Stop forwarding trace when loop is found

ledgerloops · Apr 19, 2024 · 65f4986 · 65f4986
1 parent 5c34bbb
commit 65f4986
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Showing 7 changed files with 17,415 additions and 1,333 deletions.
diff --git a/__tests__/fixtures/batched-giraffe-hourglass.json b/__tests__/fixtures/batched-giraffe-hourglass.json
diff --git a/__tests__/fixtures/batched-giraffe-hourglass.puml b/__tests__/fixtures/batched-giraffe-hourglass.puml
diff --git a/__tests__/fixtures/batched-giraffe-triangle.json b/__tests__/fixtures/batched-giraffe-triangle.json
@@ -26,6 +26,8 @@
     "[Bob]->[Charlie] okay-to-send-probes",
     "[Bob]->[Alice] trace genRanHex0 genRanHex1 genRanHex2",
     "[---]->[---] ---",
+    "[Alice]->[Charlie] trace genRanHex0 genRanHex1 genRanHex2",
+    "[---]->[---] ---",
     "[---]->[---] ---"
   ],
   "probes": {
@@ -62,11 +64,17 @@
       "[Node#receiveMessage] Alice receives message from Charlie",
       "[TraceEngine] handling trace message from Charlie: trace genRanHex0 genRanHex1 genRanHex3",
       "[Node#lookup-probe] Alice is looking up probe genRanHex0",
-      "[TraceEngine] in the context of trace message from Charlie: trace genRanHex0 genRanHex1 genRanHex3, we found these upstreams: [], and otherLeg undefined",
+      "[TraceEngine] forwarding a counter-probe-wise trace message from Charlie: trace genRanHex0 genRanHex1 genRanHex3",
+      "Looking for other leg genRanHex0 genRanHex1 genRanHex3 in {\"Charlie\":\"genRanHex3\"}",
+      "[TraceEngine] in the context of trace message from Charlie: trace genRanHex0 genRanHex1 genRanHex3, we found these counter-probe-wise next hops: [], and otherLeg undefined",
       "[Node#receiveMessage] Alice receives message from Bob",
       "[TraceEngine] handling trace message from Bob: trace genRanHex0 genRanHex1 genRanHex2",
       "[Node#lookup-probe] Alice is looking up probe genRanHex0",
-      "[TraceEngine] in the context of trace message from Bob: trace genRanHex0 genRanHex1 genRanHex2, we found these upstreams: [], and otherLeg undefined"
+      "[TraceEngine] forwarding a counter-probe-wise trace message from Bob: trace genRanHex0 genRanHex1 genRanHex2",
+      "Looking for other leg genRanHex0 genRanHex1 genRanHex2 in {\"Charlie\":\"genRanHex3\",\"Bob\":\"genRanHex2\"}",
+      "[TraceEngine] in the context of trace message from Bob: trace genRanHex0 genRanHex1 genRanHex2, we found these counter-probe-wise next hops: [], and otherLeg Charlie",
+      "[TracesEngine] found otherLeg Charlie for trace genRanHex1 of probe genRanHex0",
+      "[Node#sendTraceMessage] Alice sends trace message to Charlie: trace genRanHex0 genRanHex1 genRanHex2"
     ],
     "loopsFound": []
   },
@@ -94,7 +102,9 @@
       "[Node#receiveMessage] Bob receives message from Charlie",
       "[TraceEngine] handling trace message from Charlie: trace genRanHex0 genRanHex1 genRanHex2",
       "[Node#lookup-probe] Bob is looking up probe genRanHex0",
-      "[TraceEngine] in the context of trace message from Charlie: trace genRanHex0 genRanHex1 genRanHex2, we found these upstreams: [Alice], and otherLeg undefined",
+      "[TraceEngine] forwarding a counter-probe-wise trace message from Charlie: trace genRanHex0 genRanHex1 genRanHex2",
+      "Looking for other leg genRanHex0 genRanHex1 genRanHex2 in {\"Charlie\":\"genRanHex2\"}",
+      "[TraceEngine] in the context of trace message from Charlie: trace genRanHex0 genRanHex1 genRanHex2, we found these counter-probe-wise next hops: [Alice], and otherLeg undefined",
       "[TracesEngine] sending message to Alice: trace genRanHex0 genRanHex1 genRanHex2",
       "[Node#sendTraceMessage] Bob sends trace message to Alice: trace genRanHex0 genRanHex1 genRanHex2"
     ],
@@ -126,7 +136,10 @@
       "[Node#receiveMessage] Charlie receives message from Alice",
       "Charlie receives okay-to-send-probes from Alice",
       "[Node#receiveMessage] Charlie receives message from Bob",
-      "Charlie receives okay-to-send-probes from Bob"
+      "Charlie receives okay-to-send-probes from Bob",
+      "[Node#receiveMessage] Charlie receives message from Alice",
+      "[TraceEngine] handling trace message from Alice: trace genRanHex0 genRanHex1 genRanHex2",
+      "loop-found genRanHex0 genRanHex1"
     ],
     "loopsFound": []
   }

diff --git a/__tests__/fixtures/batched-giraffe-triangle.puml b/__tests__/fixtures/batched-giraffe-triangle.puml
@@ -8,4 +8,5 @@ Alice -[#green]-> Charlie: probe genRanHex0
 Charlie -[#green]-> Bob: trace genRanHex0 genRanHex1 genRanHex2
 Charlie -[#green]-> Alice: trace genRanHex0 genRanHex1 genRanHex3
 Bob -[#green]-> Alice: trace genRanHex0 genRanHex1 genRanHex2
+Alice -[#green]-> Charlie: trace genRanHex0 genRanHex1 genRanHex2
 @enduml
diff --git a/__tests__/self-mending-for-giraffe-hourglass.test.ts b/__tests__/self-mending-for-giraffe-hourglass.test.ts
@@ -3,7 +3,7 @@
 import { jest } from '@jest/globals';
 import { readFileSync, writeFileSync } from 'fs';
 
-const NUM_ROUNDS = 10;
+const NUM_ROUNDS = 1000;
 const TEST_NAME = 'batched-giraffe-hourglass';
 const JSON_FILE = `__tests__/fixtures/${TEST_NAME}.json`;
 const PUML_FILE = `__tests__/fixtures/${TEST_NAME}.puml`;

diff --git a/src/engine/tracesengine.ts b/src/engine/tracesengine.ts
@@ -4,45 +4,69 @@ import { genRanHex } from "../genRanHex.js";
 export class TracesEngine extends EventEmitter {
   tracesCreated = {};
   tracesForwarded = {};
-  getLegs(probeId: string, traceId: string): { [to: string]: string } | undefined {
-    if (typeof this.tracesForwarded[probeId] === 'undefined') {
-      return undefined;
-    }
-    return this.tracesForwarded[probeId][traceId];
+  getLegsForwarded(probeId: string, traceId: string): { [to: string]: string } | undefined {
+    return this.tracesForwarded[probeId]?.[traceId];
+  }
+  getLegsCreated(probeId: string, traceId: string): { [to: string]: string } | undefined {
+    return this.tracesCreated[probeId]?.[traceId];
+  }
+  wasCreatedByUs(probeId: string, traceId: string): boolean {
+    return typeof this.getLegsCreated(probeId, traceId) !== 'undefined';
   }
   getOtherLeg(probeId: string, traceId: string, thisLegId: string): string | undefined {
-    const legs = this.getLegs(probeId, traceId);
+    const legs = this.getLegsForwarded(probeId, traceId);
+    this.emit('debug', `Looking for other leg ${probeId} ${traceId} ${thisLegId} in ${JSON.stringify(legs)}`);
     if (typeof legs === 'undefined') {
       return undefined;
     }
     return Object.keys(legs).find((to) => legs[to] !== thisLegId);
   }
+  logTraceMessage(sender: string, probeId: string, traceId: string, legId: string): void {
+    if (typeof this.tracesForwarded[probeId] === 'undefined') {
+      this.tracesForwarded[probeId] = {};
+    }
+    if (typeof this.tracesForwarded[probeId][traceId] === 'undefined') {
+      this.tracesForwarded[probeId][traceId] = {};
+    }
+    this.tracesForwarded[probeId][traceId][sender] = legId;
+  }
+  forwardTraceMessage(probeId: string, traceId: string, legId: string, nextHops: string[]): void {
+    nextHops.forEach((from) => {
+      this.emit('debug', `[TracesEngine] sending message to ${from}: trace ${probeId} ${traceId} ${legId}`);
+      this.emit('message', from, `trace ${probeId} ${traceId} ${legId}`);
+    });
+  }
   handleTraceMessage(sender: string, message: string): void {
     this.emit('debug', `[TraceEngine] handling trace message from ${sender}: ${message}`);
     const [messageType, probeId, traceId, legId] = message.split(' ');
+    if (this.wasCreatedByUs(probeId, traceId)) {
+      this.emit('debug', `loop-found ${probeId} ${traceId}`);
+      this.emit('loop-found', probeId, traceId);
+      return;
+    }
     if (messageType !== 'trace') {
       throw new Error(`expected trace message but got ${messageType}`);
     }
-    this.emit('lookup-probe', probeId, (probeFrom: string[]) => {
-      const otherLeg = this.getOtherLeg(probeId, traceId, legId);
-      this.emit('debug', `[TraceEngine] in the context of trace message from ${sender}: ${message}, we found these upstreams: [${probeFrom.join(', ')}], and otherLeg ${otherLeg}`);
-      if (typeof otherLeg === 'undefined') {
-        const legs = {};
-        probeFrom.forEach((from) => {
-          legs[from] = legId;
-          this.emit('debug', `[TracesEngine] sending message to ${from}: trace ${probeId} ${traceId} ${legId}`);
-          this.emit('message', from, `trace ${probeId} ${traceId} ${legId}`);
-        });
-        if (typeof this.tracesForwarded[probeId] === 'undefined') {
-          this.tracesForwarded[probeId] = {};
+    this.logTraceMessage(sender,probeId, traceId, legId);
+    this.emit('lookup-probe', probeId, (probeFrom: string[], probeTo: string[]) => {
+      if (probeFrom.includes(sender)) {
+        this.emit('debug', `[TraceEngine] forwarding a probe-wise trace message from ${sender}: ${message}`);
+        this.forwardTraceMessage(probeId, traceId, legId, probeTo);
+      } else if (probeTo.includes(sender)) {
+        this.emit('debug', `[TraceEngine] forwarding a counter-probe-wise trace message from ${sender}: ${message}`);
+        const otherLeg = this.getOtherLeg(probeId, traceId, legId);
+        this.emit('debug', `[TraceEngine] in the context of trace message from ${sender}: ${message}, we found these counter-probe-wise next hops: [${probeFrom.join(', ')}], and otherLeg ${otherLeg}`);
+        if (typeof otherLeg === 'undefined') {  
+          this.forwardTraceMessage(probeId, traceId, legId, probeFrom);
+        } else {
+          this.emit('debug', `[TracesEngine] found otherLeg ${otherLeg} for trace ${traceId} of probe ${probeId}`);
+          if (otherLeg === sender) {
+            this.emit('debug', `UNEXPECTED: Received two different legs from the same node`);
+          }
+          this.emit('message', otherLeg, `trace ${probeId} ${traceId} ${legId}`)
         }
-        this.tracesForwarded[probeId][traceId] = legs;
       } else {
-        this.emit('debug', `[TracesEngine] found otherLeg ${otherLeg} for trace ${traceId} of probe ${probeId}`);
-        if (otherLeg === sender) {
-          this.emit('debug', `UNEXPECTED: Received two different legs from the same node`);
-        }
-        // this.emit('message', otherLeg, `trace ${probeId} ${traceId} ${legId}`)
+        throw new Error(`received trace message '${message}' from unexpected sender ${sender}`);
       }
     });
   }
@@ -59,7 +83,7 @@ export class TracesEngine extends EventEmitter {
       if (typeof this.tracesCreated[probeId] === 'undefined') {
         this.tracesCreated[probeId] = {};
       }
-      this.tracesCreated[probeId][traceId] = legs;    
+      this.tracesCreated[probeId][traceId] = legs;
     });
   }
 }

diff --git a/src/giraffe.ts b/src/giraffe.ts
@@ -37,9 +37,10 @@ export class Giraffe extends EventEmitter implements NetworkNode {
     tracesengine.on('debug', (message: string) => {
       this.debugLog.push(message);
     });
-    tracesengine.on('lookup-probe', (probeId: string, callback: (probeFrom: string[]) => void) => {
+    tracesengine.on('lookup-probe', (probeId: string, callback: (probeFrom: string[], probeTo: string[]) => void) => {
       this.debugLog.push(`[Node#lookup-probe] ${this.name} is looking up probe ${probeId}`);
-      callback(probesengine.get(probeId).getFrom());
+      const probe = probesengine.get(probeId);
+      callback(probe.getFrom(), probe.getTo());
     });
     tracesengine.on('message', (to: string, message: string) => {
       this.debugLog.push(`[Node#sendTraceMessage] ${this.name} sends trace message to ${to}: ${message}`);