Memory issue when using POSAdjustedAssetReaderIOS7

[lxzhh]

Hi, Pavel Osipov, there is a huge memory problem when reader photo using POSAdjustedAssetReaderIOS7, my iPhone 4s run into memory warning and the app crashed when I choose some photos to upload. At first I find not all photos will lead to huge memory usage. I debug by using the instruments and find only the image with POSAdjustedAssetReaderIOS7 will cause this problem.

I did not dig into the code but it seems you will use POSAdjustedAssetReaderIOS7 only here

    if (representation.metadata[@"AdjustmentXMP"] != nil) {
        POSAdjustedAssetReaderIOS7 *assetReader = [POSAdjustedAssetReaderIOS7 new];
        assetReader.JPEGCompressionQuality = _adjustedJPEGCompressionQuality;
        return assetReader;
   }

Currently I comment this and use POSFastAssetReader instead, hope this can help you find the cause.

[pavelosipov]

Good day, @lxzhh
Can you post here some photos, which cause memory warning?

[lxzhh]

Hi, Pavel Osipov, you can reproduce it by edit some photo, and use them in iOS7.

[pavelosipov]

@lxzhh, it looks like I need to do some specific filsters. For example I didn't notice any memory warnings during processing cropped photo. What kind of filters did you use?

[lxzhh]

@pavelosipov yeah, you are right, the special photo is from one of my test device, and it was took by my colleague, so we don't remember what filter it use, I'm working on it. But there is another problem, I cannot read byte while using the iOS7Reader, I get the log here:

<POSBlobInputStream: 0x19529c90>: rejected attempt to read stream with status 1.

It seems that the image data takes times while the stream already read the data, so the status is NSStreamStatusOpening, I can't figure it out, and still dig the code. Hope this is useful information.

[pavelosipov]

@lxzhh, NSInputStream is async by default. If you want to open it synchronously you should use appropriate initor, but in worker thread only:

+ (NSInputStream *)pos_inputStreamWithAssetURL:(NSURL *)assetURL asynchronous:(BOOL)asynchronous;

Alternatively you can subscribe to stream events as NSStreamDelegate and read only on specific events. You can see example in documentation.

P. S. It will be great if you can find that ugly filter. Then it will be possible to exclude photos with it from adjusting.

[lxzhh]

@pavelosipov can you offer a sample code for using iOS7Reader, I made a lot effort but it still cannot work.

[pavelosipov]

Did you try sample from the project main page (asynchronous part)?

[lxzhh]

Hi @pavelosipov , I only find some unit test in the project, there is no executable demo. Can you offer one so that I can try with my device.

[pavelosipov]

Here is a complete example of NSInputStream checksum calculation using async reading method. I hope that example s enough to figure out how to work with a stream. Method processRun is a start point:

static const NSTimeInterval kRunLoopMaxCycleInterval = 1.0f;

@interface MRCCalculateStreamAttributesTask () <NSStreamDelegate>
@property (nonatomic, readwrite) NSData *streamDigest;
@end

@implementation MRCCalculateStreamAttributesTask {
    NSInputStream *_stream;
    uint64_t _streamSize;
    CC_SHA1_CTX _streamDigestContext;
}

- (id)init {
    MRCThrowDeadlySelectorInvokation(_cmd, @selector(initWithStreamable:));
}

- (id)initWithStream:(NSInputStream *)stream {
    NSParameterAssert(streamable);
    if (self = [super init]) {
        _stream = stream;
    }
    return self;
}

#pragma mark - MRCTask

- (MRCTaskState)processRun {
    [self setupStreamDigestContext];
    [self startStreamProcessing];
    return MRCTaskStateRunning;
}

- (BOOL)processCancel {
    if (_stream != nil && [_stream streamStatus] != NSStreamStatusNotOpen) {
        [_stream close];
        _streamDigest = nil;
        _streamSize = 0L;
    }
    return YES;
}

#pragma mark - Private Methods

- (void)startStreamProcessing {
    NSParameterAssert(_stream);
    _stream.delegate = self;
    [_stream open];
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
        [_stream scheduleInRunLoop:runLoop forMode:NSDefaultRunLoopMode];
        for (;;) {
            @autoreleasepool {
                if (![runLoop runMode:NSDefaultRunLoopMode
                           beforeDate:[NSDate dateWithTimeIntervalSinceNow:kRunLoopMaxCycleInterval]]) {
                    break;
                }
                const NSStreamStatus streamStatus = [_stream streamStatus];
                if (streamStatus == NSStreamStatusError || streamStatus == NSStreamStatusClosed) {
                    break;
                }
            }
        }
    });
}

- (void)setupStreamDigestContext {
    memset(&_streamDigestContext, 0, sizeof(_streamDigestContext));
    CC_SHA1_Init(&_streamDigestContext);
}

- (BOOL)updateStreamDigestContext {
    static NSUInteger const kBufferSize = 131072;
    uint8_t buffer[kBufferSize];
    NSInteger readCount = [_stream read:buffer maxLength:kBufferSize];
    if (readCount > 0) {
        CC_SHA1_Update(&_streamDigestContext, buffer, readCount);
        _streamSize += readCount;
        return YES;
    }
    return NO;
}

- (NSData *)finalizeStreamDigestContext {
    uint8_t streamDigest[CC_SHA1_DIGEST_LENGTH];
    CC_SHA1_Final(streamDigest, &_streamDigestContext);
    return [NSData dataWithBytes:streamDigest length:CC_SHA1_DIGEST_LENGTH];
}

#pragma mark - NSStreamDelegate

- (void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode {
    __weak typeof(self) this = self;
    switch (eventCode) {
        case NSStreamEventHasBytesAvailable: {
            [self updateStreamDigestContext];
            break;
        }
        case NSStreamEventEndEncountered: {
            NSData *streamDigest = [self finalizeStreamDigestContext];
            [_stream close];
            break;
        }
        case NSStreamEventErrorOccurred: {
            [_stream close];
            break;
        }
        default:
            break;
    }
}

@end

Alternatively it should be possible to read from the stream synchronously inside some background thread after the follwing initilialization:

NSInputStream *assetStream = [NSInputStream pos_inputStreamForCFNetworkWithAssetURL:assetURL];

I think you already doing that so your question is not 100% clear for me.

[pavelosipov]

@lxzhh, by the way, can you post here AdjustmentXML from the photo which is caused memory warning?

[lxzhh]

@pavelosipov yeah, here is the AdjustmentXML:
<x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="XMP Core 5.4.0">
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
<rdf:Description rdf:about=""
xmlns:aas="http://ns.apple.com/adjustment-settings/1.0/">
aas:Filters
rdf:Seq
rdf:liCIPhotoEffectTonal/rdf:li
/rdf:Seq
/aas:Filters
/rdf:Description
/rdf:RDF
/x:xmpmeta