swarm-js
Version:
Swarm tools for JavaScript.
272 lines (224 loc) • 9.01 kB
JavaScript
// This module implements some file download utils. Its most important export
// is `safeDownloadTargzFile`, which, given a file, its md5, a tar.gz url, its
// md5 and a path, returns a Promise that will only resolve once the exact file
// you expect is available on that path.
var Q = require("bluebird");
var assert = require("assert");
var crypto = require("crypto");
var fs = require("fs-extra");
var got = require("got");
var mkdirp = require("mkdirp-promise");
var path = require("path");
var tar = require("tar"); // String -> String ~> Promise String
// Downloads a file from an url to a path.
// Returns a promise containing the path.
var download = function download(url) {
return function (filePath) {
var promise = Q.resolve(mkdirp(path.dirname(filePath))).then(function () {
return new Q(function (resolve, reject) {
var writeStream = fs.createWriteStream(filePath);
var downloadStream = got.stream(url);
downloadStream.on("end", function () {
return resolve(filePath);
});
downloadStream.on("data", function (chunk) {
return promise.onDataCallback(chunk);
});
downloadStream.on("error", reject);
downloadStream.pipe(writeStream);
});
});
promise.onDataCallback = function () {};
promise.onData = function (callback) {
promise.onDataCallback = callback || function () {};
return promise;
};
return promise;
};
}; // String -> String ~> Promise String
// Hashes a file using the given algorithm (ex: "md5").
// Returns a promise containing the hashed string.
var hash = function hash(algorithm) {
return function (path) {
return new Q(function (resolve, reject) {
var readStream = fs.ReadStream(path);
var hash = crypto.createHash(algorithm);
readStream.on("data", function (d) {
return hash.update(d);
});
readStream.on("end", function () {
return resolve(hash.digest("hex"));
});
readStream.on("error", reject);
});
};
}; // String -> String ~> Promise ()
// Asserts a file matches this md5 hash.
// Returns a promise containing its path.
var checksum = function checksum(fileHash) {
return function (path) {
return hash("md5")(path).then(function (actualHash) {
return actualHash === fileHash;
}).then(assert).then(function () {
return path;
});
};
}; // String ~> String ~> String ~> Promise String
// Downloads a file to a directory, check.
// Checks if the md5 hash matches.
// Returns a promise containing the path.
var downloadAndCheck = function downloadAndCheck(url) {
return function (path) {
return function (fileHash) {
return download(url)(path).then(checksum(fileHash));
};
};
}; // String -> String ~> Promise String
// TODO: work for zip and other types
var extract = function extract(fromPath) {
return function (toPath) {
return tar.x(fromPath, toPath).then(function () {
return toPath;
});
};
}; // String ~> Promise String
// Reads a file as an UTF8 string.
// Returns a promise containing that string.
var readUTF8 = function readUTF8(path) {
return fs.readFile(path, {
encoding: "utf8"
});
}; // String ~> Promise Bool
var isDirectory = function isDirectory(path) {
return fs.exists(path).then(assert).then(function () {
return fs.lstat(path);
}).then(function (stats) {
return stats.isDirectory();
})["catch"](function () {
return false;
});
}; // String -> Promise String
var directoryTree = function directoryTree(dirPath) {
var paths = [];
var search = function search(dirPath) {
return isDirectory(dirPath).then(function (isDir) {
if (isDir) {
var searchOnDir = function searchOnDir(dir) {
return search(path.join(dirPath, dir));
};
return Q.all(Q.map(fs.readdir(dirPath), searchOnDir));
} else {
paths.push(dirPath);
}
;
});
};
return Q.all(search(dirPath)).then(function () {
return paths;
});
}; // Regex -> String ~> Promise (Array String)
var search = function search(regex) {
return function (dirPath) {
return directoryTree(dirPath).then(function (tree) {
return tree.filter(function (path) {
return regex.test(path);
});
});
};
}; // String -> String -> String -> String ~> Promise String
// Downloads a file inside a tar.gz and places it at `filePath`.
// Checks the md5 hash of the tar before extracting it.
// Checks the md5 hash of the file after extracting it.
// If all is OK, returns a promise containing the file path.
var safeDownloadArchived = function safeDownloadArchived(url) {
return function (archiveHash) {
return function (fileHash) {
return function (filePath) {
var fileDir = path.dirname(filePath);
var fileName = path.basename(filePath);
var archivePath = path.join(fileDir, ".swarm_downloads/files.tar.gz");
var archiveDir = path.dirname(archivePath);
var promise = Q.resolve(mkdirp(archiveDir)).then(function () {
return checksum(fileHash)(filePath);
}).then(function () {
return filePath;
})["catch"](function () {
return fs.exists(archiveDir).then(function (exists) {
return !exists ? fs.mkdir(archiveDir) : null;
}).then(function () {
return download(url)(archivePath).onData(promise.onDataCallback);
}).then(function () {
return hash("md5")(archivePath);
}).then(function () {
return archiveHash ? checksum(archiveHash)(archivePath) : null;
}).then(function () {
return extract(archivePath)(archiveDir);
}).then(function () {
return search(new RegExp(fileName + "$"))(archiveDir);
}).then(function (fp) {
return fs.rename(fp[0], filePath);
}).then(function () {
return fs.unlink(archivePath);
}).then(function () {
return fileHash ? checksum(fileHash)(filePath) : null;
}).then(function () {
return filePath;
});
});
promise.onDataCallback = function () {};
promise.onData = function (callback) {
promise.onDataCallback = callback || function () {};
return promise;
};
return promise;
};
};
};
}; // String -> String ~> Promise String
// Like `safeDownloadArchivedFile`, but without the checksums.
var downloadArchived = function downloadArchived(url) {
return function (path) {
return safeDownloadArchived(url)(null)(null)(path);
};
}; // () => Promise Bool
// Tests the implementation by downloading a predetermined tar.gz
// from a mocked HTTP-server into a mocked filesystem. Does some
// redundancy tests such as checking the file constents and double
// checking its MD5 hash.
// Returns a promise containing a boolean, true if tests passed.
var test = function test() {
var filePath = "/swarm/foo.txt";
var fileHash = "d3b07384d113edec49eaa6238ad5ff00";
var archiveUrl = "http://localhost:12534";
var archiveHash = "7fa45f946bb2a696bdd9972e0fbceac2";
var archiveData = new Buffer([0x1f, 0x8b, 0x08, 0x00, 0xf1, 0x34, 0xaf, 0x58, 0x00, 0x03, 0xed, 0xcf, 0x3d, 0x0e, 0x83, 0x30, 0x0c, 0x86, 0x61, 0x66, 0x4e, 0xe1, 0x13, 0x54, 0xce, 0x0f, 0xc9, 0x79, 0x58, 0xb2, 0x46, 0x82, 0x14, 0x71, 0x7c, 0xd2, 0x06, 0x31, 0x52, 0x75, 0x40, 0x08, 0xe9, 0x7d, 0x96, 0x4f, 0x96, 0x3d, 0x7c, 0x4e, 0x39, 0xbf, 0xca, 0x5a, 0xba, 0x2b, 0xa9, 0x6a, 0xf0, 0x5e, 0x3e, 0x19, 0xc3, 0xf0, 0x4d, 0xb5, 0x6d, 0xde, 0x79, 0x31, 0x4e, 0x07, 0x17, 0x9c, 0xb5, 0x31, 0x8a, 0x1a, 0xab, 0xc6, 0x77, 0xa2, 0x97, 0xb6, 0xda, 0xbd, 0xe7, 0x32, 0x4e, 0xb5, 0xca, 0xf2, 0xe3, 0xae, 0x9e, 0xa5, 0x74, 0xb2, 0x6f, 0x8f, 0xc8, 0x91, 0x0f, 0x91, 0x72, 0xee, 0xef, 0xee, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf8, 0xdf, 0x06, 0xb3, 0x2a, 0xda, 0xed, 0x00, 0x28, 0x00, 0x00]);
var crypto = require("crypto");
var fsMock = require("mock-fs")({
"/swarm": {}
});
var httpMock = require("http").createServer(function (_, res) {
return res.end(archiveData);
}).listen(12534);
return safeDownloadArchived(archiveUrl)(archiveHash)(fileHash)(filePath).then(checksum(fileHash)).then(readUTF8).then(function (text) {
return text === "foo\n";
}).then(assert).then(function () {
return safeDownloadArchived(archiveUrl)(archiveHash)(fileHash)(filePath);
}).then(function () {
return true;
})["catch"](false)["finally"](function () {
return httpMock.close();
});
};
module.exports = {
download: download,
hash: hash,
checksum: checksum,
downloadAndCheck: downloadAndCheck,
extract: extract,
readUTF8: readUTF8,
safeDownloadArchived: safeDownloadArchived,
directoryTree: directoryTree,
downloadArchived: downloadArchived,
search: search,
test: test
};