[ADD/WIP] Start rolling in intents

include/Cytoplasm/Db.h

@@ -48,6 +48,17 @@
  */
 typedef struct Db Db;
 
+/**
+ * Some "hints" for the database backend for operations. 
+ * Hints are a way for the program to declare what to except of it
+ * (and the program MUST adhere to these hints, but the backend 
+ * MAY adhere).
+ */
+typedef enum DbHint {
+    DB_HINT_READONLY,   /* The database reference is treated as read-only */
+    DB_HINT_WRITE       /* The database reference is treated as read/write */
+} DbHint;
+
 /**
  * When an object is locked, a reference is returned. This reference
  * is owned by the current thread, and the database is inaccessible to
@@ -118,6 +129,15 @@ extern DbRef * DbCreate(Db *, size_t,...);
  */
 extern DbRef * DbLock(Db *, size_t,...);
 
+/**
+ * Behaves like
+ * .Fn DbLock ,
+ * but with hints on the reference itself, as 
+ * .Fn DbLock 
+ * itself is read/write.
+ */
+extern DbRef * DbLockIntent(Db *, DbHint, size_t,...);
+
 /**
  * Immediately and permanently remove an object from the database.
  * This function assumes the object is not locked, otherwise undefined