Added preliminary gzip support based on jsxgraph zip.js

Author: racerxdl

README.md

@@ -22,11 +22,12 @@ What is done
 *   Load progress event
 *   Get file as Base64
 *   Get file as HTML Data URI (for hide from Network Requests)
+*   GZIP Decompress Support, forked from jsxgraph/jsxgraph
 
 TODO
 ========
 *   Load files from JPAK only when needed. A.K.A. - Fetch only the necessary parts from jpak file.
-
+*   Add option to compress files on packing.
 
 How to use it
 ========
@@ -179,6 +180,26 @@ JPAK Loader Error Codes:
 *   100->600    -   HTML Status Code. Consult **RFC-2616** for details.
 *   8000        -   Wrong file magic
 
+
+GZIP Support:
+========
+
+The GZIP Decompress support is a modified version of **zip.js** from jsxgraph/jsxgraph project. For now, the default behaviour of `jpakloader` is to check the `compressed` flag at file entry. If its true, it tryes to decompress the file. 
+
+For compatible GZIPPing a file on Python you can do:
+```python
+import zlib
+f = open("uncompressed", "rb")
+data = f.read()
+f.close()
+data = zlib.compress(data, 9)   # Level 9 is important
+f = open("compressed", "wb")
+f.write(data)
+f.close()
+```
+
+*   TODO on Tools: Add option to compress files on packer.py
+
 Example
 ========
 

js/jpak.js

@@ -52,6 +52,14 @@ JPAK.Uint8ArrayToString = function(uintArray) {
     return o;
 }
 
+JPAK.String2ArrayBuffer = function(str)   {
+    var buf = new ArrayBuffer(str.length);
+    var bufView = new Uint8Array(buf);
+    for (var i=0, strLen=str.length; i<strLen; i++) 
+        bufView[i] = str.charCodeAt(i) & 0xFF;
+    return buf;
+};
+
 var u8as = JPAK.Uint8ArrayToString; //  Provided for compatibility
 
 JPAK.Base64_Encoding = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
@@ -252,7 +260,10 @@ JPAK.jpakloader.prototype.GetFile = function(path, type)  {
 
     if(file != undefined && cache == undefined)  { 
         //  Add it to file cache
-        var blob = new Blob([new Uint8Array(this.jpakdata.slice(file.offset,file.offset+file.size)).buffer], { "type":type});
+        var dataslice = this.jpakdata.slice(file.offset,file.offset+file.size);
+        if(file.compressed !== undefined && file.compressed)
+            dataslice = JPAK.GZIP.decompress(dataslice);
+        var blob = new Blob([new Uint8Array(dataslice).buffer], { "type":type});
         this.filecache.push({"path":path,"type":type,"blob":blob,"url":URL.createObjectURL(blob), "arraybuffer" : this.jpakdata.slice(file.offset,file.offset+file.size)} );
         return blob;
     }else if(cache != undefined)
@@ -284,33 +295,18 @@ JPAK.jpakloader.prototype.GetFileArrayBuffer = function(path, type) {
 
     if(file != undefined && cache == undefined)  { 
         //  Add it to file cache
-        var blob = new Blob([new Uint8Array(this.jpakdata.slice(file.offset,file.offset+file.size)).buffer], { "type":type});
-        var arraybuffer = this.jpakdata.slice(file.offset,file.offset+file.size);
+        var dataslice = this.jpakdata.slice(file.offset,file.offset+file.size);
+        if(file.compressed !== undefined && file.compressed)
+            dataslice = JPAK.GZIP.decompress(dataslice);
+        var blob = new Blob([new Uint8Array(dataslice).buffer], { "type":type});
         this.filecache.push({"path":path,"type":type,"blob":blob,"url":URL.createObjectURL(blob), "arraybuffer" : arraybuffer});
-        return arraybuffer;
+        return dataslice;
     }else if(cache != undefined)
         return cache.arraybuffer;
 
     JPAK.log("Error: Cannot find file \""+path+"\"");    
     return undefined;
 };
-//  Returns an arraybuffer with file content. It looks in the cache for already loaded files.
-JPAK.jpakloader.prototype.GetFileArrayBuffer = function(path, type) {
-    var file = this.FindFileEntry(path);
-    type = type || 'application/octet-binary';
-    var cache = this.CacheLoad(path);
-    
-    if(file != undefined && cache == undefined)  { 
-        //  Add it to file cache
-        var blob = new Blob([new Uint8Array(this.jpakdata.slice(file.offset,file.offset+file.size)).buffer], { "type":type});
-        var arraybuffer = this.jpakdata.slice(file.offset,file.offset+file.size);
-        this.filecache.push({"path":path,"type":type,"blob":blob,"url":URL.createObjectURL(blob), "arraybuffer" : arraybuffer});
-        return arraybuffer;
-    }else if(cache != undefined)
-        return cache.arraybuffer;
-        
-    return undefined;
-};
 
 //  Returns an Base64 Encoded File Content. It looks in the cache for already loaded files.
 JPAK.jpakloader.prototype.GetBase64File = function(path, type) {