plist: new module

3 files changed, 332 insertions, 0 deletions

diff --git a/Makefile.am b/Makefile.am
index 451772b..f74f1e8 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -29,6 +29,8 @@ librbraun_la_SOURCES = \
 	list.c \
 	list.h \
 	macros.h \
+	plist.c \
+	plist.h \
 	rbtree.c \
 	rbtree.h \
 	rbtree_i.h \
diff --git a/plist.c b/plist.c
new file mode 100644
index 0000000..0320b0f
--- /dev/null
+++ b/plist.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2017 Richard Braun.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *
+ * Upstream site with license notes :
+ * http://git.sceen.net/rbraun/librbraun.git/
+ */
+
+#include "list.h"
+#include "plist.h"
+
+void
+plist_add(struct plist *plist, struct plist_node *pnode)
+{
+    struct plist_node *next;
+
+    if (plist_empty(plist)) {
+        list_insert_head(&plist->list, &pnode->node);
+        list_insert_head(&plist->prio_list, &pnode->prio_node);
+        return;
+    }
+
+    list_for_each_entry(&plist->prio_list, next, prio_node) {
+        if (pnode->priority < next->priority) {
+            break;
+        }
+    }
+
+    if (list_end(&plist->prio_list, &next->prio_node)
+        || (pnode->priority != next->priority)) {
+        list_insert_before(&next->prio_node, &pnode->prio_node);
+    }
+
+    list_insert_before(&next->node, &pnode->node);
+}
+
+void
+plist_remove(struct plist *plist, struct plist_node *pnode)
+{
+    struct plist_node *next;
+
+    if (!list_node_unlinked(&pnode->prio_node)) {
+        next = list_next_entry(pnode, node);
+
+        if (!list_end(&plist->list, &next->node)
+            && list_node_unlinked(&next->prio_node)) {
+            list_insert_after(&pnode->prio_node, &next->prio_node);
+        }
+
+        list_remove(&pnode->prio_node);
+    }
+
+    list_remove(&pnode->node);
+}
diff --git a/plist.h b/plist.h
new file mode 100644
index 0000000..4ba8301
--- /dev/null
+++ b/plist.h
@@ -0,0 +1,255 @@
+/*
+ * Copyright (c) 2017 Richard Braun.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *
+ * Priority list.
+ *
+ * This container acts as a doubly-linked list sorted by priority in
+ * ascending order.
+ *
+ * Upstream site with license notes :
+ * http://git.sceen.net/rbraun/librbraun.git/
+ */
+
+#ifndef _PLIST_H
+#define _PLIST_H
+
+#include "list.h"
+
+struct plist {
+    struct list list;
+    struct list prio_list;
+};
+
+struct plist_node {
+    unsigned int priority;
+    struct list node;
+    struct list prio_node;
+};
+
+/*
+ * Static priority list initializer.
+ */
+#define PLIST_INITIALIZER(plist) \
+    { LIST_INITIALIZER((plist).list), LIST_INITIALIZER((plist).prio_list) }
+
+/*
+ * Initialize a priority list.
+ */
+static inline void
+plist_init(struct plist *plist)
+{
+    list_init(&plist->list);
+    list_init(&plist->prio_list);
+}
+
+/*
+ * Initialize a priority list node.
+ */
+static inline void
+plist_node_init(struct plist_node *pnode, unsigned int priority)
+{
+    pnode->priority = priority;
+    list_node_init(&pnode->node);
+    list_node_init(&pnode->prio_node);
+}
+
+/*
+ * Return true if pnode is in no priority lists.
+ */
+static inline bool
+plist_node_unlinked(const struct plist_node *pnode)
+{
+    return list_node_unlinked(&pnode->node);
+}
+
+/*
+ * Macro that evaluates to the address of the structure containing the
+ * given node based on the given type and member.
+ */
+#define plist_entry(pnode, type, member) structof(pnode, type, member)
+
+/*
+ * Return the first node of a priority list.
+ */
+static inline struct plist_node *
+plist_first(const struct plist *plist)
+{
+    return list_first_entry(&plist->list, struct plist_node, node);
+}
+
+/*
+ * Return the last node of a priority list.
+ */
+static inline struct plist_node *
+plist_last(const struct plist *plist)
+{
+    return list_last_entry(&plist->list, struct plist_node, node);
+}
+
+/*
+ * Return the node next to the given node.
+ */
+static inline struct plist_node *
+plist_next(const struct plist_node *pnode)
+{
+    return (struct plist_node *)list_next_entry(pnode, node);
+}
+
+/*
+ * Return the node previous to the given node.
+ */
+static inline struct plist_node *
+plist_prev(const struct plist_node *pnode)
+{
+    return (struct plist_node *)list_prev_entry(pnode, node);
+}
+
+/*
+ * Get the first entry of a priority list.
+ */
+#define plist_first_entry(plist, type, member) \
+    plist_entry(plist_first(plist), type, member)
+
+/*
+ * Get the last entry of a priority list.
+ */
+#define plist_last_entry(plist, type, member) \
+    plist_entry(plist_last(plist), type, member)
+
+/*
+ * Get the entry next to the given entry.
+ */
+#define plist_next_entry(entry, member) \
+    list_next_entry(&(entry)->member, node)
+
+/*
+ * Get the entry previous to the given entry.
+ */
+#define plist_prev_entry(entry, member) \
+    list_prev_entry(&(entry)->member, node)
+
+/*
+ * Return true if node is after the last or before the first node of
+ * a priority list.
+ */
+static inline bool
+plist_end(const struct plist *plist, const struct plist_node *pnode)
+{
+    return list_end(&plist->list, &pnode->node);
+}
+
+/*
+ * Return true if plist is empty.
+ */
+static inline bool
+plist_empty(const struct plist *plist)
+{
+    return list_empty(&plist->list);
+}
+
+/*
+ * Return true if plist contains exactly one node.
+ */
+static inline bool
+plist_singular(const struct plist *plist)
+{
+    return list_singular(&plist->list);
+}
+
+/*
+ * Add a node to a priority list.
+ *
+ * The node must be initialized before calling this function.
+ */
+void plist_add(struct plist *plist, struct plist_node *pnode);
+
+/*
+ * Remove a node from a priority list.
+ *
+ * After completion, the node is stale.
+ */
+void plist_remove(struct plist *plist, struct plist_node *pnode);
+
+/*
+ * Forge a loop to process all nodes of a priority list.
+ *
+ * The node must not be altered during the loop.
+ */
+#define plist_for_each(plist, pnode)    \
+for (pnode = plist_first(plist);        \
+     !plist_end(plist, pnode);          \
+     pnode = plist_next(pnode))
+
+/*
+ * Forge a loop to process all nodes of a priority list.
+ */
+#define plist_for_each_safe(plist, pnode, tmp)              \
+for (pnode = plist_first(plist), tmp = plist_next(pnode);   \
+     !plist_end(plist, pnode);                              \
+     pnode = tmp, tmp = plist_next(pnode))
+
+/*
+ * Version of plist_for_each() that processes nodes backward.
+ */
+#define plist_for_each_reverse(plist, pnode)    \
+for (pnode = plist_last(plist);                 \
+     !plist_end(plist, pnode);                  \
+     pnode = plist_prev(pnode))
+
+/*
+ * Version of plist_for_each_safe() that processes nodes backward.
+ */
+#define plist_for_each_reverse_safe(plist, pnode, tmp)      \
+for (pnode = plist_last(plist), tmp = plist_prev(pnode);    \
+     !plist_end(plist, pnode);                              \
+     pnode = tmp, tmp = plist_prev(pnode))
+
+/*
+ * Forge a loop to process all entries of a priority list.
+ *
+ * The entry node must not be altered during the loop.
+ */
+#define plist_for_each_entry(plist, entry, member)      \
+    list_for_each_entry(&(plist)->list, entry, member)
+
+/*
+ * Forge a loop to process all entries of a priority list.
+ */
+#define plist_for_each_entry_safe(plist, entry, tmp, member)        \
+    list_for_each_entry_safe(&(plist)->list, entry, tmp, member)
+
+/*
+ * Version of plist_for_each_entry() that processes entries backward.
+ */
+#define plist_for_each_entry_reverse(plist, entry, member)      \
+    list_for_each_entry_reverse(&(plist)->list, entry, member)
+
+/*
+ * Version of plist_for_each_entry_safe() that processes entries backward.
+ */
+#define plist_for_each_entry_reverse_safe(plist, entry, tmp, member)  \
+    list_for_each_entry_reverse_safe(&(plist)->list, entry, tmp, member)
+
+#endif /* _PLIST_H */