1 files changed, 144 insertions, 0 deletions
diff --git a/metis/ccnx/forwarder/metis/content_store/metis_LruList.c b/metis/ccnx/forwarder/metis/content_store/metis_LruList.c
new file mode 100644
index 00000000..6cbd72eb
--- /dev/null
+++ b/metis/ccnx/forwarder/metis/content_store/metis_LruList.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#include <config.h>
+#include <stdio.h>
+#include <sys/queue.h>
+
+#include <ccnx/forwarder/metis/content_store/metis_LruList.h>
+#include <parc/algol/parc_Memory.h>
+#include <LongBow/runtime.h>
+
+struct metis_lru_list_entry {
+    void *userData;
+
+    // always set to the list
+    MetisLruList *parentList;
+
+    // indicates if the Entry is currently in the list
+    bool inList;
+
+    TAILQ_ENTRY(metis_lru_list_entry)  list;
+};
+
+// this defines the TAILQ structure so we can access the tail pointer
+TAILQ_HEAD(metis_lru_s, metis_lru_list_entry);
+
+struct metis_lru_list {
+    struct metis_lru_s head;
+    size_t itemsInList;
+};
+
+void
+metisLruList_EntryDestroy(MetisLruListEntry **entryPtr)
+{
+    assertNotNull(entryPtr, "Parameter entryPtr must be non-null double pointer");
+
+    MetisLruListEntry *entry = *entryPtr;
+    if (entry->inList) {
+        TAILQ_REMOVE(&entry->parentList->head, entry, list);
+        assertTrue(entry->parentList->itemsInList > 0, "Invalid state, removed entry from list, but itemsInList is 0");
+        entry->parentList->itemsInList--;
+    }
+
+    parcMemory_Deallocate((void **) &entry);
+    *entryPtr = NULL;
+}
+
+void
+metisLruList_EntryMoveToHead(MetisLruListEntry *entry)
+{
+    assertNotNull(entry, "Parameter entry must be non-null");
+
+    TAILQ_REMOVE(&entry->parentList->head, entry, list);
+    TAILQ_INSERT_HEAD(&entry->parentList->head, entry, list);
+}
+
+void *
+metisLruList_EntryGetData(MetisLruListEntry *entry)
+{
+    return entry->userData;
+}
+
+MetisLruList *
+metisLruList_Create()
+{
+    MetisLruList *list = parcMemory_AllocateAndClear(sizeof(MetisLruList));
+    assertNotNull(list, "parcMemory_AllocateAndClear(%zu) returned NULL", sizeof(MetisLruList));
+    list->itemsInList = 0;
+    TAILQ_INIT(&list->head);
+    return list;
+}
+
+void
+metisLruList_Destroy(MetisLruList **lruPtr)
+{
+    assertNotNull(lruPtr, "Parameter lruPtr must be non-null double pointer");
+
+    MetisLruList *lru = *lruPtr;
+
+    MetisLruListEntry *entry = TAILQ_FIRST(&lru->head);
+    while (entry != NULL) {
+        MetisLruListEntry *next = TAILQ_NEXT(entry, list);
+        metisLruList_EntryDestroy(&entry);
+        entry = next;
+    }
+
+    parcMemory_Deallocate((void **) &lru);
+    *lruPtr = NULL;
+}
+
+MetisLruListEntry *
+metisLruList_NewHeadEntry(MetisLruList *lru, void *data)
+{
+    assertNotNull(lru, "Parameter lru must be non-null");
+    assertNotNull(data, "Parameter data must be non-null");
+
+    MetisLruListEntry *entry = parcMemory_AllocateAndClear(sizeof(MetisLruListEntry));
+    assertNotNull(entry, "parcMemory_AllocateAndClear(%zu) returned NULL", sizeof(MetisLruListEntry));
+    entry->userData = data;
+    entry->parentList = lru;
+    entry->inList = true;
+
+    TAILQ_INSERT_HEAD(&lru->head, entry, list);
+    lru->itemsInList++;
+
+    return entry;
+}
+
+MetisLruListEntry *
+metisLruList_PopTail(MetisLruList *lru)
+{
+    assertNotNull(lru, "Parameter lru must be non-null");
+
+    MetisLruListEntry *entry = TAILQ_LAST(&lru->head, metis_lru_s);
+
+    if (entry) {
+        assertTrue(lru->itemsInList > 0, "Invalid state, removed entry from list, but itemsInList is 0");
+        lru->itemsInList--;
+        TAILQ_REMOVE(&lru->head, entry, list);
+        entry->inList = false;
+    }
+
+    return entry;
+}
+
+size_t
+metisLruList_Length(const MetisLruList *lru)
+{
+    assertNotNull(lru, "Parameter lru must be non-null");
+    return lru->itemsInList;
+}