123', 'foo.c', 'file', ROOT_ID))
        >>> '123' in inv
        True
        >>> del inv['123']
        >>> '123' in inv
        False
        """
        ie = self[file_id]

        assert self[ie.parent_id].children[ie.name] == ie
        
        # TODO: Test deleting all children; maybe hoist to a separate
        # deltree method?
        if ie.kind == 'directory':
            for cie in ie.children.values():
                del self[cie.file_id]
            del ie.children

        del self._byid[file_id]
        del self[ie.parent_id].children[ie.name]


    def id_set(self):
        return Set(self._byid)


    def to_element(self):
        """Convert to XML Element"""
        e = Element('inventory')
        e.text = '\n'
        for path, ie in self.iter_entries():
            e.append(ie.to_element())
        return e
    

    def from_element(cls, elt):
        """Construct from XML Element

        >>> inv = Inventory()
        >>> inv.add(InventoryEntry('foo.c-123981239', 'foo.c', 'file', ROOT_ID))
        >>> elt = inv.to_element()
        >>> inv2 = Inventory.from_element(elt)
        >>> inv2 == inv
        True
        """
        assert elt.tag == 'inventory'
        o = cls()
        for e in elt:
            o.add(InventoryEntry.from_element(e))
        return o
        
    from_element = classmethod(from_element)


    def __cmp__(self, other):
        """Compare two sets by comparing their contents.

        >>> i1 = Inventory()
        >>> i2 = Inventory()
        >>> i1 == i2
        True
        >>> i1.add(InventoryEntry('123', 'foo', 'file', ROOT_ID))
        >>> i1 == i2
        False
        >>> i2.add(InventoryEntry('123', 'foo', 'file', ROOT_ID))
        >>> i1 == i2
        True
        """
        if self is other:
            return 0
        
        if not isinstance(other, Inventory):
            return NotImplemented

        if self.id_set() ^ other.id_set():
            return 1

        for file_id in self._byid:
            c = cmp(self[file_id], other[file_id])
            if c: return c

        return 0


    def get_idpath(self, file_id):
        """Return a list of file_ids for the path to an entry.

        The list contains one element for each directory followed by
        the id of the file itself.  So the length of the returned list
        is equal to the depth of the file in the tree, counting the
        root directory as depth 1.
        """
        p = []
        while file_id != None:
            try:
                ie = self._byid[file_id]
            except KeyError:
                bailout("file_id {%s} not found in inventory" % file_id)
            p.insert(0, ie.file_id)
            file_id = ie.parent_id
        return p


    def id2path(self, file_id):
        """Return as a list the path to file_id."""

        # get all names, skipping root
        p = [self[fid].name for fid in self.get_idpath(file_id)[1:]]
        return '/'.join(p)
            


    def path2id(self, name):
        """Walk down through directories to return entry of last component.

        names may be either a list of path components, or a single
        string, in which case it is automatically split.

        This returns the entry of the last component in the path,
        which may be either a file or a directory.

        Returns None iff the path is not found.
        """
        if isinstance(name, types.StringTypes):
            name = splitpath(name)

        mutter("lookup path %r" % name)

        parent = self.root
        for f in name:
            try:
                cie = parent.children[f]
                assert cie.name == f
                assert cie.parent_id == parent.file_id
                parent = cie
            except KeyError:
                # or raise an error?
                return None

        return parent.file_id


    def has_filename(self, names):
        return bool(self.path2id(names))


    def has_id(self, file_id):
        return self._byid.has_key(file_id)


    def rename(self, file_id, new_parent_id, new_name):
        """Move a file within the inventory.

        This can change either the name, or the parent, or both.

        This does not move the working file."""
        if not is_valid_name(new_name):
            bailout("not an acceptable filename: %r" % new_name)

        new_parent = self._byid[new_parent_id]
        if new_name in new_parent.children:
            bailout("%r already exists in %r" % (new_name, self.id2path(new_parent_id)))

        new_parent_idpath = self.get_idpath(new_parent_id)
        if file_id in new_parent_idpath:
            bailout("cannot move directory %r into a subdirectory of itself, %r"
                    % (self.id2path(file_id), self.id2path(new_parent_id)))

        file_ie = self._byid[file_id]
        old_parent = self._byid[file_ie.parent_id]

        # TODO: Don't leave things messed up if this fails

        del old_parent.children[file_ie.name]
        new_parent.children[new_name] = file_ie
        
        file_ie.name = new_name
        file_ie.parent_id = new_parent_id




_NAME_RE = re.compile(r'^[^/\\]+$')

def is_valid_name(name):
    return bool(_NAME_RE.match(name))