X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=buffer_tree.c;h=bdcbec8de73c0348ea0a0e223e38b3584bee488a;hp=4aeb790a6e3c6e8efe9a841e4b12fbe331f360f9;hb=d5538ff0dd9f6531a1a319b49c32bd72597fb2c3;hpb=9609fd30e0d3db45ede3ab5c6bc3a77c15b6aef8

diff --git a/buffer_tree.c b/buffer_tree.c
index 4aeb790a..bdcbec8d 100644
--- a/buffer_tree.c
+++ b/buffer_tree.c
@@ -1,3 +1,10 @@
+/*
+ * Copyright (C) 2009-2010 Andre Noll <maan@systemlinux.org>
+ *
+ * Licensed under the GPL v2. For licencing details see COPYING.
+ */
+
+/** \file buffer_tree.c Buffer tree and buffer pool implementations. */
 #include <regex.h>
 #include <stdbool.h>
 
@@ -159,6 +166,35 @@ size_t btr_pool_get_buffer(struct btr_pool *btrp, char **result)
 	return btr_pool_available(btrp);
 }
 
+/**
+ * Get references to buffers pointing to free space of the buffer pool area.
+ *
+ * \param btrp The buffer pool.
+ * \param iov The scatter array.
+ *
+ * \return Zero if the buffer pool is full, one if the free space of the buffer
+ * pool area is available as a single contiguous buffer, two if the free space
+ * consists of two buffers. If this function returns the value n, then n
+ * elements of \a iov are initialized.
+ */
+int btr_pool_get_buffers(struct btr_pool *btrp, struct iovec iov[2])
+{
+	size_t sz, unused;
+	char *buf;
+
+	sz = btr_pool_get_buffer(btrp, &buf);
+	if (sz == 0)
+		return 0;
+	iov[0].iov_len = sz;
+	iov[0].iov_base = buf;
+	unused = btr_pool_unused(btrp);
+	if (sz == unused)
+		return 1;
+	iov[1].iov_len = unused - sz;
+	iov[1].iov_base = btrp->area_start;
+	return 2;
+}
+
 /**
  * Mark a part of the buffer pool area as allocated.
  *
@@ -598,7 +634,7 @@ void btr_consume(struct btr_node *btrn, size_t numbytes)
 			numbytes -= br->btrb->size - br->consumed;
 			btr_drop_buffer_reference(br);
 		}
-		assert(true);
+		assert(false);
 	}
 	/*
 	 * We have a wrap buffer, consume from it. If in total, i.e. including
@@ -624,9 +660,10 @@ void btr_consume(struct btr_node *btrn, size_t numbytes)
 	return btr_consume(btrn, sz);
 }
 
-static void flush_input_queue(struct btr_node *btrn)
+void btr_drain(struct btr_node *btrn)
 {
 	struct btr_buffer_reference *br, *tmp;
+
 	FOR_EACH_BUFFER_REF_SAFE(br, tmp, btrn)
 		btr_drop_buffer_reference(br);
 }
@@ -634,6 +671,8 @@ static void flush_input_queue(struct btr_node *btrn)
 /**
  * Free all resources allocated by btr_new_node().
  *
+ * \param btrn Pointer to a btr node obtained by \ref btr_new_node().
+ *
  * Like free(3), it is OK to call this with a \p NULL pointer argument.
  */
 void btr_free_node(struct btr_node *btrn)
@@ -664,7 +703,7 @@ void btr_remove_node(struct btr_node *btrn)
 	PARA_NOTICE_LOG("removing btr node %s from buffer tree\n", btrn->name);
 	FOR_EACH_CHILD(ch, btrn)
 		ch->parent = NULL;
-	flush_input_queue(btrn);
+	btr_drain(btrn);
 	if (btrn->parent)
 		list_del(&btrn->node);
 }
@@ -727,12 +766,15 @@ void btr_splice_out_node(struct btr_node *btrn)
 	assert(list_empty(&btrn->children));
 }
 
-/*
- * Return the size of the largest input queue.
+/**
+ * Return number of queued output bytes of a buffer tree node.
+ *
+ * \param btrn The node whose output queue size should be computed.
  *
- * Iterates over all children of the given node.
+ * This function iterates over all children of the given node and returns the
+ * size of the largest input queue.
  */
-static size_t btr_bytes_pending(struct btr_node *btrn)
+size_t btr_get_output_queue_size(struct btr_node *btrn)
 {
 	size_t max_size = 0;
 	struct btr_node *ch;
@@ -744,15 +786,6 @@ static size_t btr_bytes_pending(struct btr_node *btrn)
 	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);
-}
-
 /**
  * Execute a inter-node command on a parent node.
  *
@@ -822,7 +855,7 @@ static void merge_input_pool(struct btr_node *btrn, size_t dest_size)
 	struct btr_buffer_reference *br, *wbr = NULL;
 	int num_refs; /* including wrap buffer */
 	char *buf, *buf1 = NULL, *buf2 = NULL;
-	size_t sz, sz1 = 0, sz2 = 0, wsz;
+	size_t sz, sz1 = 0, sz2 = 0, wb_consumed = 0;
 
 	br = get_first_input_br(btrn);
 	if (!br || br_available_bytes(br) >= dest_size)
@@ -839,6 +872,7 @@ static void merge_input_pool(struct btr_node *btrn, size_t dest_size)
 			wbr = br;
 			if (sz >= dest_size)
 				return;
+			wb_consumed = br->consumed;
 			continue;
 		}
 		if (!buf1) {
@@ -858,7 +892,7 @@ static void merge_input_pool(struct btr_node *btrn, size_t dest_size)
 		assert(buf2 + sz2 == buf);
 		sz2 += sz;
 next:
-		if (sz1 + sz2 >= dest_size)
+		if (sz1 + sz2 >= dest_size + wb_consumed)
 			break;
 	}
 	if (!buf2) /* nothing to do */
@@ -890,7 +924,6 @@ next:
 	 * We already have a wrap buffer, but it is too small. It might be
 	 * partially used.
 	 */
-	wsz = br_available_bytes(wbr);
 	if (wbr->wrap_count == sz1 && wbr->btrb->size >= sz1 + sz2) /* nothing we can do about it */
 		return;
 	sz = sz1 + sz2 - wbr->btrb->size; /* amount of new data */
@@ -1037,7 +1070,7 @@ struct btr_node *btr_search_node(const char *name, struct btr_node *root)
 }
 
 /** 640K ought to be enough for everybody ;) */
-#define BTRN_MAX_PENDING (640 * 1024)
+#define BTRN_MAX_PENDING (96 * 1024)
 
 /**
  * Return the current state of a buffer tree node.
@@ -1074,7 +1107,7 @@ int btr_node_status(struct btr_node *btrn, size_t min_iqs,
 	if (type != BTR_NT_LEAF) {
 		if (btr_no_children(btrn))
 			return -E_BTR_NO_CHILD;
-		if (btr_bytes_pending(btrn) > BTRN_MAX_PENDING)
+		if (btr_get_output_queue_size(btrn) > BTRN_MAX_PENDING)
 			return 0;
 	}
 	if (type != BTR_NT_ROOT) {