Codegen: write temporary files first, and rename them into place

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=36398
Reviewed-by: Xavier Claessens <xavier.claessens@collabora.co.uk>

8 files changed, 80 insertions, 35 deletions

diff --git a/tools/c-constants-gen.py b/tools/c-constants-gen.py
index ff2a24d47..bc0484973 100644
--- a/tools/c-constants-gen.py
+++ b/tools/c-constants-gen.py
@@ -3,6 +3,7 @@
 from sys import argv, stdout, stderr
 import xml.dom.minidom
 
+from libtpcodegen import file_set_contents
 from libglibcodegen import NS_TP, get_docstring, \
         get_descendant_text, get_by_path
 
@@ -11,19 +12,23 @@ class Generator(object):
         self.prefix = prefix + '_'
         self.spec = get_by_path(dom, "spec")[0]
 
-        self.__header = open(output_base + '.h', 'w')
-        self.__docs = open(output_base + '-gtk-doc.h', 'w')
+	self.output_base = output_base
+        self.__header = []
+        self.__docs = []
 
     def __call__(self):
         self.do_header()
         self.do_body()
         self.do_footer()
 
+        file_set_contents(self.output_base + '.h', ''.join(self.__header))
+        file_set_contents(self.output_base + '-gtk-doc.h', ''.join(self.__docs))
+
     def write(self, code):
-        self.__header.write(code.encode('utf-8'))
+        self.__header.append(code.encode('utf-8'))
 
     def d(self, code):
-        self.__docs.write(code.encode('utf-8'))
+        self.__docs.append(code.encode('utf-8'))
 
     # Header
     def do_header(self):
diff --git a/tools/glib-client-gen.py b/tools/glib-client-gen.py
index 446d198f4..c94bd2c31 100644
--- a/tools/glib-client-gen.py
+++ b/tools/glib-client-gen.py
@@ -27,6 +27,7 @@ import os.path
 import xml.dom.minidom
 from getopt import gnu_getopt
 
+from libtpcodegen import file_set_contents
 from libglibcodegen import Signature, type_to_gtype, cmp_by_name, \
         get_docstring, xml_escape, get_deprecated
 
@@ -1228,10 +1229,9 @@ class Generator(object):
         self.h('G_END_DECLS')
         self.h('')
 
-        open(self.basename + '.h', 'w').write('\n'.join(self.__header))
-        open(self.basename + '-body.h', 'w').write('\n'.join(self.__body))
-        open(self.basename + '-gtk-doc.h', 'w').write('\n'.join(self.__docs))
-
+        file_set_contents(self.basename + '.h', '\n'.join(self.__header))
+        file_set_contents(self.basename + '-body.h', '\n'.join(self.__body))
+        file_set_contents(self.basename + '-gtk-doc.h', '\n'.join(self.__docs))
 
 def types_to_gtypes(types):
     return [type_to_gtype(t)[1] for t in types]
diff --git a/tools/glib-errors-str-gen.py b/tools/glib-errors-str-gen.py
index a948a7ca8..b2cf520bd 100644
--- a/tools/glib-errors-str-gen.py
+++ b/tools/glib-errors-str-gen.py
@@ -3,6 +3,7 @@
 import sys
 import xml.dom.minidom
 
+from libtpcodegen import file_set_contents
 from libglibcodegen import NS_TP, get_docstring, xml_escape
 
 class Generator(object):
@@ -71,9 +72,9 @@ class Generator(object):
         self.h('')
         self.b('')
 
-        open(self.basename + '.h', 'w').write('\n'.join(self.__header))
-        open(self.basename + '.c', 'w').write('\n'.join(self.__body))
-        open(self.basename + '-gtk-doc.h', 'w').write('\n'.join(self.__docs))
+        file_set_contents(self.basename + '.h', '\n'.join(self.__header))
+        file_set_contents(self.basename + '.c', '\n'.join(self.__body))
+        file_set_contents(self.basename + '-gtk-doc.h', '\n'.join(self.__docs))
 
 if __name__ == '__main__':
     argv = sys.argv[1:]
diff --git a/tools/glib-ginterface-gen.py b/tools/glib-ginterface-gen.py
index cc4e1f0c4..784397738 100644
--- a/tools/glib-ginterface-gen.py
+++ b/tools/glib-ginterface-gen.py
@@ -26,6 +26,7 @@ import sys
 import os.path
 import xml.dom.minidom
 
+from libtpcodegen import file_set_contents
 from libglibcodegen import Signature, type_to_gtype, cmp_by_name, \
         NS_TP, dbus_gutils_wincaps_to_uscore
 
@@ -762,10 +763,9 @@ class Generator(object):
 
         self.h('')
         self.b('')
-        open(self.basename + '.h', 'w').write('\n'.join(self.__header))
-        open(self.basename + '.c', 'w').write('\n'.join(self.__body))
-        open(self.basename + '-gtk-doc.h', 'w').write('\n'.join(self.__docs))
-
+        file_set_contents(self.basename + '.h', '\n'.join(self.__header))
+        file_set_contents(self.basename + '.c', '\n'.join(self.__body))
+        file_set_contents(self.basename + '-gtk-doc.h', '\n'.join(self.__docs))
 
 def cmdline_error():
     print """\
diff --git a/tools/glib-gtypes-generator.py b/tools/glib-gtypes-generator.py
index a49c36e7f..e5e62904a 100644
--- a/tools/glib-gtypes-generator.py
+++ b/tools/glib-gtypes-generator.py
@@ -23,6 +23,7 @@
 import sys
 import xml.dom.minidom
 
+from libtpcodegen import file_set_contents
 from libglibcodegen import escape_as_identifier, \
                            get_docstring, \
                            NS_TP, \
@@ -42,15 +43,16 @@ class GTypesGenerator(object):
         self.PREFIX_ = self.Prefix.upper() + '_'
         self.prefix_ = self.Prefix.lower() + '_'
 
-        self.header = open(output + '.h', 'w')
-        self.body = open(output + '-body.h', 'w')
-        self.docs = open(output + '-gtk-doc.h', 'w')
+        self.header = []
+        self.body = []
+        self.docs = []
+        self.output = output
 
         for f in (self.header, self.body, self.docs):
-            f.write('/* Auto-generated, do not edit.\n *\n'
-                    ' * This file may be distributed under the same terms\n'
-                    ' * as the specification from which it was generated.\n'
-                    ' */\n\n')
+            f.append('/* Auto-generated, do not edit.\n *\n'
+                     ' * This file may be distributed under the same terms\n'
+                     ' * as the specification from which it was generated.\n'
+                     ' */\n\n')
 
         # keys are e.g. 'sv', values are the key escaped
         self.need_mappings = {}
@@ -66,13 +68,13 @@ class GTypesGenerator(object):
         self.need_other_arrays = {}
 
     def h(self, code):
-        self.header.write(code.encode("utf-8"))
+        self.header.append(code.encode("utf-8"))
 
     def c(self, code):
-        self.body.write(code.encode("utf-8"))
+        self.body.append(code.encode("utf-8"))
 
     def d(self, code):
-        self.docs.write(code.encode('utf-8'))
+        self.docs.append(code.encode('utf-8'))
 
     def do_mapping_header(self, mapping):
         members = mapping.getElementsByTagNameNS(NS_TP, 'member')
@@ -290,6 +292,10 @@ class GTypesGenerator(object):
             self.c('  return t;\n')
             self.c('}\n\n')
 
+        file_set_contents(self.output + '.h', ''.join(self.header))
+        file_set_contents(self.output + '-body.h', ''.join(self.body))
+        file_set_contents(self.output + '-gtk-doc.h', ''.join(self.docs))
+
 if __name__ == '__main__':
     argv = sys.argv[1:]
 
diff --git a/tools/glib-interfaces-gen.py b/tools/glib-interfaces-gen.py
index bc5c04da3..410762cde 100644
--- a/tools/glib-interfaces-gen.py
+++ b/tools/glib-interfaces-gen.py
@@ -3,6 +3,7 @@
 from sys import argv, stdout, stderr
 import xml.dom.minidom
 
+from libtpcodegen import file_set_contents
 from libglibcodegen import NS_TP, get_docstring, \
         get_descendant_text, get_by_path
 
@@ -13,25 +14,33 @@ class Generator(object):
         assert declfile.endswith('.h')
         docfile = declfile[:-2] + '-gtk-doc.h'
 
-        self.impls = open(implfile, 'w')
-        self.decls = open(declfile, 'w')
-        self.docs = open(docfile, 'w')
+        self.implfile = implfile
+        self.declfile = declfile
+        self.docfile = docfile
+
+        self.impls = []
+        self.decls = []
+        self.docs = []
         self.spec = get_by_path(dom, "spec")[0]
 
     def h(self, code):
-        self.decls.write(code.encode('utf-8'))
+        self.decls.append(code.encode('utf-8'))
 
     def c(self, code):
-        self.impls.write(code.encode('utf-8'))
+        self.impls.append(code.encode('utf-8'))
 
     def d(self, code):
-        self.docs.write(code.encode('utf-8'))
+        self.docs.append(code.encode('utf-8'))
 
     def __call__(self):
         for f in self.h, self.c:
             self.do_header(f)
         self.do_body()
 
+        file_set_contents(self.implfile, ''.join(self.impls))
+        file_set_contents(self.declfile, ''.join(self.decls))
+        file_set_contents(self.docfile, ''.join(self.docs))
+
     # Header
     def do_header(self, f):
         f('/* Generated from: ')
diff --git a/tools/libtpcodegen.py b/tools/libtpcodegen.py
index 837ff2f74..7e9eb9a50 100644
--- a/tools/libtpcodegen.py
+++ b/tools/libtpcodegen.py
@@ -20,7 +20,7 @@ please make any changes there.
 # License along with this library; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
-
+import os
 from string import ascii_letters, digits
 
 
@@ -28,6 +28,18 @@ NS_TP = "http://telepathy.freedesktop.org/wiki/DbusSpec#extensions-v0"
 
 _ASCII_ALNUM = ascii_letters + digits
 
+def file_set_contents(filename, contents):
+    try:
+        os.remove(filename)
+    except OSError:
+        pass
+    try:
+        os.remove(filename + '.tmp')
+    except OSError:
+        pass
+
+    open(filename + '.tmp', 'w').write(contents)
+    os.rename(filename + '.tmp', filename)
 
 def cmp_by_name(node1, node2):
     return cmp(node1.getAttributeNode("name").nodeValue,
diff --git a/tools/manager-file.py b/tools/manager-file.py
index 45f640403..e1b51a616 100644
--- a/tools/manager-file.py
+++ b/tools/manager-file.py
@@ -163,13 +163,25 @@ if __name__ == '__main__':
     environment = {}
     execfile(sys.argv[1], environment)
 
-    f = open('%s/%s.manager' % (sys.argv[2], environment['MANAGER']), 'w')
+    filename = '%s/%s.manager' % (sys.argv[2], environment['MANAGER'])
+    try:
+        os.remove(filename)
+    except OSError:
+        pass
+    f = open(filename + '.tmp', 'w')
     write_manager(f, environment['MANAGER'], environment['PARAMS'])
     f.close()
-
-    f = open('%s/param-spec-struct.h' % sys.argv[2], 'w')
+    os.rename(filename + '.tmp', filename)
+
+    filename = '%s/param-spec-struct.h' % sys.argv[2]
+    try:
+        os.remove(filename)
+    except OSError:
+        pass
+    f = open(filename + '.tmp', 'w')
     for protocol in environment['PARAMS']:
         write_c_params(f, environment['MANAGER'], protocol,
                 environment['STRUCTS'][protocol],
                 environment['PARAMS'][protocol])
     f.close()
+    os.rename(filename + '.tmp', filename)