A Simple String Compression Algorithm

5 stars based on 32 reviews

Performance is about tradeoffs. If you need to do something faster you can probably do it if you use more memory. If you need to reduce the space that your data is using you can use CPU to compress it. But you will be paying the CPU cost.

We found a few options that were specific to our product such as avoiding writing duplicate data in headers, etc but also explored using compression for each message. Here are some interesting things I found about compression using the built in. Out of the box you have two options: Both were introduced in 2.

You can see people in the web asking which one is better. GzipStream uses Deflate internally so other than adding some extra data header, footer it will be the same algorithm. Note that if your payloads are best binary compression algorithm in c# small you might be tempted to use Deflate.

Best binary compression algorithm in c# doing some bit manipulation you best binary compression algorithm in c# embed custom information in the Gzip Header. So I tried version 4. I was expecting high CPU but not a lot of allocation. Since Perfview allows you to take allocation profile as well here is the problem. If we look at the recently released. Net code for the Stream class we can see the implementation of this Stream. InternalCopy Which is called by Stream.

Read buffer, 0, buffer. As you can see we are allocating one buffer which is 80K so that it won't be allocated in the Large Object Heap for every stream we copy. This might be ok for a normal scenario but in our case there was no way we could do it for each message.

Allocating so much memory adds pressure to the GC that will need to collect much more frequently. Once we had identified this the solution was straightforward. Use our own custom method to copy the data from one stream to the other. Copy with a method that did buffer pooling and that dropped the GC load dramatically. So if you are using compression in a server where GC is something you need to take care of I recommend you use a method like this instead of using Stream.

Read streamCopyBuffer, 0, bufferSize! After doing this our allocation went back to normal. Note that there are many BufferPools implementations in the web in C. Compression algorithms available in. Net Out of the box you have two options: How well do they compress? To measure how good they compressed the data I tried a few different scenarios: Here is the data: GZip takes longer and compresses about the same that Deflate.

As mentioned before this is not a surprise since it uses the Deflate algorithm. Best binary compression algorithm in c# was about the same for all. For binary all of them are about the same. Implementation My first attempt for compressing and decompressing was something like this:

Trading tips reviews

  • Binary options momentum trading

    Digital option trading software indian

  • Orang kaya principal forex malaysia

    Best active trader online brokerages

To visit the broker click here binarycom

  • 1k daily profit 2017 binary option trading software b

    Operazioni binarie borsa truffe o realta

  • Compare binary option brokers 350z 5 minute strategies 1012

    How does binary option work trading robot

  • Binary option robot review option robot scam or

    Binary bank breaker results

Pilihan binari dalam nz

46 comments Introducing binary options brokers usa regulated

Day trading platform brokerage

Compressing data is a great way to reduce its size. This helps us reduce storage requirements as well as the bandwidth and latency of network transmissions. We will use the. Compression namespace , although it is also possible to use a third party library such as SharpZipLib. In its simplest form, GZipStream takes an underlying stream and a compression mode as parameters.

The compression mode determines whether you want to compress or decompress; the underlying stream is manipulated according to that compression mode. In the code above, we are using a memory stream as our underlying output stream. The GZipStream effectively wraps the output stream. When we write our input data into the GZipStream, it goes into the output stream as compressed data. By wrapping the write operation in a using block by itself, we ensure that the data is flushed. The bytes resulting from the GZip compression are actually binary data.

They are not intelligible when rendered , and may also cause problems when transmitted over a network due to byte ordering, for instance. One way to deal with this is to encode the compressed bytes in base Update 28th January As some people pointed out, it is not necessary to baseencode compressed data, and it will transmit fine over a network even without it.

However I do recall having issues transmitting binary compressed data via RabbitMQ, so you may want to apply base64 encoding as needed in order to render compressed data or work around issues. Base64, however, is far from a compact representation. In this specific example, the length of the output string goes from 32 bytes binary to 44 base64 , reducing the effectiveness of compression. However, for larger strings, this still represents significant savings over the plain, uncompressed string.

Which brings us to the next question: Thus, compression should typically be applied only to data whose length exceeds an arbitrary threshold.

When decompressing, the underlying stream is an input stream. The GZipStream still wraps it, but the flow is inverted so that when you read data from the GZipStream, it translates compressed data into uncompressed data.

There are different ways to implement this, even if we just focus on decompressing from a string to a string. However, a low-level buffer read such as the following will not work:. The Length property is not supported in a GZipStream, so the above code gives a runtime error. Rather than read the entire length of the buffer, you could read block by block until you reach the end of the stream. One way to get this working with very little effort is to introduce a third stream, and copy the GZipStream into it:.

Or you might want to work exclusively with bytes rather than converting back to a string. In any case, hopefully the code in this article will give you a head start when you need to compress and decompress some data. Your email address will not be published. Notify me of follow-up comments by email. Notify me of new posts by email. Write inputBytes, 0, inputBytes. GetString outputBytes ; Console. WriteLine outputStr ; Console. ToBase64String outputBytes ; Console. WriteLine outputbase64 ; Console.

The basic workflow looks something like this: However, a low-level buffer read such as the following will not work: One way to get this working with very little effort is to introduce a third stream, and copy the GZipStream into it: WriteLine decompressed ; Console. Leave a Reply Cancel reply Your email address will not be published. You learn by doing, and by falling over.