Node.js Stream writable.destroy() 方法
writable.destroy() 方法是 Stream 模块内置的应用程序编程接口,用于销毁创建的流,在销毁创建的流后不能再调用 write() 方法写入数据。
句法:
writable.destroy()
参数:此方法不接受任何参数。
返回值:它返回可写的所有属性,其中destroyed属性设置为true。
下面的例子说明了 Node.js 中writable.cork() 方法的使用:
示例 1:
// Node.js program to demonstrate the
// writable.uncork() method
const stream = require('stream');
// Creating a stream and creating
// a write function
const writable = new stream.Writable({
// Write function with its
// parameters
write: function(chunk, encoding, next) {
// Converting the chunk of
// data to string
console.log(chunk.toString());
next();
}
});
// Writing data
writable.write('hi');
// Again writing some data
writable.write('hello');
// Calling destroy function
writable.destroy();
输出:
hi
hello
Writable { _writableState:
WritableState {
objectMode: false, highWaterMark: 16384,
finalCalled: false,
needDrain: false,
ending: false,
ended: false,
finished: false,
destroyed: true,
decodeStrings: true,
defaultEncoding: 'utf8',
length: 0,
writing: false,
corked: 0,
sync: false,
bufferProcessing: false,
onwrite: [Function: bound onwrite],
writecb: null,
writelen: 0,
bufferedRequest: null,
lastBufferedRequest: null,
pendingcb: 2,
prefinished: false,
errorEmitted: false,
emitClose: true,
autoDestroy: false,
bufferedRequestCount: 0,
corkedRequestsFree:
{ next: null,
entry: null,
finish: [Function: bound onCorkedFinish] } },
writable: true,
_write: [Function: write],
domain: null,
_events: [Object: null prototype] {},
_eventsCount: 0,
_maxListeners: undefined }
因此,创建的流被销毁。
示例 2:
// Node.js program to demonstrate the
// writable.uncork() method
const stream = require('stream');
// Creating a stream and creating
// a write function
const writable = new stream.Writable({
// Write function with its
// parameters
write: function(chunk, encoding, next) {
// Converting the chunk of
// data to string
console.log(chunk.toString());
next();
}
});
// Writing data
writable.write('hi');
// Again writing some data
writable.write('hello');
// Calling destroy function
writable.destroy();
writable.write('');
输出:
hi
hello
Error [ERR_STREAM_DESTROYED]: Cannot call write after a stream was destro
yed
at doWrite (_stream_writable.js:411:19)
at writeOrBuffer (_stream_writable.js:399:5)
at Writable.write (_stream_writable.js:299:11)
at /home/runner/QuizzicalFluffyOperation/index.js:29:10
at Script.runInContext (vm.js:133:20)
at Object. (/run_dir/interp.js:156:20)
at Module._compile (internal/modules/cjs/loader.js:778:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:
10)
at Module.load (internal/modules/cjs/loader.js:653:32)
在上面的示例中,由于在销毁流之后调用了 write() 方法,因此发生错误。
参考: https://nodejs.org/api/stream.html#stream_writable_destroy_error