stos: ob: Add directory object operations

This commit adds operations for appending directories and top-level
lookups.

Signed-off-by: Chloe M. <chloe@mensia.org>

paw/stos/ob/ob.c

@@ -104,3 +104,83 @@ ObReclaimObject(ST_OBJECT *Object)
         ObReclaimToCache(&gObCache, Object);
     }
 }
+
+ST_STATUS
+ObAppendDirectory(ST_OBJECT *DirecParent, ST_OBJECT *Object)
+{
+    OBJECT_DIRECTORY *Directory;
+    ST_OBJECT *Last;
+
+    if (DirecParent == NULL || Object == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    if (DirecParent->Type != OBJECT_TYPE_DIRECTORY) {
+        return STATUS_NOT_DIRECTORY;
+    }
+
+    Directory = DirecParent->Data;
+    if (Directory == NULL) {
+        return STATUS_IO_ERROR;
+    }
+
+    /* TODO: Place lock here */
+    if (Directory->First == NULL || Directory->Last == NULL) {
+        Directory->First = Object;
+        Directory->Last = Object;
+    } else {
+        Last = Directory->Last;
+        Last->DirecNext = Object;
+        Directory->Last = Object;
+    }
+
+    return STATUS_SUCCESS;
+}
+
+ST_STATUS
+ObLookupFromTop(ST_OBJECT *Parent, const CHAR *Name, ST_OBJECT **Result)
+{
+    ST_OBJECT *Entry;
+    OBJECT_DIRECTORY *ParentDirec;
+    USIZE NameLen;
+
+    if (Parent == NULL || Name == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    if (Result == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    /* Must be a directory */
+    if (Parent->Type != OBJECT_TYPE_DIRECTORY) {
+        return STATUS_NOT_DIRECTORY;
+    }
+
+    ParentDirec = Parent->Data;
+    if (ParentDirec == NULL) {
+        return STATUS_IO_ERROR;
+    }
+
+    Entry = ParentDirec->First;
+    NameLen = RtlStrLen(Name);
+    if (NameLen >= OBJECT_NAMESZ - 1) {
+        return STATUS_NAME_TOO_LONG;
+    }
+
+    while (Entry != NULL) {
+        if (*Entry->Name != *Name) {
+            Entry = Entry->DirecNext;
+            continue;
+        }
+
+        if (RtlMemCmp(Entry->Name, Name, NameLen) == 0) {
+            *Result = Entry;
+            return STATUS_SUCCESS;
+        }
+
+        Entry = Entry->DirecNext;
+    }
+
+    return STATUS_NOT_FOUND;
+}