X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=buffer_tree.c;h=1cb295b4de02e3ca3003f83043cf34d536f2ffc5;hp=bbd055b970c09d22beb13b03d446294752426d71;hb=d29a1515fbb74f7853fa771698e90646c24bde33;hpb=5bd897365d6e849b01b34cef28ea542d9cfbdfa9

diff --git a/buffer_tree.c b/buffer_tree.c
index bbd055b9..1cb295b4 100644
--- a/buffer_tree.c
+++ b/buffer_tree.c
@@ -4,7 +4,8 @@
 #include "para.h"
 #include "list.h"
 #include "string.h"
-//#include "buffer_tree.h"
+#include "buffer_tree.h"
+#include "error.h"
 
 
 struct btr_buffer {
@@ -34,31 +35,45 @@ struct btr_node {
 	 * used by this btr node.
 	 */
 	struct list_head input_queue;
+	btr_command_handler execute;
+	void *context;
 };
 
-#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_CHILD_SAFE(_tn, _tmp, _btrn) \
+	list_for_each_entry_safe((_tn), (_tmp), &((_btrn)->children), node)
 
 #define FOR_EACH_BUFFER_REF(_br, _btrn) \
 	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)->input_queue, node)
 
-INIT_STDERR_LOGGING(0);
-
-struct btr_node *btr_new_node(char *name, struct btr_node *parent)
+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);
 	INIT_LIST_HEAD(&btrn->input_queue);
+	if (parent)
+		PARA_INFO_LOG("added %s as child of %s\n", name, parent->name);
+	else
+		PARA_INFO_LOG("added %s as btr root\n", name);
 	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));
@@ -69,10 +84,14 @@ 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;
 
+	//PARA_CRIT_LOG("dropping buffer reference %p\n", br);
 	list_del(&br->node);
 	free(br);
 	btrb->refcount--;
@@ -82,15 +101,16 @@ 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, size_t consumed)
 {
-	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->input_queue);
+		br->consumed = consumed;
+		list_add_tail(&br->node, &ch->input_queue);
 		btrb->refcount++;
 	}
 }
@@ -100,12 +120,12 @@ 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, 0);
 }
 
-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, br->consumed);
 	btr_drop_buffer_reference(br);
 }
 
@@ -117,6 +137,7 @@ void btr_pushdown(struct btr_node *btrn)
 		btr_pushdown_br(br, btrn);
 }
 
+/* Return true if this node has no children. */
 bool btr_no_children(struct btr_node *btrn)
 {
 	return list_empty(&btrn->children);
@@ -134,13 +155,6 @@ 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->input_queue))
-		return NULL;
-	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;
@@ -152,9 +166,29 @@ 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)
+/**
+ * \return zero if the input buffer queue is empty.
+ */
+size_t btr_next_buffer(struct btr_node *btrn, char **bufp)
 {
-	br->consumed += consumed;
+	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)
+{
+	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 +202,13 @@ 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);
@@ -184,12 +221,133 @@ size_t btr_get_input_queue_size(struct btr_node *btrn)
 	struct btr_buffer_reference *br;
 	size_t size = 0;
 
-	FOR_EACH_BUFFER_REF(br, btrn)
+	FOR_EACH_BUFFER_REF(br, btrn) {
+		//PARA_CRIT_LOG("size: %zu\n", size);
 		size += br_available_bytes(br);
+	}
 	return size;
 }
 
-int main(void)
+void btr_splice_out_node(struct btr_node *btrn)
+{
+	struct btr_node *ch, *tmp;
+
+	assert(btrn);
+	PARA_NOTICE_LOG("splicing out %s\n", btrn->name);
+	btr_pushdown(btrn);
+	if (btrn->parent)
+		list_del(&btrn->node);
+	FOR_EACH_CHILD_SAFE(ch, tmp, btrn) {
+		PARA_INFO_LOG("parent(%s): %s\n", ch->name,
+			btrn->parent? btrn->parent->name : "NULL");
+		ch->parent = btrn->parent;
+		if (btrn->parent)
+			list_move(&ch->node, &btrn->parent->children);
+	}
+	assert(list_empty(&btrn->children));
+	free(btrn->name);
+	free(btrn);
+}
+
+/**
+ * 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)
+{
+	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;
+}
+
+int btr_exec(struct btr_node *btrn, const char *command, char **value_result)
+{
+	if (!btrn)
+		return -ERRNO_TO_PARA_ERROR(EINVAL);
+	if (!btrn->execute)
+		return -ERRNO_TO_PARA_ERROR(ENOTSUP);
+	return btrn->execute(btrn, command, value_result);
+}
+
+int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result)
 {
-	return 1;
+	int ret;
+
+	for (; btrn; btrn = btrn->parent) {
+		struct btr_node *parent = btrn->parent;
+		if (!parent)
+			return -ERRNO_TO_PARA_ERROR(ENOTSUP);
+		if (!parent->execute)
+			continue;
+		PARA_INFO_LOG("parent: %s, cmd: %s\n", parent->name, command);
+		ret = parent->execute(parent, command, value_result);
+		if (ret == -ERRNO_TO_PARA_ERROR(ENOTSUP))
+			continue;
+		if (ret < 0)
+			return ret;
+		if (value_result && *value_result)
+			PARA_NOTICE_LOG("%s(%s): %s\n", command, parent->name,
+				*value_result);
+		return 1;
+	}
+	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;
 }