Implemented basic directory service

nomadnet/Directory.py

@@ -0,0 +1,101 @@
+import os
+import RNS
+import LXMF
+import RNS.vendor.umsgpack as msgpack
+
+class Directory:
+    def __init__(self, app):
+        self.directory_entries = {}
+        self.app = app
+        self.load_from_disk()
+
+    def save_to_disk(self):
+        try:
+            packed_list = []
+            for source_hash in self.directory_entries:
+                e = self.directory_entries[source_hash]
+                packed_list.append((e.source_hash, e.display_name, e.trust_level))
+
+            file = open(self.app.directorypath, "wb")
+            file.write(msgpack.packb(packed_list))
+            file.close()
+        except Exception as e:
+            RNS.log("Could not write directory to disk. Then contained exception was: "+str(e), RNS.LOG_ERROR)
+
+    def load_from_disk(self):
+        if os.path.isfile(self.app.directorypath):
+            try:
+                file = open(self.app.directorypath, "rb")
+                unpacked_list = msgpack.unpackb(file.read())
+                file.close()
+
+                entries = {}
+                for e in unpacked_list:
+                    entries[e[0]] = DirectoryEntry(e[0], e[1], e[2])
+
+                self.directory_entries = entries
+
+            except Exception as e:
+                RNS.log("Could not load directory from disk. The contained exception was: "+str(e), RNS.LOG_ERROR)
+
+    def display_name(self, source_hash):
+        if source_hash in self.directory_entries:
+            return self.directory_entries[source_hash].display_name
+        else:
+            return None
+
+    def simplest_display_str(self, source_hash):
+        trust_level = self.trust_level(source_hash)
+        if trust_level == DirectoryEntry.WARNING or trust_level == DirectoryEntry.UNTRUSTED:
+            return "<"+RNS.hexrep(source_hash, delimit=False)+">"
+        else:
+            if source_hash in self.directory_entries:
+                return self.directory_entries[source_hash].display_name
+            else:
+                return "<"+RNS.hexrep(source_hash, delimit=False)+">"
+
+    def trust_level(self, source_hash, announced_display_name=None):
+        if source_hash in self.directory_entries:
+            if announced_display_name == None:
+                return self.directory_entries[source_hash].trust_level
+            else:
+                for entry in self.directory_entries:
+                    e = self.directory_entries[entry]
+                    if e.display_name == announced_display_name:
+                        if e.source_hash != source_hash:
+                            return DirectoryEntry.WARNING
+
+                return self.directory_entries[source_hash].trust_level
+        else:
+            return DirectoryEntry.UNKNOWN
+
+    def remember(self, entry):
+        self.directory_entries[entry.source_hash] = entry
+
+    def forget(self, source_hash):
+        if source_hash in self.directory_entries:
+            self.directory_entries.pop(source_hash)
+
+    def find(self, source_hash):
+        if source_hash in self.directory_entries:
+            return self.directory_entries[source_hash]
+        else:
+            return None
+
+
+class DirectoryEntry:
+    WARNING   = 0x00
+    UNTRUSTED = 0x01
+    UNKNOWN   = 0x02
+    TRUSTED   = 0xFF
+
+    def __init__(self, source_hash, display_name=None, trust_level=UNKNOWN):
+        if len(source_hash) == RNS.Identity.TRUNCATED_HASHLENGTH//8:
+            self.source_hash  = source_hash
+            self.display_name = display_name
+            if display_name  == None:
+                display_name  = source_hash
+
+            self.trust_level  = trust_level
+        else:
+            raise TypeError("Attempt to add invalid source hash to directory")