1 files changed, 191 insertions, 0 deletions
diff --git a/metis/ccnx/forwarder/metis/strategies/strategy_Rnd.c b/metis/ccnx/forwarder/metis/strategies/strategy_Rnd.c
new file mode 100644
index 00000000..a170b9b7
--- /dev/null
+++ b/metis/ccnx/forwarder/metis/strategies/strategy_Rnd.c
@@ -0,0 +1,191 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#include <config.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include <stdlib.h>
+
+#include <LongBow/runtime.h>
+
+#include <parc/algol/parc_Memory.h>
+#include <parc/algol/parc_HashMap.h>
+
+#include <ccnx/forwarder/metis/strategies/strategy_Rnd.h>
+
+
+static void             _strategyRnd_ReceiveObject(MetisStrategyImpl *strategy, const MetisNumberSet *egressId, const MetisMessage *objectMessage, MetisTicks rtt);
+static void             _strategyRnd_OnTimeout(MetisStrategyImpl *strategy, const MetisNumberSet *egressId);
+static MetisNumberSet *_strategyRnd_LookupNexthop(MetisStrategyImpl *strategy, const MetisMessage *interestMessage);
+static MetisNumberSet *_strategyRnd_ReturnNexthops(MetisStrategyImpl *strategy);
+static unsigned         _strategyRnd_CountNexthops(MetisStrategyImpl *strategy);
+static void             _strategyRnd_AddNexthop(MetisStrategyImpl *strategy, CPIRouteEntry *route);
+static void             _strategyRnd_RemoveNexthop(MetisStrategyImpl *strategy, CPIRouteEntry *route);
+static void             _strategyRnd_ImplDestroy(MetisStrategyImpl **strategyPtr);
+static const char *_strategyRnd_GetStrategy(MetisStrategyImpl *strategy);
+
+static MetisStrategyImpl _template = {
+    .context        = NULL,
+    .receiveObject  = &_strategyRnd_ReceiveObject,
+    .onTimeout      = &_strategyRnd_OnTimeout,
+    .lookupNexthop  = &_strategyRnd_LookupNexthop,
+    .returnNexthops = &_strategyRnd_ReturnNexthops,
+    .countNexthops  = &_strategyRnd_CountNexthops,
+    .addNexthop     = &_strategyRnd_AddNexthop,
+    .removeNexthop  = &_strategyRnd_RemoveNexthop,
+    .destroy        = &_strategyRnd_ImplDestroy,
+    .getStrategy    = &_strategyRnd_GetStrategy,
+};
+
+struct strategy_rnd;
+typedef struct strategy_rnd StrategyRnd;
+
+
+struct strategy_rnd {
+    MetisNumberSet *nexthops;
+};
+
+MetisStrategyImpl *
+strategyRnd_Create()
+{
+    StrategyRnd *strategy = parcMemory_AllocateAndClear(sizeof(StrategyRnd));
+    assertNotNull(strategy, "parcMemory_AllocateAndClear(%zu) returned NULL", sizeof(StrategyRnd));
+
+    strategy->nexthops = metisNumberSet_Create();
+    srand(time(NULL));
+
+    MetisStrategyImpl *impl = parcMemory_AllocateAndClear(sizeof(MetisStrategyImpl));
+    assertNotNull(impl, "parcMemory_AllocateAndClear(%zu) returned NULL", sizeof(MetisStrategyImpl));
+    memcpy(impl, &_template, sizeof(MetisStrategyImpl));
+    impl->context = strategy;
+
+    return impl;
+}
+
+// =======================================================
+// Dispatch API
+
+static const char*
+_strategyRnd_GetStrategy(MetisStrategyImpl *strategy)
+{
+    return FWD_STRATEGY_RANDOM;
+}
+
+
+static int
+_select_Nexthop(StrategyRnd *strategy)
+{
+    unsigned len = metisNumberSet_Length(strategy->nexthops);
+    if (len == 0) {
+        return -1;
+    }
+
+    int rnd = (rand() % len);
+    return metisNumberSet_GetItem(strategy->nexthops, rnd);
+}
+
+
+static void
+_strategyRnd_ReceiveObject(MetisStrategyImpl *strategy, const MetisNumberSet *egressId, const MetisMessage *objectMessage, MetisTicks rtt)
+{
+}
+
+static void
+_strategyRnd_OnTimeout(MetisStrategyImpl *strategy, const MetisNumberSet *egressId)
+{
+}
+
+//ATTENTION!! This interface force us to create a MetisNumberSet which need to be delited somewhere (maybe in the FIB where we call this function)
+//The specification in the interface requires that this function never returns NULL. in case we have no output face we need to return an empty MetisNumberSet
+static MetisNumberSet *
+_strategyRnd_LookupNexthop(MetisStrategyImpl *strategy, const MetisMessage *interestMessage)
+{
+    StrategyRnd *srnd = (StrategyRnd *) strategy->context;
+
+    unsigned in_connection = metisMessage_GetIngressConnectionId(interestMessage);
+    unsigned nexthopSize = metisNumberSet_Length(srnd->nexthops);
+
+    MetisNumberSet *out = metisNumberSet_Create();
+    if ((nexthopSize == 0) || ((nexthopSize == 1) && metisNumberSet_Contains(srnd->nexthops, in_connection))) {
+        //there are no output faces or the input face is also the only output face. return null to avoid loops
+        return out;
+    }
+
+    unsigned out_connection;
+    do {
+        out_connection = _select_Nexthop(srnd);
+    } while (out_connection == in_connection);
+
+    if (out_connection == -1) {
+        return out;
+    }
+
+    metisNumberSet_Add(out, out_connection);
+    return out;
+}
+
+static MetisNumberSet *
+_strategyRnd_ReturnNexthops(MetisStrategyImpl *strategy)
+{
+    StrategyRnd *srnd = (StrategyRnd *) strategy->context;
+    return srnd->nexthops;
+}
+
+unsigned
+_strategyRnd_CountNexthops(MetisStrategyImpl *strategy)
+{
+    StrategyRnd *srnd = (StrategyRnd *) strategy->context;
+    return metisNumberSet_Length(srnd->nexthops);
+}
+
+static void
+_strategyRnd_AddNexthop(MetisStrategyImpl *strategy, CPIRouteEntry *route)
+{
+    unsigned connectionId = cpiRouteEntry_GetInterfaceIndex(route); //this returns what in all the rest of the ccnx code is called connection id!
+
+    StrategyRnd *srnd = (StrategyRnd *) strategy->context;
+    if (!metisNumberSet_Contains(srnd->nexthops, connectionId)) {
+        metisNumberSet_Add(srnd->nexthops, connectionId);
+    }
+}
+
+static void
+_strategyRnd_RemoveNexthop(MetisStrategyImpl *strategy, CPIRouteEntry *route)
+{
+    unsigned connectionId = cpiRouteEntry_GetInterfaceIndex(route);
+    StrategyRnd *srnd = (StrategyRnd *) strategy->context;
+
+    if (metisNumberSet_Contains(srnd->nexthops, connectionId)) {
+        metisNumberSet_Remove(srnd->nexthops, connectionId);
+    }
+}
+
+static void
+_strategyRnd_ImplDestroy(MetisStrategyImpl **strategyPtr)
+{
+    assertNotNull(strategyPtr, "Parameter must be non-null double pointer");
+    assertNotNull(*strategyPtr, "Parameter must dereference to non-null pointer");
+
+    MetisStrategyImpl *impl = *strategyPtr;
+    StrategyRnd *strategy = (StrategyRnd *) impl->context;
+
+    metisNumberSet_Release(&(strategy->nexthops));
+
+    parcMemory_Deallocate((void **) &strategy);
+    parcMemory_Deallocate((void **) &impl);
+    *strategyPtr = NULL;
+}