Added an unmodified copy of SCons to third_party.

scons-2.0.1/engine/SCons/SConsign.py

+"""SCons.SConsign
+
+Writing and reading information to the .sconsign file or files.
+
+"""
+
+#
+# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 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 5134 2010/08/16 23:02:40 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 anydbm modules have sync() methods.
+        else:
+            syncmethod()
+
+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: