X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=buffer_tree.c;h=28999df50a38b31277a156acfd012e2e54806535;hb=c87045a40b9462ebeb28cc169d7bb3721c9a81d3;hp=2a52f097a325641c5695ae841eaa4608263d3d99;hpb=c4d243653174f3f4ffc331a4bfc54de94d612f34;p=paraslash.git

diff --git a/buffer_tree.c b/buffer_tree.c
index 2a52f097..28999df5 100644
--- a/buffer_tree.c
+++ b/buffer_tree.c
@@ -36,6 +36,7 @@ struct btr_node {
 	 */
 	struct list_head input_queue;
 	btr_command_handler execute;
+	void *context;
 };
 
 #define FOR_EACH_CHILD(_tn, _btrn) list_for_each_entry((_tn), \
@@ -46,14 +47,15 @@ struct btr_node {
 #define FOR_EACH_BUFFER_REF_SAFE(_br, _tmp, _btrn) \
 	list_for_each_entry_safe((_br), (_tmp), &(_btrn)->input_queue, node)
 
-struct btr_node *btr_new_node(char *name, struct btr_node *parent,
-		btr_command_handler handler)
+struct btr_node *btr_new_node(const char *name, struct btr_node *parent,
+		btr_command_handler handler, void *context)
 {
 	struct btr_node *btrn = para_malloc(sizeof(*btrn));
 
 	btrn->name = para_strdup(name);
 	btrn->parent = parent;
 	btrn->execute = handler;
+	btrn->context = context;
 	if (parent)
 		list_add_tail(&btrn->node, &parent->children);
 	INIT_LIST_HEAD(&btrn->children);
@@ -93,14 +95,15 @@ static void btr_drop_buffer_reference(struct btr_buffer_reference *br)
 	}
 }
 
-static void add_btrb_to_children(struct btr_buffer *btrb, struct btr_node *btrn)
+static void add_btrb_to_children(struct btr_buffer *btrb,
+		struct btr_node *btrn, size_t consumed)
 {
 	struct btr_node *ch;
 
 	FOR_EACH_CHILD(ch, btrn) {
 		struct btr_buffer_reference *br = para_malloc(sizeof(*br));
 		br->btrb = btrb;
-		br->consumed = 0;
+		br->consumed = consumed;
 		list_add_tail(&br->node, &ch->input_queue);
 		btrb->refcount++;
 	}
@@ -111,12 +114,12 @@ void btr_add_output(char *buf, size_t size, struct btr_node *btrn)
 	struct btr_buffer *btrb;
 
 	btrb = new_btrb(buf, size);
-	add_btrb_to_children(btrb, btrn);
+	add_btrb_to_children(btrb, btrn, 0);
 }
 
 static void btr_pushdown_br(struct btr_buffer_reference *br, struct btr_node *btrn)
 {
-	add_btrb_to_children(br->btrb, btrn);
+	add_btrb_to_children(br->btrb, btrn, br->consumed);
 	btr_drop_buffer_reference(br);
 }
 
@@ -216,6 +219,24 @@ size_t btr_get_input_queue_size(struct btr_node *btrn)
 	return size;
 }
 
+int btr_splice_out_node(struct btr_node *btrn)
+{
+	struct btr_node *ch;
+
+	if (!btrn)
+		return -ERRNO_TO_PARA_ERROR(EINVAL);
+	if (btr_get_input_queue_size(btrn) != 0)
+		return -ERRNO_TO_PARA_ERROR(EINVAL);
+	PARA_NOTICE_LOG("splicing out %s\n", btrn->name);
+	if (btrn->parent)
+		list_del(&btrn->node);
+	FOR_EACH_CHILD(ch, btrn)
+		ch->parent = btrn->parent;
+	free(btrn->name);
+	free(btrn);
+	return 1;
+}
+
 /**
  * Return the size of the largest input queue.
  *
@@ -239,7 +260,7 @@ int btr_exec(struct btr_node *btrn, const char *command, char **value_result)
 		return -ERRNO_TO_PARA_ERROR(EINVAL);
 	if (!btrn->execute)
 		return -ERRNO_TO_PARA_ERROR(ENOTSUP);
-	return btrn->execute(command, value_result);
+	return btrn->execute(btrn, command, value_result);
 }
 
 int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result)
@@ -253,7 +274,7 @@ int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result)
 			return -ERRNO_TO_PARA_ERROR(ENOTSUP);
 		if (!parent->execute)
 			continue;
-		ret = parent->execute(command, value_result);
+		ret = parent->execute(parent, command, value_result);
 		if (ret == -ERRNO_TO_PARA_ERROR(ENOTSUP))
 			continue;
 		if (ret < 0)
@@ -261,3 +282,56 @@ int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result)
 	}
 	return -ERRNO_TO_PARA_ERROR(ENOTSUP);
 }
+
+void *btr_context(struct btr_node *btrn)
+{
+	return btrn->context;
+}
+
+/**
+ * Merge the first two input buffers into one.
+ *
+ * This is a quite expensive operation.
+ *
+ * \return The number of buffers that have been merged (zero, one or two).
+ */
+int btr_merge(struct btr_node *btrn)
+{
+	struct btr_buffer_reference *brs[2], *br;
+	char *bufs[2], *buf;
+	size_t szs[2], sz;
+	int i;
+
+	if (list_empty(&btrn->input_queue))
+		return 0;
+	if (list_is_singular(&btrn->input_queue))
+		return 1;
+	i = 0;
+	/* get references to the first two buffers */
+	FOR_EACH_BUFFER_REF(br, btrn) {
+		brs[i] = br;
+		szs[i] = btr_get_buffer_by_reference(brs[i], bufs + i);
+		i++;
+		if (i == 2)
+			break;
+	}
+	/* make a new btrb that combines the two buffers and a br to it. */
+	sz = szs[0] + szs[1];
+	//PARA_CRIT_LOG("merging input buffers: (%zu, %zu) -> %zu\n",
+	//	szs[0], szs[1], sz);
+	buf = para_malloc(sz);
+	/* TODO: Avoid this memcopy by introducing btr buffer pool. */
+	memcpy(buf, bufs[0], szs[0]);
+	memcpy(buf + szs[0], bufs[1], szs[1]);
+
+	br = para_malloc(sizeof(*br));
+	br->btrb = new_btrb(buf, sz);
+	br->btrb->refcount = 1;
+	br->consumed = 0;
+
+	/* replace the first two refs by the new one */
+	btr_drop_buffer_reference(brs[0]);
+	btr_drop_buffer_reference(brs[1]);
+	para_list_add(&br->node, &btrn->input_queue);
+	return 2;
+}