cleanup directory structure

src/mesh/FloodingRouter.h

@@ -0,0 +1,83 @@
+#pragma once
+
+#include "PeriodicTask.h"
+#include "Router.h"
+#include <vector>
+
+/**
+ * A record of a recent message broadcast
+ */
+struct BroadcastRecord {
+    NodeNum sender;
+    PacketId id;
+    uint32_t rxTimeMsec; // Unix time in msecs - the time we received it
+};
+
+/**
+ * This is a mixin that extends Router with the ability to do Naive Flooding (in the standard mesh protocol sense)
+ *
+ *   Rules for broadcasting (listing here for now, will move elsewhere eventually):
+
+  If to==BROADCAST and id==0, this is a simple broadcast (0 hops).  It will be
+  sent only by the current node and other nodes will not attempt to rebroadcast
+  it.
+
+  If to==BROADCAST and id!=0, this is a "naive flooding" broadcast.  The initial
+  node will send it on all local interfaces.
+
+  When other nodes receive this message, they will
+  first check if their recentBroadcasts table contains the (from, id) pair that
+  indicates this message.  If so, we've already seen it - so we discard it.  If
+  not, we add it to the table and then resend this message on all interfaces.
+  When resending we are careful to use the "from" ID of the original sender. Not
+  our own ID.  When resending we pick a random delay between 0 and 10 seconds to
+  decrease the chance of collisions with transmitters we can not even hear.
+
+  Any entries in recentBroadcasts that are older than X seconds (longer than the
+  max time a flood can take) will be discarded.
+ */
+class FloodingRouter : public Router, public PeriodicTask
+{
+  private:
+    /** FIXME: really should be a std::unordered_set with the key being sender,id.
+     * This would make checking packets in wasSeenRecently faster.
+     */
+    std::vector<BroadcastRecord> recentBroadcasts;
+
+    /**
+     * Packets we've received that we need to resend after a short delay
+     */
+    PointerQueue<MeshPacket> toResend;
+
+  public:
+    /**
+     * Constructor
+     *
+     */
+    FloodingRouter();
+
+    /**
+     * Send a packet on a suitable interface.  This routine will
+     * later free() the packet to pool.  This routine is not allowed to stall.
+     * If the txmit queue is full it might return an error
+     */
+    virtual ErrorCode send(MeshPacket *p);
+
+  protected:
+    /**
+     * Called from loop()
+     * Handle any packet that is received by an interface on this node.
+     * Note: some packets may merely being passed through this node and will be forwarded elsewhere.
+     *
+     * Note: this method will free the provided packet
+     */
+    virtual void handleReceived(MeshPacket *p);
+
+    virtual void doTask();
+
+  private:
+    /**
+     * Update recentBroadcasts and return true if we have already seen this packet
+     */
+    bool wasSeenRecently(const MeshPacket *p);
+};