Revert "Revert "Manage AST NODEs out of GC""

This re-introduces r60485.
This reverts commit 5a176b75b1187cbd3861c387bde65ff66396a07c.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60488 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 104 insertions, 0 deletions

diff --git a/node.c b/node.c
index f6011d585d..d9c115ba3c 100644
--- a/node.c
+++ b/node.c
@@ -1211,3 +1211,107 @@ rb_gc_mark_node(NODE *obj)
     }
     return 0;
 }
+
+typedef struct node_buffer_elem_struct {
+    struct node_buffer_elem_struct *next;
+    NODE buf[1];
+} node_buffer_elem_t;
+
+typedef struct node_buffer_struct {
+    long idx, len;
+    node_buffer_elem_t *head;
+    node_buffer_elem_t body;
+} node_buffer_t;
+
+node_buffer_t *
+rb_node_buffer_new()
+{
+    node_buffer_t *nb = xmalloc(sizeof(node_buffer_t) + 16 * sizeof(NODE));
+    nb->idx = 0;
+    nb->len = 16;
+    nb->head = &nb->body;
+    nb->head->next = NULL;
+    return nb;
+}
+
+void
+rb_node_buffer_free(node_buffer_t *nb)
+{
+    node_buffer_elem_t *nbe = nb->head;
+
+    while (nbe != &nb->body) {
+	void *buf = nbe;
+	nbe = nbe->next;
+	xfree(buf);
+    }
+    xfree(nb);
+}
+
+NODE *
+rb_ast_newnode(ast_t *ast)
+{
+    node_buffer_t *nb = ast->node_buffer;
+    if (nb->idx >= nb->len) {
+	long n = nb->len * 2;
+	node_buffer_elem_t *nbe;
+	nbe = xmalloc(sizeof(node_buffer_elem_t) + n * sizeof(NODE));
+	nb->idx = 0;
+	nb->len = n;
+	nbe->next = nb->head;
+	nb->head = nbe;
+    }
+    return &nb->head->buf[nb->idx++];
+}
+
+void
+rb_ast_delete_node(ast_t *ast, NODE *n)
+{
+    (void)ast;
+    (void)n;
+    /* should we implement freelist? */
+}
+
+ast_t *
+rb_ast_new(void)
+{
+    return (ast_t *)rb_imemo_new(imemo_ast, 0, (VALUE)rb_node_buffer_new(), rb_ary_tmp_new(0), 0);
+}
+
+void
+rb_ast_mark(ast_t *ast)
+{
+    if (ast->node_buffer) rb_gc_mark(ast->mark_ary);
+}
+
+void
+rb_ast_free(ast_t *ast)
+{
+    if (ast->node_buffer) rb_node_buffer_free(ast->node_buffer);
+    ast->node_buffer = 0;
+    ast->root = 0;
+    ast->mark_ary = 0;
+}
+
+void
+rb_ast_dispose(ast_t *ast)
+{
+    rb_ast_free(ast);
+    rb_gc_writebarrier_remember((VALUE)ast);
+}
+
+void
+rb_ast_add_mark_object(ast_t *ast, VALUE obj)
+{
+    rb_ary_push(ast->mark_ary, obj);
+}
+
+void
+rb_ast_delete_mark_object(ast_t *ast, VALUE obj)
+{
+    long i;
+    for (i = 0; i < RARRAY_LEN(ast->mark_ary); i++) {
+	if (obj == RARRAY_AREF(ast->mark_ary, i)) {
+	    RARRAY_ASET(ast->mark_ary, i, Qnil);
+	}
+    }
+}