T39690: Modifications to Blender's 'temp dir' system.

Current temporary data of Blender suffers one major issue - default 'temp' dir on Windows is never
automatically cleaned up, and can end being quite big when used by Blender, especially when we have
to store per-process data (using getpid() in file names).

To address this, this patch:
* Divides tempdir paths in two, one for 'base' temp dir (the same as previous unique tempdir path),
  the other is a mkdtemp-generated sub-dir, specific to each Blender instance.
* Only uses base tempdir when we need some shallow persistance accross Blender sessions - and we always
  reuse the same filename (quit.blend...) or generate small file (crash reports...).
* Uses temp sub-dir for heavy files like pointcache or renderEXRs (Save Buffer option).
* Erases temp sub-dir on quit or crash.

To get this working it also adds a working 'recursive delete' to BLI_delete() under Windows.

Note that, as in current code, the 'recover render result' hack-feature that was possible
with SaveBuffer option is still removed. A real renderresult cache feature will be added
soon, though.

Reviewers: campbellbarton, brecht, sergey

Reviewed By: campbellbarton, sergey

CC: sergey

Differential Revision: https://developer.blender.org/D531

4 files changed, 5 insertions, 7 deletions

diff --git a/source/blender/blenkernel/intern/blender.c b/source/blender/blenkernel/intern/blender.c
index 38a180f85bc..a71d3987c58 100644
--- a/source/blender/blenkernel/intern/blender.c
+++ b/source/blender/blenkernel/intern/blender.c
@@ -668,7 +668,7 @@ void BKE_write_undo(bContext *C, const char *name)
 		counter = counter % U.undosteps;
 	
 		BLI_snprintf(numstr, sizeof(numstr), "%d.blend", counter);
-		BLI_make_file_string("/", filepath, BLI_temporary_dir(), numstr);
+		BLI_make_file_string("/", filepath, BLI_temp_dir_session(), numstr);
 	
 		/* success = */ /* UNUSED */ BLO_write_file(CTX_data_main(C), filepath, fileflags, NULL, NULL);
 		
diff --git a/source/blender/blenkernel/intern/modifier.c b/source/blender/blenkernel/intern/modifier.c
index b5cbec2870b..1c42603cf4a 100644
--- a/source/blender/blenkernel/intern/modifier.c
+++ b/source/blender/blenkernel/intern/modifier.c
@@ -709,7 +709,7 @@ const char *modifier_path_relbase(Object *ob)
 	else {
 		/* last resort, better then using "" which resolves to the current
 		 * working directory */
-		return BLI_temporary_dir();
+		return BLI_temp_dir_session();
 	}
 }
 
@@ -719,7 +719,7 @@ void modifier_path_init(char *path, int path_maxlen, const char *name)
 	/* elubie: changed this to default to the same dir as the render output
 	 * to prevent saving to C:\ on Windows */
 	BLI_join_dirfile(path, path_maxlen,
-	                 G.relbase_valid ? "//" : BLI_temporary_dir(),
+	                 G.relbase_valid ? "//" : BLI_temp_dir_session(),
 	                 name);
 }
 
diff --git a/source/blender/blenkernel/intern/pointcache.c b/source/blender/blenkernel/intern/pointcache.c
index c8042171a94..063a81e6efb 100644
--- a/source/blender/blenkernel/intern/pointcache.c
+++ b/source/blender/blenkernel/intern/pointcache.c
@@ -51,7 +51,6 @@
 #include "BLI_math.h"
 #include "BLI_utildefines.h"
 #include "BLI_system.h"
-#include BLI_SYSTEM_PID_H
 
 #include "BLF_translation.h"
 
@@ -96,7 +95,6 @@
 #endif
 
 /* needed for directory lookup */
-/* untitled blend's need getpid for a unique name */
 #ifndef WIN32
 #  include <dirent.h>
 #else
@@ -1466,7 +1464,7 @@ static int ptcache_path(PTCacheID *pid, char *filename)
 	
 	/* use the temp path. this is weak but better then not using point cache at all */
 	/* temporary directory is assumed to exist and ALWAYS has a trailing slash */
-	BLI_snprintf(filename, MAX_PTCACHE_PATH, "%s"PTCACHE_PATH"%d", BLI_temporary_dir(), abs(getpid()));
+	BLI_snprintf(filename, MAX_PTCACHE_PATH, "%s"PTCACHE_PATH, BLI_temp_dir_session());
 	
 	return BLI_add_slash(filename); /* new strlen() */
 }
diff --git a/source/blender/blenkernel/intern/smoke.c b/source/blender/blenkernel/intern/smoke.c
index bfbd8c6595c..89245d2300d 100644
--- a/source/blender/blenkernel/intern/smoke.c
+++ b/source/blender/blenkernel/intern/smoke.c
@@ -205,7 +205,7 @@ void smoke_reallocate_highres_fluid(SmokeDomainSettings *sds, float dx, int res[
 	/* smoke_turbulence_init uses non-threadsafe functions from fftw3 lib (like fftw_plan & co). */
 	BLI_lock_thread(LOCK_FFTW);
 
-	sds->wt = smoke_turbulence_init(res, sds->amplify + 1, sds->noise, BLI_temporary_dir(), use_fire, use_colors);
+	sds->wt = smoke_turbulence_init(res, sds->amplify + 1, sds->noise, BLI_temp_dir_session(), use_fire, use_colors);
 
 	BLI_unlock_thread(LOCK_FFTW);