85 lines
2.3 KiB
JavaScript
85 lines
2.3 KiB
JavaScript
import { create } from 'ipfs';
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import { writeFile } from 'fs/promises';
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import { fileTypeFromBuffer } from 'file-type';
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class IPFSFileManager {
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constructor() {
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this.node = null;
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}
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async initIPFS() {
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this.node = await create();
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console.log('IPFS node is ready');
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}
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async retrieveFileFromIPFS(cid, filepath) {
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try {
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await this.initIPFS();
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const chunks = [];
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for await (const chunk of this.node.cat(cid)) {
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chunks.push(chunk);
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}
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const fileData = Buffer.concat(chunks);
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// Determine the file extension based on the MIME type
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const { mime } = await this.getfileTypeFromFile(fileData);
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const fileExtension = this.getFileExtension(mime);
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// Save the file data to a local file with the appropriate extension
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const filePath = `${filepath}.${fileExtension}`;
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await this.saveFileToLocal(filePath, fileData);
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console.log('File retrieved from IPFS and saved as:', filePath);
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} catch (error) {
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console.error('Failed to retrieve the file from IPFS', error);
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} finally {
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this.closeIPFS();
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}
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}
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async saveFileToLocal(filePath, fileData) {
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try {
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await writeFile(filePath, fileData);
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} catch (error) {
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console.error('Failed to save the file locally', error);
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throw error;
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}
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}
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async getfileTypeFromFile(fileData) {
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try {
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return fileTypeFromBuffer(fileData);
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} catch (error) {
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console.error('Failed to determine the file type', error);
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throw error;
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}
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}
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getFileExtension(mimeType) {
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// Map commonly used MIME types to file extensions
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const extensionMap = {
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'application/pdf': 'pdf',
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'image/jpeg': 'jpg',
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'image/png': 'png',
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'text/plain': 'txt',
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// Add more MIME types and extensions as needed
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};
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// Return the corresponding extension if available, otherwise fallback to 'dat'
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return extensionMap[mimeType] || 'dat';
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}
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async closeIPFS() {
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if (this.node) {
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await this.node.stop();
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console.log('IPFS node connection closed');
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}
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}
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}
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const cid = 'QmZ6h18zefo1DEEN5QC3WberbAFAkhvKmhEF6eJou6TC3h'; // Replace with the CID of the file you want to retrieve
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const filepath = './retrievedFile'; // Specify the file path without the extension
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const ipfsFileManager = new IPFSFileManager();
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ipfsFileManager.retrieveFileFromIPFS(cid, filepath);
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