在 xml2js 的帮助下将 xml 文件转换为 json 文件时出错

Question

我有大约 35000 个 xml 个文件（总大小 7Gb）我需要转换为 json 个文件。

我在 npm 包的帮助下编写了一个转换脚本 xml2js.

抱怨我没有回调函数

看起来内存也有一些问题（致命错误：CALL_AND_RETRY_LAST 分配失败 - JavaScript 堆内存不足）。

我对 JS 很陌生，所以如果有人能指出正确的方向来解决这个错误，我将不胜感激。

代码：

const fs = require('fs');
const path = require('path');
const xml2js = require('xml2js');
const parser = new xml2js.Parser();
const pxmls = path.join(__dirname, 'xml-files');
const pjsons = path.join(__dirname, 'json-files');

function onError(err) {
  console.log(err);
}

// Here's the reading part:
function readFiles(pxmls, onError) {
  fs.readdir(pxmls, (err, filenames) => {
    if (err) {
      onError(err);
      return;
    }
    filenames.forEach((filename) => {
      fs.readFile(`${pxmls}/${filename}`, 'utf-8', (err, data) => {
        if (err) {
          console.log(err);
          return;
        }
        // changing file extension from .xml to .json
        const x = filename.replace(/\.[^/.]+$/, '.json');
        parser.parseString(data, (err, result) => {
          fs.writeFile(`${pjsons}/${x}`, JSON.stringify(result, null, 4));
        });
      });
    });
  });
}
readFiles(pxmls);

错误：

(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.
(node:778) [DEP0013] DeprecationWarning: Calling an asynchronous function without callback is deprecated.

<--- Last few GCs --->

[778:0x103000000]    76652 ms: Mark-sweep 1410.3 (1572.0) -> 1410.1 (1572.0) MB, 84.1 / 0.2 ms  allocation failure GC in old space requested
[778:0x103000000]    76737 ms: Mark-sweep 1410.1 (1572.0) -> 1410.0 (1552.5) MB, 83.2 / 0.0 ms  last resort
[778:0x103000000]    76827 ms: Mark-sweep 1410.0 (1552.5) -> 1410.0 (1552.5) MB, 87.9 / 0.0 ms  last resort


<--- JS stacktrace --->

==== JS stack trace =========================================

Security context: 0x9a5c35a9891 <JS Object>
    1: stringSlice(aka stringSlice) [buffer.js:527] [pc=0x36d4804ed77c](this=0x1c76a5982311 <undefined>,buf=0x1b593f84b2a1 <an Uint8Array with map 0x2a3c739b1a61>,encoding=0x9a5c35bd099 <String[5]: utf-8>,start=0,end=524715)
    2: toString [buffer.js:~569] [pc=0x36d48048b5b3](this=0x1b593f84b2a1 <an Uint8Array with map 0x2a3c739b1a61>,encoding=0x9a5c35bd099 <String[5]: utf-8>,start=0x1c76a59823...

FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory
 1: node::Abort() [/usr/local/bin/node]
 2: node::FatalException(v8::Isolate*, v8::Local<v8::Value>, v8::Local<v8::Message>) [/usr/local/bin/node]
 3: v8::internal::V8::FatalProcessOutOfMemory(char const*, bool) [/usr/local/bin/node]
 4: v8::internal::Factory::NewRawOneByteString(int, v8::internal::PretenureFlag) [/usr/local/bin/node]
 5: v8::internal::Factory::NewStringFromUtf8(v8::internal::Vector<char const>, v8::internal::PretenureFlag) [/usr/local/bin/node]
 6: v8::String::NewFromUtf8(v8::Isolate*, char const*, v8::NewStringType, int) [/usr/local/bin/node]
 7: node::StringBytes::Encode(v8::Isolate*, char const*, unsigned long, node::encoding, v8::Local<v8::Value>*) [/usr/local/bin/node]
 8: void node::Buffer::(anonymous namespace)::StringSlice<(node::encoding)1>(v8::FunctionCallbackInfo<v8::Value> const&) [/usr/local/bin/node]
 9: v8::internal::FunctionCallbackArguments::Call(void (*)(v8::FunctionCallbackInfo<v8::Value> const&)) [/usr/local/bin/node]
10: v8::internal::MaybeHandle<v8::internal::Object> v8::internal::(anonymous namespace)::HandleApiCallHelper<false>(v8::internal::Isolate*, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::FunctionTemplateInfo>, v8::internal::Handle<v8::internal::Object>, v8::internal::BuiltinArguments) [/usr/local/bin/node]
11: v8::internal::Builtin_Impl_HandleApiCall(v8::internal::BuiltinArguments, v8::internal::Isolate*) [/usr/local/bin/node]
12: 0x36d47ff0437d
[1]    778 abort      node batch_xml_convert_to_json.js

Answer 1

你的问题是 fs.writeFile

fs.writeFile(`${pjsons}/${x}`, JSON.stringify(result, null, 4));

需要回调

fs.writeFile(`${pjsons}/${x}`, JSON.stringify(result, null, 4), (writeError) => {
  onError(writeError)
});

或更简洁

fs.writeFile(`${pjsons}/${x}`, JSON.stringify(result, null, 4), onError);

更多信息在这里： https://nodejs.org/api/fs.html#fs_fs_writefile_file_data_options_callback

Answer 2

堆 space 错误可能表示内存泄漏。否则，要增加最大堆，

node --max-old-space-size=8192 server.js

开始 server.js 使用 8GB 堆。

在 xml2js 的帮助下将 xml 文件转换为 json 文件时出错

Error when converting xml files to json files with help of xml2js

javascript

json

node.js

xml

xml2js