1 files changed, 194 insertions, 0 deletions
diff --git a/CordovaLib/Classes/Public/CDVCommandQueue.m b/CordovaLib/Classes/Public/CDVCommandQueue.m
new file mode 100644
index 0000000..b78ed83
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+++ b/CordovaLib/Classes/Public/CDVCommandQueue.m
@@ -0,0 +1,194 @@
+/*
+ Licensed to the Apache Software Foundation (ASF) under one
+ or more contributor license agreements.  See the NOTICE file
+ distributed with this work for additional information
+ regarding copyright ownership.  The ASF licenses this file
+ to you under the Apache License, Version 2.0 (the
+ "License"); you may not use this file except in compliance
+ with the License.  You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing,
+ software distributed under the License is distributed on an
+ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ KIND, either express or implied.  See the License for the
+ specific language governing permissions and limitations
+ under the License.
+ */
+
+#include <objc/message.h>
+#import "CDVCommandQueue.h"
+#import "CDVViewController.h"
+#import "CDVCommandDelegateImpl.h"
+#import "CDVJSON_private.h"
+#import "CDVDebug.h"
+
+// Parse JS on the main thread if it's shorter than this.
+static const NSInteger JSON_SIZE_FOR_MAIN_THREAD = 4 * 1024; // Chosen arbitrarily.
+// Execute multiple commands in one go until this many seconds have passed.
+static const double MAX_EXECUTION_TIME = .008; // Half of a 60fps frame.
+
+@interface CDVCommandQueue () {
+    NSInteger _lastCommandQueueFlushRequestId;
+    __weak CDVViewController* _viewController;
+    NSMutableArray* _queue;
+    NSTimeInterval _startExecutionTime;
+}
+@end
+
+@implementation CDVCommandQueue
+
+- (BOOL)currentlyExecuting
+{
+    return _startExecutionTime > 0;
+}
+
+- (id)initWithViewController:(CDVViewController*)viewController
+{
+    self = [super init];
+    if (self != nil) {
+        _viewController = viewController;
+        _queue = [[NSMutableArray alloc] init];
+    }
+    return self;
+}
+
+- (void)dispose
+{
+    // TODO(agrieve): Make this a zeroing weak ref once we drop support for 4.3.
+    _viewController = nil;
+}
+
+- (void)resetRequestId
+{
+    _lastCommandQueueFlushRequestId = 0;
+}
+
+- (void)enqueueCommandBatch:(NSString*)batchJSON
+{
+    if ([batchJSON length] > 0) {
+        NSMutableArray* commandBatchHolder = [[NSMutableArray alloc] init];
+        [_queue addObject:commandBatchHolder];
+        if ([batchJSON length] < JSON_SIZE_FOR_MAIN_THREAD) {
+            [commandBatchHolder addObject:[batchJSON cdv_JSONObject]];
+        } else {
+            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^() {
+                NSMutableArray* result = [batchJSON cdv_JSONObject];
+                @synchronized(commandBatchHolder) {
+                    [commandBatchHolder addObject:result];
+                }
+                [self performSelectorOnMainThread:@selector(executePending) withObject:nil waitUntilDone:NO];
+            });
+        }
+    }
+}
+
+- (void)fetchCommandsFromJs
+{
+    __weak CDVCommandQueue* weakSelf = self;
+    NSString* js = @"cordova.require('cordova/exec').nativeFetchMessages()";
+
+    [_viewController.webViewEngine evaluateJavaScript:js
+                                    completionHandler:^(id obj, NSError* error) {
+        if ((error == nil) && [obj isKindOfClass:[NSString class]]) {
+            NSString* queuedCommandsJSON = (NSString*)obj;
+            CDV_EXEC_LOG(@"Exec: Flushed JS->native queue (hadCommands=%d).", [queuedCommandsJSON length] > 0);
+            [weakSelf enqueueCommandBatch:queuedCommandsJSON];
+            // this has to be called here now, because fetchCommandsFromJs is now async (previously: synchronous)
+            [self executePending];
+        }
+    }];
+}
+
+- (void)executePending
+{
+    // Make us re-entrant-safe.
+    if (_startExecutionTime > 0) {
+        return;
+    }
+    @try {
+        _startExecutionTime = [NSDate timeIntervalSinceReferenceDate];
+
+        while ([_queue count] > 0) {
+            NSMutableArray* commandBatchHolder = _queue[0];
+            NSMutableArray* commandBatch = nil;
+            @synchronized(commandBatchHolder) {
+                // If the next-up command is still being decoded, wait for it.
+                if ([commandBatchHolder count] == 0) {
+                    break;
+                }
+                commandBatch = commandBatchHolder[0];
+            }
+
+            while ([commandBatch count] > 0) {
+                @autoreleasepool {
+                    // Execute the commands one-at-a-time.
+                    NSArray* jsonEntry = [commandBatch cdv_dequeue];
+                    if ([commandBatch count] == 0) {
+                        [_queue removeObjectAtIndex:0];
+                    }
+                    CDVInvokedUrlCommand* command = [CDVInvokedUrlCommand commandFromJson:jsonEntry];
+                    CDV_EXEC_LOG(@"Exec(%@): Calling %@.%@", command.callbackId, command.className, command.methodName);
+
+                    if (![self execute:command]) {
+#ifdef DEBUG
+                            NSString* commandJson = [jsonEntry cdv_JSONString];
+                            static NSUInteger maxLogLength = 1024;
+                            NSString* commandString = ([commandJson length] > maxLogLength) ?
+                                [NSString stringWithFormat : @"%@[...]", [commandJson substringToIndex:maxLogLength]] :
+                                commandJson;
+
+                            DLog(@"FAILED pluginJSON = %@", commandString);
+#endif
+                    }
+                }
+
+                // Yield if we're taking too long.
+                if (([_queue count] > 0) && ([NSDate timeIntervalSinceReferenceDate] - _startExecutionTime > MAX_EXECUTION_TIME)) {
+                    [self performSelector:@selector(executePending) withObject:nil afterDelay:0];
+                    return;
+                }
+            }
+        }
+    } @finally
+    {
+        _startExecutionTime = 0;
+    }
+}
+
+- (BOOL)execute:(CDVInvokedUrlCommand*)command
+{
+    if ((command.className == nil) || (command.methodName == nil)) {
+        NSLog(@"ERROR: Classname and/or methodName not found for command.");
+        return NO;
+    }
+
+    // Fetch an instance of this class
+    CDVPlugin* obj = [_viewController.commandDelegate getCommandInstance:command.className];
+
+    if (!([obj isKindOfClass:[CDVPlugin class]])) {
+        NSLog(@"ERROR: Plugin '%@' not found, or is not a CDVPlugin. Check your plugin mapping in config.xml.", command.className);
+        return NO;
+    }
+    BOOL retVal = YES;
+    double started = [[NSDate date] timeIntervalSince1970] * 1000.0;
+    // Find the proper selector to call.
+    NSString* methodName = [NSString stringWithFormat:@"%@:", command.methodName];
+    SEL normalSelector = NSSelectorFromString(methodName);
+    if ([obj respondsToSelector:normalSelector]) {
+        // [obj performSelector:normalSelector withObject:command];
+        ((void (*)(id, SEL, id))objc_msgSend)(obj, normalSelector, command);
+    } else {
+        // There's no method to call, so throw an error.
+        NSLog(@"ERROR: Method '%@' not defined in Plugin '%@'", methodName, command.className);
+        retVal = NO;
+    }
+    double elapsed = [[NSDate date] timeIntervalSince1970] * 1000.0 - started;
+    if (elapsed > 10) {
+        NSLog(@"THREAD WARNING: ['%@'] took '%f' ms. Plugin should use a background thread.", command.className, elapsed);
+    }
+    return retVal;
+}
+
+@end