add comments and remove native in-mem caching

Author: geof90

CodePush.js

@@ -70,7 +70,7 @@ async function checkForUpdate(deploymentKey = null) {
    *    because we want to avoid having to install diff updates against the binary's
    *    version, which we can't do yet on Android.
    */
-  if (!update || update.updateAppVersion || localPackage && (update.packageHash === localPackage.packageHash) || localPackage && config.packageHash === localPackage.packageHash) {
+  if (!update || update.updateAppVersion || localPackage && (update.packageHash === localPackage.packageHash) || config.packageHash === update.packageHash) {
     if (update && update.updateAppVersion) {
       log("An update is available but it is targeting a newer binary version than you are currently running.");
     }

android/app/src/main/java/com/microsoft/codepush/react/CodePush.java

@@ -404,6 +404,8 @@ public void getConfiguration(Promise promise) {
                             android.provider.Settings.Secure.ANDROID_ID));
             String binaryHash = CodePushUpdateUtils.getHashForBinaryContents(mainActivity, isDebugMode);
             if (binaryHash != null) {
+                // binaryHash will be null if the React Native assets were not bundled into the APK
+                // (e.g. in Debug builds)
                 configMap.putString(PACKAGE_HASH_KEY, binaryHash);
             }
 

android/app/src/main/java/com/microsoft/codepush/react/CodePushUpdateUtils.java

@@ -24,10 +24,6 @@ public class CodePushUpdateUtils {
 
     private static final String CODE_PUSH_HASH_FILE_NAME = "CodePushHash.json";
 
-    // These variables are used to cache the hash of the binary contents in memory.
-    private static String binaryHash = null;
-    private static boolean didLoadBinaryHash = false;
-
     private static void addContentsOfFolderToManifest(String folderPath, String pathPrefix, ArrayList<String> manifest) {
         File folder = new File(folderPath);
         File[] folderFiles = folder.listFiles();
@@ -110,22 +106,17 @@ public static String findJSBundleInUpdateContents(String folderPath) {
     }
 
     public static String getHashForBinaryContents(Activity mainActivity, boolean isDebugMode) {
-        if (!didLoadBinaryHash) {
-            didLoadBinaryHash = true;
-            try {
-                binaryHash = CodePushUtils.getStringFromInputStream(mainActivity.getAssets().open(CODE_PUSH_HASH_FILE_NAME));
-            } catch (IOException e) {
-                if (!isDebugMode) {
-                    // Only print this message in "Release" mode. In "Debug", we may not have the
-                    // hash if the build skips bundling the files.
-                    CodePushUtils.log("Unable to get the hash of the binary's bundled resources - \"codepush.gradle\" may have not been added to the build definition.");
-                }
-
-                return null;
+        try {
+            return CodePushUtils.getStringFromInputStream(mainActivity.getAssets().open(CODE_PUSH_HASH_FILE_NAME));
+        } catch (IOException e) {
+            if (!isDebugMode) {
+                // Only print this message in "Release" mode. In "Debug", we may not have the
+                // hash if the build skips bundling the files.
+                CodePushUtils.log("Unable to get the hash of the binary's bundled resources - \"codepush.gradle\" may have not been added to the build definition.");
             }
-        }
 
-        return binaryHash;
+            return null;
+        }
     }
 
     public static void verifyHashForDiffUpdate(String folderPath, String expectedHash) {

ios/CodePush/CodePush.m

@@ -447,6 +447,9 @@ - (void)savePendingUpdate:(NSString *)packageHash
         }
 
         if (binaryHash == nil) {
+            // The hash was not generated either due to a previous unknown error or the fact that
+            // the React Native assets were not bundled in the binary (e.g. during dev/simulator)
+            // builds.
             resolve(configuration);
             return;
         }

ios/CodePush/CodePushUpdateUtils.m

@@ -7,10 +7,6 @@ @implementation CodePushUpdateUtils
 NSString * const BinaryHashKey = @"CodePushBinaryHash";
 NSString * const ManifestFolderPrefix = @"CodePush";
 
-// These variables are used to cache the hash of the binary contents in memory.
-static NSString *binaryHash = nil;
-static BOOL didLoadBinaryHash = NO;
-
 + (void)addContentsOfFolderToManifest:(NSString *)folderPath
                            pathPrefix:(NSString *)pathPrefix
                              manifest:(NSMutableArray *)manifest
@@ -162,49 +158,43 @@ + (NSString *)getAssetsFolderName
 + (NSString *)getHashForBinaryContents:(NSURL *)binaryBundleUrl
                                  error:(NSError **)error
 {
-    if (!didLoadBinaryHash) {
-        didLoadBinaryHash = YES;
-        
-        // Get the cached hash from user preferences if it exists.
-        NSString *binaryModifiedDate = [self modifiedDateStringOfFileAtURL:binaryBundleUrl];
-        NSUserDefaults *preferences = [NSUserDefaults standardUserDefaults];
-        NSMutableDictionary *binaryHashDictionary = [preferences objectForKey:BinaryHashKey];
-        if (binaryHashDictionary != nil) {
-            binaryHash = [binaryHashDictionary objectForKey:binaryModifiedDate];
-            if (binaryHash == nil) {
-                [preferences removeObjectForKey:BinaryHashKey];
-                [preferences synchronize];
-            } else {
-                return binaryHash;
-            }
-        }
-        
-        binaryHashDictionary = [NSMutableDictionary dictionary];
-        
-        NSString *assetsPath = [CodePushPackage getBinaryAssetsPath];
-        NSMutableArray *manifest = [NSMutableArray array];
-        [self addContentsOfFolderToManifest:assetsPath
-                                 pathPrefix:[NSString stringWithFormat:@"%@/%@", [self getManifestFolderPrefix], @"assets"]
-                                   manifest:manifest
-                                      error:error];
-        if (*error) {
-            return nil;
+    // Get the cached hash from user preferences if it exists.
+    NSString *binaryModifiedDate = [self modifiedDateStringOfFileAtURL:binaryBundleUrl];
+    NSUserDefaults *preferences = [NSUserDefaults standardUserDefaults];
+    NSMutableDictionary *binaryHashDictionary = [preferences objectForKey:BinaryHashKey];
+    NSString *binaryHash = nil;
+    if (binaryHashDictionary != nil) {
+        binaryHash = [binaryHashDictionary objectForKey:binaryModifiedDate];
+        if (binaryHash == nil) {
+            [preferences removeObjectForKey:BinaryHashKey];
+            [preferences synchronize];
+        } else {
+            return binaryHash;
         }
-        
-        NSData *jsBundleContents = [NSData dataWithContentsOfURL:binaryBundleUrl];
-        NSString *jsBundleContentsHash = [self computeHashForData:jsBundleContents];
-        [manifest addObject:[[NSString stringWithFormat:@"%@/%@:", [self getManifestFolderPrefix], [binaryBundleUrl lastPathComponent]] stringByAppendingString:jsBundleContentsHash]];
-        binaryHash = [self computeFinalHashFromManifest:manifest error:error];
-        
-        // Cache the hash in user preferences. This assumes that the modified date for the
-        // JS bundle changes every time a new bundle is generated by the packager.
-        [binaryHashDictionary setObject:binaryHash forKey:binaryModifiedDate];
-        [preferences setObject:binaryHashDictionary forKey:BinaryHashKey];
-        [preferences synchronize];
-        return binaryHash;
     }
 
-    // Use the cached hash in memory.
+    binaryHashDictionary = [NSMutableDictionary dictionary];
+    
+    NSString *assetsPath = [CodePushPackage getBinaryAssetsPath];
+    NSMutableArray *manifest = [NSMutableArray array];
+    [self addContentsOfFolderToManifest:assetsPath
+                             pathPrefix:[NSString stringWithFormat:@"%@/%@", [self getManifestFolderPrefix], @"assets"]
+                               manifest:manifest
+                                  error:error];
+    if (*error) {
+        return nil;
+    }
+    
+    NSData *jsBundleContents = [NSData dataWithContentsOfURL:binaryBundleUrl];
+    NSString *jsBundleContentsHash = [self computeHashForData:jsBundleContents];
+    [manifest addObject:[[NSString stringWithFormat:@"%@/%@:", [self getManifestFolderPrefix], [binaryBundleUrl lastPathComponent]] stringByAppendingString:jsBundleContentsHash]];
+    binaryHash = [self computeFinalHashFromManifest:manifest error:error];
+    
+    // Cache the hash in user preferences. This assumes that the modified date for the
+    // JS bundle changes every time a new bundle is generated by the packager.
+    [binaryHashDictionary setObject:binaryHash forKey:binaryModifiedDate];
+    [preferences setObject:binaryHashDictionary forKey:BinaryHashKey];
+    [preferences synchronize];
     return binaryHash;
 }