Add btr_bytes_pending().

[paraslash.git] / buffer_tree.c

diff --git a/buffer_tree.c b/buffer_tree.c
index ba2a08754f33a794a19309a1fd7287b749a0f9e5..941d58dba07521dc773721b93262b56ea2466f4f 100644 (file)
--- 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);
 }
@@ -136,11 +143,12 @@ bool btr_inplace_ok(struct btr_node *btrn)
 
 struct btr_buffer_reference *btr_next_br(struct btr_node *btrn)
 {
-       if (list_empty(&btrn->buffer_queue))
+       if (list_empty(&btrn->input_queue))
                return NULL;
-       return list_first_entry(&btrn->buffer_queue, struct btr_buffer_reference, node);
+       return list_first_entry(&btrn->input_queue, struct btr_buffer_reference, node);
 }
 
+
 static inline size_t br_available_bytes(struct btr_buffer_reference *br)
 {
        return br->btrb->size - br->consumed;
@@ -168,10 +176,10 @@ 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;
+       FOR_EACH_CHILD(ch, btrn)
+               ch->parent = NULL;
        flush_input_queue(btrn);
        if (btrn->parent)
                list_del(&btrn->node);
@@ -189,7 +197,19 @@ 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;
 }