copy the entire datafile in one chunk into the heap, avoiding one malloc per file, but at the cost of not being able to free them

2 files changed, 8 insertions, 14 deletions

diff --git a/src/library_memfs.js b/src/library_memfs.js
index 63326c42..354f5e95 100644
--- a/src/library_memfs.js
+++ b/src/library_memfs.js
@@ -2,17 +2,13 @@ mergeInto(LibraryManager.library, {
   $MEMFS__deps: ['$FS'],
   $MEMFS: {
     // content modes
-    CONTENT_OWNING: 1, // contains a subarray into the heap, and we own it - need to free() when no longer needed
+    CONTENT_OWNING: 1, // contains a subarray into the heap, and we own it, without copying (note: someone else needs to free() it, if that is necessary)
     CONTENT_FLEXIBLE: 2, // has been modified or never set to anything, and is a flexible js array that can grow/shrink
     CONTENT_FIXED: 3, // contains some fixed-size content written into it, in a typed array
     ensureFlexible: function(node) {
       if (node.contentMode !== MEMFS.CONTENT_FLEXIBLE) {
         var contents = node.contents;
         node.contents = Array.prototype.slice.call(contents);
-        if (node.contentMode === MEMFS.CONTENT_OWNING) {
-          assert(contents.byteOffset);
-          Module['_free'](contents.byteOffset);
-        }
         node.contentMode = MEMFS.CONTENT_FLEXIBLE;
       }
     },
diff --git a/tools/file_packager.py b/tools/file_packager.py
index 2871f1ed..8a1f1ba5 100644
--- a/tools/file_packager.py
+++ b/tools/file_packager.py
@@ -344,14 +344,7 @@ if has_preloaded:
       },
       send: function() {},
       onload: function() {
-        var data = this.byteArray.subarray(this.start, this.end);
-        var size = this.end - this.start;
-        var ptr = Module['_malloc'](size); // XXX leaked if a preload plugin replaces with new data
-        Module['HEAPU8'].set(data, ptr);
-        var arrayBuffer = Module['HEAPU8'].subarray(ptr, ptr + size);
-        assert(arrayBuffer, 'Loading file ' + name + ' failed');
-        var byteArray = !arrayBuffer.subarray ? new Uint8Array(arrayBuffer) : arrayBuffer;
-
+        var byteArray = this.byteArray.subarray(this.start, this.end);
         if (this.crunched) {
           var ddsHeader = byteArray.subarray(0, 128);
           var that = this;
@@ -419,7 +412,12 @@ for file_ in data_files:
 
 if has_preloaded:
   # Get the big archive and split it up
-  use_data = '          DataRequest.prototype.byteArray = byteArray;\n'
+  use_data = '''
+      // copy the entire loaded file into a spot in the heap. Files will refer to slices in that. They cannot be freed though.
+      var ptr = Module['_malloc'](byteArray.length);
+      Module['HEAPU8'].set(byteArray, ptr);
+      DataRequest.prototype.byteArray = Module['HEAPU8'].subarray(ptr, ptr+byteArray.length);
+'''
   for file_ in data_files:
     if file_['mode'] == 'preload':
       use_data += '          DataRequest.prototype.requests["%s"].onload();\n' % (file_['dstpath'])