1 files changed, 165 insertions, 0 deletions
diff --git a/src/libopkg/active_list.c b/src/libopkg/active_list.c
new file mode 100644
index 0000000..69ac1d1
--- /dev/null
+++ b/src/libopkg/active_list.c
@@ -0,0 +1,165 @@
+/* active_list.h - the opkg package management system
+
+   Tick Chen <tick@openmoko.com>
+
+   Copyright (C) 2008 Openmoko Inc.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+*/
+
+
+#include "active_list.h"
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "libbb/libbb.h"
+
+void active_list_init(struct active_list *ptr) {
+    INIT_LIST_HEAD(&ptr->node);
+    INIT_LIST_HEAD(&ptr->depend);
+    ptr->depended = NULL;
+}
+
+/**
+ */
+struct active_list * active_list_next(struct active_list *head, struct active_list *ptr) {
+    struct active_list *next=NULL;
+    if ( !head ) {
+        opkg_msg(ERROR, "Internal error: head=%p, ptr=%p\n", head, ptr);
+        return NULL;
+    }
+    if ( !ptr )
+        ptr = head;
+    next = list_entry(ptr->node.next, struct active_list, node);
+    if ( next == head ) {
+        return NULL;
+    }
+    if ( ptr->depended && &ptr->depended->depend == ptr->node.next ) {
+        return ptr->depended;
+    }
+    while ( next->depend.next != &next->depend ) {
+        next = list_entry(next->depend.next, struct active_list, node);
+    }
+    return next;
+}
+
+
+struct active_list * active_list_prev(struct active_list *head, struct active_list *ptr) {
+    struct active_list *prev=NULL;
+    if ( !head ) {
+        opkg_msg(ERROR, "Internal error: head=%p, ptr=%p\n", head, ptr);
+        return NULL;
+    }
+    if ( !ptr )
+        ptr = head;
+    if ( ptr->depend.prev != &ptr->depend ) {
+        prev = list_entry(ptr->depend.prev, struct active_list, node);
+        return prev;
+    }
+    if ( ptr->depended  && ptr->depended != head && &ptr->depended->depend == ptr->node.prev ) {
+        prev = list_entry(ptr->depended->node.prev, struct active_list, node);
+    } else
+        prev = list_entry(ptr->node.prev, struct active_list, node);
+    if ( prev == head )
+        return NULL;
+    return prev;
+}
+
+
+struct active_list *active_list_move_node(struct active_list *old_head, struct active_list *new_head, struct active_list *node) {
+    struct active_list *prev;
+    if (!old_head || !new_head || !node)
+        return NULL;
+    if (old_head == new_head)
+        return node;
+    prev = active_list_prev(old_head, node);
+    active_list_add(new_head, node);
+    return prev;
+}
+
+static void list_head_clear (struct list_head *head) {
+    struct active_list *next;
+    struct list_head *n, *ptr;
+    if (!head)
+        return;
+    list_for_each_safe(ptr, n , head) {
+        next = list_entry(ptr, struct active_list, node);
+        if (next->depend.next != &next->depend) {
+            list_head_clear(&next->depend);
+        }
+        active_list_init(next);
+    }
+}
+void active_list_clear(struct active_list *head) {
+    list_head_clear(&head->node);
+    if (head->depend.next != &head->depend) {
+        list_head_clear(&head->depend);
+    }
+    active_list_init(head);
+}
+
+void active_list_add_depend(struct active_list *node, struct active_list *depend) {
+    list_del_init(&depend->node);
+    list_add_tail(&depend->node, &node->depend);
+    depend->depended  = node;
+}
+
+void active_list_add(struct active_list *head, struct active_list *node) {
+    list_del_init(&node->node);
+    list_add_tail(&node->node, &head->node);
+    node->depended  = head;
+}
+
+struct active_list * active_list_head_new(void) {
+    struct active_list * head = xcalloc(1, sizeof(struct active_list));
+    active_list_init(head);
+    return head;
+}
+
+void active_list_head_delete(struct active_list *head) {
+    active_list_clear(head);
+    free(head);
+}
+
+/*
+ *  Using insert sort.
+ *  Note. the list should not be large, or it will be very inefficient.
+ *
+ */
+struct active_list * active_list_sort(struct active_list *head, int (*compare)(const void *, const void *)) {
+    struct active_list tmphead;
+    struct active_list *node, *ptr;
+    if ( !head )
+        return NULL;
+    active_list_init(&tmphead);
+    for (node = active_list_next(head, NULL); node; node = active_list_next(head, NULL)) {
+        if (tmphead.node.next == &tmphead.node) {
+            active_list_move_node(head, &tmphead, node);
+        } else {
+            for (ptr = active_list_next(&tmphead, NULL); ptr; ptr=active_list_next(&tmphead, ptr)) {
+                if (compare(ptr, node) <= 0) {
+                    break;
+                }
+            }
+            if (!ptr) {
+                active_list_move_node(head, &tmphead, node);
+            } else {
+                active_list_move_node(head, ptr, node);
+            }
+        }
+        node->depended = &tmphead;
+    }
+    for (ptr = active_list_prev(&tmphead, NULL); ptr; ptr=active_list_prev(&tmphead, NULL)) {
+        active_list_move_node(&tmphead, head, ptr);
+    }
+    return head;
+}