zip-iterator
Version:
Extract contents from zip archive type using an iterator API using streams or paths. Use stream interface and pipe transforms to add decompression algorithms
187 lines • 8.49 kB
JavaScript
/**
* Central Directory Reader
*
* Reads the Central Directory from seekable files to get
* external file attributes (needed for symlink detection).
*/ "use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
Object.defineProperty(exports, "readCentralDirectory", {
enumerable: true,
get: function() {
return readCentralDirectory;
}
});
var _extractbaseiterator = require("extract-base-iterator");
var _gracefulfs = /*#__PURE__*/ _interop_require_default(require("graceful-fs"));
var _constantsts = /*#__PURE__*/ _interop_require_wildcard(require("./constants.js"));
var _cp437ts = require("./cp437.js");
function _interop_require_default(obj) {
return obj && obj.__esModule ? obj : {
default: obj
};
}
function _getRequireWildcardCache(nodeInterop) {
if (typeof WeakMap !== "function") return null;
var cacheBabelInterop = new WeakMap();
var cacheNodeInterop = new WeakMap();
return (_getRequireWildcardCache = function(nodeInterop) {
return nodeInterop ? cacheNodeInterop : cacheBabelInterop;
})(nodeInterop);
}
function _interop_require_wildcard(obj, nodeInterop) {
if (!nodeInterop && obj && obj.__esModule) {
return obj;
}
if (obj === null || typeof obj !== "object" && typeof obj !== "function") {
return {
default: obj
};
}
var cache = _getRequireWildcardCache(nodeInterop);
if (cache && cache.has(obj)) {
return cache.get(obj);
}
var newObj = {
__proto__: null
};
var hasPropertyDescriptor = Object.defineProperty && Object.getOwnPropertyDescriptor;
for(var key in obj){
if (key !== "default" && Object.prototype.hasOwnProperty.call(obj, key)) {
var desc = hasPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : null;
if (desc && (desc.get || desc.set)) {
Object.defineProperty(newObj, key, desc);
} else {
newObj[key] = obj[key];
}
}
}
newObj.default = obj;
if (cache) {
cache.set(obj, newObj);
}
return newObj;
}
function readCentralDirectory(filePath, callback) {
_gracefulfs.default.stat(filePath, function(err, stats) {
if (err) return callback(err);
var fileSize = stats.size;
// EOCD is at most 65557 bytes from end (22 bytes min + 65535 max comment)
var searchSize = Math.min(65557, fileSize);
var searchBuffer = (0, _extractbaseiterator.allocBuffer)(searchSize);
var searchStart = fileSize - searchSize;
_gracefulfs.default.open(filePath, 'r', function(err, fd) {
if (err) return callback(err);
_gracefulfs.default.read(fd, searchBuffer, 0, searchSize, searchStart, function(err, bytesRead) {
if (err) {
_gracefulfs.default.close(fd, function() {
return callback(err);
});
return;
}
// Find End of Central Directory signature
var eocdPos = -1;
for(var i = bytesRead - 22; i >= 0; i--){
if ((0, _extractbaseiterator.bufferEquals)(searchBuffer, i, _constantsts.SIG_END_OF_CENTRAL_DIR)) {
eocdPos = i;
break;
}
}
if (eocdPos < 0) {
_gracefulfs.default.close(fd, function() {
return callback(new Error('Cannot find End of Central Directory'));
});
return;
}
// Parse EOCD
var eocd = searchBuffer.slice(eocdPos);
var cdOffset = eocd.readUInt32LE(16);
var cdSize = eocd.readUInt32LE(12);
// Check for ZIP64
if (cdOffset === _constantsts.ZIP64_MARKER_32) {
// Need to find ZIP64 EOCD locator
if (eocdPos >= 20) {
var locatorPos = eocdPos - 20;
if ((0, _extractbaseiterator.bufferEquals)(searchBuffer, locatorPos, _constantsts.SIG_ZIP64_EOCD_LOCATOR)) {
// Get ZIP64 EOCD position
var zip64EocdOffset = (0, _extractbaseiterator.readUInt64LE)(searchBuffer, locatorPos + 8);
// Read ZIP64 EOCD
var zip64EocdBuf = (0, _extractbaseiterator.allocBuffer)(56);
_gracefulfs.default.read(fd, zip64EocdBuf, 0, 56, zip64EocdOffset, function(err) {
if (err) {
_gracefulfs.default.close(fd, function() {
return callback(err);
});
return;
}
if (!(0, _extractbaseiterator.bufferEquals)(zip64EocdBuf, 0, _constantsts.SIG_ZIP64_END_OF_CENTRAL_DIR)) {
_gracefulfs.default.close(fd, function() {
return callback(new Error('Invalid ZIP64 EOCD'));
});
return;
}
cdSize = (0, _extractbaseiterator.readUInt64LE)(zip64EocdBuf, 40);
cdOffset = (0, _extractbaseiterator.readUInt64LE)(zip64EocdBuf, 48);
readCentralDirEntries(fd, cdOffset, cdSize, function(err, map) {
_gracefulfs.default.close(fd, function() {
return callback(err, map);
});
});
});
return;
}
}
}
readCentralDirEntries(fd, cdOffset, cdSize, function(err, map) {
_gracefulfs.default.close(fd, function() {
return callback(err, map);
});
});
});
});
});
}
/**
* Read and parse Central Directory entries
*/ function readCentralDirEntries(fd, offset, size, callback) {
var buffer = (0, _extractbaseiterator.allocBuffer)(size);
_gracefulfs.default.read(fd, buffer, 0, size, offset, function(err, bytesRead) {
if (err) return callback(err);
var map = {};
var pos = 0;
while(pos + 46 <= bytesRead){
// Check signature
if (!(0, _extractbaseiterator.bufferEquals)(buffer, pos, _constantsts.SIG_CENTRAL_DIR)) {
break;
}
var platform = buffer.readUInt8(pos + 5); // Version made by - high byte is platform
var flags = buffer.readUInt16LE(pos + 8); // General purpose bit flags
var fileNameLength = buffer.readUInt16LE(pos + 28);
var extraFieldLength = buffer.readUInt16LE(pos + 30);
var commentLength = buffer.readUInt16LE(pos + 32);
var externalAttributes = buffer.readUInt32LE(pos + 38);
var headerSize = 46 + fileNameLength + extraFieldLength + commentLength;
if (pos + headerSize > bytesRead) {
break;
}
// Check UTF-8 flag (bit 11) to determine filename encoding
var isUtf8 = (flags & _constantsts.FLAG_UTF8) !== 0;
var fileName = void 0;
if (isUtf8) {
fileName = buffer.toString('utf8', pos + 46, pos + 46 + fileNameLength);
} else {
// CP437 is the original IBM PC character set and ZIP default
fileName = (0, _cp437ts.decodeCP437)(buffer, pos + 46, pos + 46 + fileNameLength);
}
map[fileName] = {
fileName: fileName,
externalAttributes: externalAttributes,
platform: platform
};
pos += headerSize;
}
callback(null, map);
});
}
/* CJS INTEROP */ if (exports.__esModule && exports.default) { try { Object.defineProperty(exports.default, '__esModule', { value: true }); for (var key in exports) { exports.default[key] = exports[key]; } } catch (_) {}; module.exports = exports.default; }