iOS 错误处理

错误码处理

1. 检查 API 返回值

所有 API 调用都应该检查返回值：

// 检查引擎创建
FBEngineConfig *config = [[FBEngineConfig alloc] init];
config.appId = @"your_app_id";
config.appKey = @"your_app_key";
self.engine = [FBBeautyEffectEngine createEngineWithConfig:config];

if (self.engine == nil) {
    NSLog(@"Failed to create beauty engine");
    return;
}

// 检查美颜类型启用
int ret = [self.engine setBeautyTypeEnabled:FBBeautyType_Basic enabled:YES];
if (ret == 0) {
    NSLog(@"Successfully enabled basic beauty");
} else {
    NSLog(@"Failed to enable basic beauty, error code: %d", ret);
}

// 检查参数设置
int ret = [self.engine setBasicParam:FBBeautyParam_Smoothing floatValue:0.5f];
if (ret != 0) {
    NSLog(@"Failed to set smoothing param, error code: %d", ret);
}

2. 常见错误码

根据 API 文档，主要错误码：

• 0: 成功
• -1: 引擎未初始化

@interface BeautyErrorHandler : NSObject
@end

@implementation BeautyErrorHandler

+ (void)handleError:(int)errorCode operation:(NSString *)operation {
    switch (errorCode) {
        case 0:
            NSLog(@"%@ succeeded", operation);
            break;
        case -1:
            NSLog(@"%@ failed: Engine not initialized", operation);
            break;
        default:
            NSLog(@"%@ failed: Unknown error code %d", operation, errorCode);
            break;
    }
}

@end

处理图像数据

1. 输入图像验证

@interface ImageValidator : NSObject
+ (BOOL)validateImageFrame:(FBImageFrame *)imageFrame;
@end

@implementation ImageValidator

+ (BOOL)validateImageFrame:(FBImageFrame *)imageFrame {
    if (imageFrame == nil) {
        NSLog(@"ImageFrame is nil");
        return NO;
    }
    
    // 检查图像尺寸
    int width = imageFrame.width;
    int height = imageFrame.height;
    if (width <= 0 || height <= 0) {
        NSLog(@"Invalid image dimensions: %dx%d", width, height);
        return NO;
    }
    
    return YES;
}

@end

2. 图像处理错误处理

@interface ImageProcessor : NSObject
@property (nonatomic, strong) FBBeautyEffectEngine *engine;
@end

@implementation ImageProcessor

- (FBImageFrame *)processImageSafely:(FBImageFrame *)input {
    // 验证输入
    if (![ImageValidator validateImageFrame:input]) {
        return nil;
    }
    
    @try {
        // 处理图像
        FBImageFrame *output = [self.engine processImage:input processMode:FBProcessModeVideo];
        
        if (output == nil) {
            NSLog(@"Failed to process image: output is nil");
            return nil;
        }
        
        return output;
    } @catch (NSException *exception) {
        NSLog(@"Exception during image processing: %@", exception.reason);
        return nil;
    }
}

@end

3. 内存管理

@interface SafeImageProcessor : NSObject
@property (nonatomic, strong) FBBeautyEffectEngine *engine;
@end

@implementation SafeImageProcessor

- (BOOL)processImageSafe:(FBImageFrame *)input output:(FBImageFrame *)output {
    FBImageFrame *result = nil;
    
    @try {
        // 处理图像
        result = [self.engine processImage:input processMode:FBProcessModeVideo];
        
        if (result == nil) {
            NSLog(@"Processing returned nil");
            return NO;
        }
        
        // 复制结果到输出
        [self copyImageFrame:result to:output];
        
        return YES;
    } @catch (NSException *exception) {
        NSLog(@"Exception during processing: %@", exception.reason);
        return NO;
    }
}

- (void)copyImageFrame:(FBImageFrame *)src to:(FBImageFrame *)dst {
    // 实现图像复制逻辑
    FBImageBuffer *srcBuffer = [src toRGBA];
    FBImageBuffer *dstBuffer = [dst toRGBA];
    
    if (srcBuffer != nil && dstBuffer != nil) {
        const uint8_t *srcData = [srcBuffer data];
        uint8_t *dstData = (uint8_t *)[dstBuffer data];
        
        if (srcData != nil && dstData != nil) {
            memcpy(dstData, srcData, MIN(srcBuffer.size, dstBuffer.size));
        }
    }
}

@end

日志和文件操作

1. 日志配置错误处理

@interface LogConfigHandler : NSObject
+ (BOOL)configureLogging:(BOOL)enableConsole 
              enableFile:(BOOL)enableFile 
             logFilePath:(NSString *)logFilePath;
@end

@implementation LogConfigHandler

+ (BOOL)configureLogging:(BOOL)enableConsole 
              enableFile:(BOOL)enableFile 
             logFilePath:(NSString *)logFilePath {
    @try {
        FBLogConfig *logConfig = [[FBLogConfig alloc] init];
        logConfig.consoleEnabled = enableConsole;
        logConfig.fileEnabled = enableFile;
        logConfig.level = FBLogLevel_Info;
        
        if (enableFile && logFilePath != nil && logFilePath.length > 0) {
            // 检查目录是否存在
            NSString *logDir = [logFilePath stringByDeletingLastPathComponent];
            NSFileManager *fileManager = [NSFileManager defaultManager];
            
            if (![fileManager fileExistsAtPath:logDir]) {
                NSError *error = nil;
                if (![fileManager createDirectoryAtPath:logDir 
                             withIntermediateDirectories:YES 
                                              attributes:nil 
                                                   error:&error]) {
                    NSLog(@"Failed to create log directory: %@", error.localizedDescription);
                    return NO;
                }
            }
            
            logConfig.fileName = logFilePath;
        }
        
        int ret = [FBBeautyEffectEngine setLogConfig:logConfig];
        return ret == 0;
    } @catch (NSException *exception) {
        NSLog(@"Failed to configure logging: %@", exception.reason);
        return NO;
    }
}

@end

2. 文件写入错误处理

@interface FileWriteHandler : NSObject
+ (BOOL)saveImageBuffer:(FBImageBuffer *)buffer toPath:(NSString *)filePath;
@end

@implementation FileWriteHandler

+ (BOOL)saveImageBuffer:(FBImageBuffer *)buffer toPath:(NSString *)filePath {
    if (buffer == nil) {
        NSLog(@"ImageBuffer is nil");
        return NO;
    }
    
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSString *dir = [filePath stringByDeletingLastPathComponent];
    
    // 创建目录
    if (![fileManager fileExistsAtPath:dir]) {
        NSError *error = nil;
        if (![fileManager createDirectoryAtPath:dir 
                     withIntermediateDirectories:YES 
                                      attributes:nil 
                                           error:&error]) {
            NSLog(@"Failed to create directory: %@", error.localizedDescription);
            return NO;
        }
    }
    
    // 写入文件
    const uint8_t *data = [buffer data];
    NSData *nsData = [NSData dataWithBytes:data length:buffer.size];
    
    NSError *error = nil;
    BOOL success = [nsData writeToFile:filePath options:NSDataWritingAtomic error:&error];
    
    if (!success) {
        NSLog(@"Failed to write file: %@", error.localizedDescription);
        return NO;
    }
    
    NSLog(@"Image saved successfully: %@", filePath);
    return YES;
}

@end

异常处理

1. 捕获和处理异常

@interface ExceptionHandler : NSObject
+ (void)safeExecute:(void(^)(void))block operation:(NSString *)operation;
@end

@implementation ExceptionHandler

+ (void)safeExecute:(void(^)(void))block operation:(NSString *)operation {
    @try {
        if (block != nil) {
            block();
        }
    } @catch (NSInvalidArgumentException *exception) {
        NSLog(@"%@ failed: Invalid argument - %@", operation, exception.reason);
    } @catch (NSException *exception) {
        NSLog(@"%@ failed: Unexpected exception - %@", operation, exception.reason);
    }
}

@end

2. 重试机制

@interface RetryHandler : NSObject
@property (nonatomic, strong) FBBeautyEffectEngine *engine;
@end

@implementation RetryHandler

static const int MAX_RETRY = 3;
static const NSTimeInterval RETRY_DELAY = 0.1;

- (FBImageFrame *)processImageWithRetry:(FBImageFrame *)input {
    for (int i = 0; i < MAX_RETRY; i++) {
        @try {
            FBImageFrame *result = [self.engine processImage:input processMode:FBProcessModeVideo];
            if (result != nil) {
                return result;
            }
        } @catch (NSException *exception) {
            NSLog(@"Attempt %d failed: %@", i + 1, exception.reason);
        }
        
        if (i < MAX_RETRY - 1) {
            [NSThread sleepForTimeInterval:RETRY_DELAY];
        }
    }
    
    NSLog(@"All retry attempts failed");
    return nil;
}

@end

调试技巧

1. 错误信息收集

@interface DebugInfoCollector : NSObject
+ (NSString *)collectErrorInfo:(int)errorCode operation:(NSString *)operation exception:(NSException *)exception;
@end

@implementation DebugInfoCollector

+ (NSString *)collectErrorInfo:(int)errorCode operation:(NSString *)operation exception:(NSException *)exception {
    NSMutableString *info = [NSMutableString string];
    [info appendFormat:@"Operation: %@\n", operation];
    [info appendFormat:@"Error Code: %d\n", errorCode];
    [info appendFormat:@"Timestamp: %lld\n", (long long)([[NSDate date] timeIntervalSince1970] * 1000)];
    
    if (exception != nil) {
        [info appendFormat:@"Exception: %@\n", exception.name];
        [info appendFormat:@"Reason: %@\n", exception.reason];
    }
    
    // 添加内存信息
    struct mach_task_basic_info taskInfo;
    mach_msg_type_number_t size = MACH_TASK_BASIC_INFO_COUNT;
    kern_return_t kerr = task_info(mach_task_self(), MACH_TASK_BASIC_INFO, (task_info_t)&taskInfo, &size);
    if (kerr == KERN_SUCCESS) {
        [info appendFormat:@"Memory - Resident: %llu MB\n", taskInfo.resident_size / 1024 / 1024];
        [info appendFormat:@"Memory - Virtual: %llu MB\n", taskInfo.virtual_size / 1024 / 1024];
    }
    
    return [info copy];
}

@end

2. 性能监控

@interface PerformanceMonitor : NSObject
@property (nonatomic, assign) NSTimeInterval startTime;
@property (nonatomic, assign) NSInteger errorCount;
@end

@implementation PerformanceMonitor

- (void)startOperation {
    self.startTime = [[NSDate date] timeIntervalSince1970];
}

- (void)endOperation:(NSString *)operation success:(BOOL)success {
    NSTimeInterval duration = [[NSDate date] timeIntervalSince1970] - self.startTime;
    
    if (!success) {
        self.errorCount++;
        NSLog(@"%@ failed after %.2fms (Error count: %ld)", 
              operation, duration * 1000, (long)self.errorCount);
    } else if (duration > 0.1) {
        NSLog(@"%@ took %.2fms (slow operation)", operation, duration * 1000);
    }
}

@end

总结

遵循这些错误处理最佳实践可以帮助你：

1. 提高应用稳定性: 通过检查 API 返回值和异常处理
2. 改善用户体验: 通过友好的错误提示和恢复机制
3. 便于问题排查: 通过详细的日志记录和错误信息收集
4. 优化性能: 通过合理的错误恢复策略和资源管理

记住要根据实际 SDK 的错误码定义调整错误处理逻辑，并持续监控和改进错误处理机制。iOS 平台使用 ARC 自动管理内存，但仍需要注意避免循环引用和及时释放不需要的资源。