From df6d26a066936cdcc9987feecd051541522d459a Mon Sep 17 00:00:00 2001
From: Jaifroid <egk10@cam.ac.uk>
Date: Sat, 15 Feb 2020 12:34:28 +0000
Subject: [PATCH] Make fs.read compatible with filecache

Former-commit-id: 38f9dc7c7f825a77969ad55d7c4d25e4dc1aef22 [formerly a2c490caa3e19bab560b1f231b9985a881f170e9]
Former-commit-id: dd3ec30dc2ed7ce373eb2c2dcb3bb7f0629de83e
---
 www/index.html          |  7 +++----
 www/js/lib/filecache.js | 35 +++++++++++++++++++++++++++--------
 www/js/lib/util.js      | 34 +++++++++++++++++-----------------
 3 files changed, 47 insertions(+), 29 deletions(-)

diff --git a/www/index.html b/www/index.html
index cae01e34..87656f30 100644
--- a/www/index.html
+++ b/www/index.html
@@ -55,10 +55,9 @@
             window.requireNode = window.require;
             window.require = undefined;
             window.fs = requireNode('fs');
-        }
-        // Try to activate Service Worker
-        console.log('Trying to activate Service Worker...');
-        if ("serviceWorker" in navigator) {
+        } else if ("serviceWorker" in navigator) {
+            // Try to activate Service Worker
+            console.log('Trying to activate Service Worker...');
             // Register the service worker
             navigator.serviceWorker.register("../pwabuilder-sw.js", {
                 scope: "../"
diff --git a/www/js/lib/filecache.js b/www/js/lib/filecache.js
index d701ce2f..9c310efa 100644
--- a/www/js/lib/filecache.js
+++ b/www/js/lib/filecache.js
@@ -156,14 +156,33 @@ define(['q'], function(Q) {
     };
     var readInternal = function(file, begin, end) {
         return Q.Promise(function(resolve, reject) {
-            var reader = new FileReader();
-            reader.readAsArrayBuffer(file.slice(begin, end));
-            reader.onload = function(e) {
-                resolve(new Uint8Array(e.target.result));
-            };
-            reader.onerror = reader.onabort = function(e) {
-                reject(e);
-            };
+            if (file.readMode === 'electron') {
+                // We are reading a packaged file and have to use Electron fs.read (so we don't have to pick the file)
+                fs.open(file.path, 'r', function (err, fd) {
+                    if (err) { 
+                        console.error('Could not find file!', err);
+                        reject(err);
+                    } else {
+                        var size = end - begin;
+                        fs.read(fd, Buffer.alloc(size), 0, size, begin, function (err, bytesRead, data) {
+                            if (err) reject(err);
+                            else resolve(data);
+                            fs.close(fd, function (err) {
+                                if (err) console.log('Could not close file...', err);
+                            });
+                        });
+                    }
+                });
+            } else {
+                var reader = new FileReader();
+                reader.readAsArrayBuffer(file.slice(begin, end));
+                reader.onload = function(e) {
+                    resolve(new Uint8Array(e.target.result));
+                };
+                reader.onerror = reader.onabort = function(e) {
+                    reject(e);
+                };
+            }
         });
     };
 
diff --git a/www/js/lib/util.js b/www/js/lib/util.js
index 5e3a1666..2709c6f3 100644
--- a/www/js/lib/util.js
+++ b/www/js/lib/util.js
@@ -212,22 +212,22 @@ define(['q', 'filecache'], function(q, FileCache) {
      */
     function readFileSlice(file, begin, size) {
         // var deferred = q.defer();
-        if (file.readMode === 'electron') {
-            // We are reading a packaged file and have to use Electron fs.read (so we don't have to pick the file)
-            fs.open(file.path, 'r', function (err, fd) {
-                if (err) { 
-                    console.error('Could not find file!', err);
-                } else {
-                    fs.read(fd, new Uint8Array(size), 0, size, begin, function (err, bytesRead, data) {
-                        if (err) deferred.reject(err);
-                        else deferred.resolve(data);
-                        fs.close(fd, function (err) {
-                            if (err) console.log('Could not close file...', err);
-                        });
-                    });
-                }
-            });
-        } else {
+        // if (file.readMode === 'electron') {
+        //     // We are reading a packaged file and have to use Electron fs.read (so we don't have to pick the file)
+        //     fs.open(file.path, 'r', function (err, fd) {
+        //         if (err) { 
+        //             console.error('Could not find file!', err);
+        //         } else {
+        //             fs.read(fd, Buffer.alloc(size), 0, size, begin, function (err, bytesRead, data) {
+        //                 if (err) deferred.reject(err);
+        //                 else deferred.resolve(data);
+        //                 fs.close(fd, function (err) {
+        //                     if (err) console.log('Could not close file...', err);
+        //                 });
+        //             });
+        //         }
+        //     });
+        // } else {
             // We are reading a picked file, so use vanilla JS methods
         //     var reader = new FileReader();
         //     reader.onload = function (e) {
@@ -240,7 +240,7 @@ define(['q', 'filecache'], function(q, FileCache) {
         // }
         // return deferred.promise;
             return FileCache.read(file, begin, begin + size);
-        }
+        // }
     }
 
     /**