jpg.decodedBlock should it release memory after usage?

[mhamri]

Prerequisites

• I have written a descriptive issue title
• I have verified that I am running the latest version of ImageSharp
• I have verified if the problem exist in both DEBUG and RELEASE mode
• I have searched open and closed issues to ensure it has not already been reported

Description

I was using imagesharp 1 alpha 4 48 previousely and my app for a normal task took up to 4gb, today I updated to latest version and saw it decreased to 3gb. thanks for the improvement.

I just ran a profiler and saw that the type of decoded block and color block from static type changed to normal property so I got some concern if i'm doing something wrong. I assume that it should release the resources when I call the dispose method or it reach end of the using statement.

I checked almost all of my code, i have using and dispose for every usage. also the class that wrapp the imagesharp is implementing IDisposable.

Steps to Reproduce

i'm using imagesharp with DI in startup.cs, configServices method:

services.AddTransient<ImageSharpHelper>();

and the imageSharpHelper is like bellow:

using ImageSharp;
using ImageSharp.Formats;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.IO;

namespace namespace1.namespace2.Image
{
    public class ImageSharpHelper : IDisposable
    {
        private readonly ILogger<ImageSharpHelper> _logger;

        public ImageSharpHelper(ILogger<ImageSharpHelper> logger)
        {
            _logger = logger;
        }

        public Image<Rgba32> Client { get; set; }
        public int? CompressRate { get; set; }
        public string Mime { get; set; }
        public ImageOutPutTypes OutPutTypes { get; set; }
        public int? QualityRate { get; set; }

        private Dictionary<ImageOutPutTypes, Func<MemoryStream, string>> SaveImageMapper => new Dictionary<ImageOutPutTypes, Func<MemoryStream, string>>()
        {
            [ImageOutPutTypes.Bmp] = SaveAsBmp,
            [ImageOutPutTypes.Jpg] = SaveAsJpg,
            [ImageOutPutTypes.Png] = SaveAsPng,
            [ImageOutPutTypes.None] = SaveImage
        };

        public void Compress(int compress, int quality)
        {
            CompressRate = compress;
            QualityRate = quality;
        }

        public void Crop(int? x, int? y, int? width, int? height)
        {
            if (x == null || y == null || width == null || height == null)
            {
                throw new NullReferenceException("Crop- Neither Width or height or X or Y can be null");
            }
            _logger.LogDebug($"croping with x:{x} y:{y} width:{width} height:{height}");

            var rectangle = new Rectangle((int)x, (int)y, (int)width, (int)height);
            Client.Crop(rectangle);
        }

        public void Resize(int? width, int? height)
        {
            if (width == null || height == null)
            {
                throw new NullReferenceException("Resize- Neither Width or height can be null");
            }

            _logger.LogDebug($"croping width:{width} - height:{height}");

            Client.Resize((int)width, (int)height);
        }

        public Stream SaveAs()
        {
            var fileStream = new MemoryStream();
            Func<MemoryStream, string> saveOutputMethod;

            if (SaveImageMapper.TryGetValue(OutPutTypes, out saveOutputMethod))
            {
                Mime = saveOutputMethod(fileStream);
            }
            else
            {
                Mime = SaveImage(fileStream);
            }
            return fileStream;
        }

        public void SetImage(Stream file)
        {
            Client?.Dispose();
            Client = ImageSharp.Image.Load<Rgba32>(file);
            Mime = Client.CurrentImageFormat.MimeType;
            OutPutTypes = ImageOutPutTypes.None;
        }
        private string SaveAsBmp(MemoryStream fileStream)
        {
            Client.SaveAsBmp(fileStream);
            return "image/bmp";
        }

        private string SaveAsJpg(MemoryStream fileStream)
        {
            var jpegEncoderOptions = new JpegEncoderOptions()
            {
                IgnoreMetadata = true,
            };

            if (QualityRate != null)
            {
                jpegEncoderOptions.Quality = (int)QualityRate;
            }
            Client.SaveAsJpeg(fileStream, jpegEncoderOptions);
            return "image/jpg";
        }

        private string SaveAsPng(MemoryStream fileStream)
        {
            var pngEncoderOptions = new PngEncoderOptions()
            {
                //Quantizer = new OctreeQuantizer<Color>() {/*Dither = false*/},
                IgnoreMetadata = true
            };

            if (QualityRate != null)
            {
                pngEncoderOptions.Quality = (int)QualityRate;
            }
            if (CompressRate != null)
            {
                pngEncoderOptions.CompressionLevel = (int)CompressRate;
            }
            Client.SaveAsPng(fileStream, pngEncoderOptions);
            return "image/png";
        }

        private string SaveImage(MemoryStream fileStream)
        {
            Client.Save(fileStream);
            return Client.CurrentImageFormat.MimeType;
        }

        public void Dispose()
        {
            Client?.Dispose();
        }
    }
}

and i'm calling the class like bellow:

using (var imageSharpHelper = _serviceProvider.GetService<ImageSharpHelper>())
            {
                imageSharpHelper.SetImage(latestAvailableVersion.Image);
                imageSharpHelper.Resize(x, y);
                return imageSharpHelper.SaveAs();
            }

System Configuration

• ImageSharp version: 1.0.0-alpha9-00058
• Other ImageSharp packages and versions:
• Environment (Operating system, version and so on): windows 10
• .NET Framework version: asp.net core 1.1.1
• Additional information:

[antonfirsov]

@mhamri it looks like duplicate of #151, but thanks for the detailed description of your use-case!

The memory usage drop from 4GB to 3GB is random, we haven't done actual improvements on this. I think it depends on the input images your service is processing. Do your inputs have a common characteristic? (eg: large photos). If yes, it might be helpful to post a few of them.

Implementing #225 and certain points of #192 should help on this. Unfortunately both are big tasks, so we need your patience here.

[mhamri]

well, about the 3gb to 4gb, i'm sure there was some changes, i have a batch of 40 images in one xml file that generates 4gb memory usage. i ran this test file almost 50 times, even before i do update to latest package. after update to the latest package, the usage decreased to 3gb.

i'm not sure it's same with #151, because my question is why the referenced object is not releasing memory if i'm disposing the object correctly? what is keeping a reference to those color and decoder array? I understand the previous memory usage when the decoder and color array was static. but now that is not static why still a reference is kept somewhere to those arrays? you got what do I mean?

[antonfirsov]

It is ArrayPool. Pools large arrays in a shared (static) pool to reduce gc pressure and prevent LOH issues. We understand this is not the best behavior for many users though, so we want to make this configurable.

[mhamri]

I am aware of that, but in memory dump, against previous version the pool didn't mark as static, that's why i thought in new version the behavior of pool has changed. Btw is the pool getting reuse again? I observed in linux debian 0.8 that if i run the same test file multiple times the memory pool grow up to 8gb , look like the pool is keep getting added instead of reusing.

…

On May 25, 2017 8:42 PM, "Anton Firsov" ***@***.***> wrote: It is ArrayPool. Pools large arrays in a shared (static) pool to reduce gc pressure and prevent LOH issues. We understand this is not the best behavior for many users though, so we want to make this configurable. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#224 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AIk0J-Xp6p6U0zVjLmAhDYQ8RDJTcs8Sks5r9XdAgaJpZM4Nl6sw> .

[antonfirsov]

There might be an unexpected behavior (missing dispose calls?) that came with #210. Looks like we need to do a deeper investigation here. @JimBobSquarePants I think we really need to find a way to stress test the library with a larger test image pack.

[JimBobSquarePants]

Agreed, we do.

[mhamri]

I hope this help, it's my set of test images, all are stock photos, good quality, and high dpi and pixel

url

[JimBobSquarePants]

Thanks! Really appreciate it.

[antonfirsov]

@mhamri If you are still using ImageSharp, check out the beta, the Jpeg decoder uses much less memory now! Let me know if the situation is still critical for you!