关于使用fs.readdir进行异步目录搜索有什么想法吗?我意识到我们可以引入递归,并调用read目录函数来读取下一个目录,但我有点担心它不是异步的…
什么好主意吗?我已经看了node-walk,它很棒,但它不能像readdir那样只给我数组中的文件。虽然
寻找这样的输出…
['file1.txt', 'file2.txt', 'dir/file3.txt']
关于使用fs.readdir进行异步目录搜索有什么想法吗?我意识到我们可以引入递归,并调用read目录函数来读取下一个目录,但我有点担心它不是异步的…
什么好主意吗?我已经看了node-walk,它很棒,但它不能像readdir那样只给我数组中的文件。虽然
寻找这样的输出…
['file1.txt', 'file2.txt', 'dir/file3.txt']
当前回答
递归-readdir模块具有此功能。
其他回答
对于Node 10.3+,这里是一个For -await解决方案:
#!/usr/bin/env node
const FS = require('fs');
const Util = require('util');
const readDir = Util.promisify(FS.readdir);
const Path = require('path');
async function* readDirR(path) {
const entries = await readDir(path,{withFileTypes:true});
for(let entry of entries) {
const fullPath = Path.join(path,entry.name);
if(entry.isDirectory()) {
yield* readDirR(fullPath);
} else {
yield fullPath;
}
}
}
async function main() {
const start = process.hrtime.bigint();
for await(const file of readDirR('/mnt/home/media/Unsorted')) {
console.log(file);
}
console.log((process.hrtime.bigint()-start)/1000000n);
}
main().catch(err => {
console.error(err);
});
这种解决方案的好处是,您可以立即开始处理结果;例如,读取媒体目录中的所有文件需要12秒,但如果我这样做,我可以在几毫秒内得到第一个结果。
这是另一个实现。上述解决方案都没有任何限制,因此如果您的目录结构很大,它们都会崩溃并最终耗尽资源。
var async = require('async');
var fs = require('fs');
var resolve = require('path').resolve;
var scan = function(path, concurrency, callback) {
var list = [];
var walker = async.queue(function(path, callback) {
fs.stat(path, function(err, stats) {
if (err) {
return callback(err);
} else {
if (stats.isDirectory()) {
fs.readdir(path, function(err, files) {
if (err) {
callback(err);
} else {
for (var i = 0; i < files.length; i++) {
walker.push(resolve(path, files[i]));
}
callback();
}
});
} else {
list.push(path);
callback();
}
}
});
}, concurrency);
walker.push(path);
walker.drain = function() {
callback(list);
}
};
使用50的并发工作得非常好,并且几乎和小型目录结构的简单实现一样快。
因为每个人都应该写自己的,所以我写了一个。
步行(dir, cb, endCb) cb(文件) 零endCb (err |)
脏
module.exports = walk;
function walk(dir, cb, endCb) {
var fs = require('fs');
var path = require('path');
fs.readdir(dir, function(err, files) {
if (err) {
return endCb(err);
}
var pending = files.length;
if (pending === 0) {
endCb(null);
}
files.forEach(function(file) {
fs.stat(path.join(dir, file), function(err, stats) {
if (err) {
return endCb(err)
}
if (stats.isDirectory()) {
walk(path.join(dir, file), cb, function() {
pending--;
if (pending === 0) {
endCb(null);
}
});
} else {
cb(path.join(dir, file));
pending--;
if (pending === 0) {
endCb(null);
}
}
})
});
});
}
短小、现代、高效:
import {readdir} from 'node:fs/promises'
import {join} from 'node:path'
const deepReadDir = async (dirPath) => await Promise.all(
(await readdir(dirPath, {withFileTypes: true})).map(async (dirent) => {
const path = join(dirPath, dirent.name)
return dirent.isDirectory() ? await deepReadDir(path) : path
}),
)
特别感谢函数提示使用{withFileTypes: true}。
这将自动将每个嵌套路径折叠成一个新的嵌套数组。例如,如果:
await deepReadDir('src')
返回如下内容:
[
[
'src/client/api.js',
'src/client/http-constants.js',
'src/client/index.html',
'src/client/index.js',
[ 'src/client/res/favicon.ico' ],
'src/client/storage.js'
],
[ 'src/crypto/keygen.js' ],
'src/discover.js',
[
'src/mutations/createNewMutation.js',
'src/mutations/newAccount.js',
'src/mutations/transferCredit.js',
'src/mutations/updateApp.js'
],
[
'src/server/authentication.js',
'src/server/handlers.js',
'src/server/quick-response.js',
'src/server/server.js',
'src/server/static-resources.js'
],
[ 'src/util/prompt.js', 'src/util/safeWriteFile.js' ],
'src/util.js'
]
但如果你想,你可以很容易地把它压平:
(await deepReadDir('src')).flat(Number.POSITIVE_INFINITY)
[
'src/client/api.js',
'src/client/http-constants.js',
'src/client/index.html',
'src/client/index.js',
'src/client/res/favicon.ico',
'src/client/storage.js',
'src/crypto/keygen.js',
'src/discover.js',
'src/mutations/createNewMutation.js',
'src/mutations/newAccount.js',
'src/mutations/transferCredit.js',
'src/mutations/updateApp.js',
'src/server/authentication.js',
'src/server/handlers.js',
'src/server/quick-response.js',
'src/server/server.js',
'src/server/static-resources.js',
'src/util/prompt.js',
'src/util/safeWriteFile.js',
'src/util.js'
]
为了好玩,这里有一个基于流的版本,它与highland.js streams库一起工作。作者之一是维克多·伍。
###
directory >---m------> dirFilesStream >---------o----> out
| |
| |
+--------< returnPipe <-----------+
legend: (m)erge (o)bserve
+ directory has the initial file
+ dirListStream does a directory listing
+ out prints out the full path of the file
+ returnPipe runs stat and filters on directories
###
_ = require('highland')
fs = require('fs')
fsPath = require('path')
directory = _(['someDirectory'])
mergePoint = _()
dirFilesStream = mergePoint.merge().flatMap((parentPath) ->
_.wrapCallback(fs.readdir)(parentPath).sequence().map (path) ->
fsPath.join parentPath, path
)
out = dirFilesStream
# Create the return pipe
returnPipe = dirFilesStream.observe().flatFilter((path) ->
_.wrapCallback(fs.stat)(path).map (v) ->
v.isDirectory()
)
# Connect up the merge point now that we have all of our streams.
mergePoint.write directory
mergePoint.write returnPipe
mergePoint.end()
# Release backpressure. This will print files as they are discovered
out.each H.log
# Another way would be to queue them all up and then print them all out at once.
# out.toArray((files)-> console.log(files))