Refactored NPL message processing. Passed lcl to contract args. (#105)

examples/nodejs_contract/hp-contract-lib.js

@@ -4,8 +4,18 @@ function HotPocketContract() {
     const hpargs = JSON.parse(fs.readFileSync(0, 'utf8'));
     this.readonly = hpargs.readonly;
     this.timestamp = hpargs.ts;
-    this.users = {};
 
+    if (!this.readonly) {
+        const lclParts = hpargs.lcl.split("-");
+        this.lcl = {
+            seqNo: parseInt(lclParts[0]),
+            hash: lclParts[1]
+        };
+
+        this.npl = new HotPocketNplChannel(hpargs.nplfd[0], hpargs.nplfd[1]);
+    }
+
+    this.users = {};
     Object.keys(hpargs.usrfd).forEach((userPubKey) => {
         const userfds = hpargs.usrfd[userPubKey];
         this.users[userPubKey] = new HotPocketChannel(userfds[0], userfds[1]);
@@ -22,6 +32,59 @@ function HotPocketChannel(infd, outfd) {
     }
 }
 
+function HotPocketNplChannel(infd, outfd) {
+    this.readInput = function () {
+        if (infd == -1)
+            return null;
+
+        // Input may consist of multiple messages.
+        // Each message has the format:
+        // | NPL version (1 byte) | reserve (1 byte) | msg length (2 bytes BE) | peer pubkey (32 bytes) | msg |
+
+        const inputs = []; // Peer inputs will be populated to this.
+
+        const buf = fs.readFileSync(infd);
+        let pos = 0;
+        while (pos < buf.byteLength) {
+
+            pos += 2; // Skip version and reserve.
+
+            // Read message len.
+            const msgLenBuf = readBytes(buf, pos, 2);
+            if (!msgLenBuf) break;
+            const msgLen = msgLenBuf.readUInt16BE();
+
+            pos += 2;
+            const pubKeyBuf = readBytes(buf, pos, 32);
+            if (!pubKeyBuf) break;
+
+            pos += 32;
+
+            const msgBuf = readBytes(buf, pos, msgLen)
+            if (!msgBuf) break;
+
+            inputs.push({
+                pubkey: pubKeyBuf.toString("hex"),
+                input: msgBuf
+            });
+
+            pos += msgLen;
+        }
+
+        return inputs;
+    }
+
+    this.sendOutput = function (output) {
+        fs.writeFileSync(outfd, output);
+    }
+
+    const readBytes = function (buf, pos, count) {
+        if (pos + count > buf.byteLength)
+            return null;
+        return buf.slice(pos, pos + count);
+    }
+}
+
 module.exports = {
     HotPocketContract
 }