nostrdb: initial Ndb class

nostrdb/Ndb.swift

@@ -0,0 +1,47 @@
+//
+//  Ndb.swift
+//  damus
+//
+//  Created by William Casarin on 2023-08-25.
+//
+
+import Foundation
+
+class Ndb {
+    let ndb: ndb_t
+
+    init?() {
+        var ndb_p: OpaquePointer? = nil
+
+        let dir = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first?.absoluteString.replacingOccurrences(of: "file://", with: "")
+
+        let ok = dir!.withCString { testdir in
+            return ndb_init(&ndb_p, testdir, 1024 * 1024 * 700, 4) != 0
+        }
+
+        if !ok {
+            return nil
+        }
+
+        self.ndb = ndb_t(ndb: ndb_p)
+    }
+
+    func lookup_note(_ id: NoteId) -> NdbNote? {
+        id.id.withUnsafeBytes { bs in
+            guard let note_p = ndb_get_note_by_id(ndb.ndb, bs) else {
+                return nil
+            }
+            return NdbNote(note: note_p, owned_size: nil)
+        }
+    }
+
+    func process_events(_ str: String) -> Bool {
+        return str.withCString { cstr in
+            return ndb_process_events(ndb.ndb, cstr, str.utf8.count) != 0
+        }
+    }
+
+    deinit {
+        ndb_destroy(ndb.ndb)
+    }
+}