Adding upstream version 2.7.6.upstream/2.7.6

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 268 insertions, 0 deletions

diff --git a/python/lock.cc b/python/lock.cc
new file mode 100644
index 0000000..009605e
--- /dev/null
+++ b/python/lock.cc
@@ -0,0 +1,268 @@
+/*
+ * lock.cc - Context managers for implementing locking.
+ *
+ * Copyright 2009 Julian Andres Klode <jak@debian.org>
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#include <Python.h>
+#include <apt-pkg/init.h>
+#include <apt-pkg/error.h>
+#include <apt-pkg/fileutl.h>
+#include <apt-pkg/pkgsystem.h>
+#include "generic.h"
+
+static PyObject *systemlock_exit(PyObject *self, PyObject *args)
+{
+
+    PyObject *exc_type = 0;
+    PyObject *exc_value = 0;
+    PyObject *traceback = 0;
+    if (!PyArg_UnpackTuple(args, "__exit__", 3, 3, &exc_type, &exc_value,
+                           &traceback)) {
+        return 0;
+    }
+
+    if (_system->UnLock() == 0) {
+        // The unlock failed. If no exception happened within the suite, we
+        // will raise an error here. Otherwise, we just display the error, so
+        // Python can handle the original exception instead.
+        HandleErrors();
+        if (exc_type == Py_None)
+            return NULL;
+        else
+            PyErr_WriteUnraisable(self);
+    }
+    // Return False, as required by the context manager protocol.
+    Py_RETURN_FALSE;
+}
+
+static PyObject *systemlock_enter(PyObject *self, PyObject *args)
+{
+    if (!PyArg_ParseTuple(args, ""))
+        return NULL;
+    if (!_system->Lock())
+        return HandleErrors();
+    Py_INCREF(self);
+    return self;
+}
+
+static PyObject *systemlock_new(PyTypeObject *type, PyObject *args,
+                                PyObject *kwds)
+{
+    if (_system == 0) {
+        PyErr_SetString(PyExc_ValueError,"_system not initialized");
+        return 0;
+    }
+    return PyType_GenericNew(type,args,kwds);
+}
+
+static PyMethodDef systemlock_methods[] = {
+    {"__enter__",systemlock_enter,METH_VARARGS,"Lock the system."},
+    {"__exit__",systemlock_exit,METH_VARARGS,"Unlock the system."},
+    {NULL}
+};
+
+static char *systemlock_doc = "SystemLock()\n\n"
+    "Context manager for locking the package system. The lock is established\n"
+    "as soon as the method __enter__() is called. It is released when\n"
+    "__exit__() is called.\n\n"
+    "This should be used via the 'with' statement, for example:\n\n"
+    "   with apt_pkg.SystemLock():\n"
+    "       ...\n\n"
+    "Once the block is left, the lock is released automatically. The object\n"
+    "can be used multiple times:\n\n"
+    "   lock = apt_pkg.SystemLock()\n"
+    "   with lock:\n"
+    "       ...\n"
+    "   with lock:\n"
+    "       ...\n\n";
+
+PyTypeObject PySystemLock_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    "apt_pkg.SystemLock",                // tp_name
+    0,                                   // tp_basicsize
+    0,                                   // tp_itemsize
+    // Methods
+    0,                                   // tp_dealloc
+    0,                                   // tp_print
+    0,                                   // tp_getattr
+    0,                                   // tp_setattr
+    0,                                   // tp_compare
+    0,                                   // tp_repr
+    0,                                   // tp_as_number
+    0,                                   // tp_as_sequence
+    0,                                   // tp_as_mapping
+    0,                                   // tp_hash
+    0,                                   // tp_call
+    0,                                   // tp_str
+    0,                                   // tp_getattro
+    0,                                   // tp_setattro
+    0,                                   // tp_as_buffer
+    (Py_TPFLAGS_DEFAULT |                // tp_flags
+     Py_TPFLAGS_BASETYPE),
+    systemlock_doc,                      // tp_doc
+    0,                                   // tp_traverse
+    0,                                   // tp_clear
+    0,                                   // tp_richcompare
+    0,                                   // tp_weaklistoffset
+    0,                                   // tp_iter
+    0,                                   // tp_iternext
+    systemlock_methods,                  // tp_methods
+    0,                                   // tp_members
+    0,                                   // tp_getset
+    0,                                   // tp_base
+    0,                                   // tp_dict
+    0,                                   // tp_descr_get
+    0,                                   // tp_descr_set
+    0,                                   // tp_dictoffset
+    0,                                   // tp_init
+    0,                                   // tp_alloc
+    systemlock_new,                      // tp_new
+};
+
+
+/**
+ * File Based locking.
+ *
+ * The counter is increased by every call to filelock_enter() and decreased by
+ * every call to filelock_exit(). When the counter reaches 0, the underlying
+ * file descriptor is closed.
+ *
+ * Members:
+ * @member char* filename   The name of the file
+ * @member int   lock_count How many times we have locked it.
+ * @member int   fd         The filedescriptor returned by GetLock() or 0.
+ */
+struct filelock_object {
+    PyObject_HEAD
+    char *filename;
+    int lock_count;
+    int fd;
+};
+
+static PyObject *filelock_enter(filelock_object *self, PyObject *args)
+{
+    self->lock_count++;
+    // If we have no lock yet, get a lock.
+    if (self->lock_count == 1) {
+        self->fd = GetLock(self->filename, true);
+        if (self->fd == -1) {
+            self->lock_count--;
+            return HandleErrors();
+        }
+    }
+    Py_INCREF(self);
+    return (PyObject *)self;
+}
+
+static PyObject *filelock_exit(filelock_object *self, PyObject *args)
+{
+    // Count down the lock_count, if it is less than 0, reset it to 0.
+    self->lock_count--;
+    if (self->lock_count < 0)
+        self->lock_count = 0;
+    if (self->lock_count == 0 && self->fd != 0 && close(self->fd) == -1) {
+        return PyErr_SetFromErrno(PyExc_OSError);
+    }
+    Py_RETURN_FALSE;
+}
+
+static PyObject *filelock_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+{
+    PyApt_Filename filename;
+    char *kwlist[] = {"filename",  NULL};
+    if (PyArg_ParseTupleAndKeywords(args, kwds, "O&:__init__", kwlist,
+                                    PyApt_Filename::Converter,
+                                    &filename) == 0) {
+        return NULL;
+    }
+    filelock_object *self = (filelock_object *)type->tp_alloc(type, 0);
+    // Copy the string into the object.
+    self->filename = new char[strlen(filename) + 1];
+    strcpy(self->filename, filename);
+    return (PyObject *)self;
+}
+
+static void filelock_dealloc(filelock_object *self)
+{
+    delete[] self->filename;
+    ((PyObject*)self)->ob_type->tp_free(self);
+}
+
+static PyMethodDef filelock_methods[] = {
+    {"__enter__",(PyCFunction)filelock_enter,METH_VARARGS,"Lock the system."},
+    {"__exit__",(PyCFunction)filelock_exit,METH_VARARGS,"Unlock the system."},
+    {NULL}
+};
+
+static char *filelock_doc = "FileLock(filename: str)\n\n"
+    "Context manager for locking using a file. The lock is established\n"
+    "as soon as the method __enter__() is called. It is released when\n"
+    "__exit__() is called.\n\n"
+    "This should be used via the 'with' statement, for example:\n\n"
+    "   with apt_pkg.FileLock(filename):\n"
+    "       ...\n\n"
+    "Once the block is left, the lock is released automatically. The object\n"
+    "can be used multiple times:\n\n"
+    "   lock = apt_pkg.FileLock(filename)\n"
+    "   with lock:\n"
+    "       ...\n"
+    "   with lock:\n"
+    "       ...\n\n";
+
+PyTypeObject PyFileLock_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    "apt_pkg.FileLock",                  // tp_name
+    sizeof(filelock_object),            // tp_basicsize
+    0,                                   // tp_itemsize
+    // Methods
+    destructor(filelock_dealloc),        // tp_dealloc
+    0,                                   // tp_print
+    0,                                   // tp_getattr
+    0,                                   // tp_setattr
+    0,                                   // tp_compare
+    0,                                   // tp_repr
+    0,                                   // tp_as_number
+    0,                                   // tp_as_sequence
+    0,                                   // tp_as_mapping
+    0,                                   // tp_hash
+    0,                                   // tp_call
+    0,                                   // tp_str
+    0,                                   // tp_getattro
+    0,                                   // tp_setattro
+    0,                                   // tp_as_buffer
+    (Py_TPFLAGS_DEFAULT |                // tp_flags
+     Py_TPFLAGS_BASETYPE),
+    filelock_doc,                        // tp_doc
+    0,                                   // tp_traverse
+    0,                                   // tp_clear
+    0,                                   // tp_richcompare
+    0,                                   // tp_weaklistoffset
+    0,                                   // tp_iter
+    0,                                   // tp_iternext
+    filelock_methods,                    // tp_methods
+    0,                                   // tp_members
+    0,                                   // tp_getset
+    0,                                   // tp_base
+    0,                                   // tp_dict
+    0,                                   // tp_descr_get
+    0,                                   // tp_descr_set
+    0,                                   // tp_dictoffset
+    0,                                   // tp_init
+    0,                                   // tp_alloc
+    filelock_new,                        // tp_new
+};