Iterate over entries without storing their metadata

adm-zip.js

@@ -339,6 +339,14 @@ module.exports = function (/*String*/input) {
 			return getEntry(name);
 		},
 
+		getEntryCount: function() {
+			return _zip.getEntryCount();
+		},
+
+		forEach: function(callback) {
+			return _zip.forEach(callback);
+		},
+
 		/**
 		 * Extracts the given entry to the given targetPath
 		 * If the entry is a directory inside the archive, the entire directory and it's subdirectories will be extracted

zipFile.js

@@ -9,7 +9,8 @@ module.exports = function (/*String|Buffer*/input, /*Number*/inputType) {
 		filename = "",
 		fs = Utils.FileSystem.require(),
 		inBuffer = null,
-		mainHeader = new Headers.MainHeader();
+		mainHeader = new Headers.MainHeader(),
+		loadedEntries = false;
 
 	if (inputType === Utils.Constants.FILE) {
 		// is a filename
@@ -22,9 +23,28 @@ module.exports = function (/*String|Buffer*/input, /*Number*/inputType) {
 		readMainHeader();
 	} 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
@@ -90,7 +110,7 @@ module.exports = function (/*String|Buffer*/input, /*Number*/inputType) {
 		if (mainHeader.commentLength) {
 			_comment = inBuffer.slice(commentEnd + Utils.Constants.ENDHDR);
 		}
-		readEntries();
+		// readEntries();
 	}
 
 	return {
@@ -99,6 +119,9 @@ module.exports = function (/*String|Buffer*/input, /*Number*/inputType) {
 		 * @return Array
 		 */
 		get entries() {
+			if (!loadedEntries) {
+				readEntries();
+			}
 			return entryList;
 		},
 
@@ -114,13 +137,33 @@ module.exports = function (/*String|Buffer*/input, /*Number*/inputType) {
 			_comment = val;
 		},
 
+		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;
 		},
 
@@ -130,6 +173,9 @@ module.exports = function (/*String|Buffer*/input, /*Number*/inputType) {
 		 * @param entry
 		 */
 		setEntry: function (/*ZipEntry*/entry) {
+			if (!loadedEntries) {
+				readEntries();
+			}
 			entryList.push(entry);
 			entryTable[entry.entryName] = entry;
 			mainHeader.totalEntries = entryList.length;
@@ -142,6 +188,9 @@ module.exports = function (/*String|Buffer*/input, /*Number*/inputType) {
 		 * @param entryName
 		 */
 		deleteEntry: function (/*String*/entryName) {
+			if (!loadedEntries) {
+				readEntries();
+			}
 			var entry = entryTable[entryName];
 			if (entry && entry.isDirectory) {
 				var _self = this;
@@ -163,6 +212,9 @@ module.exports = function (/*String|Buffer*/input, /*Number*/inputType) {
 		 * @return Array
 		 */
 		getEntryChildren: function (/*ZipEntry*/entry) {
+			if (!loadedEntries) {
+				readEntries();
+			}
 			if (entry.isDirectory) {
 				var list = [],
 					name = entry.entryName,
@@ -184,6 +236,9 @@ module.exports = function (/*String|Buffer*/input, /*Number*/inputType) {
 		 * @return Buffer
 		 */
 		compressToBuffer: function () {
+			if (!loadedEntries) {
+				readEntries();
+			}
 			if (entryList.length > 1) {
 				entryList.sort(function (a, b) {
 					var nameA = a.entryName.toLowerCase();
@@ -258,6 +313,9 @@ module.exports = function (/*String|Buffer*/input, /*Number*/inputType) {
 		},
 
 		toAsyncBuffer: function (/*Function*/onSuccess, /*Function*/onFail, /*Function*/onItemStart, /*Function*/onItemEnd) {
+			if (!loadedEntries) {
+				readEntries();
+			}
 			if (entryList.length > 1) {
 				entryList.sort(function (a, b) {
 					var nameA = a.entryName.toLowerCase();