wxGUI/core: replace grass.script.tempfile by tempfile.NamedTemporaryFile (fixes https://trac.osgeo.org/grass/ticket/3637)

Switches from mapset temporary directory to system temporary
directory which was previously set up for the session for
all GUI rendering files.

This also refactors and unifies handling of the temporary files related
to rendering, although on error and when removing/deleting the layers
removing of the files happens in the same way as before.

All files are now using NamedTemporaryFile instead of some using
g.tempfile and some NamedTemporaryFile. This means that when mapset
is switched, files are present in the (correct) session directory,
not incorrect mapset directory and then not deleted later.
(Deleting these files could cause rendering errors, while not deleting
them would lead to accumulating of files in mapset temporary directory).

See also:
 * https://trac.osgeo.org/grass/changeset/28605 which adds glob for one delete when core.utils.GetTempfile(),
   i.e., g.tempfile was still used (the glob part is still there)
 * https://trac.osgeo.org/grass/changeset/56444 which adds mkstemp() for some of the files
 * https://trac.osgeo.org/grass/changeset/60947 attempt to fix cleaning of deleting temporary files (https://trac.osgeo.org/grass/ticket/560)
   which changes mkstemp to NamedTemporaryFile (still used now)
 * https://trac.osgeo.org/grass/changeset/69085 which checked legend row file (legrow) name of last character
   being digit (isdigit()) which was true for files from g.tempfile
   but does not seem to have a reason (removed now)
 * https://trac.osgeo.org/grass/ticket/3635 which investigates a suspicious cleanups of mapset temporary
   directory which at this point seemed to be cleaning rendering files
   from GUI (https://trac.osgeo.org/grass/changeset/37863, https://trac.osgeo.org/grass/changeset/21048)


git-svn-id: https://svn.osgeo.org/grass/grass/trunk@73334 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/core/render.py

@@ -47,6 +47,22 @@ from core.settings import UserSettings
 from core.gthread import gThread
 
 
+def get_tempfile_name(suffix, create=False):
+    """Returns a name for a temporary file in system directory"""
+    # this picks TMPDIR which we have set for GRASS session
+    # which may mitigate problems (like not cleaning files) in case we
+    # go little beyond what is in the documentation in terms of opening
+    # closing and removing the tmp file
+    tmp = tempfile.NamedTemporaryFile(suffix=suffix, delete=False)
+    # we don't want it open, we just need the name
+    name = tmp.name
+    tmp.close()
+    if not create:
+        # remove empty file to have a clean state later
+        os.remove(name)
+    return name
+
+
 class Layer(object):
     """Virtual class which stores information about layers (map layers and
     overlays) of the map composition.
@@ -81,12 +97,7 @@ class Layer(object):
             else:
                 tempfile_sfx = ".ppm"
 
-            mapfile = tempfile.NamedTemporaryFile(
-                suffix=tempfile_sfx, delete=False)
-            # we don't want it open, we just need the name
-            self.mapfile = mapfile.name
-            mapfile.close()
-            os.remove(self.mapfile)  # remove empty file
+            self.mapfile = get_tempfile_name(suffix=tempfile_sfx)
 
         self.maskfile = self.mapfile.rsplit(".", 1)[0] + ".pgm"
 
@@ -118,6 +129,7 @@ class Layer(object):
                    self.active, self.opacity, self.hidden))
 
     def __del__(self):
+        self.Clean()
         Debug.msg(3, "Layer.__del__(): layer=%s, cmd='%s'" %
                   (self.name, self.GetCmd(string=True)))
 
@@ -317,6 +329,14 @@ class Layer(object):
         """Get render manager """
         return self.renderMgr
 
+    def Clean(self):
+        if self.mapfile:
+            try_remove(self.mapfile)
+            self.mapfile = None
+        if self.maskfile:
+            try_remove(self.maskfile)
+            self.maskfile = None
+
 
 class MapLayer(Layer):
 
@@ -325,7 +345,7 @@ class MapLayer(Layer):
         """
         Layer.__init__(self, *args, **kwargs)
         if self.type in ('vector', 'thememap'):
-            self._legrow = grass.tempfile(create=True)
+            self._legrow = get_tempfile_name(suffix=".legrow", create=True)
         else:
             self._legrow = ''
 
@@ -343,6 +363,12 @@ class MapLayer(Layer):
         except IndexError:
             return self.name
 
+    def Clean(self):
+        Layer.Clean(self)
+        if self._legrow:
+            try_remove(self._legrow)
+            self._legrow = None
+
 
 class Overlay(Layer):
 
@@ -633,8 +659,7 @@ class RenderMapMgr(wx.EvtHandler):
                 if layer.GetType() not in ('vector', 'thememap'):
                     continue
 
-                if os.path.isfile(layer._legrow) and layer._legrow[-1].isdigit() \
-                   and layer.hidden is False:
+                if os.path.isfile(layer._legrow) and not layer.hidden:
                     with open(layer._legrow) as infile:
                         line = infile.read()
                         outfile.write(line)
@@ -744,10 +769,8 @@ class Map(object):
         self.gisrc = gisrc
 
         # generated file for g.pnmcomp output for rendering the map
-        self.legfile = grass.tempfile(create=False) + '.leg'
-        self.tmpdir = os.path.dirname(self.legfile)
-        self.mapfile = grass.tempfile(create=False) + '.ppm'
-
+        self.legfile = get_tempfile_name(suffix='.leg')
+        self.mapfile = get_tempfile_name(suffix='.ppm')
 
         # setting some initial env. variables
         if not self.GetWindow():
@@ -1318,6 +1341,9 @@ class Map(object):
                 if base == '' or tempbase == '':
                     return None
                 basefile = os.path.join(base, tempbase) + r'.*'
+                # this comes all the way from r28605, so leaving
+                # it as it is, although it does not really fit with the
+                # new system (but probably works well enough)
                 for f in glob.glob(basefile):
                     os.remove(f)
 
@@ -1566,11 +1592,8 @@ class Map(object):
 
     def _clean(self, llist):
         for layer in llist:
-            if layer.maskfile:
-                try_remove(layer.maskfile)
-            if layer.mapfile:
-                try_remove(layer.mapfile)
-            llist.remove(layer)
+            layer.Clean()
+        del llist[:]
 
     def Clean(self):
         """Clean layer stack - go trough all layers and remove them
@@ -1580,6 +1603,8 @@ class Map(object):
         """
         self._clean(self.layers)
         self._clean(self.overlays)
+        try_remove(self.mapfile)
+        try_remove(self.legfile)
 
     def ReverseListOfLayers(self):
         """Reverse list of layers"""