Have the dpnodes stick received DPs in a table and look for collisions

dpnode.cc

@@ -9,12 +9,15 @@ extern "C" {
 #include <arpa/inet.h>
 
 #include <set>
+#include <map>
 #include <stdlib.h>
 #include <string.h>
 
 #include "evutils.h"
 #include "subproblem.h"
 
+typedef map<std::string, pair<ZZ,ZZ> > DTable;
+
 typedef enum {
     DPSTATE_START,
     DPSTATE_END
@@ -26,6 +29,16 @@ struct DPNodeConnInfo {
     DPNodeConnInfo() : state(DPSTATE_START) {}
 };
 
+static struct DPControllerState {
+    Subproblem *current_problem;
+    struct evconnlistener *listener;
+    std::set<struct bufferevent *> workers;
+    DTable table;
+    unsigned long long numdps;
+
+    DPControllerState() : current_problem(NULL), listener(NULL) {}
+} dpctrlstate;
+
 static void dpnode_event_cb(struct bufferevent *bev, short events,
     void *ctx)
 {
@@ -41,13 +54,29 @@ static void dpnode_reader(struct bufferevent *bev, void *ctx)
 {
     struct evbuffer *input = bufferevent_get_input(bev);
     unsigned int dp[WORDS+6];
-    int num_read = 0;
+    pair<DTable::iterator, bool> res;
 
     while(1) {
 	size_t len = evbuffer_get_length(input);
 	if (len < ((WORDS+6)*sizeof(unsigned int))) break;
 	bufferevent_read(bev, dp, (WORDS+6)*sizeof(unsigned int));
-	++num_read;
+	// The (WORDS+6) unsigned ints we read are:
+	// - WORDS words for the value of the dp
+	// - 3 words for a
+	// - 3 words for b
+	ZZ zz_a, zz_b;
+	ZZFromBytes(zz_a, (const unsigned char *)(dp+WORDS),
+		3*sizeof(unsigned int));
+	ZZFromBytes(zz_b, (const unsigned char *)(dp+WORDS+3),
+		3*sizeof(unsigned int));
+	string x((const char *)(dp), WORDS*sizeof(unsigned int));
+	pair<ZZ,ZZ> ab(zz_a,zz_b);
+	res = dpctrlstate.table.insert(DTable::value_type(x,ab));
+	if (!res.second) {
+	    // Collision!
+	    cerr << "Collision!\n";
+	}
+	++dpctrlstate.numdps;
     }
     // cerr << num_read << " DPs read\n";
 }
@@ -66,7 +95,7 @@ static void dpnode_accept_cb(struct evconnlistener *listener,
     bufferevent_setcb(bev, dpnode_reader, NULL,
 	    dpnode_event_cb, info);
 
-    bufferevent_enable(bev, EV_READ|EV_WRITE);
+    bufferevent_enable(bev, EV_READ);
 }
 
 // Create a new DPnode socket.  ip and boundport are set to the IP and
@@ -90,14 +119,6 @@ struct DPControllerConnInfo {
     DPControllerConnInfo() : state(DPCCSTATE_AWAITCMD) {}
 };
 
-static struct DPControllerState {
-    Subproblem *current_problem;
-    struct evconnlistener *listener;
-    std::set<struct bufferevent *> workers;
-
-    DPControllerState() : current_problem(NULL), listener(NULL) {}
-} dpctrlstate;
-
 static void stop_problem(void)
 {
     if (dpctrlstate.current_problem) {
@@ -113,6 +134,8 @@ static void stop_problem(void)
 	bufferevent_free(*wit);
     }
     dpctrlstate.workers.clear();
+    dpctrlstate.table.clear();
+    dpctrlstate.numdps = 0;
 }
 
 static void start_problem(struct bufferevent *bev,