Refactor ID copying (and to some extent, ID freeing).

This will allow much finer controll over how we copy data-blocks, from
full copy in Main database, to "lighter" ones (out of Main, inside an
already allocated datablock, etc.).

This commit also transfers a llot of what was previously handled by
per-ID-type custom code to generic ID handling code in BKE_library.
Hopefully will avoid in future inconsistencies and missing bits we had
all over the codebase in the past.

It also adds missing copying handling for a few types, most notably
Scene (which where using a fully customized handling previously).

Note that the type of allocation used during copying (regular in Main,
allocated but outside of Main, or not allocated by ID handling code at
all) is stored in ID's, which allows to handle them correctly when
freeing. This needs to be taken care of with caution when doing 'weird'
unusual things with ID copying and/or allocation!

As a final note, while rather noisy, this commit will hopefully not
break too much existing branches, old 'API' has been kept for the main
part, as a wrapper around new code. Cleaning it up will happen later.

Design task : T51804
Phab Diff: D2714

1 files changed, 29 insertions, 22 deletions

diff --git a/source/blender/blenkernel/intern/idprop.c b/source/blender/blenkernel/intern/idprop.c
index a3bd15252cb..9796903afc4 100644
--- a/source/blender/blenkernel/intern/idprop.c
+++ b/source/blender/blenkernel/intern/idprop.c
@@ -90,7 +90,7 @@ IDProperty *IDP_NewIDPArray(const char *name)
 	return prop;
 }
 
-IDProperty *IDP_CopyIDPArray(const IDProperty *array)
+IDProperty *IDP_CopyIDPArray(const IDProperty *array, const int flag)
 {
 	/* don't use MEM_dupallocN because this may be part of an array */
 	IDProperty *narray, *tmp;
@@ -109,7 +109,7 @@ IDProperty *IDP_CopyIDPArray(const IDProperty *array)
 		 * then free it.  this makes for more maintainable
 		 * code than simply reimplementing the copy functions
 		 * in this loop.*/
-		tmp = IDP_CopyProperty(GETPROP(narray, i));
+		tmp = IDP_CopyProperty_ex(GETPROP(narray, i), flag);
 		memcpy(GETPROP(narray, i), tmp, sizeof(IDProperty));
 		MEM_freeN(tmp);
 	}
@@ -285,9 +285,9 @@ void IDP_FreeArray(IDProperty *prop)
 }
 
 
-static IDProperty *idp_generic_copy(const IDProperty *prop)
+static IDProperty *idp_generic_copy(const IDProperty *prop, const int UNUSED(flag))
 {
-	IDProperty *newp = MEM_callocN(sizeof(IDProperty), "IDProperty array dup");
+	IDProperty *newp = MEM_callocN(sizeof(IDProperty), __func__);
 
 	BLI_strncpy(newp->name, prop->name, MAX_IDPROP_NAME);
 	newp->type = prop->type;
@@ -298,9 +298,9 @@ static IDProperty *idp_generic_copy(const IDProperty *prop)
 	return newp;
 }
 
-static IDProperty *IDP_CopyArray(const IDProperty *prop)
+static IDProperty *IDP_CopyArray(const IDProperty *prop, const int flag)
 {
-	IDProperty *newp = idp_generic_copy(prop);
+	IDProperty *newp = idp_generic_copy(prop, flag);
 
 	if (prop->data.pointer) {
 		newp->data.pointer = MEM_dupallocN(prop->data.pointer);
@@ -310,7 +310,7 @@ static IDProperty *IDP_CopyArray(const IDProperty *prop)
 			int a;
 
 			for (a = 0; a < prop->len; a++)
-				array[a] = IDP_CopyProperty(array[a]);
+				array[a] = IDP_CopyProperty_ex(array[a], flag);
 		}
 	}
 	newp->len = prop->len;
@@ -363,12 +363,12 @@ IDProperty *IDP_NewString(const char *st, const char *name, int maxlen)
 	return prop;
 }
 
-static IDProperty *IDP_CopyString(const IDProperty *prop)
+static IDProperty *IDP_CopyString(const IDProperty *prop, const int flag)
 {
 	IDProperty *newp;
 
 	BLI_assert(prop->type == IDP_STRING);
-	newp = idp_generic_copy(prop);
+	newp = idp_generic_copy(prop, flag);
 
 	if (prop->data.pointer)
 		newp->data.pointer = MEM_dupallocN(prop->data.pointer);
@@ -442,15 +442,17 @@ void IDP_FreeString(IDProperty *prop)
 /** \name IDProperty ID API
  * \{ */
 
-static IDProperty *IDP_CopyID(const IDProperty *prop)
+static IDProperty *IDP_CopyID(const IDProperty *prop, const int flag)
 {
 	IDProperty *newp;
 
 	BLI_assert(prop->type == IDP_ID);
-	newp = idp_generic_copy(prop);
+	newp = idp_generic_copy(prop, flag);
 
 	newp->data.pointer = prop->data.pointer;
-	id_us_plus(IDP_Id(newp));
+	if ((flag & LIB_ID_CREATE_NO_USER_REFCOUNT) == 0) {
+		id_us_plus(IDP_Id(newp));
+	}
 
 	return newp;
 }
@@ -467,17 +469,17 @@ static IDProperty *IDP_CopyID(const IDProperty *prop)
 /**
  * Checks if a property with the same name as prop exists, and if so replaces it.
  */
-static IDProperty *IDP_CopyGroup(const IDProperty *prop)
+static IDProperty *IDP_CopyGroup(const IDProperty *prop, const int flag)
 {
 	IDProperty *newp, *link;
 	
 	BLI_assert(prop->type == IDP_GROUP);
-	newp = idp_generic_copy(prop);
+	newp = idp_generic_copy(prop, flag);
 	newp->len = prop->len;
 	newp->subtype = prop->subtype;
 
 	for (link = prop->data.group.first; link; link = link->next) {
-		BLI_addtail(&newp->data.group, IDP_CopyProperty(link));
+		BLI_addtail(&newp->data.group, IDP_CopyProperty_ex(link, flag));
 	}
 
 	return newp;
@@ -748,18 +750,23 @@ static void IDP_FreeGroup(IDProperty *prop, const bool do_id_user)
 
 /** \name IDProperty Main API
  * \{ */
-IDProperty *IDP_CopyProperty(const IDProperty *prop)
+IDProperty *IDP_CopyProperty_ex(const IDProperty *prop, const int flag)
 {
 	switch (prop->type) {
-		case IDP_GROUP: return IDP_CopyGroup(prop);
-		case IDP_STRING: return IDP_CopyString(prop);
-		case IDP_ID: return IDP_CopyID(prop);
-		case IDP_ARRAY: return IDP_CopyArray(prop);
-		case IDP_IDPARRAY: return IDP_CopyIDPArray(prop);
-		default: return idp_generic_copy(prop);
+		case IDP_GROUP: return IDP_CopyGroup(prop, flag);
+		case IDP_STRING: return IDP_CopyString(prop, flag);
+		case IDP_ID: return IDP_CopyID(prop, flag);
+		case IDP_ARRAY: return IDP_CopyArray(prop, flag);
+		case IDP_IDPARRAY: return IDP_CopyIDPArray(prop, flag);
+		default: return idp_generic_copy(prop, flag);
 	}
 }
 
+IDProperty *IDP_CopyProperty(const IDProperty *prop)
+{
+	return IDP_CopyProperty_ex(prop, 0);
+}
+
 /* Updates ID pointers after an object has been copied */
 /* TODO Nuke this once its only user has been correctly converted to use generic ID management from BKE_library! */
 void IDP_RelinkProperty(struct IDProperty *prop)