Don't set map_size=1TB in util/db_lmdb

Instead, double the map size on the MDB_MAP_FULL exception.

include/caffe/util/db_lmdb.hpp

@@ -3,6 +3,7 @@
 #define CAFFE_UTIL_DB_LMDB_HPP
 
 #include <string>
+#include <vector>
 
 #include "lmdb.h"
 
@@ -54,14 +55,16 @@ class LMDBCursor : public Cursor {
 
 class LMDBTransaction : public Transaction {
  public:
-  explicit LMDBTransaction(MDB_dbi* mdb_dbi, MDB_txn* mdb_txn)
-    : mdb_dbi_(mdb_dbi), mdb_txn_(mdb_txn) { }
+  explicit LMDBTransaction(MDB_env* mdb_env)
+    : mdb_env_(mdb_env) { }
   virtual void Put(const string& key, const string& value);
-  virtual void Commit() { MDB_CHECK(mdb_txn_commit(mdb_txn_)); }
+  virtual void Commit();
 
  private:
-  MDB_dbi* mdb_dbi_;
-  MDB_txn* mdb_txn_;
+  MDB_env* mdb_env_;
+  vector<string> keys, values;
+
+  void DoubleMapSize();
 
   DISABLE_COPY_AND_ASSIGN(LMDBTransaction);
 };

src/caffe/util/db_lmdb.cpp

@@ -7,11 +7,8 @@
 
 namespace caffe { namespace db {
 
-const size_t LMDB_MAP_SIZE = 1099511627776;  // 1 TB
-
 void LMDB::Open(const string& source, Mode mode) {
   MDB_CHECK(mdb_env_create(&mdb_env_));
-  MDB_CHECK(mdb_env_set_mapsize(mdb_env_, LMDB_MAP_SIZE));
   if (mode == NEW) {
     CHECK_EQ(mkdir(source.c_str(), 0744), 0) << "mkdir " << source << "failed";
   }
@@ -48,19 +45,61 @@ LMDBCursor* LMDB::NewCursor() {
 }
 
 LMDBTransaction* LMDB::NewTransaction() {
-  MDB_txn* mdb_txn;
-  MDB_CHECK(mdb_txn_begin(mdb_env_, NULL, 0, &mdb_txn));
-  MDB_CHECK(mdb_dbi_open(mdb_txn, NULL, 0, &mdb_dbi_));
-  return new LMDBTransaction(&mdb_dbi_, mdb_txn);
+  return new LMDBTransaction(mdb_env_);
 }
 
 void LMDBTransaction::Put(const string& key, const string& value) {
-  MDB_val mdb_key, mdb_value;
-  mdb_key.mv_data = const_cast<char*>(key.data());
-  mdb_key.mv_size = key.size();
-  mdb_value.mv_data = const_cast<char*>(value.data());
-  mdb_value.mv_size = value.size();
-  MDB_CHECK(mdb_put(mdb_txn_, *mdb_dbi_, &mdb_key, &mdb_value, 0));
+  keys.push_back(key);
+  values.push_back(value);
+}
+
+void LMDBTransaction::Commit() {
+  MDB_dbi mdb_dbi;
+  MDB_val mdb_key, mdb_data;
+  MDB_txn *mdb_txn;
+
+  // Initialize MDB variables
+  MDB_CHECK(mdb_txn_begin(mdb_env_, NULL, 0, &mdb_txn));
+  MDB_CHECK(mdb_dbi_open(mdb_txn, NULL, 0, &mdb_dbi));
+
+  bool out_of_memory = false;
+  for (int i = 0; i < keys.size(); i++) {
+    mdb_key.mv_size = keys[i].size();
+    mdb_key.mv_data = const_cast<char*>(keys[i].data());
+    mdb_data.mv_size = values[i].size();
+    mdb_data.mv_data = const_cast<char*>(values[i].data());
+
+    int put_rc = mdb_put(mdb_txn, mdb_dbi, &mdb_key, &mdb_data, 0);
+    if (put_rc == MDB_MAP_FULL) {
+      out_of_memory = true;
+      break;
+    } else {
+      // Failed for some other reason
+      MDB_CHECK(put_rc);
+    }
+  }
+
+  if (!out_of_memory) {
+    // Commit the transaction
+    MDB_CHECK(mdb_txn_commit(mdb_txn));
+    mdb_dbi_close(mdb_env_, mdb_dbi);
+    keys.clear();
+    values.clear();
+  } else {
+    // Double the map size and retry
+    mdb_txn_abort(mdb_txn);
+    mdb_dbi_close(mdb_env_, mdb_dbi);
+    DoubleMapSize();
+    Commit();
+  }
+}
+
+void LMDBTransaction::DoubleMapSize() {
+  struct MDB_envinfo current_info;
+  MDB_CHECK(mdb_env_info(mdb_env_, &current_info));
+  size_t new_size = current_info.me_mapsize * 2;
+  DLOG(INFO) << "Doubling LMDB map size to " << (new_size>>20) << "MB ...";
+  MDB_CHECK(mdb_env_set_mapsize(mdb_env_, new_size));
 }
 
 }  // namespace db