Prepare for external-merge.

db:get_by_leaf_hash(): Return notfound instead of crashing when no
entry could be found.

db:get_by_entry_hash(): Don't fetch index, isn't used and might not
exist.

index:add(): Allow writes at exiting indicies.

Conflicts:
	src/index.erl

1 files changed, 19 insertions, 6 deletions

diff --git a/src/db.erl b/src/db.erl
index a0855b9..640718c 100644
--- a/src/db.erl
+++ b/src/db.erl
@@ -103,7 +103,12 @@ entry_for_leafhash(LeafHash) ->
     perm:readfile(entry_root_path(), LeafHash).
 
 index_for_leafhash(LeafHash) ->
-    binary_to_integer(perm:readfile(indexforhash_root_path(), LeafHash)).
+    case perm:readfile(indexforhash_root_path(), LeafHash) of
+        noentry ->
+            noentry;
+        Index ->
+            binary_to_integer(Index)
+    end.
 
 leafhash_for_index(Index) ->
     index:get(index_path(), Index).
@@ -150,9 +155,17 @@ handle_call({get_by_index, Index}, _From, State) ->
     {reply, R, State};
 
 handle_call({get_by_leaf_hash, LeafHash}, _From, State) ->
-    Entry = entry_for_leafhash(LeafHash),
-    Index = index_for_leafhash(LeafHash),
-    R = {Index, LeafHash, Entry},
+    R = case entry_for_leafhash(LeafHash) of
+            noentry ->
+                notfound;
+            Entry ->
+                case index_for_leafhash(LeafHash) of
+                    noentry ->
+                        notfound;
+                    Index ->
+                        {Index, LeafHash, Entry}
+                end
+        end,
     {reply, R, State};
 
 handle_call({get_by_entry_hash, EntryHash}, _From, State) ->
@@ -161,7 +174,7 @@ handle_call({get_by_entry_hash, EntryHash}, _From, State) ->
                 notfound;
             LeafHash ->
                 Entry = entry_for_leafhash(LeafHash),
-                Index = index_for_leafhash(LeafHash),
-                {Index, LeafHash, Entry}
+                %% Don't fetch index, isn't used and might not exist
+                {notfetched, LeafHash, Entry}
         end,
     {reply, R, State}.