lmdb.pl: Work around a memory leak in the extract functionHEADmaster

1 files changed, 13 insertions, 8 deletions

diff --git a/lmdb.pl b/lmdb.pl
index 1e5e11f..35931eb 100755
--- a/lmdb.pl
+++ b/lmdb.pl
@@ -17,7 +17,7 @@ my($env, $txn, $dbi);
 sub db {
     my $wr = shift;
     $env = LMDB::Env->new($dbfile, { mapsize => 1<<36, maxdbs => 1, flags => MDB_NOSUBDIR|($wr?0:MDB_RDONLY) });
-    $txn = $env->BeginTxn();
+    $txn = $env->BeginTxn($wr ? 0 : MDB_RDONLY);
     $dbi = $txn->open('db', $wr ? MDB_CREATE : undef);
 }
 
@@ -43,15 +43,20 @@ sub bench {
 
 
 sub extract {
-    db;
-    my $db = LMDB_File->new($txn, $dbi);
-    my $cur = $db->Cursor();
+    # This ugly periodic opening/closing of the database is to work around a
+    # memory leak somewhere.
     eval {
-        my($key, $value);
-        $cur->get($key, $value, MDB_FIRST);
+        my $key;
         while(1) {
-            print "$key\n";
-            $cur->get($key, $value, MDB_NEXT);
+            $env = $txn = $dbi = undef;
+            db;
+            my $db = LMDB_File->new($txn, $dbi);
+            my $cur = $db->Cursor();
+            $cur->get($key, (my $value), defined($key) ? MDB_SET_KEY : MDB_FIRST);
+            for (0..10_000) {
+                print "$key\n";
+                $cur->get($key, $value, MDB_NEXT);
+            }
         }
     }
 }