[3360] Memfile db access string uses persist parameter to disable writes.

src/lib/dhcpsrv/memfile_lease_mgr.cc

@@ -415,6 +415,19 @@ Memfile_LeaseMgr::persistLeases(Universe u) const {
 
 std::string
 Memfile_LeaseMgr::initLeaseFilePath(Universe u) {
+    bool persist = true;
+    try {
+        std::string persist_str = getParameter("persist");
+        if (persist_str == "no") {
+            persist = false;
+        }
+    } catch (const Exception& ex) {
+        persist = true;
+    }
+    if (!persist) {
+        return ("");
+    }
+
     std::string param_name = (u == V4 ? "leasefile4" : "leasefile6");
     std::string lease_file;
     try {

src/lib/dhcpsrv/memfile_lease_mgr.h

@@ -329,8 +329,9 @@ protected:
     /// initialize the location of the lease file. If the lease file is not
     /// specified, the method will use the default location for the universe
     /// (v4 or v6) selected. If the location is specified in the map as empty
-    /// it will set the empty location, which implies that leases belonging to
-    /// the specified universe will not be written to disk.
+    /// or the "persist" parameter is set to "no" it will set the empty
+    /// location, which implies that leases belonging to the specified universe
+    /// will not be written to disk.
     ///
     /// @param u Universe (v4 or v6)
     /// @param parameters Map holding parameters of the Lease Manager, passed to
@@ -454,6 +455,7 @@ protected:
 
     /// @brief Holds the pointer to the DHCPv6 lease file IO.
     boost::shared_ptr<CSVLeaseFile6> lease_file6_;
+
 };
 
 }; // end of isc::dhcp namespace

src/lib/dhcpsrv/tests/alloc_engine_unittest.cc

@@ -101,7 +101,7 @@ public:
 
         initFqdn("", false, false);
 
-        factory_.create("type=memfile leasefile4= leasefile6=");
+        factory_.create("type=memfile persist=no");
     }
 
     /// @brief Configures a subnet and adds one pool to it.
@@ -424,7 +424,7 @@ public:
         subnet_->addPool(pool_);
         cfg_mgr.addSubnet4(subnet_);
 
-        factory_.create("type=memfile leasefile4= leasefile6=");
+        factory_.create("type=memfile persist=no");
     }
 
     /// @brief checks if Lease4 matches expected configuration

src/lib/dhcpsrv/tests/dbaccess_parser_unittest.cc

@@ -410,9 +410,9 @@ TEST_F(DbAccessParserTest, commit) {
             }, isc::dhcp::NoLeaseManager);
 
     // Set up the parser to open the memfile database.
-    const char* config[] = {"type", "memfile", "leasefile4", "",
-                            "leasefile6", "", NULL};
+    const char* config[] = {"type", "memfile", "persist", "no", NULL};
     string json_config = toJson(config);
+
     ConstElementPtr json_elements = Element::fromJSON(json_config);
     EXPECT_TRUE(json_elements);
 
@@ -420,7 +420,7 @@ TEST_F(DbAccessParserTest, commit) {
     EXPECT_NO_THROW(parser.build(json_elements));
 
     // Ensure that the access string is as expected.
-    EXPECT_EQ(std::string("type=memfile"), parser.getDbAccessString());
+    EXPECT_EQ(std::string("persist=no type=memfile"), parser.getDbAccessString());
 
     // Committal of the parser changes should open the database.
     EXPECT_NO_THROW(parser.commit());

src/lib/dhcpsrv/tests/memfile_lease_mgr_unittest.cc

@@ -113,8 +113,7 @@ public:
 TEST_F(MemfileLeaseMgrTest, constructor) {
 
     LeaseMgr::ParameterMap pmap;
-    pmap["leasefile4"] = "";
-    pmap["leasefile6"] = "";
+    pmap["persist"] = "no";
     boost::scoped_ptr<Memfile_LeaseMgr> lease_mgr;
 
     ASSERT_NO_THROW(lease_mgr.reset(new Memfile_LeaseMgr(pmap)));
@@ -143,8 +142,7 @@ TEST_F(MemfileLeaseMgrTest, getLeaseFilePath) {
     EXPECT_EQ(pmap["leasefile6"],
               lease_mgr->getLeaseFilePath(Memfile_LeaseMgr::V6));
 
-    pmap["leasefile4"] = "";
-    pmap["leasefile6"] = "";
+    pmap["persist"] = "no";
     lease_mgr.reset(new Memfile_LeaseMgr(pmap));
     EXPECT_TRUE(lease_mgr->getLeaseFilePath(Memfile_LeaseMgr::V4).empty());
     EXPECT_TRUE(lease_mgr->getLeaseFilePath(Memfile_LeaseMgr::V6).empty());
@@ -168,10 +166,8 @@ TEST_F(MemfileLeaseMgrTest, persistLeases) {
     EXPECT_TRUE(lease_mgr->persistLeases(Memfile_LeaseMgr::V4));
     EXPECT_TRUE(lease_mgr->persistLeases(Memfile_LeaseMgr::V6));
 
-    // Specify empty names of the lease files. This should disable writes
-    // of leases to disk.
-    pmap["leasefile4"] = "";
-    pmap["leasefile6"] = "";
+    // This should disable writes of leases to disk.
+    pmap["persist"] = "no";
     lease_mgr.reset(new Memfile_LeaseMgr(pmap));
     EXPECT_FALSE(lease_mgr->persistLeases(Memfile_LeaseMgr::V4));
     EXPECT_FALSE(lease_mgr->persistLeases(Memfile_LeaseMgr::V6));