init

scons-local-3.0.0/SCons/dblite.py

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+# dblite.py module contributed by Ralf W. Grosse-Kunstleve.
+# Extended for Unicode by Steven Knight.
+from __future__ import print_function
+
+import os
+import pickle
+import shutil
+import time
+
+from SCons.compat import PICKLE_PROTOCOL
+
+keep_all_files = 00000
+ignore_corrupt_dbfiles = 0
+
+
+def corruption_warning(filename):
+    print("Warning: Discarding corrupt database:", filename)
+
+
+try:
+    unicode
+except NameError:
+    def is_string(s):
+        return isinstance(s, str)
+else:
+    def is_string(s):
+        return type(s) in (str, unicode)
+
+
+def is_bytes(s):
+    return isinstance(s, bytes)
+
+
+try:
+    unicode('a')
+except NameError:
+    def unicode(s):
+        return s
+
+dblite_suffix = '.dblite'
+
+# TODO: Does commenting this out break switching from py2/3?
+# if bytes is not str:
+#     dblite_suffix += '.p3'
+tmp_suffix = '.tmp'
+
+
+class dblite(object):
+    """
+    Squirrel away references to the functions in various modules
+    that we'll use when our __del__() method calls our sync() method
+    during shutdown.  We might get destroyed when Python is in the midst
+    of tearing down the different modules we import in an essentially
+    arbitrary order, and some of the various modules's global attributes
+    may already be wiped out from under us.
+
+    See the discussion at:
+      http://mail.python.org/pipermail/python-bugs-list/2003-March/016877.html
+    """
+
+    _open = open
+    _pickle_dump = staticmethod(pickle.dump)
+    _pickle_protocol = PICKLE_PROTOCOL
+    _os_chmod = os.chmod
+
+    try:
+        _os_chown = os.chown
+    except AttributeError:
+        _os_chown = None
+
+    _os_rename = os.rename
+    _os_unlink = os.unlink
+    _shutil_copyfile = shutil.copyfile
+    _time_time = time.time
+
+    def __init__(self, file_base_name, flag, mode):
+        assert flag in (None, "r", "w", "c", "n")
+        if (flag is None): flag = "r"
+
+        base, ext = os.path.splitext(file_base_name)
+        if ext == dblite_suffix:
+            # There's already a suffix on the file name, don't add one.
+            self._file_name = file_base_name
+            self._tmp_name = base + tmp_suffix
+        else:
+            self._file_name = file_base_name + dblite_suffix
+            self._tmp_name = file_base_name + tmp_suffix
+
+        self._flag = flag
+        self._mode = mode
+        self._dict = {}
+        self._needs_sync = 00000
+
+        if self._os_chown is not None and (os.geteuid() == 0 or os.getuid() == 0):
+            # running as root; chown back to current owner/group when done
+            try:
+                statinfo = os.stat(self._file_name)
+                self._chown_to = statinfo.st_uid
+                self._chgrp_to = statinfo.st_gid
+            except OSError as e:
+                # db file doesn't exist yet.
+                # Check os.environ for SUDO_UID, use if set
+                self._chown_to = int(os.environ.get('SUDO_UID', -1))
+                self._chgrp_to = int(os.environ.get('SUDO_GID', -1))
+        else:
+            self._chown_to = -1  # don't chown
+            self._chgrp_to = -1  # don't chgrp
+
+        if (self._flag == "n"):
+            self._open(self._file_name, "wb", self._mode)
+        else:
+            try:
+                f = self._open(self._file_name, "rb")
+            except IOError as e:
+                if (self._flag != "c"):
+                    raise e
+                self._open(self._file_name, "wb", self._mode)
+            else:
+                p = f.read()
+                if len(p) > 0:
+                    try:
+                        if bytes is not str:
+                            self._dict = pickle.loads(p, encoding='bytes')
+                        else:
+                            self._dict = pickle.loads(p)
+                    except (pickle.UnpicklingError, EOFError, KeyError):
+                        # Note how we catch KeyErrors too here, which might happen
+                        # when we don't have cPickle available (default pickle
+                        # throws it).
+                        if (ignore_corrupt_dbfiles == 0): raise
+                        if (ignore_corrupt_dbfiles == 1):
+                            corruption_warning(self._file_name)
+
+    def close(self):
+        if (self._needs_sync):
+            self.sync()
+
+    def __del__(self):
+        self.close()
+
+    def sync(self):
+        self._check_writable()
+        f = self._open(self._tmp_name, "wb", self._mode)
+        self._pickle_dump(self._dict, f, self._pickle_protocol)
+        f.close()
+
+        # Windows doesn't allow renaming if the file exists, so unlink
+        # it first, chmod'ing it to make sure we can do so.  On UNIX, we
+        # may not be able to chmod the file if it's owned by someone else
+        # (e.g. from a previous run as root).  We should still be able to
+        # unlink() the file if the directory's writable, though, so ignore
+        # any OSError exception  thrown by the chmod() call.
+        try:
+            self._os_chmod(self._file_name, 0o777)
+        except OSError:
+            pass
+        self._os_unlink(self._file_name)
+        self._os_rename(self._tmp_name, self._file_name)
+        if self._os_chown is not None and self._chown_to > 0:  # don't chown to root or -1
+            try:
+                self._os_chown(self._file_name, self._chown_to, self._chgrp_to)
+            except OSError:
+                pass
+        self._needs_sync = 00000
+        if (keep_all_files):
+            self._shutil_copyfile(
+                self._file_name,
+                self._file_name + "_" + str(int(self._time_time())))
+
+    def _check_writable(self):
+        if (self._flag == "r"):
+            raise IOError("Read-only database: %s" % self._file_name)
+
+    def __getitem__(self, key):
+        return self._dict[key]
+
+    def __setitem__(self, key, value):
+        self._check_writable()
+        if (not is_string(key)):
+            raise TypeError("key `%s' must be a string but is %s" % (key, type(key)))
+        if (not is_bytes(value)):
+            raise TypeError("value `%s' must be a bytes but is %s" % (value, type(value)))
+        self._dict[key] = value
+        self._needs_sync = 0o001
+
+    def keys(self):
+        return list(self._dict.keys())
+
+    def has_key(self, key):
+        return key in self._dict
+
+    def __contains__(self, key):
+        return key in self._dict
+
+    def iterkeys(self):
+        # Wrapping name in () prevents fixer from "fixing" this
+        return (self._dict.iterkeys)()
+
+    __iter__ = iterkeys
+
+    def __len__(self):
+        return len(self._dict)
+
+
+def open(file, flag=None, mode=0o666):
+    return dblite(file, flag, mode)
+
+
+def _exercise():
+    db = open("tmp", "n")
+    assert len(db) == 0
+    db["foo"] = "bar"
+    assert db["foo"] == "bar"
+    db[unicode("ufoo")] = unicode("ubar")
+    assert db[unicode("ufoo")] == unicode("ubar")
+    db.sync()
+    db = open("tmp", "c")
+    assert len(db) == 2, len(db)
+    assert db["foo"] == "bar"
+    db["bar"] = "foo"
+    assert db["bar"] == "foo"
+    db[unicode("ubar")] = unicode("ufoo")
+    assert db[unicode("ubar")] == unicode("ufoo")
+    db.sync()
+    db = open("tmp", "r")
+    assert len(db) == 4, len(db)
+    assert db["foo"] == "bar"
+    assert db["bar"] == "foo"
+    assert db[unicode("ufoo")] == unicode("ubar")
+    assert db[unicode("ubar")] == unicode("ufoo")
+    try:
+        db.sync()
+    except IOError as e:
+        assert str(e) == "Read-only database: tmp.dblite"
+    else:
+        raise RuntimeError("IOError expected.")
+    db = open("tmp", "w")
+    assert len(db) == 4
+    db["ping"] = "pong"
+    db.sync()
+    try:
+        db[(1, 2)] = "tuple"
+    except TypeError as e:
+        assert str(e) == "key `(1, 2)' must be a string but is <type 'tuple'>", str(e)
+    else:
+        raise RuntimeError("TypeError exception expected")
+    try:
+        db["list"] = [1, 2]
+    except TypeError as e:
+        assert str(e) == "value `[1, 2]' must be a string but is <type 'list'>", str(e)
+    else:
+        raise RuntimeError("TypeError exception expected")
+    db = open("tmp", "r")
+    assert len(db) == 5
+    db = open("tmp", "n")
+    assert len(db) == 0
+    dblite._open("tmp.dblite", "w")
+    db = open("tmp", "r")
+    dblite._open("tmp.dblite", "w").write("x")
+    try:
+        db = open("tmp", "r")
+    except pickle.UnpicklingError:
+        pass
+    else:
+        raise RuntimeError("pickle exception expected.")
+    global ignore_corrupt_dbfiles
+    ignore_corrupt_dbfiles = 2
+    db = open("tmp", "r")
+    assert len(db) == 0
+    os.unlink("tmp.dblite")
+    try:
+        db = open("tmp", "w")
+    except IOError as e:
+        assert str(e) == "[Errno 2] No such file or directory: 'tmp.dblite'", str(e)
+    else:
+        raise RuntimeError("IOError expected.")
+
+
+if (__name__ == "__main__"):
+    _exercise()
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4: