@ chunkd/ fs (中文(简体) )

文件系统抽象层

方便本地文件系统或远程ASync应用程序与文件系统如接口工作

• 文件 - 读取/写入本地文件系统
• 内存 - 作为模拟文件系统的内存
• 小时 -HTTP请求到远程网络服务器
• 自动取款机 - AWS S3作为远程文件系统

使用量

基础

读取文本文件

import { fsa } from '@chunkd/fs';

const bytes = await fsa.read(fsa.toUrl('../foo.txt'));

列出文件夹

for await (const url of fsa.list(fsa.toUrl('/'))) {
  const bytes = await fsa.read(url);
}

多文件系统

注册多个文件系统

import { fsa, FsMemory } from '@chunkd/fs';

fsa.register('memory://', new FsMemory());

await fsa.write(fsa.toUrl('memory://foo.txt'), 'Hello World');

// Stream the file from memory into the local file system
await fsa.write(fsa.toUrl('/foo.txt'), fsa.readStream(fsa.toUrl(()'memory://foo.txt')));

远程文件系统

远程文件系统也可以使用

import { fsa, FsHttp } from '@chunkd/fs';
import { FsAwsS3 } from '@chunkd/fs-aws';

fsa.register('https://', new FsHttp());
fsa.register('s3://', new FsAwsS3());

// Stream a file from https://example.com into AWS S3
await fsa.write(fsa.toUrl('s3://example/foo.txt'), fsa.readStream(fsa.toUrl('https://example.com/foo.txt')));

多个 S3 证书

多个 s3 客户端可以用不同的证书注册,然后用于在 AWS 账户或角色之间流出文件

import { fsa } from '@chunkd/fs';
import { FsAwsS3 } from '@chunkd/fs-aws';

fsa.register('s3://bucket-a/', new FsAwsS3(new S3Client({ credentials: bucketA })));
fsa.register('s3://bucket-b/', new FsAwsS3(new S3Client({ credentials: bucketB })));

fsa.write(fsa.toUrl('s3://bucket-a/foo.txt'), fsa.readStream(fsa.toUrl('s3://bucket-b/foo.txt')));

错误

所有文件系统错误都应该被包入一个 FsError

try {
  await fsa.read('s3://foo/bar.txt')
} catch(e) {
  if(FsError.is(e)) {
    e.status // Http Status code eg 403
    e.cause // original error
    e.action // `read`
    e.url // `s3://foo/bar.txt`
  }
}

# Interface

All file systems implement then following interface interface

```typescript
export interface FileSystem {
  /** Read a file into a buffer */
  read(location: URL): Promise<Buffer>;
  /** Create a read stream */
  readStream(location: URL): Readable;
  /** Write a file from either a buffer or stream */
  write(location: URL, buffer: Buffer | Readable | string, opts?: Partial<WriteOptions>): Promise<void>;
  /** list all files in path */
  list(location: URL, opt?: ListOptions): AsyncGenerator<URL>;
  /** list all files with file info in path */
  details(location: URL, opt?: ListOptions): AsyncGenerator<FileInfo>;
  /** Get information about the path  */
  head(location: URL): Promise<FileInfo | null>;
  /** Create a chunk source to read chunks out of */
  source(location: URL): Source;
  /** Delete a file from the location */
  delete(location: URL): Promise<void>;
}