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a package manager for JavaScript
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JavaScript
;
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.DefaultFetcher = exports.BaseFetcher = void 0;
const debug_1 = __importDefault(require("debug"));
const fs_1 = __importDefault(require("fs"));
const util_1 = __importDefault(require("util"));
const error_1 = require("./error");
const tmpfile_1 = require("./utils/tmpfile");
const promise_retry_1 = require("@gar/promise-retry");
const log = (0, debug_1.default)('tuf:fetch');
const USER_AGENT_HEADER = 'User-Agent';
class BaseFetcher {
// Download file from given URL. The file is downloaded to a temporary
// location and then passed to the given handler. The handler is responsible
// for moving the file to its final location. The temporary file is deleted
// after the handler returns.
async downloadFile(url, maxLength, handler) {
return (0, tmpfile_1.withTempFile)(async (tmpFile) => {
const reader = await this.fetch(url);
let numberOfBytesReceived = 0;
const fileStream = fs_1.default.createWriteStream(tmpFile);
// Read the stream a chunk at a time so that we can check
// the length of the file as we go
const streamReader = reader.getReader();
try {
while (true) {
const { done, value: chunk } = await streamReader.read();
if (done) {
break;
}
numberOfBytesReceived += chunk.length;
if (numberOfBytesReceived > maxLength) {
throw new error_1.DownloadLengthMismatchError('Max length reached');
}
await writeBufferToStream(fileStream, Buffer.from(chunk));
}
}
finally {
streamReader.releaseLock();
// Make sure we always close the stream
// eslint-disable-next-line @typescript-eslint/unbound-method
await util_1.default.promisify(fileStream.close).bind(fileStream)();
}
return handler(tmpFile);
});
}
// Download bytes from given URL.
async downloadBytes(url, maxLength) {
return this.downloadFile(url, maxLength, async (file) => {
const stream = fs_1.default.createReadStream(file);
const chunks = [];
for await (const chunk of stream) {
chunks.push(chunk);
}
return Buffer.concat(chunks);
});
}
}
exports.BaseFetcher = BaseFetcher;
class DefaultFetcher extends BaseFetcher {
userAgent;
timeout;
retry;
constructor(options = {}) {
super();
this.userAgent = options.userAgent;
this.timeout = options.timeout;
// Map retry to OperationOptions
if (options.retry === true) {
this.retry = { forever: true };
}
else if (options.retry === false || options.retry === undefined) {
this.retry = undefined;
}
else if (typeof options.retry === 'number') {
if (options.retry < 0) {
throw new Error('Retry count must be non-negative number');
}
this.retry = { retries: options.retry };
}
else {
this.retry = options.retry;
}
}
async fetch(url) {
const shouldRetry = this.retry !== undefined;
return (0, promise_retry_1.promiseRetry)(async (retry, number) => {
log('GET %s (attempt %d)', url, number);
let response;
try {
response = await fetch(url, {
headers: {
[USER_AGENT_HEADER]: this.userAgent || '',
},
signal: this.timeout
? AbortSignal.timeout(this.timeout)
: undefined,
});
}
catch (error) {
const err = error instanceof Error ? error : new Error(String(error));
if (shouldRetry) {
return retry(err);
}
throw err;
}
if (!response.ok || !response.body) {
const err = new error_1.DownloadHTTPError('Failed to download', response.status);
if (shouldRetry && response.status >= 500 && response.status < 600) {
return retry(err);
}
throw err;
}
return response.body;
}, this.retry);
}
}
exports.DefaultFetcher = DefaultFetcher;
const writeBufferToStream = async (stream, buffer) => {
return new Promise((resolve, reject) => {
stream.write(buffer, (err) => {
if (err) {
reject(err);
}
resolve(true);
});
});
};