如何使用 Node.js 创建带缓冲区的读取流

Question

我有这个json：

var myJSON = '{"kind": "person", "fullName": "Rivka3"}';

我正在尝试使用 createReadStream 将它上传到 bigquery。 当我在本地保存它时，我成功了：

fs.writeFile("/tmp/bq_json_file_new.json", myJSON, function(err){});
fs.createReadStream("/tmp/bq_json_file_new.json")
  .pipe(table.createWriteStream(metadata))
  .on('complete', function(job) {
    job
      .on('error', console.log)
      .on('complete', function(metadata) {
        console.log('job completed', metadata);
      });
  });

现在我尝试在不在本地保存的情况下执行此操作 - 使用缓冲区：

fs.createReadStream(new Buffer(myJSON, "utf8"))
  .pipe(table.createWriteStream(metadata))
  .on('complete', function(job) {
    job
      .on('error', console.log)
      .on('complete', function(metadata) {
        console.log('job completed', metadata);
      });
  });

但我收到此错误：

fs.js:575
  binding.open(pathModule._makeLong(path),

TypeError: path must be a string

Answer 1

使用stream解决问题：

var stream = require('stream');

var bufferStream = new stream.PassThrough();

bufferStream.end(new Buffer(myJSON));

bufferStream.pipe(table.createWriteStream(metadata))
                   .on('complete', function(job) {
                     job
                       .on('error', console.log)
                       .on('complete', function(metadata) {
                         console.log('job completed', metadata);
                       });
                   });