Function write

lib/internal/streams/iter/classic.js:578–618

(chunk)

    // Classic stream.Writable has no per-write abort signal support;
    // cancellation should be handled at the pipeline level instead.
    write(chunk) {
      if (!isWritable()) {
        return PromiseReject(new ERR_STREAM_WRITE_AFTER_END());
      }

      let bytes;
      try {
        bytes = toUint8Array(chunk);
      } catch (err) {
        return PromiseReject(err);
      }

      if (backpressure === 'strict' && isFull()) {
        return PromiseReject(new ERR_INVALID_STATE.RangeError(
          'Backpressure violation: buffer is full. ' +
          'Await each write() call to respect backpressure.'));
      }

      if (backpressure === 'drop-newest' && isFull()) {
        // Silently discard. Still count bytes for consistency with
        // PushWriter, which counts dropped bytes in totalBytes.
        totalBytes += TypedArrayPrototypeGetByteLength(bytes);
        return PromiseResolve();
      }

      totalBytes += TypedArrayPrototypeGetByteLength(bytes);
      const ok = writable.write(bytes);
      if (ok) return PromiseResolve();

      // backpressure === 'block' (or strict with room that filled on
      // this write -- writable.write() accepted the data but returned
      // false indicating the buffer is now at/over hwm).
      if (backpressure === 'block') {
        return waitForDrain();
      }

      // strict: the write was accepted (there was room before writing)
      // but the buffer is now full. Resolve -- the *next* write will
      // be rejected if the caller ignores backpressure.
      return PromiseResolve();
    },

    writev(chunks) {
      if (!ArrayIsArray(chunks)) {