From f1c8603e9591187542718e43ec7f4202e0da202f Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@gnu.org>
Date: Fri, 19 Jun 2009 22:52:40 -0700
Subject: [PATCH] output: Make tables reference-counted.

Adding a reference count to tab_table allows output drivers to retain
a copy of a table even after the main output engine is done.  This
will be useful for the GUI output driver.
---
 src/output/table.c | 16 ++++++++++++++--
 src/output/table.h |  2 ++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/output/table.c b/src/output/table.c
index 9457923a..1b052888 100644
--- a/src/output/table.c
+++ b/src/output/table.c
@@ -62,6 +62,7 @@ tab_create (int nc, int nr, int reallocable UNUSED)
   struct tab_table *t;
 
   t = pool_create_container (struct tab_table, container);
+  t->ref_cnt = 1;
   t->col_style = TAB_COL_NONE;
   t->col_group = 0;
   t->title = NULL;
@@ -86,17 +87,28 @@ tab_create (int nc, int nr, int reallocable UNUSED)
   return t;
 }
 
-/* Destroys table T. */
+/* Increases T's reference count and, if this causes T's
+   reference count to reach 0, destroys T. */
 void
 tab_destroy (struct tab_table *t)
 {
-  assert (t != NULL);
+  assert (t->ref_cnt > 0);
+  if (--t->ref_cnt > 0)
+    return;
   if (t->dim_free != NULL)
     t->dim_free (t->dim_aux);
   free (t->title);
   pool_destroy (t->container);
 }
 
+/* Increases T's reference count. */
+void
+tab_ref (struct tab_table *t)
+{
+  assert (t->ref_cnt > 0);
+  t->ref_cnt++;
+}
+
 /* Sets the width and height of a table, in columns and rows,
    respectively.  Use only to reduce the size of a table, since it
    does not change the amount of allocated memory. */
diff --git a/src/output/table.h b/src/output/table.h
index 516db6a5..03c981a3 100644
--- a/src/output/table.h
+++ b/src/output/table.h
@@ -76,6 +76,7 @@ typedef void tab_dim_free_func (void *aux);
 struct tab_table
   {
     struct pool *container;
+    int ref_cnt;                /* Reference count. */
 
     /* Contents. */
     int col_style;		/* Columns: One of TAB_COL_*. */
@@ -129,6 +130,7 @@ struct tab_rendering
 /* Tables. */
 struct tab_table *tab_create (int nc, int nr, int reallocable);
 void tab_destroy (struct tab_table *);
+void tab_ref (struct tab_table *);
 void tab_resize (struct tab_table *, int nc, int nr);
 void tab_realloc (struct tab_table *, int nc, int nr);
 void tab_headers (struct tab_table *, int l, int r, int t, int b);
-- 
2.30.2