775 lines
31 KiB
JavaScript
775 lines
31 KiB
JavaScript
var fs = require("fs");
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var zlib = require("zlib");
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var fd_slicer = require("fd-slicer");
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var crc32 = require("buffer-crc32");
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var util = require("util");
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var EventEmitter = require("events").EventEmitter;
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var Transform = require("stream").Transform;
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var PassThrough = require("stream").PassThrough;
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var Writable = require("stream").Writable;
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exports.open = open;
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exports.fromFd = fromFd;
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exports.fromBuffer = fromBuffer;
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exports.fromRandomAccessReader = fromRandomAccessReader;
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exports.dosDateTimeToDate = dosDateTimeToDate;
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exports.validateFileName = validateFileName;
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exports.ZipFile = ZipFile;
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exports.Entry = Entry;
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exports.RandomAccessReader = RandomAccessReader;
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function open(path, options, callback) {
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if (typeof options === "function") {
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callback = options;
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options = null;
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}
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if (options == null) options = {};
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if (options.autoClose == null) options.autoClose = true;
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if (options.lazyEntries == null) options.lazyEntries = false;
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if (options.decodeStrings == null) options.decodeStrings = true;
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if (options.validateEntrySizes == null) options.validateEntrySizes = true;
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if (callback == null) callback = defaultCallback;
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fs.open(path, "r", function(err, fd) {
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if (err) return callback(err);
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fromFd(fd, options, function(err, zipfile) {
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if (err) fs.close(fd, defaultCallback);
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callback(err, zipfile);
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});
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});
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}
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function fromFd(fd, options, callback) {
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if (typeof options === "function") {
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callback = options;
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options = null;
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}
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if (options == null) options = {};
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if (options.autoClose == null) options.autoClose = false;
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if (options.lazyEntries == null) options.lazyEntries = false;
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if (options.decodeStrings == null) options.decodeStrings = true;
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if (options.validateEntrySizes == null) options.validateEntrySizes = true;
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if (callback == null) callback = defaultCallback;
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fs.fstat(fd, function(err, stats) {
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if (err) return callback(err);
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var reader = fd_slicer.createFromFd(fd, {autoClose: true});
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fromRandomAccessReader(reader, stats.size, options, callback);
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});
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}
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function fromBuffer(buffer, options, callback) {
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if (typeof options === "function") {
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callback = options;
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options = null;
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}
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if (options == null) options = {};
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options.autoClose = false;
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if (options.lazyEntries == null) options.lazyEntries = false;
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if (options.decodeStrings == null) options.decodeStrings = true;
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if (options.validateEntrySizes == null) options.validateEntrySizes = true;
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// i got your open file right here.
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var reader = fd_slicer.createFromBuffer(buffer);
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fromRandomAccessReader(reader, buffer.length, options, callback);
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}
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function fromRandomAccessReader(reader, totalSize, options, callback) {
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if (typeof options === "function") {
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callback = options;
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options = null;
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}
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if (options == null) options = {};
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if (options.autoClose == null) options.autoClose = true;
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if (options.lazyEntries == null) options.lazyEntries = false;
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if (options.decodeStrings == null) options.decodeStrings = true;
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var decodeStrings = !!options.decodeStrings;
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if (options.validateEntrySizes == null) options.validateEntrySizes = true;
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if (callback == null) callback = defaultCallback;
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if (typeof totalSize !== "number") throw new Error("expected totalSize parameter to be a number");
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if (totalSize > Number.MAX_SAFE_INTEGER) {
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throw new Error("zip file too large. only file sizes up to 2^52 are supported due to JavaScript's Number type being an IEEE 754 double.");
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}
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// the matching unref() call is in zipfile.close()
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reader.ref();
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// eocdr means End of Central Directory Record.
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// search backwards for the eocdr signature.
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// the last field of the eocdr is a variable-length comment.
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// the comment size is encoded in a 2-byte field in the eocdr, which we can't find without trudging backwards through the comment to find it.
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// as a consequence of this design decision, it's possible to have ambiguous zip file metadata if a coherent eocdr was in the comment.
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// we search backwards for a eocdr signature, and hope that whoever made the zip file was smart enough to forbid the eocdr signature in the comment.
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var eocdrWithoutCommentSize = 22;
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var maxCommentSize = 0xffff; // 2-byte size
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var bufferSize = Math.min(eocdrWithoutCommentSize + maxCommentSize, totalSize);
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var buffer = new Buffer(bufferSize);
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var bufferReadStart = totalSize - buffer.length;
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readAndAssertNoEof(reader, buffer, 0, bufferSize, bufferReadStart, function(err) {
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if (err) return callback(err);
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for (var i = bufferSize - eocdrWithoutCommentSize; i >= 0; i -= 1) {
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if (buffer.readUInt32LE(i) !== 0x06054b50) continue;
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// found eocdr
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var eocdrBuffer = buffer.slice(i);
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// 0 - End of central directory signature = 0x06054b50
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// 4 - Number of this disk
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var diskNumber = eocdrBuffer.readUInt16LE(4);
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if (diskNumber !== 0) {
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return callback(new Error("multi-disk zip files are not supported: found disk number: " + diskNumber));
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}
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// 6 - Disk where central directory starts
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// 8 - Number of central directory records on this disk
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// 10 - Total number of central directory records
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var entryCount = eocdrBuffer.readUInt16LE(10);
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// 12 - Size of central directory (bytes)
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// 16 - Offset of start of central directory, relative to start of archive
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var centralDirectoryOffset = eocdrBuffer.readUInt32LE(16);
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// 20 - Comment length
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var commentLength = eocdrBuffer.readUInt16LE(20);
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var expectedCommentLength = eocdrBuffer.length - eocdrWithoutCommentSize;
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if (commentLength !== expectedCommentLength) {
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return callback(new Error("invalid comment length. expected: " + expectedCommentLength + ". found: " + commentLength));
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}
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// 22 - Comment
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// the encoding is always cp437.
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var comment = decodeStrings ? decodeBuffer(eocdrBuffer, 22, eocdrBuffer.length, false)
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: eocdrBuffer.slice(22);
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if (!(entryCount === 0xffff || centralDirectoryOffset === 0xffffffff)) {
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return callback(null, new ZipFile(reader, centralDirectoryOffset, totalSize, entryCount, comment, options.autoClose, options.lazyEntries, decodeStrings, options.validateEntrySizes));
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}
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// ZIP64 format
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// ZIP64 Zip64 end of central directory locator
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var zip64EocdlBuffer = new Buffer(20);
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var zip64EocdlOffset = bufferReadStart + i - zip64EocdlBuffer.length;
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readAndAssertNoEof(reader, zip64EocdlBuffer, 0, zip64EocdlBuffer.length, zip64EocdlOffset, function(err) {
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if (err) return callback(err);
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// 0 - zip64 end of central dir locator signature = 0x07064b50
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if (zip64EocdlBuffer.readUInt32LE(0) !== 0x07064b50) {
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return callback(new Error("invalid zip64 end of central directory locator signature"));
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}
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// 4 - number of the disk with the start of the zip64 end of central directory
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// 8 - relative offset of the zip64 end of central directory record
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var zip64EocdrOffset = readUInt64LE(zip64EocdlBuffer, 8);
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// 16 - total number of disks
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// ZIP64 end of central directory record
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var zip64EocdrBuffer = new Buffer(56);
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readAndAssertNoEof(reader, zip64EocdrBuffer, 0, zip64EocdrBuffer.length, zip64EocdrOffset, function(err) {
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if (err) return callback(err);
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// 0 - zip64 end of central dir signature 4 bytes (0x06064b50)
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if (zip64EocdrBuffer.readUInt32LE(0) !== 0x06064b50) {
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return callback(new Error("invalid zip64 end of central directory record signature"));
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}
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// 4 - size of zip64 end of central directory record 8 bytes
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// 12 - version made by 2 bytes
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// 14 - version needed to extract 2 bytes
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// 16 - number of this disk 4 bytes
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// 20 - number of the disk with the start of the central directory 4 bytes
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// 24 - total number of entries in the central directory on this disk 8 bytes
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// 32 - total number of entries in the central directory 8 bytes
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entryCount = readUInt64LE(zip64EocdrBuffer, 32);
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// 40 - size of the central directory 8 bytes
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// 48 - offset of start of central directory with respect to the starting disk number 8 bytes
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centralDirectoryOffset = readUInt64LE(zip64EocdrBuffer, 48);
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// 56 - zip64 extensible data sector (variable size)
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return callback(null, new ZipFile(reader, centralDirectoryOffset, totalSize, entryCount, comment, options.autoClose, options.lazyEntries, decodeStrings, options.validateEntrySizes));
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});
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});
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return;
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}
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callback(new Error("end of central directory record signature not found"));
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});
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}
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util.inherits(ZipFile, EventEmitter);
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function ZipFile(reader, centralDirectoryOffset, fileSize, entryCount, comment, autoClose, lazyEntries, decodeStrings, validateEntrySizes) {
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var self = this;
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EventEmitter.call(self);
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self.reader = reader;
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// forward close events
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self.reader.on("error", function(err) {
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// error closing the fd
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emitError(self, err);
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});
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self.reader.once("close", function() {
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self.emit("close");
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});
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self.readEntryCursor = centralDirectoryOffset;
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self.fileSize = fileSize;
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self.entryCount = entryCount;
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self.comment = comment;
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self.entriesRead = 0;
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self.autoClose = !!autoClose;
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self.lazyEntries = !!lazyEntries;
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self.decodeStrings = !!decodeStrings;
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self.validateEntrySizes = !!validateEntrySizes;
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self.isOpen = true;
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self.emittedError = false;
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if (!self.lazyEntries) self._readEntry();
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}
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ZipFile.prototype.close = function() {
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if (!this.isOpen) return;
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this.isOpen = false;
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this.reader.unref();
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};
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function emitErrorAndAutoClose(self, err) {
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if (self.autoClose) self.close();
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emitError(self, err);
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}
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function emitError(self, err) {
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if (self.emittedError) return;
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self.emittedError = true;
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self.emit("error", err);
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}
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ZipFile.prototype.readEntry = function() {
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if (!this.lazyEntries) throw new Error("readEntry() called without lazyEntries:true");
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this._readEntry();
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};
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ZipFile.prototype._readEntry = function() {
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var self = this;
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if (self.entryCount === self.entriesRead) {
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// done with metadata
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setImmediate(function() {
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if (self.autoClose) self.close();
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if (self.emittedError) return;
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self.emit("end");
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});
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return;
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}
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if (self.emittedError) return;
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var buffer = new Buffer(46);
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readAndAssertNoEof(self.reader, buffer, 0, buffer.length, self.readEntryCursor, function(err) {
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if (err) return emitErrorAndAutoClose(self, err);
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if (self.emittedError) return;
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var entry = new Entry();
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// 0 - Central directory file header signature
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var signature = buffer.readUInt32LE(0);
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if (signature !== 0x02014b50) return emitErrorAndAutoClose(self, new Error("invalid central directory file header signature: 0x" + signature.toString(16)));
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// 4 - Version made by
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entry.versionMadeBy = buffer.readUInt16LE(4);
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// 6 - Version needed to extract (minimum)
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entry.versionNeededToExtract = buffer.readUInt16LE(6);
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// 8 - General purpose bit flag
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entry.generalPurposeBitFlag = buffer.readUInt16LE(8);
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// 10 - Compression method
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entry.compressionMethod = buffer.readUInt16LE(10);
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// 12 - File last modification time
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entry.lastModFileTime = buffer.readUInt16LE(12);
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// 14 - File last modification date
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entry.lastModFileDate = buffer.readUInt16LE(14);
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// 16 - CRC-32
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entry.crc32 = buffer.readUInt32LE(16);
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// 20 - Compressed size
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entry.compressedSize = buffer.readUInt32LE(20);
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// 24 - Uncompressed size
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entry.uncompressedSize = buffer.readUInt32LE(24);
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// 28 - File name length (n)
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entry.fileNameLength = buffer.readUInt16LE(28);
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// 30 - Extra field length (m)
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entry.extraFieldLength = buffer.readUInt16LE(30);
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// 32 - File comment length (k)
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entry.fileCommentLength = buffer.readUInt16LE(32);
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// 34 - Disk number where file starts
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// 36 - Internal file attributes
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entry.internalFileAttributes = buffer.readUInt16LE(36);
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// 38 - External file attributes
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entry.externalFileAttributes = buffer.readUInt32LE(38);
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// 42 - Relative offset of local file header
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entry.relativeOffsetOfLocalHeader = buffer.readUInt32LE(42);
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if (entry.generalPurposeBitFlag & 0x40) return emitErrorAndAutoClose(self, new Error("strong encryption is not supported"));
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self.readEntryCursor += 46;
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buffer = new Buffer(entry.fileNameLength + entry.extraFieldLength + entry.fileCommentLength);
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readAndAssertNoEof(self.reader, buffer, 0, buffer.length, self.readEntryCursor, function(err) {
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if (err) return emitErrorAndAutoClose(self, err);
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if (self.emittedError) return;
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// 46 - File name
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var isUtf8 = (entry.generalPurposeBitFlag & 0x800) !== 0;
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entry.fileName = self.decodeStrings ? decodeBuffer(buffer, 0, entry.fileNameLength, isUtf8)
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: buffer.slice(0, entry.fileNameLength);
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// 46+n - Extra field
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var fileCommentStart = entry.fileNameLength + entry.extraFieldLength;
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var extraFieldBuffer = buffer.slice(entry.fileNameLength, fileCommentStart);
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entry.extraFields = [];
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var i = 0;
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while (i < extraFieldBuffer.length - 3) {
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var headerId = extraFieldBuffer.readUInt16LE(i + 0);
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var dataSize = extraFieldBuffer.readUInt16LE(i + 2);
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var dataStart = i + 4;
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var dataEnd = dataStart + dataSize;
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if (dataEnd > extraFieldBuffer.length) return emitErrorAndAutoClose(self, new Error("extra field length exceeds extra field buffer size"));
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var dataBuffer = new Buffer(dataSize);
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extraFieldBuffer.copy(dataBuffer, 0, dataStart, dataEnd);
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entry.extraFields.push({
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id: headerId,
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data: dataBuffer,
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});
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i = dataEnd;
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}
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// 46+n+m - File comment
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entry.fileComment = self.decodeStrings ? decodeBuffer(buffer, fileCommentStart, fileCommentStart + entry.fileCommentLength, isUtf8)
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: buffer.slice(fileCommentStart, fileCommentStart + entry.fileCommentLength);
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// compatibility hack for https://github.com/thejoshwolfe/yauzl/issues/47
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entry.comment = entry.fileComment;
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self.readEntryCursor += buffer.length;
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self.entriesRead += 1;
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if (entry.uncompressedSize === 0xffffffff ||
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entry.compressedSize === 0xffffffff ||
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entry.relativeOffsetOfLocalHeader === 0xffffffff) {
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// ZIP64 format
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// find the Zip64 Extended Information Extra Field
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var zip64EiefBuffer = null;
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for (var i = 0; i < entry.extraFields.length; i++) {
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var extraField = entry.extraFields[i];
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if (extraField.id === 0x0001) {
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zip64EiefBuffer = extraField.data;
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break;
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}
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}
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if (zip64EiefBuffer == null) {
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return emitErrorAndAutoClose(self, new Error("expected zip64 extended information extra field"));
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}
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var index = 0;
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// 0 - Original Size 8 bytes
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if (entry.uncompressedSize === 0xffffffff) {
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if (index + 8 > zip64EiefBuffer.length) {
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return emitErrorAndAutoClose(self, new Error("zip64 extended information extra field does not include uncompressed size"));
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}
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entry.uncompressedSize = readUInt64LE(zip64EiefBuffer, index);
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index += 8;
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}
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// 8 - Compressed Size 8 bytes
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if (entry.compressedSize === 0xffffffff) {
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if (index + 8 > zip64EiefBuffer.length) {
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return emitErrorAndAutoClose(self, new Error("zip64 extended information extra field does not include compressed size"));
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}
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entry.compressedSize = readUInt64LE(zip64EiefBuffer, index);
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index += 8;
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}
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// 16 - Relative Header Offset 8 bytes
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if (entry.relativeOffsetOfLocalHeader === 0xffffffff) {
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if (index + 8 > zip64EiefBuffer.length) {
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return emitErrorAndAutoClose(self, new Error("zip64 extended information extra field does not include relative header offset"));
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}
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entry.relativeOffsetOfLocalHeader = readUInt64LE(zip64EiefBuffer, index);
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index += 8;
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}
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// 24 - Disk Start Number 4 bytes
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}
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// check for Info-ZIP Unicode Path Extra Field (0x7075)
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// see https://github.com/thejoshwolfe/yauzl/issues/33
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if (self.decodeStrings) {
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for (var i = 0; i < entry.extraFields.length; i++) {
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var extraField = entry.extraFields[i];
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if (extraField.id === 0x7075) {
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if (extraField.data.length < 6) {
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// too short to be meaningful
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continue;
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}
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// Version 1 byte version of this extra field, currently 1
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if (extraField.data.readUInt8(0) !== 1) {
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// > Changes may not be backward compatible so this extra
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// > field should not be used if the version is not recognized.
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continue;
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}
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// NameCRC32 4 bytes File Name Field CRC32 Checksum
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var oldNameCrc32 = extraField.data.readUInt32LE(1);
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if (crc32.unsigned(buffer.slice(0, entry.fileNameLength)) !== oldNameCrc32) {
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// > If the CRC check fails, this UTF-8 Path Extra Field should be
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// > ignored and the File Name field in the header should be used instead.
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continue;
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}
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// UnicodeName Variable UTF-8 version of the entry File Name
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entry.fileName = decodeBuffer(extraField.data, 5, extraField.data.length, true);
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break;
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}
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}
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}
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// validate file size
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if (self.validateEntrySizes && entry.compressionMethod === 0) {
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var expectedCompressedSize = entry.uncompressedSize;
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if (entry.isEncrypted()) {
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// traditional encryption prefixes the file data with a header
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expectedCompressedSize += 12;
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}
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if (entry.compressedSize !== expectedCompressedSize) {
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var msg = "compressed/uncompressed size mismatch for stored file: " + entry.compressedSize + " != " + entry.uncompressedSize;
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return emitErrorAndAutoClose(self, new Error(msg));
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}
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}
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if (self.decodeStrings) {
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var errorMessage = validateFileName(entry.fileName);
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if (errorMessage != null) return emitErrorAndAutoClose(self, new Error(errorMessage));
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}
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self.emit("entry", entry);
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if (!self.lazyEntries) self._readEntry();
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});
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});
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};
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ZipFile.prototype.openReadStream = function(entry, options, callback) {
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var self = this;
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// parameter validation
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var relativeStart = 0;
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var relativeEnd = entry.compressedSize;
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if (callback == null) {
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callback = options;
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options = {};
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} else {
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// validate options that the caller has no excuse to get wrong
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if (options.decrypt != null) {
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if (!entry.isEncrypted()) {
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throw new Error("options.decrypt can only be specified for encrypted entries");
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}
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if (options.decrypt !== false) throw new Error("invalid options.decrypt value: " + options.decrypt);
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if (entry.isCompressed()) {
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if (options.decompress !== false) throw new Error("entry is encrypted and compressed, and options.decompress !== false");
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}
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}
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if (options.decompress != null) {
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if (!entry.isCompressed()) {
|
|
throw new Error("options.decompress can only be specified for compressed entries");
|
|
}
|
|
if (!(options.decompress === false || options.decompress === true)) {
|
|
throw new Error("invalid options.decompress value: " + options.decompress);
|
|
}
|
|
}
|
|
if (options.start != null || options.end != null) {
|
|
if (entry.isCompressed() && options.decompress !== false) {
|
|
throw new Error("start/end range not allowed for compressed entry without options.decompress === false");
|
|
}
|
|
if (entry.isEncrypted() && options.decrypt !== false) {
|
|
throw new Error("start/end range not allowed for encrypted entry without options.decrypt === false");
|
|
}
|
|
}
|
|
if (options.start != null) {
|
|
relativeStart = options.start;
|
|
if (relativeStart < 0) throw new Error("options.start < 0");
|
|
if (relativeStart > entry.compressedSize) throw new Error("options.start > entry.compressedSize");
|
|
}
|
|
if (options.end != null) {
|
|
relativeEnd = options.end;
|
|
if (relativeEnd < 0) throw new Error("options.end < 0");
|
|
if (relativeEnd > entry.compressedSize) throw new Error("options.end > entry.compressedSize");
|
|
if (relativeEnd < relativeStart) throw new Error("options.end < options.start");
|
|
}
|
|
}
|
|
// any further errors can either be caused by the zipfile,
|
|
// or were introduced in a minor version of yauzl,
|
|
// so should be passed to the client rather than thrown.
|
|
if (!self.isOpen) return callback(new Error("closed"));
|
|
if (entry.isEncrypted()) {
|
|
if (options.decrypt !== false) return callback(new Error("entry is encrypted, and options.decrypt !== false"));
|
|
}
|
|
// make sure we don't lose the fd before we open the actual read stream
|
|
self.reader.ref();
|
|
var buffer = new Buffer(30);
|
|
readAndAssertNoEof(self.reader, buffer, 0, buffer.length, entry.relativeOffsetOfLocalHeader, function(err) {
|
|
try {
|
|
if (err) return callback(err);
|
|
// 0 - Local file header signature = 0x04034b50
|
|
var signature = buffer.readUInt32LE(0);
|
|
if (signature !== 0x04034b50) {
|
|
return callback(new Error("invalid local file header signature: 0x" + signature.toString(16)));
|
|
}
|
|
// all this should be redundant
|
|
// 4 - Version needed to extract (minimum)
|
|
// 6 - General purpose bit flag
|
|
// 8 - Compression method
|
|
// 10 - File last modification time
|
|
// 12 - File last modification date
|
|
// 14 - CRC-32
|
|
// 18 - Compressed size
|
|
// 22 - Uncompressed size
|
|
// 26 - File name length (n)
|
|
var fileNameLength = buffer.readUInt16LE(26);
|
|
// 28 - Extra field length (m)
|
|
var extraFieldLength = buffer.readUInt16LE(28);
|
|
// 30 - File name
|
|
// 30+n - Extra field
|
|
var localFileHeaderEnd = entry.relativeOffsetOfLocalHeader + buffer.length + fileNameLength + extraFieldLength;
|
|
var decompress;
|
|
if (entry.compressionMethod === 0) {
|
|
// 0 - The file is stored (no compression)
|
|
decompress = false;
|
|
} else if (entry.compressionMethod === 8) {
|
|
// 8 - The file is Deflated
|
|
decompress = options.decompress != null ? options.decompress : true;
|
|
} else {
|
|
return callback(new Error("unsupported compression method: " + entry.compressionMethod));
|
|
}
|
|
var fileDataStart = localFileHeaderEnd;
|
|
var fileDataEnd = fileDataStart + entry.compressedSize;
|
|
if (entry.compressedSize !== 0) {
|
|
// bounds check now, because the read streams will probably not complain loud enough.
|
|
// since we're dealing with an unsigned offset plus an unsigned size,
|
|
// we only have 1 thing to check for.
|
|
if (fileDataEnd > self.fileSize) {
|
|
return callback(new Error("file data overflows file bounds: " +
|
|
fileDataStart + " + " + entry.compressedSize + " > " + self.fileSize));
|
|
}
|
|
}
|
|
var readStream = self.reader.createReadStream({
|
|
start: fileDataStart + relativeStart,
|
|
end: fileDataStart + relativeEnd,
|
|
});
|
|
var endpointStream = readStream;
|
|
if (decompress) {
|
|
var destroyed = false;
|
|
var inflateFilter = zlib.createInflateRaw();
|
|
readStream.on("error", function(err) {
|
|
// setImmediate here because errors can be emitted during the first call to pipe()
|
|
setImmediate(function() {
|
|
if (!destroyed) inflateFilter.emit("error", err);
|
|
});
|
|
});
|
|
readStream.pipe(inflateFilter);
|
|
|
|
if (self.validateEntrySizes) {
|
|
endpointStream = new AssertByteCountStream(entry.uncompressedSize);
|
|
inflateFilter.on("error", function(err) {
|
|
// forward zlib errors to the client-visible stream
|
|
setImmediate(function() {
|
|
if (!destroyed) endpointStream.emit("error", err);
|
|
});
|
|
});
|
|
inflateFilter.pipe(endpointStream);
|
|
} else {
|
|
// the zlib filter is the client-visible stream
|
|
endpointStream = inflateFilter;
|
|
}
|
|
// this is part of yauzl's API, so implement this function on the client-visible stream
|
|
endpointStream.destroy = function() {
|
|
destroyed = true;
|
|
if (inflateFilter !== endpointStream) inflateFilter.unpipe(endpointStream);
|
|
readStream.unpipe(inflateFilter);
|
|
// TODO: the inflateFilter may cause a memory leak. see Issue #27.
|
|
readStream.destroy();
|
|
};
|
|
}
|
|
callback(null, endpointStream);
|
|
} finally {
|
|
self.reader.unref();
|
|
}
|
|
});
|
|
};
|
|
|
|
function Entry() {
|
|
}
|
|
Entry.prototype.getLastModDate = function() {
|
|
return dosDateTimeToDate(this.lastModFileDate, this.lastModFileTime);
|
|
};
|
|
Entry.prototype.isEncrypted = function() {
|
|
return (this.generalPurposeBitFlag & 0x1) !== 0;
|
|
};
|
|
Entry.prototype.isCompressed = function() {
|
|
return this.compressionMethod === 8;
|
|
};
|
|
|
|
function dosDateTimeToDate(date, time) {
|
|
var day = date & 0x1f; // 1-31
|
|
var month = (date >> 5 & 0xf) - 1; // 1-12, 0-11
|
|
var year = (date >> 9 & 0x7f) + 1980; // 0-128, 1980-2108
|
|
|
|
var millisecond = 0;
|
|
var second = (time & 0x1f) * 2; // 0-29, 0-58 (even numbers)
|
|
var minute = time >> 5 & 0x3f; // 0-59
|
|
var hour = time >> 11 & 0x1f; // 0-23
|
|
|
|
return new Date(year, month, day, hour, minute, second, millisecond);
|
|
}
|
|
|
|
function validateFileName(fileName) {
|
|
if (fileName.indexOf("\\") !== -1) {
|
|
return "invalid characters in fileName: " + fileName;
|
|
}
|
|
if (/^[a-zA-Z]:/.test(fileName) || /^\//.test(fileName)) {
|
|
return "absolute path: " + fileName;
|
|
}
|
|
if (fileName.split("/").indexOf("..") !== -1) {
|
|
return "invalid relative path: " + fileName;
|
|
}
|
|
// all good
|
|
return null;
|
|
};
|
|
|
|
function readAndAssertNoEof(reader, buffer, offset, length, position, callback) {
|
|
if (length === 0) {
|
|
// fs.read will throw an out-of-bounds error if you try to read 0 bytes from a 0 byte file
|
|
return setImmediate(function() { callback(null, new Buffer(0)); });
|
|
}
|
|
reader.read(buffer, offset, length, position, function(err, bytesRead) {
|
|
if (err) return callback(err);
|
|
if (bytesRead < length) {
|
|
return callback(new Error("unexpected EOF"));
|
|
}
|
|
callback();
|
|
});
|
|
}
|
|
|
|
util.inherits(AssertByteCountStream, Transform);
|
|
function AssertByteCountStream(byteCount) {
|
|
Transform.call(this);
|
|
this.actualByteCount = 0;
|
|
this.expectedByteCount = byteCount;
|
|
}
|
|
AssertByteCountStream.prototype._transform = function(chunk, encoding, cb) {
|
|
this.actualByteCount += chunk.length;
|
|
if (this.actualByteCount > this.expectedByteCount) {
|
|
var msg = "too many bytes in the stream. expected " + this.expectedByteCount + ". got at least " + this.actualByteCount;
|
|
return cb(new Error(msg));
|
|
}
|
|
cb(null, chunk);
|
|
};
|
|
AssertByteCountStream.prototype._flush = function(cb) {
|
|
if (this.actualByteCount < this.expectedByteCount) {
|
|
var msg = "not enough bytes in the stream. expected " + this.expectedByteCount + ". got only " + this.actualByteCount;
|
|
return cb(new Error(msg));
|
|
}
|
|
cb();
|
|
};
|
|
|
|
util.inherits(RandomAccessReader, EventEmitter);
|
|
function RandomAccessReader() {
|
|
EventEmitter.call(this);
|
|
this.refCount = 0;
|
|
}
|
|
RandomAccessReader.prototype.ref = function() {
|
|
this.refCount += 1;
|
|
};
|
|
RandomAccessReader.prototype.unref = function() {
|
|
var self = this;
|
|
self.refCount -= 1;
|
|
|
|
if (self.refCount > 0) return;
|
|
if (self.refCount < 0) throw new Error("invalid unref");
|
|
|
|
self.close(onCloseDone);
|
|
|
|
function onCloseDone(err) {
|
|
if (err) return self.emit('error', err);
|
|
self.emit('close');
|
|
}
|
|
};
|
|
RandomAccessReader.prototype.createReadStream = function(options) {
|
|
var start = options.start;
|
|
var end = options.end;
|
|
if (start === end) {
|
|
var emptyStream = new PassThrough();
|
|
setImmediate(function() {
|
|
emptyStream.end();
|
|
});
|
|
return emptyStream;
|
|
}
|
|
var stream = this._readStreamForRange(start, end);
|
|
|
|
var destroyed = false;
|
|
var refUnrefFilter = new RefUnrefFilter(this);
|
|
stream.on("error", function(err) {
|
|
setImmediate(function() {
|
|
if (!destroyed) refUnrefFilter.emit("error", err);
|
|
});
|
|
});
|
|
refUnrefFilter.destroy = function() {
|
|
stream.unpipe(refUnrefFilter);
|
|
refUnrefFilter.unref();
|
|
stream.destroy();
|
|
};
|
|
|
|
var byteCounter = new AssertByteCountStream(end - start);
|
|
refUnrefFilter.on("error", function(err) {
|
|
setImmediate(function() {
|
|
if (!destroyed) byteCounter.emit("error", err);
|
|
});
|
|
});
|
|
byteCounter.destroy = function() {
|
|
destroyed = true;
|
|
refUnrefFilter.unpipe(byteCounter);
|
|
refUnrefFilter.destroy();
|
|
};
|
|
|
|
return stream.pipe(refUnrefFilter).pipe(byteCounter);
|
|
};
|
|
RandomAccessReader.prototype._readStreamForRange = function(start, end) {
|
|
throw new Error("not implemented");
|
|
};
|
|
RandomAccessReader.prototype.read = function(buffer, offset, length, position, callback) {
|
|
var readStream = this.createReadStream({start: position, end: position + length});
|
|
var writeStream = new Writable();
|
|
var written = 0;
|
|
writeStream._write = function(chunk, encoding, cb) {
|
|
chunk.copy(buffer, offset + written, 0, chunk.length);
|
|
written += chunk.length;
|
|
cb();
|
|
};
|
|
writeStream.on("finish", callback);
|
|
readStream.on("error", function(error) {
|
|
callback(error);
|
|
});
|
|
readStream.pipe(writeStream);
|
|
};
|
|
RandomAccessReader.prototype.close = function(callback) {
|
|
setImmediate(callback);
|
|
};
|
|
|
|
util.inherits(RefUnrefFilter, PassThrough);
|
|
function RefUnrefFilter(context) {
|
|
PassThrough.call(this);
|
|
this.context = context;
|
|
this.context.ref();
|
|
this.unreffedYet = false;
|
|
}
|
|
RefUnrefFilter.prototype._flush = function(cb) {
|
|
this.unref();
|
|
cb();
|
|
};
|
|
RefUnrefFilter.prototype.unref = function(cb) {
|
|
if (this.unreffedYet) return;
|
|
this.unreffedYet = true;
|
|
this.context.unref();
|
|
};
|
|
|
|
var cp437 = '\u0000☺☻♥♦♣♠•◘○◙♂♀♪♫☼►◄↕‼¶§▬↨↑↓→←∟↔▲▼ !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~⌂ÇüéâäàåçêëèïîìÄÅÉæÆôöòûùÿÖÜ¢£¥₧ƒáíóúñѪº¿⌐¬½¼¡«»░▒▓│┤╡╢╖╕╣║╗╝╜╛┐└┴┬├─┼╞╟╚╔╩╦╠═╬╧╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀αßΓπΣσµτΦΘΩδ∞φε∩≡±≥≤⌠⌡÷≈°∙·√ⁿ²■ ';
|
|
function decodeBuffer(buffer, start, end, isUtf8) {
|
|
if (isUtf8) {
|
|
return buffer.toString("utf8", start, end);
|
|
} else {
|
|
var result = "";
|
|
for (var i = start; i < end; i++) {
|
|
result += cp437[buffer[i]];
|
|
}
|
|
return result;
|
|
}
|
|
}
|
|
|
|
function readUInt64LE(buffer, offset) {
|
|
// there is no native function for this, because we can't actually store 64-bit integers precisely.
|
|
// after 53 bits, JavaScript's Number type (IEEE 754 double) can't store individual integers anymore.
|
|
// but since 53 bits is a whole lot more than 32 bits, we do our best anyway.
|
|
var lower32 = buffer.readUInt32LE(offset);
|
|
var upper32 = buffer.readUInt32LE(offset + 4);
|
|
// we can't use bitshifting here, because JavaScript bitshifting only works on 32-bit integers.
|
|
return upper32 * 0x100000000 + lower32;
|
|
// as long as we're bounds checking the result of this function against the total file size,
|
|
// we'll catch any overflow errors, because we already made sure the total file size was within reason.
|
|
}
|
|
|
|
function defaultCallback(err) {
|
|
if (err) throw err;
|
|
}
|