mapnik/scons/scons-local-2.1.0/SCons/SConsign.py

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2011-10-04 20:36:00 +02:00
"""SCons.SConsign
Writing and reading information to the .sconsign file or files.
"""
#
# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 The SCons Foundation
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
__revision__ = "src/engine/SCons/SConsign.py 5357 2011/09/09 21:31:03 bdeegan"
import SCons.compat
import os
# compat layer imports "cPickle" for us if it's available.
import pickle
import SCons.dblite
import SCons.Warnings
def corrupt_dblite_warning(filename):
SCons.Warnings.warn(SCons.Warnings.CorruptSConsignWarning,
"Ignoring corrupt .sconsign file: %s"%filename)
SCons.dblite.ignore_corrupt_dbfiles = 1
SCons.dblite.corruption_warning = corrupt_dblite_warning
#XXX Get rid of the global array so this becomes re-entrant.
sig_files = []
# Info for the database SConsign implementation (now the default):
# "DataBase" is a dictionary that maps top-level SConstruct directories
# to open database handles.
# "DB_Module" is the Python database module to create the handles.
# "DB_Name" is the base name of the database file (minus any
# extension the underlying DB module will add).
DataBase = {}
DB_Module = SCons.dblite
DB_Name = ".sconsign"
DB_sync_list = []
def Get_DataBase(dir):
global DataBase, DB_Module, DB_Name
top = dir.fs.Top
if not os.path.isabs(DB_Name) and top.repositories:
mode = "c"
for d in [top] + top.repositories:
if dir.is_under(d):
try:
return DataBase[d], mode
except KeyError:
path = d.entry_abspath(DB_Name)
try: db = DataBase[d] = DB_Module.open(path, mode)
except (IOError, OSError): pass
else:
if mode != "r":
DB_sync_list.append(db)
return db, mode
mode = "r"
try:
return DataBase[top], "c"
except KeyError:
db = DataBase[top] = DB_Module.open(DB_Name, "c")
DB_sync_list.append(db)
return db, "c"
except TypeError:
print "DataBase =", DataBase
raise
def Reset():
"""Reset global state. Used by unit tests that end up using
SConsign multiple times to get a clean slate for each test."""
global sig_files, DB_sync_list
sig_files = []
DB_sync_list = []
normcase = os.path.normcase
def write():
global sig_files
for sig_file in sig_files:
sig_file.write(sync=0)
for db in DB_sync_list:
try:
syncmethod = db.sync
except AttributeError:
pass # Not all dbm modules have sync() methods.
else:
syncmethod()
try:
closemethod = db.close
except AttributeError:
pass # Not all dbm modules have close() methods.
else:
closemethod()
class SConsignEntry(object):
"""
Wrapper class for the generic entry in a .sconsign file.
The Node subclass populates it with attributes as it pleases.
XXX As coded below, we do expect a '.binfo' attribute to be added,
but we'll probably generalize this in the next refactorings.
"""
current_version_id = 1
def __init__(self):
# Create an object attribute from the class attribute so it ends up
# in the pickled data in the .sconsign file.
_version_id = self.current_version_id
def convert_to_sconsign(self):
self.binfo.convert_to_sconsign()
def convert_from_sconsign(self, dir, name):
self.binfo.convert_from_sconsign(dir, name)
class Base(object):
"""
This is the controlling class for the signatures for the collection of
entries associated with a specific directory. The actual directory
association will be maintained by a subclass that is specific to
the underlying storage method. This class provides a common set of
methods for fetching and storing the individual bits of information
that make up signature entry.
"""
def __init__(self):
self.entries = {}
self.dirty = False
self.to_be_merged = {}
def get_entry(self, filename):
"""
Fetch the specified entry attribute.
"""
return self.entries[filename]
def set_entry(self, filename, obj):
"""
Set the entry.
"""
self.entries[filename] = obj
self.dirty = True
def do_not_set_entry(self, filename, obj):
pass
def store_info(self, filename, node):
entry = node.get_stored_info()
entry.binfo.merge(node.get_binfo())
self.to_be_merged[filename] = node
self.dirty = True
def do_not_store_info(self, filename, node):
pass
def merge(self):
for key, node in self.to_be_merged.items():
entry = node.get_stored_info()
try:
ninfo = entry.ninfo
except AttributeError:
# This happens with SConf Nodes, because the configuration
# subsystem takes direct control over how the build decision
# is made and its information stored.
pass
else:
ninfo.merge(node.get_ninfo())
self.entries[key] = entry
self.to_be_merged = {}
class DB(Base):
"""
A Base subclass that reads and writes signature information
from a global .sconsign.db* file--the actual file suffix is
determined by the database module.
"""
def __init__(self, dir):
Base.__init__(self)
self.dir = dir
db, mode = Get_DataBase(dir)
# Read using the path relative to the top of the Repository
# (self.dir.tpath) from which we're fetching the signature
# information.
path = normcase(dir.tpath)
try:
rawentries = db[path]
except KeyError:
pass
else:
try:
self.entries = pickle.loads(rawentries)
if not isinstance(self.entries, dict):
self.entries = {}
raise TypeError
except KeyboardInterrupt:
raise
except Exception, e:
SCons.Warnings.warn(SCons.Warnings.CorruptSConsignWarning,
"Ignoring corrupt sconsign entry : %s (%s)\n"%(self.dir.tpath, e))
for key, entry in self.entries.items():
entry.convert_from_sconsign(dir, key)
if mode == "r":
# This directory is actually under a repository, which means
# likely they're reaching in directly for a dependency on
# a file there. Don't actually set any entry info, so we
# won't try to write to that .sconsign.dblite file.
self.set_entry = self.do_not_set_entry
self.store_info = self.do_not_store_info
global sig_files
sig_files.append(self)
def write(self, sync=1):
if not self.dirty:
return
self.merge()
db, mode = Get_DataBase(self.dir)
# Write using the path relative to the top of the SConstruct
# directory (self.dir.path), not relative to the top of
# the Repository; we only write to our own .sconsign file,
# not to .sconsign files in Repositories.
path = normcase(self.dir.path)
for key, entry in self.entries.items():
entry.convert_to_sconsign()
db[path] = pickle.dumps(self.entries, 1)
if sync:
try:
syncmethod = db.sync
except AttributeError:
# Not all anydbm modules have sync() methods.
pass
else:
syncmethod()
class Dir(Base):
def __init__(self, fp=None, dir=None):
"""
fp - file pointer to read entries from
"""
Base.__init__(self)
if not fp:
return
self.entries = pickle.load(fp)
if not isinstance(self.entries, dict):
self.entries = {}
raise TypeError
if dir:
for key, entry in self.entries.items():
entry.convert_from_sconsign(dir, key)
class DirFile(Dir):
"""
Encapsulates reading and writing a per-directory .sconsign file.
"""
def __init__(self, dir):
"""
dir - the directory for the file
"""
self.dir = dir
self.sconsign = os.path.join(dir.path, '.sconsign')
try:
fp = open(self.sconsign, 'rb')
except IOError:
fp = None
try:
Dir.__init__(self, fp, dir)
except KeyboardInterrupt:
raise
except:
SCons.Warnings.warn(SCons.Warnings.CorruptSConsignWarning,
"Ignoring corrupt .sconsign file: %s"%self.sconsign)
global sig_files
sig_files.append(self)
def write(self, sync=1):
"""
Write the .sconsign file to disk.
Try to write to a temporary file first, and rename it if we
succeed. If we can't write to the temporary file, it's
probably because the directory isn't writable (and if so,
how did we build anything in this directory, anyway?), so
try to write directly to the .sconsign file as a backup.
If we can't rename, try to copy the temporary contents back
to the .sconsign file. Either way, always try to remove
the temporary file at the end.
"""
if not self.dirty:
return
self.merge()
temp = os.path.join(self.dir.path, '.scons%d' % os.getpid())
try:
file = open(temp, 'wb')
fname = temp
except IOError:
try:
file = open(self.sconsign, 'wb')
fname = self.sconsign
except IOError:
return
for key, entry in self.entries.items():
entry.convert_to_sconsign()
pickle.dump(self.entries, file, 1)
file.close()
if fname != self.sconsign:
try:
mode = os.stat(self.sconsign)[0]
os.chmod(self.sconsign, 0666)
os.unlink(self.sconsign)
except (IOError, OSError):
# Try to carry on in the face of either OSError
# (things like permission issues) or IOError (disk
# or network issues). If there's a really dangerous
# issue, it should get re-raised by the calls below.
pass
try:
os.rename(fname, self.sconsign)
except OSError:
# An OSError failure to rename may indicate something
# like the directory has no write permission, but
# the .sconsign file itself might still be writable,
# so try writing on top of it directly. An IOError
# here, or in any of the following calls, would get
# raised, indicating something like a potentially
# serious disk or network issue.
open(self.sconsign, 'wb').write(open(fname, 'rb').read())
os.chmod(self.sconsign, mode)
try:
os.unlink(temp)
except (IOError, OSError):
pass
ForDirectory = DB
def File(name, dbm_module=None):
"""
Arrange for all signatures to be stored in a global .sconsign.db*
file.
"""
global ForDirectory, DB_Name, DB_Module
if name is None:
ForDirectory = DirFile
DB_Module = None
else:
ForDirectory = DB
DB_Name = name
if not dbm_module is None:
DB_Module = dbm_module
# Local Variables:
# tab-width:4
# indent-tabs-mode:nil
# End:
# vim: set expandtab tabstop=4 shiftwidth=4: