fix: cleanups and simplifications

Agoric · Feb 11, 2021 · 1fe4eae · 1fe4eae
1 parent 8f41058
commit 1fe4eae
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Showing 3 changed files with 28 additions and 48 deletions.
diff --git a/packages/SwingSet/src/kernel/vatManager/types.js b/packages/SwingSet/src/kernel/vatManager/types.js
@@ -1,6 +1,6 @@
 /**
  * @typedef { [unknown, ...unknown[]] } Tagged
- * @typedef { { workerType: string, allocate: number, compute: number } }
+ * @typedef { { meterType: string, allocate: number|null, compute: number|null } }
  * CrankStats
  * @typedef { { reply: Tagged, crankStats: CrankStats } } CrankResults
  */
diff --git a/packages/xsnap/src/xsnap.c b/packages/xsnap/src/xsnap.c
@@ -3,6 +3,7 @@
 #include "xsSnapshot.h"
 #include "xs.h"
 
+#define SNAPSHOT_SIGNATURE "xsnap 1"
 #ifndef XSNAP_VERSION
 # error "You must define XSNAP_VERSION in the right Makefile"
 #endif
@@ -176,8 +177,8 @@ static int fxSnapshotWrite(void* stream, void* address, size_t size)
 	#define xsEndMetering(_THE)
 	#define xsPatchHostFunction(_FUNCTION,_PATCH)
 	#define xsMeterHostFunction(_COUNT) (void)(_COUNT)
-  #define xsBeginCrank(_THE, _LIMIT)
-  #define xsEndCrank(_THE) 0
+	#define xsBeginCrank(_THE, _LIMIT)
+	#define xsEndCrank(_THE) 0
 #endif
 
 static xsUnsignedValue gxCrankMeteringLimit = 0;
@@ -218,8 +219,8 @@ int main(int argc, char* argv[])
 	xsCreation* creation = &_creation;
 
 	txSnapshot snapshot = {
-		"xsnap-" XSNAP_VERSION,
-		11,
+		SNAPSHOT_SIGNATURE,
+		sizeof(SNAPSHOT_SIGNATURE) - 1,
 		gxSnapshotCallbacks,
 		mxSnapshotCallbackCount,
 		fxSnapshotRead,
@@ -328,7 +329,7 @@ int main(int argc, char* argv[])
 		char done = 0;
 		while (!done) {
 			// By default, use the infinite meter.
-      gxCurrentMeter = 0;
+			gxCurrentMeter = 0;
 
 			xsUnsignedValue meterIndex = 0;
 			char* nsbuf;
@@ -830,10 +831,10 @@ void fx_Array_prototype_meter(xsMachine* the)
 
 void fxPatchBuiltIns(txMachine* machine)
 {
-  // FIXME: This function is disabled because it caused failures.
-  // https://github.com/Moddable-OpenSource/moddable/issues/550
+	// FIXME: This function is disabled because it caused failures.
+	// https://github.com/Moddable-OpenSource/moddable/issues/550
 
-  // TODO: Provide complete metering of builtins and operators.
+	// TODO: Provide complete metering of builtins and operators.
 #if 0
 	xsBeginHost(machine);
 	xsVars(2);
@@ -1332,7 +1333,7 @@ static char* fxReadNetStringError(int code)
 static int fxWriteOkay(FILE* outStream, xsUnsignedValue meterIndex, char* buf, size_t length) {
 	char prefix[32];
 	// Prepend the meter usage to the reply.
-	snprintf(prefix, sizeof(prefix) - 1, ".%u;", meterIndex);
+	snprintf(prefix, sizeof(prefix) - 1, ".%u\1", meterIndex);
 	return fxWriteNetString(outStream, prefix, buf, length);
 }
 

diff --git a/packages/xsnap/src/xsnap.js b/packages/xsnap/src/xsnap.js
@@ -17,11 +17,15 @@ import * as node from './node-stream';
 // This will need adjustment, but seems to be fine for a start.
 const DEFAULT_CRANK_METERING_LIMIT = 1e7;
 
+// The version identifier for our meter type.
+// TODO Bump this whenever there's a change to metering semantics.
+const METER_TYPE = 'xs-meter-1';
+
 const OK = '.'.charCodeAt(0);
 const ERROR = '!'.charCodeAt(0);
 const QUERY = '?'.charCodeAt(0);
 
-const SEMI = ';'.charCodeAt(0);
+const OK_SEPARATOR = 1;
 
 const importMetaUrl = `file://${__filename}`;
 
@@ -115,36 +119,11 @@ export function xsnap(options) {
   /** @type {Promise<void>} */
   let baton = Promise.resolve();
 
-  /** @type {string} */
-  let xsWorkerType;
-  async function getWorkerType() {
-    if (xsWorkerType) {
-      return xsWorkerType;
-    }
-    await new Promise(resolve => {
-      // Inititialize the worker type before sending messages.
-      const bufs = [];
-      const xsnapQueryVersion = spawn(bin, ['-v'], {
-        stdio: ['ignore', 'pipe', 'inherit'],
-      });
-      xsnapQueryVersion.stdout.on('data', chunk => {
-        bufs.push(chunk);
-      });
-      xsnapQueryVersion.on('close', () => {
-        const str = Buffer.concat(bufs).toString('utf-8');
-        const firstLine = str.split(/^/m)[0];
-        xsWorkerType = firstLine.trimEnd();
-        resolve();
-      });
-    });
-    return xsWorkerType;
-  }
-
   /**
    * @template T
    * @typedef {Object} RunResult
    * @property {T} reply
-   * @property {{ workerType: string, allocate: number, compute: number }} crankStats
+   * @property {{ meterType: string, allocate: number|null, compute: number|null }} crankStats
    */
 
   /**
@@ -163,23 +142,23 @@ export function xsnap(options) {
         xsnapProcess.kill();
         throw new Error('xsnap protocol error: received empty message');
       } else if (message[0] === OK) {
-        let compute = NaN;
-        const semi = message.indexOf(SEMI, 1);
-        if (semi >= 0) {
-          // The message is `.938586;reply`.
-          const computeBuf = message.slice(1, semi);
-          const computeStr = decoder.decode(computeBuf);
-          compute = JSON.parse(computeStr);
+        let compute = null;
+        const meterSeparator = message.indexOf(OK_SEPARATOR, 1);
+        if (meterSeparator >= 0) {
+          // The message is `.meterdata\1reply`.
+          const meterData = message.slice(1, meterSeparator);
+          // We parse the meter data as JSON.
+          // For now it is just a number for the used compute meter.
+          compute = JSON.parse(decoder.decode(meterData));
         }
-        const workerType = await getWorkerType();
         const crankStats = {
-          workerType,
-          allocate: NaN,
+          meterType: METER_TYPE,
+          allocate: null, // No allocation meter yet.
           compute,
         };
         // console.log('have crankStats', crankStats);
         return {
-          reply: message.subarray(semi < 0 ? 1 : semi + 1),
+          reply: message.subarray(meterSeparator < 0 ? 1 : meterSeparator + 1),
           crankStats,
         };
       } else if (message[0] === ERROR) {