added dlist

CMakeLists.txt

@@ -48,6 +48,7 @@ set(EXTRA_CFLAGS
 # libwebfuse-core
 
 add_library(webfuse-core STATIC 
+	lib/webfuse/core/dlist.c
 	lib/webfuse/core/message.c
 	lib/webfuse/core/message_queue.c
 	lib/webfuse/core/status.c
@@ -273,6 +274,7 @@ add_executable(alltests
 	test/msleep.cc
 	test/mock_authenticator.cc
 	test/test_container_of.cc
+	test/test_dlist.cc
 	test/test_response_parser.cc
 	test/test_server.cc
 	test/test_timepoint.cc

lib/webfuse/core/dlist.c

@@ -0,0 +1,87 @@
+#include "webfuse/core/dlist.h"
+#include "webfuse/core/util.h"
+#include <stddef.h>
+
+void wf_dlist_init(
+    struct wf_dlist * list)
+{
+    list->first = NULL;
+}
+
+static void wf_dlist_item_cleanup_default(
+    struct wf_dlist_item * WF_UNUSED_PARAM(item),
+    void * WF_UNUSED_PARAM(user_data))
+{
+    // empty
+}
+
+void wf_dlist_cleanup(
+    struct wf_dlist * list,
+    wf_dlist_item_cleanup_fn * cleanup,
+    void * user_data)
+{
+    wf_dlist_item_cleanup_fn * effective_cleanup = (NULL != cleanup) ? cleanup : &wf_dlist_item_cleanup_default;
+    struct wf_dlist_item * item = list->first;
+ 
+    while (NULL != item)
+    {
+        struct wf_dlist_item * next = item->next;
+        effective_cleanup(item, user_data);
+        item = next;
+    }
+
+    list->first = NULL;
+}
+
+void wf_dlist_prepend(
+    struct wf_dlist * list,
+    struct wf_dlist_item * item)
+{
+    if (NULL != list->first)
+    {
+        list->first->prev = item;
+    }
+
+    item->prev = NULL;
+    item->next = list->first;
+    list->first = item;
+}
+
+void wf_dlist_remove(
+    struct wf_dlist * list,
+    struct wf_dlist_item * item)
+{
+    if (NULL != item->prev)
+    {
+        item->prev->next = item->next;
+    }
+
+    if (NULL != item->next)
+    {
+        item->next->prev = item->prev;
+    }
+
+    if (list->first == item)
+    {
+        list->first = item->next;
+    }
+}
+
+struct wf_dlist_item * wf_dlist_find_first(
+    struct wf_dlist * list,
+    wf_dlist_item_predicate_fn * predicate,
+    void * user_data)
+{
+    struct wf_dlist_item * item = list->first;
+
+    while (NULL != item)
+    {
+        if (predicate(item, user_data))
+        {
+            break;
+        }
+        item = item->next;
+    }
+
+    return item;
+}

lib/webfuse/core/dlist.h

@@ -0,0 +1,59 @@
+#ifndef WF_DLIST_H
+#define WF_DLIST_H
+
+#ifndef __cplusplus
+#include <stdbool.h>
+#endif
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+struct wf_dlist_item
+{
+    struct wf_dlist_item * prev;
+    struct wf_dlist_item * next;
+};
+
+struct wf_dlist
+{
+    struct wf_dlist_item * first;
+};
+
+typedef void wf_dlist_item_cleanup_fn(
+    struct wf_dlist_item * item,
+    void * user_data);
+
+typedef bool wf_dlist_item_predicate_fn(
+    struct wf_dlist_item * item,
+    void * user_data);
+
+
+extern void wf_dlist_init(
+    struct wf_dlist * list);
+
+extern void wf_dlist_cleanup(
+    struct wf_dlist * list,
+    wf_dlist_item_cleanup_fn * cleanup,
+    void * user_data);
+
+extern void wf_dlist_prepend(
+    struct wf_dlist * list,
+    struct wf_dlist_item * item);
+
+extern void wf_dlist_remove(
+    struct wf_dlist * list,
+    struct wf_dlist_item * item);
+
+extern struct wf_dlist_item * wf_dlist_find_first(
+    struct wf_dlist * list,
+    wf_dlist_item_predicate_fn * predicate,
+    void * user_data);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

test/test_dlist.cc

@@ -0,0 +1,49 @@
+#include <gtest/gtest.h>
+#include "webfuse/core/dlist.h"
+#include "webfuse/core/container_of.h"
+
+namespace
+{
+    struct Item
+    {
+        wf_dlist_item item;
+        char value;
+    };
+}
+
+TEST(DList, prepend)
+{
+    struct wf_dlist list;
+    wf_dlist_init(&list);
+    ASSERT_EQ(nullptr, list.first);
+
+    Item a;
+    a.value = 'a';
+    wf_dlist_prepend(&list, &a.item);
+    ASSERT_EQ(&a.item, list.first);
+    ASSERT_EQ(nullptr, a.item.next);
+    ASSERT_EQ(nullptr, a.item.prev);
+
+    Item b;
+    b.value = 'b';
+    wf_dlist_prepend(&list, &b.item);
+    ASSERT_EQ(&b.item, list.first);
+    ASSERT_EQ(&a.item, b.item.next);
+    ASSERT_EQ(nullptr, b.item.prev);
+    ASSERT_EQ(nullptr, a.item.next);
+    ASSERT_EQ(&b.item, a.item.prev);
+
+    Item c;
+    c.value = 'c';
+    wf_dlist_prepend(&list, &c.item);
+    ASSERT_EQ(&c.item, list.first);
+    ASSERT_EQ(&b.item, c.item.next);
+    ASSERT_EQ(nullptr, c.item.prev);
+    ASSERT_EQ(&a.item, b.item.next);
+    ASSERT_EQ(&c.item, b.item.prev);
+    ASSERT_EQ(nullptr, a.item.next);
+    ASSERT_EQ(&b.item, a.item.prev);
+
+    wf_dlist_cleanup(&list, nullptr, nullptr);
+    ASSERT_EQ(nullptr, list.first);
+}