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385 lines
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JavaScript

const ZipEntry = require("./zipEntry");
const Headers = require("./headers");
const Utils = require("./util");
module.exports = function (/*Buffer|null*/ inBuffer, /** object */ options) {
var entryList = [],
entryTable = {},
_comment = Buffer.alloc(0),
mainHeader = new Headers.MainHeader(),
loadedEntries = false;
// assign options
const opts = Object.assign(Object.create(null), options);
const { noSort } = opts;
if (inBuffer) {
// is a memory buffer
readMainHeader(opts.readEntries);
} else {
// none. is a new file
loadedEntries = true;
}
function iterateEntries(callback) {
const totalEntries = mainHeader.diskEntries; // total number of entries
let index = mainHeader.offset; // offset of first CEN header
for (let i = 0; i < totalEntries; i++) {
let tmp = index;
const entry = new ZipEntry(inBuffer);
entry.header = inBuffer.slice(tmp, (tmp += Utils.Constants.CENHDR));
entry.entryName = inBuffer.slice(tmp, (tmp += entry.header.fileNameLength));
index += entry.header.entryHeaderSize;
callback(entry);
}
}
function readEntries() {
loadedEntries = true;
entryTable = {};
entryList = new Array(mainHeader.diskEntries); // total number of entries
var index = mainHeader.offset; // offset of first CEN header
for (var i = 0; i < entryList.length; i++) {
var tmp = index,
entry = new ZipEntry(inBuffer);
entry.header = inBuffer.slice(tmp, (tmp += Utils.Constants.CENHDR));
entry.entryName = inBuffer.slice(tmp, (tmp += entry.header.fileNameLength));
if (entry.header.extraLength) {
entry.extra = inBuffer.slice(tmp, (tmp += entry.header.extraLength));
}
if (entry.header.commentLength) entry.comment = inBuffer.slice(tmp, tmp + entry.header.commentLength);
index += entry.header.entryHeaderSize;
entryList[i] = entry;
entryTable[entry.entryName] = entry;
}
}
function readMainHeader(/*Boolean*/ readNow) {
var i = inBuffer.length - Utils.Constants.ENDHDR, // END header size
max = Math.max(0, i - 0xffff), // 0xFFFF is the max zip file comment length
n = max,
endStart = inBuffer.length,
endOffset = -1, // Start offset of the END header
commentEnd = 0;
for (i; i >= n; i--) {
if (inBuffer[i] !== 0x50) continue; // quick check that the byte is 'P'
if (inBuffer.readUInt32LE(i) === Utils.Constants.ENDSIG) {
// "PK\005\006"
endOffset = i;
commentEnd = i;
endStart = i + Utils.Constants.ENDHDR;
// We already found a regular signature, let's look just a bit further to check if there's any zip64 signature
n = i - Utils.Constants.END64HDR;
continue;
}
if (inBuffer.readUInt32LE(i) === Utils.Constants.END64SIG) {
// Found a zip64 signature, let's continue reading the whole zip64 record
n = max;
continue;
}
if (inBuffer.readUInt32LE(i) === Utils.Constants.ZIP64SIG) {
// Found the zip64 record, let's determine it's size
endOffset = i;
endStart = i + Utils.readBigUInt64LE(inBuffer, i + Utils.Constants.ZIP64SIZE) + Utils.Constants.ZIP64LEAD;
break;
}
}
if (!~endOffset) throw new Error(Utils.Errors.INVALID_FORMAT);
mainHeader.loadFromBinary(inBuffer.slice(endOffset, endStart));
if (mainHeader.commentLength) {
_comment = inBuffer.slice(commentEnd + Utils.Constants.ENDHDR);
}
if (readNow) readEntries();
}
function sortEntries() {
if (entryList.length > 1 && !noSort) {
entryList.sort((a, b) => a.entryName.toLowerCase().localeCompare(b.entryName.toLowerCase()));
}
}
return {
/**
* Returns an array of ZipEntry objects existent in the current opened archive
* @return Array
*/
get entries() {
if (!loadedEntries) {
readEntries();
}
return entryList;
},
/**
* Archive comment
* @return {String}
*/
get comment() {
return _comment.toString();
},
set comment(val) {
_comment = Utils.toBuffer(val);
mainHeader.commentLength = _comment.length;
},
getEntryCount: function () {
if (!loadedEntries) {
return mainHeader.diskEntries;
}
return entryList.length;
},
forEach: function (callback) {
if (!loadedEntries) {
iterateEntries(callback);
return;
}
entryList.forEach(callback);
},
/**
* Returns a reference to the entry with the given name or null if entry is inexistent
*
* @param entryName
* @return ZipEntry
*/
getEntry: function (/*String*/ entryName) {
if (!loadedEntries) {
readEntries();
}
return entryTable[entryName] || null;
},
/**
* Adds the given entry to the entry list
*
* @param entry
*/
setEntry: function (/*ZipEntry*/ entry) {
if (!loadedEntries) {
readEntries();
}
entryList.push(entry);
entryTable[entry.entryName] = entry;
mainHeader.totalEntries = entryList.length;
},
/**
* Removes the entry with the given name from the entry list.
*
* If the entry is a directory, then all nested files and directories will be removed
* @param entryName
*/
deleteEntry: function (/*String*/ entryName) {
if (!loadedEntries) {
readEntries();
}
var entry = entryTable[entryName];
if (entry && entry.isDirectory) {
var _self = this;
this.getEntryChildren(entry).forEach(function (child) {
if (child.entryName !== entryName) {
_self.deleteEntry(child.entryName);
}
});
}
entryList.splice(entryList.indexOf(entry), 1);
delete entryTable[entryName];
mainHeader.totalEntries = entryList.length;
},
/**
* Iterates and returns all nested files and directories of the given entry
*
* @param entry
* @return Array
*/
getEntryChildren: function (/*ZipEntry*/ entry) {
if (!loadedEntries) {
readEntries();
}
if (entry && entry.isDirectory) {
const list = [];
const name = entry.entryName;
const len = name.length;
entryList.forEach(function (zipEntry) {
if (zipEntry.entryName.substr(0, len) === name) {
list.push(zipEntry);
}
});
return list;
}
return [];
},
/**
* Returns the zip file
*
* @return Buffer
*/
compressToBuffer: function () {
if (!loadedEntries) {
readEntries();
}
sortEntries();
const dataBlock = [];
const entryHeaders = [];
let totalSize = 0;
let dindex = 0;
mainHeader.size = 0;
mainHeader.offset = 0;
for (const entry of entryList) {
// compress data and set local and entry header accordingly. Reason why is called first
const compressedData = entry.getCompressedData();
// 1. construct data header
entry.header.offset = dindex;
const dataHeader = entry.header.dataHeaderToBinary();
const entryNameLen = entry.rawEntryName.length;
// 1.2. postheader - data after data header
const postHeader = Buffer.alloc(entryNameLen + entry.extra.length);
entry.rawEntryName.copy(postHeader, 0);
postHeader.copy(entry.extra, entryNameLen);
// 2. offsets
const dataLength = dataHeader.length + postHeader.length + compressedData.length;
dindex += dataLength;
// 3. store values in sequence
dataBlock.push(dataHeader);
dataBlock.push(postHeader);
dataBlock.push(compressedData);
// 4. construct entry header
const entryHeader = entry.packHeader();
entryHeaders.push(entryHeader);
// 5. update main header
mainHeader.size += entryHeader.length;
totalSize += dataLength + entryHeader.length;
}
totalSize += mainHeader.mainHeaderSize; // also includes zip file comment length
// point to end of data and beginning of central directory first record
mainHeader.offset = dindex;
dindex = 0;
const outBuffer = Buffer.alloc(totalSize);
// write data blocks
for (const content of dataBlock) {
content.copy(outBuffer, dindex);
dindex += content.length;
}
// write central directory entries
for (const content of entryHeaders) {
content.copy(outBuffer, dindex);
dindex += content.length;
}
// write main header
const mh = mainHeader.toBinary();
if (_comment) {
_comment.copy(mh, Utils.Constants.ENDHDR); // add zip file comment
}
mh.copy(outBuffer, dindex);
return outBuffer;
},
toAsyncBuffer: function (/*Function*/ onSuccess, /*Function*/ onFail, /*Function*/ onItemStart, /*Function*/ onItemEnd) {
try {
if (!loadedEntries) {
readEntries();
}
sortEntries();
const dataBlock = [];
const entryHeaders = [];
let totalSize = 0;
let dindex = 0;
mainHeader.size = 0;
mainHeader.offset = 0;
const compress2Buffer = function (entryLists) {
if (entryLists.length) {
const entry = entryLists.pop();
const name = entry.entryName + entry.extra.toString();
if (onItemStart) onItemStart(name);
entry.getCompressedDataAsync(function (compressedData) {
if (onItemEnd) onItemEnd(name);
entry.header.offset = dindex;
// data header
const dataHeader = entry.header.dataHeaderToBinary();
const postHeader = Buffer.alloc(name.length, name);
const dataLength = dataHeader.length + postHeader.length + compressedData.length;
dindex += dataLength;
dataBlock.push(dataHeader);
dataBlock.push(postHeader);
dataBlock.push(compressedData);
const entryHeader = entry.packHeader();
entryHeaders.push(entryHeader);
mainHeader.size += entryHeader.length;
totalSize += dataLength + entryHeader.length;
compress2Buffer(entryLists);
});
} else {
totalSize += mainHeader.mainHeaderSize; // also includes zip file comment length
// point to end of data and beginning of central directory first record
mainHeader.offset = dindex;
dindex = 0;
const outBuffer = Buffer.alloc(totalSize);
dataBlock.forEach(function (content) {
content.copy(outBuffer, dindex); // write data blocks
dindex += content.length;
});
entryHeaders.forEach(function (content) {
content.copy(outBuffer, dindex); // write central directory entries
dindex += content.length;
});
const mh = mainHeader.toBinary();
if (_comment) {
_comment.copy(mh, Utils.Constants.ENDHDR); // add zip file comment
}
mh.copy(outBuffer, dindex); // write main header
onSuccess(outBuffer);
}
};
compress2Buffer(entryList);
} catch (e) {
onFail(e);
}
}
};
};