Make display lists reference counted objects.

Remove fz_free_display_list from the API; instead use fz_drop_display_list.

10 files changed, 84 insertions, 77 deletions

diff --git a/android/jni/mupdf.c b/android/jni/mupdf.c
index f436a65d..e4333df0 100644
--- a/android/jni/mupdf.c
+++ b/android/jni/mupdf.c
@@ -134,9 +134,9 @@ static void drop_page_cache(globals *glo, page_cache *pc)
 	fz_document *doc = glo->doc;
 
 	LOGI("Drop page %d", pc->number);
-	fz_free_display_list(ctx, pc->page_list);
+	fz_drop_display_list(ctx, pc->page_list);
 	pc->page_list = NULL;
-	fz_free_display_list(ctx, pc->annot_list);
+	fz_drop_display_list(ctx, pc->annot_list);
 	pc->annot_list = NULL;
 	fz_free_page(doc, pc->page);
 	pc->page = NULL;
@@ -150,7 +150,7 @@ static void dump_annotation_display_lists(globals *glo)
 	int i;
 
 	for (i = 0; i < NUM_CACHE; i++) {
-		fz_free_display_list(ctx, glo->pages[i].annot_list);
+		fz_drop_display_list(ctx, glo->pages[i].annot_list);
 		glo->pages[i].annot_list = NULL;
 	}
 }
diff --git a/apps/mudraw.c b/apps/mudraw.c
index 38ac47d2..768298f1 100644
--- a/apps/mudraw.c
+++ b/apps/mudraw.c
@@ -389,7 +389,7 @@ static void drawpage(fz_context *ctx, fz_document *doc, int pagenum)
 		}
 		fz_catch(ctx)
 		{
-			fz_free_display_list(ctx, list);
+			fz_drop_display_list(ctx, list);
 			fz_free_page(doc, page);
 			fz_throw(ctx, "cannot draw page %d in file '%s'", pagenum, filename);
 		}
@@ -412,7 +412,7 @@ static void drawpage(fz_context *ctx, fz_document *doc, int pagenum)
 		}
 		fz_catch(ctx)
 		{
-			fz_free_display_list(ctx, list);
+			fz_drop_display_list(ctx, list);
 			fz_free_page(doc, page);
 			fz_rethrow(ctx);
 		}
@@ -459,7 +459,7 @@ static void drawpage(fz_context *ctx, fz_document *doc, int pagenum)
 		}
 		fz_catch(ctx)
 		{
-			fz_free_display_list(ctx, list);
+			fz_drop_display_list(ctx, list);
 			fz_free_page(doc, page);
 			fz_rethrow(ctx);
 		}
@@ -508,7 +508,7 @@ static void drawpage(fz_context *ctx, fz_document *doc, int pagenum)
 		}
 		fz_catch(ctx)
 		{
-			fz_free_display_list(ctx, list);
+			fz_drop_display_list(ctx, list);
 			fz_free_page(doc, page);
 			fz_rethrow(ctx);
 		}
@@ -682,14 +682,14 @@ static void drawpage(fz_context *ctx, fz_document *doc, int pagenum)
 		}
 		fz_catch(ctx)
 		{
-			fz_free_display_list(ctx, list);
+			fz_drop_display_list(ctx, list);
 			fz_free_page(doc, page);
 			fz_rethrow(ctx);
 		}
 	}
 
 	if (list)
-		fz_free_display_list(ctx, list);
+		fz_drop_display_list(ctx, list);
 
 	fz_free_page(doc, page);
 
diff --git a/apps/pdfapp.c b/apps/pdfapp.c
index 13d51a30..7371ea0c 100644
--- a/apps/pdfapp.c
+++ b/apps/pdfapp.c
@@ -223,59 +223,44 @@ void pdfapp_open(pdfapp_t *app, char *filename, int reload)
 
 void pdfapp_close(pdfapp_t *app)
 {
-	if (app->page_list)
-		fz_free_display_list(app->ctx, app->page_list);
+	fz_drop_display_list(app->ctx, app->page_list);
 	app->page_list = NULL;
 
-	if (app->annotations_list)
-		fz_free_display_list(app->ctx, app->annotations_list);
+	fz_drop_display_list(app->ctx, app->annotations_list);
 	app->annotations_list = NULL;
 
-	if (app->page_text)
-		fz_free_text_page(app->ctx, app->page_text);
+	fz_free_text_page(app->ctx, app->page_text);
 	app->page_text = NULL;
 
-	if (app->page_sheet)
-		fz_free_text_sheet(app->ctx, app->page_sheet);
+	fz_free_text_sheet(app->ctx, app->page_sheet);
 	app->page_sheet = NULL;
 
-	if (app->page_links)
-		fz_drop_link(app->ctx, app->page_links);
+	fz_drop_link(app->ctx, app->page_links);
 	app->page_links = NULL;
 
-	if (app->doctitle)
-		fz_free(app->ctx, app->doctitle);
+	fz_free(app->ctx, app->doctitle);
 	app->doctitle = NULL;
 
-	if (app->docpath)
-		fz_free(app->ctx, app->docpath);
+	fz_free(app->ctx, app->docpath);
 	app->docpath = NULL;
 
-	if (app->image)
-		fz_drop_pixmap(app->ctx, app->image);
+	fz_drop_pixmap(app->ctx, app->image);
 	app->image = NULL;
 
-	if (app->new_image)
-		fz_drop_pixmap(app->ctx, app->new_image);
+	fz_drop_pixmap(app->ctx, app->new_image);
 	app->new_image = NULL;
 
-	if (app->old_image)
-		fz_drop_pixmap(app->ctx, app->old_image);
+	fz_drop_pixmap(app->ctx, app->old_image);
 	app->old_image = NULL;
 
-	if (app->outline)
-		fz_free_outline(app->ctx, app->outline);
+	fz_free_outline(app->ctx, app->outline);
 	app->outline = NULL;
 
-	if (app->page)
-		fz_free_page(app->doc, app->page);
+	fz_free_page(app->doc, app->page);
 	app->page = NULL;
 
-	if (app->doc)
-	{
-		fz_close_document(app->doc);
-		app->doc = NULL;
-	}
+	fz_close_document(app->doc);
+	app->doc = NULL;
 
 	fz_flush_warnings(app->ctx);
 }
@@ -417,18 +402,12 @@ static void pdfapp_loadpage(pdfapp_t *app)
 
 	fz_var(mdev);
 
-	if (app->page_list)
-		fz_free_display_list(app->ctx, app->page_list);
-	if (app->annotations_list)
-		fz_free_display_list(app->ctx, app->annotations_list);
-	if (app->page_text)
-		fz_free_text_page(app->ctx, app->page_text);
-	if (app->page_sheet)
-		fz_free_text_sheet(app->ctx, app->page_sheet);
-	if (app->page_links)
-		fz_drop_link(app->ctx, app->page_links);
-	if (app->page)
-		fz_free_page(app->doc, app->page);
+	fz_drop_display_list(app->ctx, app->page_list);
+	fz_drop_display_list(app->ctx, app->annotations_list);
+	fz_free_text_page(app->ctx, app->page_text);
+	fz_free_text_sheet(app->ctx, app->page_sheet);
+	fz_drop_link(app->ctx, app->page_links);
+	fz_free_page(app->doc, app->page);
 
 	app->page_list = NULL;
 	app->annotations_list = NULL;
@@ -503,11 +482,8 @@ static void pdfapp_recreate_annotationslist(pdfapp_t *app)
 
 	fz_var(mdev);
 
-	if (app->annotations_list)
-	{
-		fz_free_display_list(app->ctx, app->annotations_list);
-		app->annotations_list = NULL;
-	}
+	fz_drop_display_list(app->ctx, app->annotations_list);
+	app->annotations_list = NULL;
 
 	fz_try(app->ctx)
 	{
diff --git a/fitz/dev_list.c b/fitz/dev_list.c
index 5caf34fd..972c4ba5 100644
--- a/fitz/dev_list.c
+++ b/fitz/dev_list.c
@@ -52,6 +52,7 @@ struct fz_display_node_s
 
 struct fz_display_list_s
 {
+	fz_storable storable;
 	fz_display_node *first;
 	fz_display_node *last;
 	int len;
@@ -586,10 +587,29 @@ fz_new_list_device(fz_context *ctx, fz_display_list *list)
 	return dev;
 }
 
+static void
+fz_free_display_list(fz_context *ctx, fz_storable *list_)
+{
+	fz_display_list *list = (fz_display_list *)list_;
+	fz_display_node *node;
+
+	if (list == NULL)
+		return;
+	node = list->first;
+	while (node)
+	{
+		fz_display_node *next = node->next;
+		fz_free_display_node(ctx, node);
+		node = next;
+	}
+	fz_free(ctx, list);
+}
+
 fz_display_list *
 fz_new_display_list(fz_context *ctx)
 {
 	fz_display_list *list = fz_malloc_struct(ctx, fz_display_list);
+	FZ_INIT_STORABLE(list, 1, fz_free_display_list);
 	list->first = NULL;
 	list->last = NULL;
 	list->len = 0;
@@ -598,21 +618,16 @@ fz_new_display_list(fz_context *ctx)
 	return list;
 }
 
-void
-fz_free_display_list(fz_context *ctx, fz_display_list *list)
+fz_display_list *
+fz_keep_display_list(fz_context *ctx, fz_display_list *list)
 {
-	fz_display_node *node;
+	return (fz_display_list *)fz_keep_storable(ctx, &list->storable);
+}
 
-	if (list == NULL)
-		return;
-	node = list->first;
-	while (node)
-	{
-		fz_display_node *next = node->next;
-		fz_free_display_node(ctx, node);
-		node = next;
-	}
-	fz_free(ctx, list);
+void
+fz_drop_display_list(fz_context *ctx, fz_display_list *list)
+{
+	fz_drop_storable(ctx, &list->storable);
 }
 
 static fz_display_node *
diff --git a/fitz/fitz.h b/fitz/fitz.h
index 1dc12ff9..73bf8bcd 100644
--- a/fitz/fitz.h
+++ b/fitz/fitz.h
@@ -2380,7 +2380,7 @@ struct fz_cookie_s
 	Create a displaylist with fz_new_display_list, hand it over to
 	fz_new_list_device to have it populated, and later replay the
 	list (once or many times) by calling fz_run_display_list. When
-	the list is no longer needed free it with fz_free_display_list.
+	the list is no longer needed drop it with fz_drop_display_list.
 */
 typedef struct fz_display_list_s fz_display_list;
 
@@ -2434,14 +2434,19 @@ fz_device *fz_new_list_device(fz_context *ctx, fz_display_list *list);
 void fz_run_display_list(fz_display_list *list, fz_device *dev, const fz_matrix *ctm, const fz_rect *area, fz_cookie *cookie);
 
 /*
-	fz_free_display_list: Frees a display list.
+	fz_keep_display_list: Keep a reference to a display list.
 
-	list: Display list to be freed. Any objects put into the
-	display list by a list device will also be freed.
+	Does not throw exceptions.
+*/
+fz_display_list *fz_keep_display_list(fz_context *ctx, fz_display_list *list);
+
+/*
+	fz_drop_display_list: Drop a reference to a display list, freeing it
+	if the reference count reaches zero.
 
 	Does not throw exceptions.
 */
-void fz_free_display_list(fz_context *ctx, fz_display_list *list);
+void fz_drop_display_list(fz_context *ctx, fz_display_list *list);
 
 /*
 	Links
diff --git a/fitz/res_font.c b/fitz/res_font.c
index 3263f88c..db2ffe5d 100644
--- a/fitz/res_font.c
+++ b/fitz/res_font.c
@@ -103,7 +103,7 @@ fz_drop_font(fz_context *ctx, fz_font *font)
 			if (font->t3procs[i])
 				fz_drop_buffer(ctx, font->t3procs[i]);
 			if (font->t3lists[i])
-				fz_free_display_list(ctx, font->t3lists[i]);
+				fz_drop_display_list(ctx, font->t3lists[i]);
 		}
 		fz_free(ctx, font->t3procs);
 		fz_free(ctx, font->t3lists);
diff --git a/fitz/text_extract.c b/fitz/text_extract.c
index bf50e6a4..01a789fd 100644
--- a/fitz/text_extract.c
+++ b/fitz/text_extract.c
@@ -369,7 +369,12 @@ fz_new_text_sheet(fz_context *ctx)
 void
 fz_free_text_sheet(fz_context *ctx, fz_text_sheet *sheet)
 {
-	fz_text_style *style = sheet->style;
+	fz_text_style *style;
+	
+	if (sheet == NULL)
+		return;
+
+	style = sheet->style;
 	while (style)
 	{
 		fz_text_style *next = style->next;
@@ -478,6 +483,8 @@ void
 fz_free_text_page(fz_context *ctx, fz_text_page *page)
 {
 	fz_page_block *block;
+	if (page == NULL)
+		return;
 	for (block = page->blocks; block < page->blocks + page->len; block++)
 	{
 		switch (block->type)
diff --git a/pdf/pdf_annot.c b/pdf/pdf_annot.c
index 4407616a..ad89725b 100644
--- a/pdf/pdf_annot.c
+++ b/pdf/pdf_annot.c
@@ -1086,7 +1086,7 @@ pdf_set_markup_obj_appearance(pdf_document *doc, pdf_obj *annot, float color[3],
 		fz_free_device(dev);
 		fz_drop_stroke_state(ctx, stroke);
 		fz_free_path(ctx, path);
-		fz_free_display_list(ctx, strike_list);
+		fz_drop_display_list(ctx, strike_list);
 	}
 	fz_catch(ctx)
 	{
@@ -1178,7 +1178,7 @@ pdf_set_ink_obj_appearance(pdf_document *doc, pdf_obj *annot)
 		fz_free_device(dev);
 		fz_drop_stroke_state(ctx, stroke);
 		fz_free_path(ctx, path);
-		fz_free_display_list(ctx, strike_list);
+		fz_drop_display_list(ctx, strike_list);
 	}
 	fz_catch(ctx)
 	{
diff --git a/pdf/pdf_page.c b/pdf/pdf_page.c
index 99776f42..c86cc6ee 100644
--- a/pdf/pdf_page.c
+++ b/pdf/pdf_page.c
@@ -468,6 +468,8 @@ pdf_load_links(pdf_document *xref, pdf_page *page)
 void
 pdf_free_page(pdf_document *xref, pdf_page *page)
 {
+	if (page == NULL)
+		return;
 	pdf_drop_obj(page->resources);
 	pdf_drop_obj(page->contents);
 	if (page->links)
diff --git a/xps/xps_doc.c b/xps/xps_doc.c
index 96eee8bc..178f2d6b 100644
--- a/xps/xps_doc.c
+++ b/xps/xps_doc.c
@@ -523,6 +523,8 @@ xps_bound_page(xps_document *doc, xps_page *page, fz_rect *bounds)
 void
 xps_free_page(xps_document *doc, xps_page *page)
 {
+	if (page == NULL)
+		return;
 	/* only free the XML contents */
 	if (page->root)
 		fz_free_xml(doc->ctx, page->root);