Outofmemory in exception memorystream

Question

0.00/5 (No votes)

See more:

Deal All

I got error OutOfMemory Exception when Write Byte Array data through MemoryStream.

My PC-64bit
RAM- 4GB
DataSize-750MB- 786432000

My Code :-

C#

using (MemoryStream MemStream = new MemoryStream())
                    {
                        using (CryptoStream CryptoStream = new CryptoStream(MemStream, Encryptor, CryptoStreamMode.Write))
                        {
                            CryptoStream.Write(PlainTextBytes, 0, PlainTextBytes.Length);

                            //System.Buffer.BlockCopy(PlainTextBytes, 0, MemStream.ToArray(), 0, PlainTextBytes.Length);

                            CryptoStream.FlushFinalBlock();
                            CipherTextBytes = MemStream.ToArray();
                            MemStream.Close();
                            CryptoStream.Close();
                        }
                    }

Error coming Near :-

C#

CryptoStream.Write(PlainTextBytes, 0, PlainTextBytes.Length);

OutOfMemoryException.

Any Solution please help.

Thanks.

What I have tried:

CryptoStream.Write(PlainTextBytes, 0, PlainTextBytes.Length);

Posted 6-Sep-16 0:04am

Member 12352638

Updated 6-Sep-16 1:14am

Add a Solution

Comments

InbarBarkai 6-Sep-16 6:21am

How long is your text?

Member 12352638 6-Sep-16 9:32am

750MB

Mehdi Gholam 6-Sep-16 6:32am

Make sure your process is 64bit not 32bit.

Member 12352638 6-Sep-16 9:32am

Process is 64bit

Philippe Mori 6-Sep-16 9:04am

If your data is large, then you should process it by blocks. You should avoid working with data that is larger than a few hundreds megabytes if alternative algorithms are possible.

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Jochen Arndt · Accepted Answer · 2016-09-06T01:14:00

There is an article here at CodeProject that explains what is happening and what can be done: A replacement for MemoryStream[^].

A short explanation with my own words:

Objects like MemoryStream initially don't know about the size of the required memory. So they will start with a rather small amount of allocated memory. When this memory is used up, they will allocate a new block of typically twice the size, copy the content of the previous block and free that. When needing large amounts of memory this may result in out memory exceptions for three reasons:

During re-allocation more memory is required (old size * 3)
The newly allocated block must be contiguous
With 32-bit applications the limit of 2 GB may be reached

To explain this with your example of 750 MB:
Assuming that the stream actually holds 700 MB, it will try to allocate 1400 MB. This will fail when there is no free contiguous block of this size. Having the existing 700 MB in mind, your stream would actually own more than the half of your installed memory at that time.

[EDIT]
If you know the required size in advance, you should use the constructor that accepts the capacity argument. This avoids multiple re-allocations and allocating unused memory, and you will get an immediate exception if allocation fails.
[/EDIT]