X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=buffer_tree.c;h=1046460d1d1c56dd424b0cc9a7a3e33c76857188;hb=0b101563e67c91bc660f6a16b5889901d9e8eeff;hp=ba2a08754f33a794a19309a1fd7287b749a0f9e5;hpb=5374ad8fad0d5eabc002b01aa5a2815880a9e019;p=paraslash.git

diff --git a/buffer_tree.c b/buffer_tree.c
index ba2a0875..1046460d 100644
--- a/buffer_tree.c
+++ b/buffer_tree.c
@@ -4,7 +4,7 @@
 #include "para.h"
 #include "list.h"
 #include "string.h"
-//#include "buffer_tree.h"
+#include "buffer_tree.h"
 
 
 struct btr_buffer {
@@ -33,18 +33,16 @@ struct btr_node {
 	 * the list represents an input buffer which has not been completely
 	 * used by this btr node.
 	 */
-	struct list_head buffer_queue;
+	struct list_head input_queue;
 };
 
-#define FOR_EACH_TARGET_NODE(_tn, _btrn) list_for_each_entry((_tn), \
+#define FOR_EACH_CHILD(_tn, _btrn) list_for_each_entry((_tn), \
 	&((_btrn)->children), node)
 
 #define FOR_EACH_BUFFER_REF(_br, _btrn) \
-	list_for_each_entry((_br), &(_btrn)->buffer_queue, node)
+	list_for_each_entry((_br), &(_btrn)->input_queue, node)
 #define FOR_EACH_BUFFER_REF_SAFE(_br, _tmp, _btrn) \
-	list_for_each_entry_safe((_br), (_tmp), &(_btrn)->buffer_queue, node)
-
-INIT_STDERR_LOGGING(0);
+	list_for_each_entry_safe((_br), (_tmp), &(_btrn)->input_queue, node)
 
 struct btr_node *btr_new_node(char *name, struct btr_node *parent)
 {
@@ -55,10 +53,15 @@ struct btr_node *btr_new_node(char *name, struct btr_node *parent)
 	if (parent)
 		list_add_tail(&btrn->node, &parent->children);
 	INIT_LIST_HEAD(&btrn->children);
-	INIT_LIST_HEAD(&btrn->buffer_queue);
+	INIT_LIST_HEAD(&btrn->input_queue);
 	return btrn;
 }
 
+/*
+ * Allocate a new btr buffer.
+ *
+ * The freshly allocated buffer will have a zero refcount.
+ */
 static struct btr_buffer *new_btrb(char *buf, size_t size)
 {
 	struct btr_buffer *btrb = para_malloc(sizeof(*btrb));
@@ -69,7 +72,10 @@ static struct btr_buffer *new_btrb(char *buf, size_t size)
 	return btrb;
 }
 
-void btr_drop_buffer_reference(struct btr_buffer_reference *br)
+/*
+ * Deallocate the reference, release the resources if refcount drops to zero.
+ */
+static void btr_drop_buffer_reference(struct btr_buffer_reference *br)
 {
 	struct btr_buffer *btrb = br->btrb;
 
@@ -82,15 +88,15 @@ void btr_drop_buffer_reference(struct btr_buffer_reference *br)
 	}
 }
 
-static void add_btrb_to_targets(struct btr_buffer *btrb, struct btr_node *btrn)
+static void add_btrb_to_children(struct btr_buffer *btrb, struct btr_node *btrn)
 {
-	struct btr_node *tn; /* target node */
+	struct btr_node *ch;
 
-	FOR_EACH_TARGET_NODE(tn, btrn) {
+	FOR_EACH_CHILD(ch, btrn) {
 		struct btr_buffer_reference *br = para_malloc(sizeof(*br));
 		br->btrb = btrb;
 		br->consumed = 0;
-		list_add_tail(&br->node, &tn->buffer_queue);
+		list_add_tail(&br->node, &ch->input_queue);
 		btrb->refcount++;
 	}
 }
@@ -100,12 +106,12 @@ 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_targets(btrb, btrn);
+	add_btrb_to_children(btrb, btrn);
 }
 
-void btr_pushdown_br(struct btr_buffer_reference *br, struct btr_node *btrn)
+static void btr_pushdown_br(struct btr_buffer_reference *br, struct btr_node *btrn)
 {
-	add_btrb_to_targets(br->btrb, btrn);
+	add_btrb_to_children(br->btrb, btrn);
 	btr_drop_buffer_reference(br);
 }
 
@@ -117,7 +123,8 @@ void btr_pushdown(struct btr_node *btrn)
 		btr_pushdown_br(br, btrn);
 }
 
-bool btr_no_children(struct btr_node *btrn)
+/* Return true if this node has no children. */
+bool btr_is_leaf_node(struct btr_node *btrn)
 {
 	return list_empty(&btrn->children);
 }
@@ -134,13 +141,6 @@ bool btr_inplace_ok(struct btr_node *btrn)
 	return list_is_singular(&btrn->parent->children);
 }
 
-struct btr_buffer_reference *btr_next_br(struct btr_node *btrn)
-{
-	if (list_empty(&btrn->buffer_queue))
-		return NULL;
-	return list_first_entry(&btrn->buffer_queue, struct btr_buffer_reference, node);
-}
-
 static inline size_t br_available_bytes(struct btr_buffer_reference *br)
 {
 	return br->btrb->size - br->consumed;
@@ -152,9 +152,26 @@ size_t btr_get_buffer_by_reference(struct btr_buffer_reference *br, char **buf)
 	return br_available_bytes(br);
 }
 
-void btr_increase_used_bytes(struct btr_buffer_reference *br, size_t consumed)
+size_t btr_next_buffer(struct btr_node *btrn, char **bufp)
+{
+	struct btr_buffer_reference *br;
+
+	if (list_empty(&btrn->input_queue)) {
+		*bufp = NULL;
+		return 0;
+	}
+	br = list_first_entry(&btrn->input_queue, struct btr_buffer_reference, node);
+	return btr_get_buffer_by_reference(br, bufp);
+}
+
+void btr_consume(struct btr_node *btrn, size_t numbytes)
 {
-	br->consumed += consumed;
+	struct btr_buffer_reference *br;
+
+	assert(!list_empty(&btrn->input_queue));
+	br = list_first_entry(&btrn->input_queue, struct btr_buffer_reference, node);
+	assert(br->consumed + numbytes <= br->btrb->size);
+	br->consumed += numbytes;
 	if (br->consumed == br->btrb->size)
 		btr_drop_buffer_reference(br);
 }
@@ -168,10 +185,13 @@ static void flush_input_queue(struct btr_node *btrn)
 
 void btr_del_node(struct btr_node *btrn)
 {
-	struct btr_node *tn;
+	struct btr_node *ch;
 
-	FOR_EACH_TARGET_NODE(tn, btrn)
-		tn->parent = NULL;
+	if (!btrn)
+		return;
+	PARA_NOTICE_LOG("deleting %s\n", btrn->name);
+	FOR_EACH_CHILD(ch, btrn)
+		ch->parent = NULL;
 	flush_input_queue(btrn);
 	if (btrn->parent)
 		list_del(&btrn->node);
@@ -189,7 +209,19 @@ size_t btr_get_input_queue_size(struct btr_node *btrn)
 	return size;
 }
 
-int main(void)
+/**
+ * Return the size of the largest input queue.
+ *
+ * Iterates over all children of the given node.
+ */
+size_t btr_bytes_pending(struct btr_node *btrn)
 {
-	return 1;
+	size_t max_size = 0;
+	struct btr_node *ch;
+
+	FOR_EACH_CHILD(ch, btrn) {
+		size_t size = btr_get_input_queue_size(ch);
+		max_size = PARA_MAX(max_size, size);
+	}
+	return max_size;
 }