perf: optimize Writable

PR-URL: #50012

Author: ronag

lib/internal/streams/writable.js

@@ -108,6 +108,7 @@ const kWriteCb = 1 << 26;
 const kExpectWriteCb = 1 << 27;
 const kAfterWriteTickInfo = 1 << 28;
 const kAfterWritePending = 1 << 29;
+const kEmptyBuffer = 1 << 30;
 
 // TODO(benjamingr) it is likely slower to do it this way than with free functions
 function makeBitMapDescriptor(bit) {
@@ -339,7 +340,7 @@ function WritableState(options, stream, isDuplex) {
 function resetBuffer(state) {
   state.buffered = [];
   state.bufferedIndex = 0;
-  state.state |= kAllBuffers | kAllNoop;
+  state.state |= kAllBuffers | kAllNoop | kEmptyBuffer;
 }
 
 WritableState.prototype.getBuffer = function getBuffer() {
@@ -523,6 +524,7 @@ function writeOrBuffer(stream, state, chunk, encoding, callback) {
 
   if ((state.state & (kWriting | kErrored | kCorked | kConstructed)) !== kConstructed) {
     state.buffered.push({ chunk, encoding, callback });
+    state.state &= ~kEmptyBuffer;
     if ((state.state & kAllBuffers) !== 0 && encoding !== 'buffer') {
       state.state &= ~kAllBuffers;
     }
@@ -591,8 +593,9 @@ function onwrite(stream, er) {
     // Avoid V8 leak, https://github.com/nodejs/node/pull/34103#issuecomment-652002364
     er.stack; // eslint-disable-line no-unused-expressions
 
-    if (!state.errored) {
-      state.errored = er;
+    if ((state.state & kErrored) === 0) {
+      state[kErroredValue] = er;
+      state.state |= kErrored;
     }
 
     // In case of duplex streams we need to notify the readable side of the
@@ -607,12 +610,12 @@ function onwrite(stream, er) {
       onwriteError(stream, state, er, cb);
     }
   } else {
-    if (state.buffered.length > state.bufferedIndex) {
+    if ((state.state & kEmptyBuffer) === 0) {
       clearBuffer(stream, state);
     }
 
     if (sync) {
-      const needDrain = state.length === 0 && (state.state & kNeedDrain) !== 0;
+      const needDrain = (state.state & kNeedDrain) !== 0 && state.length === 0;
       const needTick = needDrain || (state.state & kDestroyed !== 0) || cb !== nop;
 
       // It is a common case that the callback passed to .write() is always
@@ -625,7 +628,9 @@ function onwrite(stream, er) {
           state.state |= kAfterWritePending;
         } else {
           state.pendingcb--;
-          finishMaybe(stream, state, true);
+          if ((state.state & kEnding) !== 0) {
+            finishMaybe(stream, state, true);
+          }
         }
       } else if ((state.state & kAfterWriteTickInfo) !== 0 &&
                  state[kAfterWriteTickInfoValue].cb === cb) {
@@ -636,7 +641,9 @@ function onwrite(stream, er) {
         state.state |= (kAfterWritePending | kAfterWriteTickInfo);
       } else {
         state.pendingcb--;
-        finishMaybe(stream, state, true);
+        if ((state.state & kEnding) !== 0) {
+          finishMaybe(stream, state, true);
+        }
       }
     } else {
       afterWrite(stream, state, 1, cb);
@@ -692,7 +699,7 @@ function errorBuffer(state) {
 
 // If there's something in the buffer waiting, then process it.
 function clearBuffer(stream, state) {
-  if ((state.state & (kDestroyed | kBufferProcessing | kCorked)) !== 0 ||
+  if ((state.state & (kDestroyed | kBufferProcessing | kCorked | kEmptyBuffer)) !== 0 ||
     (state.state & kConstructed) === 0) {
     return;
   }