diff --git a/liveupdate_reszip/lib/web/library_reszip.js b/liveupdate_reszip/lib/web/library_reszip.js
index 5f60202..0b67a4d 100644
--- a/liveupdate_reszip/lib/web/library_reszip.js
+++ b/liveupdate_reszip/lib/web/library_reszip.js
@@ -4,6 +4,108 @@ var LibraryResZip = {
         _preloads: {},
     },
 
+    // FIXME: replace with `http.request`
+    // file downloader
+    // wraps XMLHttpRequest and adds retry support and progress updates when the
+    // content is gzipped (gzipped content doesn't report a computable content length
+    // on Google Chrome)
+    $ResZipFileLoader: {
+        options: {
+            retryCount: 5,
+            retryInterval: 1000,
+        },
+        // do xhr request with retries
+        request: function(url, method, responseType, currentAttempt) {
+            if (typeof method === 'undefined') throw "No method specified";
+            if (typeof method === 'responseType') throw "No responseType specified";
+            if (typeof currentAttempt === 'undefined') currentAttempt = 0;
+            var obj = {
+                send: function() {
+                    var onprogress = this.onprogress;
+                    var onload = this.onload;
+                    var onerror = this.onerror;
+
+                    var xhr = new XMLHttpRequest();
+                    xhr.open(method, url, true);
+                    xhr.responseType = responseType;
+                    xhr.onprogress = function(e) {
+                        if (onprogress) onprogress(xhr, e);
+                    };
+                    xhr.onerror = function(e) {
+                        if (currentAttempt == ResZipFileLoader.options.retryCount) {
+                            if (onerror) onerror(xhr, e);
+                            return;
+                        }
+                        currentAttempt = currentAttempt + 1;
+                        setTimeout(obj.send.bind(obj), ResZipFileLoader.options.retryInterval);
+                    };
+                    xhr.onload = function(e) {
+                        if (onload) onload(xhr, e);
+                    };
+                    xhr.send(null);
+                }
+            };
+            return obj;
+        },
+        // Do HTTP HEAD request to get size of resource
+        // callback will receive size or undefined in case of an error
+        size: function(url, callback) {
+            var request = ResZipFileLoader.request(url, "HEAD", "text");
+            request.onerror = function(xhr, e) {
+                callback(undefined);
+            };
+            request.onload = function(xhr, e) {
+                if (xhr.readyState === 4) {
+                    if (xhr.status === 200) {
+                        var total = xhr.getResponseHeader('content-length');
+                        callback(total);
+                    } else {
+                        callback(undefined);
+                    }
+                }
+            };
+            request.send();
+        },
+        // Do HTTP GET request
+        // onprogress(loaded, total)
+        // onerror(error)
+        // onload(response)
+        load: function(url, responseType, estimatedSize, onprogress, onerror, onload) {
+            var request = ResZipFileLoader.request(url, "GET", responseType);
+            request.onprogress = function(xhr, e) {
+                if (e.lengthComputable) {
+                    onprogress(e.loaded, e.total);
+                    return;
+                }
+                var contentLength = xhr.getResponseHeader('content-length');
+                var size = contentLength != undefined ? contentLength : estimatedSize;
+                if (size) {
+                    onprogress(e.loaded, size);
+                } else {
+                    onprogress(e.loaded, e.loaded);
+                }
+            };
+            request.onerror = function(xhr, e) {
+                onerror("Error loading '" + url + "' (" + e + ")");
+            };
+            request.onload = function(xhr, e) {
+                if (xhr.readyState === 4) {
+                    if (xhr.status === 200) {
+                        var res = xhr.response;
+                        if (responseType == "json" && typeof res === "string") {
+                            onload(JSON.parse(res));
+                        } else {
+                            onload(res);
+                        }
+                    } else {
+                        onerror("Error loading '" + url + "' (" + e + ")");
+                    }
+                }
+            };
+            request.send();
+        }
+    },
+
     dmResZipRequestFileAsync: function (url, context, onprogress, onerror, onload) {
         var callbacks = {
             onprogress: function (loaded, total) {
@@ -40,9 +142,10 @@ var LibraryResZip = {
             };
             ResZip._preloads[url] = preload;
 
-            FileLoader.load(
+            ResZipFileLoader.load(
                 url,
                 "arraybuffer",
+                0,
                 function (loaded, total) {
                     preload.handler("onprogress", loaded, total);
                 },
@@ -51,8 +154,7 @@ var LibraryResZip = {
                 },
                 function (response) {
                     preload.handler("onload", response);
-                },
-                function () { }
+                }
             );
             return;
         }
@@ -84,10 +186,11 @@ var LibraryResZip = {
             //
             // Normal usage - load something from URL
             //
-            FileLoader.load(url, "arraybuffer", callbacks.onprogress, callbacks.onerror, callbacks.onload, function() { });
+            ResZipFileLoader.load(url, "arraybuffer", 0, callbacks.onprogress, callbacks.onerror, callbacks.onload);
         }
     },
 };
 
 autoAddDeps(LibraryResZip, "$ResZip");
+autoAddDeps(LibraryResZip, "$ResZipFileLoader");
 addToLibrary(LibraryResZip);