@rytass/storages/storages.js

Rytass Utils Storages

import { PassThrough } from 'stream';
import { createHash } from 'crypto';
import { Buffer } from 'buffer';
import { fileTypeFromBuffer, fileTypeFromStream } from 'file-type';
import { ConverterManager } from '@rytass/file-converter';

const MIN_BUFFER_LENGTH = 16;
class Storage {
    converterManager;
    hashAlgorithm;
    constructor(options){
        this.converterManager = new ConverterManager(options?.converters ?? []);
        this.hashAlgorithm = options?.hashAlgorithm || 'sha256';
    }
    getExtension(file) {
        if (file instanceof Buffer) {
            return fileTypeFromBuffer(file);
        }
        const extensionStream = new PassThrough();
        file.pipe(extensionStream);
        return fileTypeFromStream(extensionStream);
    }
    async getBufferFilename(buffer) {
        const extension = await fileTypeFromBuffer(buffer);
        return [
            `${createHash(this.hashAlgorithm).update(buffer).digest('hex')}${extension?.ext ? `.${extension.ext}` : ''}`,
            extension?.mime ?? undefined
        ];
    }
    getStreamFilename(stream) {
        return new Promise((resolve, reject)=>{
            const hashStream = new PassThrough();
            const extensionStream = new PassThrough();
            const getStreamHash = new Promise((subResolve)=>{
                const hash = createHash(this.hashAlgorithm);
                hashStream.on('data', (buffer)=>{
                    hash.update(buffer);
                });
                hashStream.on('end', ()=>{
                    subResolve(hash.digest('hex'));
                });
            });
            const getStreamFileType = new Promise((subResolve)=>{
                let resolved = false;
                let isEnd = false;
                const bufferStorage = [];
                const waitingTasks = [];
                extensionStream.on('data', (buffer)=>{
                    if (resolved) return;
                    bufferStorage.push(buffer);
                    const targetBuffer = Buffer.concat(bufferStorage);
                    if (targetBuffer.length >= MIN_BUFFER_LENGTH) {
                        const taskIndex = waitingTasks.length;
                        waitingTasks.push(true);
                        fileTypeFromBuffer(targetBuffer).then((result)=>{
                            waitingTasks[taskIndex] = false;
                            if (!result && !isEnd) return;
                            resolved = true;
                            subResolve(result);
                        });
                    } else {
                        waitingTasks.push(false);
                    }
                });
                extensionStream.on('end', ()=>{
                    isEnd = true;
                    if (waitingTasks.every((task)=>!task) && !resolved) {
                        resolved = true;
                        subResolve(undefined);
                    }
                });
            });
            Promise.all([
                getStreamHash,
                getStreamFileType
            ]).then(([filename, extension])=>{
                resolve([
                    `${filename}${extension?.ext ? `.${extension.ext}` : ''}`,
                    extension?.mime ?? undefined
                ]);
            }).catch(reject);
            stream.pipe(hashStream).pipe(extensionStream);
        });
    }
    write(_file, _options) {
        throw new Error('Method not implemented.');
    }
    batchWrite(_files, _options) {
        throw new Error('Method not implemented.');
    }
    read(_key, _options) {
        throw new Error('Method not implemented.');
    }
    remove(_key) {
        throw new Error('Method not implemented.');
    }
    isExists(_key) {
        throw new Error('Method not implemented.');
    }
}

export { Storage };