dedupfs | Python FUSE file system that features transparent | Compression library

by xolox Python Version: Current License: Non-SPDX

X-Ray Key Features Code Snippets Community Discussions(10)Vulnerabilities Install Support

kandi X-RAY | dedupfs Summary

dedupfs is a Python library typically used in Utilities, Compression applications. dedupfs has no bugs, it has no vulnerabilities and it has low support. However dedupfs build file is not available and it has a Non-SPDX License. You can download it from GitHub.

The Python program dedupfs.py implements a file system in user space using FUSE. It's called DedupFS because the file system's primary feature is data deduplication, which enables it to store virtually unlimited copies of files because unchanged data is only stored once. In addition to deduplication the file system also supports transparent compression using the compression methods lzo, zlib and bz2. These properties make the file system ideal for backups: I'm currently storing 250 GB worth of backups using only 8 GB of disk space. Several aspects of the design of DedupFS were inspired by Venti (ignoring the distributed aspect, for now…) and ZFS, though I've never personally used either. The ArchiveFS and lessfs projects share similar goals but have very different implementations.

Support

Quality

Security

License

Reuse

Support

dedupfs has a low active ecosystem.

It has 115 star(s) with 14 fork(s). There are 8 watchers for this library.

It had no major release in the last 6 months.

dedupfs has no issues reported. There are 1 open pull requests and 0 closed requests.

It has a neutral sentiment in the developer community.

The latest version of dedupfs is current.

Quality

dedupfs has 0 bugs and 0 code smells.

Security

dedupfs has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.

dedupfs code analysis shows 0 unresolved vulnerabilities.

There are 0 security hotspots that need review.

License

dedupfs has a Non-SPDX License.

Non-SPDX licenses can be open source with a non SPDX compliant license, or non open source licenses, and you need to review them closely before use.

Reuse

dedupfs releases are not available. You will need to build from source code and install.

dedupfs has no build file. You will be need to create the build yourself to build the component from source.

Installation instructions are not available. Examples and code snippets are available.

dedupfs saves you 672 person hours of effort in developing the same functionality from scratch.

It has 1558 lines of code, 135 functions and 5 files.

It has high code complexity. Code complexity directly impacts maintainability of the code.

Top functions reviewed by kandi - BETA

kandi has reviewed dedupfs and discovered the below as its top functions. This is intended to give you an instant insight into dedupfs implemented functionality, and help decide if they suit your requirements.

Return a human readable size
Round nbytes to divisor

Get all kandi verified functions for this library.

dedupfs Key Features

No Key Features are available at this moment for dedupfs.

dedupfs Examples and Code Snippets

No Code Snippets are available at this moment for dedupfs.

Community Discussions

Trending Discussions on Compression

Is there any (invertible) way (in c#) to convert a string into a smaller one, and when I say smaller I mean "with reduced length"?

Deflate floating point data bytes encoded as Base64

How To Asynchronously Check Video File size During Transcoding Process In fluent-ffmpeg

Is Shannon-Fano coding ambiguous?

PowerShell reading and writing compressed files with byte arrays

How to zip a file in python?

Cannot extract the contents of a TGZ file using F# and SharpZipLib

Nested zip contents listing

Compress output raster and parallelize gdalwarp from R

How to convert ZIP to GZIP in python, in-memory (AWS Lambda)

QUESTION

Is there any (invertible) way (in c#) to convert a string into a smaller one, and when I say smaller I mean "with reduced length"?

Asked 2022-Apr-16 at 07:31

Let me explain: in my use case a system gives me many strings that can vary in size (number of characters; length), sometimes it can be really huge! The problem is that I have to save this string in a column of a table of a "SQL Server" database, the bad news is that I am not allowed to do any migration in this database, the good news is that the column already has type nvarchar(max).

I've done some research before and followed the following post to write a data compressor using "Gzip" and "Brotli".

https://khalidabuhakmeh.com/compress-strings-with-dotnet-and-csharp

...

ANSWER

Answered 2022-Apr-15 at 13:55

The max size for a column of type NVARCHAR(MAX) is 2 GByte of storage.

Since NVARCHAR uses 2 bytes per character, that's approx. 1 billion characters.

So I don't think you actually need to make a compression, if the problem is the performance when retrieving data, then you can use a server side caching system.

Source https://stackoverflow.com/questions/71884821

QUESTION

Deflate floating point data bytes encoded as Base64

Asked 2022-Apr-02 at 06:07

Good Day!

I would like ask for your help on decompressing String back to its original data.

Here's the document that was sent to me by the provider.

Data description

First part describes the threshold data.

All data are managed as Little Endian IEEE 754 single precision floating numbers. Their binary representation are (represented in hexadecimal data) :

Compressed data (zip) Threshold binary data are compressed using the ‘deflate’ algorithm. Each compression result is given here (represented in hexadecimal data) :

Thresholds: $63 00 03 05 47 24 DA 81 81 A1 C1 9E 81 61 01 98 06 00

Encoded data (base64) Threshold compressed data are encoded in ‘base64’ to be transmitted as ASCII characters. Each conversion results is given here (represented in hexadecimal data) :

Thresholds: $59 77 41 44 42 55 63 6B 32 6F 47 42 6F 63 47 65 67 57 45 42 6D 41 59 41

Here is the output frame (Manufacturer frame content) The thresholds data are then sent using their corresponding ASCII character Here is the resulting Histogram ASTM frame sent :

YwADBUck2oGBocGegWEBmAYA

As explained in above details, what I want to do is backwards.

The packets that we received is

YwADBUck2oGBocGegWEBmAYA

then from there convert it to Hex value Base64 which is the output is.

Thresholds: $59 77 41 44 42 55 63 6B 32 6F 47 42 6F 63 47 65 67 57 45 42 6D 41 59 41

This first part was already been implemented using this line of codes.

...

ANSWER

Answered 2022-Mar-23 at 16:03

Your input string is a base64 encoded array of bytes, representing a compressed (deflated) sequence of floating point values (float / Single).

You can use Convert.FromBase64String() to get the compressed bytes
Initialize a MemoryStream with this byte array. It's used as the input stream of a DeflateStream
Initialize a new MemoryStream to receive the deflated content from the DeflateStream.CopyTo() method
Get a series of 4 bytes from the decompressed array of bytes and reconstruct the original values (here, using BitConverter.ToSingle() and an ArraySegment(Of Byte)).

An example:

Source https://stackoverflow.com/questions/71567706

QUESTION

How To Asynchronously Check Video File size During Transcoding Process In fluent-ffmpeg

Asked 2022-Mar-22 at 01:56

Is there a way during the ffmpeg compression process to determine over various intervals the exact filesize that a video is at?

Such as a method to get current filesize during the process to use when comparing against the videos original filesize.

For example, a potential video being transcoded takes 5 minutes, but during the process, a function will check the file size on intervals of 100 frames or every 5 seconds to ensure that the filesize hasn't exceeded the original. If it has, it will kill the process with command.kill('SIGSTOP');

...

ANSWER

Answered 2022-Mar-22 at 01:56

You can use the targetSize property from the "progress" event to get the current size of the target file:

Source https://stackoverflow.com/questions/71565913

QUESTION

Is Shannon-Fano coding ambiguous?

Asked 2022-Mar-08 at 19:38

In a nutshell:

Is the Shannon-Fano coding as described in Fano's paper The Transmission of Information (1952) really ambiguous?

In Detail:

3 papers
Claude E. Shannon published his famous paper A Mathematical Theory of Communication in July 1948. In this paper he invented the term bit as we know it today and he also defined what we call Shannon entropy today. And he also proposed an entropy based data compression algorithm in this paper. But Shannon's algorithm was so weak, that under certain circumstances the "compressed" messages could be even longer than in fix length coding. A few month later (March 1949) Robert M. Fano published an improved version of Shannons algorithm in the paper The Transmission of Information. 3 years after Fano (in September 1952) his student David A. Huffman published an even better version in his paper A Method for the Construction of Minimum-Redundancy Codes. Hoffman Coding is more efficient than its two predecessors and it is still used today. But my question is about the algorithm published by Fano which usually is called Shannon-Fano-Coding.

The algorithm
This description is based on the description from Wikipedia. Sorry, I did not fully read Fano's paper. I only browsed through it. It is 37 pages long and I really tried hard to find a passage where he talks about the topic of my question, but I could not find it. So, here is how Shannon-Fano encoding works:

Count how often each character appears in the message.
Sort all characters by frequency, characters with highest frequency on top of the list
Divide the list into two parts, such that the sums of frequencies in both parts are as equal as possible. Add the bit 0 to one part and the bit 1 to the other part.
Repeat step 3 on each part that contains 2 or more characters until all parts consist of only 1 character.
Concatenate all bits from all rounds. This is the Shannon-Fano-code of that character.

An example
Let's execute this on a really tiny example (I think it's the smallest message where the problem appears). Here is the message to encode:

...

ANSWER

Answered 2022-Mar-08 at 19:00

To directly answer your question, without further elaboration about how to break ties, two different implementations of Shannon-Fano could produce different codes of different lengths for the same inputs.

As @MattTimmermans noted in the comments, Shannon-Fano does not always produce optimal prefix-free codings the way that, say, Huffman coding does. It might therefore be helpful to think of it less as an algorithm and more of a heuristic - something that likely will produce a good code but isn't guaranteed to give an optimal solution. Many heuristics suffer from similar issues, where minor tweaks in the input or how ties are broken could result in different results. A good example of this is the greedy coloring algorithm for finding vertex colorings of graphs. The linked Wikipedia article includes an example in which changing the order in which nodes are visited by the same basic algorithm yields wildly different results.

Even algorithms that produce optimal results, however, can sometimes produce different optimal results based on tiebreaks. Take Huffman coding, for example, which works by repeatedly finding the two lowest-weight trees assembled so far and merging them together. In the event that there are three or more trees at some intermediary step that are all tied for the same weight, different implementations of Huffman coding could produce different prefix-free codes based on which two they join together. The resulting trees would all be equally "good," though, in that they'd all produce outputs of the same length. (That's largely because, unlike Shannon-Fano, Huffman coding is guaranteed to produce an optimal encoding.)

That being said, it's easy to adjust Shannon-Fano so that it always produces a consistent result. For example, you could say "in the event of a tie, choose the partition that puts fewer items into the top group," at which point you would always consistently produce the same coding. It wouldn't necessarily be an optimal encoding, but, then again, since Shannon-Fano was never guaranteed to do so, this is probably not a major concern.

If, on the other hand, you're interested in the question of "when Shannon-Fano has to break a tie, how do I decide how to break the tie to produce the optimal solution?," then I'm not sure of a way to do this other than recursively trying both options and seeing which one is better, which in the worst case leads to exponentially-slow runtimes. But perhaps someone else here can find a way to do that>

Source https://stackoverflow.com/questions/71399572

QUESTION

PowerShell reading and writing compressed files with byte arrays

Asked 2022-Mar-04 at 02:56

Final Update: Turns out I didn't need Binary writer. I could just copy memory streams from one archive to another.

I'm re-writing a PowerShell script which works with archives. I'm using two functions from here

Expand-Archive without Importing and Exporting files

and can successfully read and write files to the archive. I've posted the whole program just in case it makes things clearer for someone to help me.

However, there are three issues (besides the fact that I don't really know what I'm doing).

1.) Most files have this error on when trying to run Add-ZipEntry -ZipFilePath ($OriginalArchivePath + $PartFileDirectoryName) -EntryPath $entry.FullName -Content $fileBytes}

Cannot convert value "507" to type "System.Byte". Error: "Value was either too large or too small for an unsigned byte." (replace 507 with whatever number from the byte array is there)

2.) When it reads a file and adds it to the zip archive (*.imscc) it adds a character "a" to the beginning of the file contents.

3.) The only file it doesn't error on are text files, when I really want it to handle any file

Thank you for any assistance!

Update: I've tried using System.IO.BinaryWriter, with the same errors.

...

ANSWER

Answered 2022-Feb-27 at 13:55

System.IO.StreamWriter is a text writer, and therefore not suitable for writing raw bytes. Cannot convert value "507" to type "System.Byte" indicates that an inappropriate attempt was made to convert text - a .NET string composed of [char] instances which are in effect [uint16] code points (range 0x0 - 0xffff) - to [byte] instances (0x0 - 0xff). Therefore, any Unicode character whose code point is greater than 255 (0xff) will cause this error.

The solution is to use a .NET API that allows writing raw bytes, namely System.IO.BinaryWriter:

Source https://stackoverflow.com/questions/71280721

QUESTION

How to zip a file in python?

Asked 2022-Feb-26 at 16:09

I have been trying to make a python script to zip a file with the zipfile module. Although the text file is made into a zip file, It doesn't seem to be compressing it; testtext.txt is 1024KB whilst testtext.zip (The code's creation) is also equal to 1024KB. However, if I compress testtext.txt manually in File Explorer, the resulting zip file is compressed (To 2KB, specifically). How, if possible, can I combat this logical error?

Below is the script that I have used to (unsuccessfully) zip a text file.

...

ANSWER

Answered 2022-Feb-26 at 16:09

https://docs.python.org/3/library/zipfile.html#:~:text=with%20ZipFile(%27spam.zip%27%2C%20%27w%27)%20as%20myzip%3A%0A%20%20%20%20myzip.write(%27eggs.txt%27)

In the docs they have it written with a with statement so I would try that first.

Edit:

I just came back to say that you have to specify your compression method but Mark beat me to the punch.

Here is a link to a StackOverflow post about it https://stackoverflow.com/questions/4166447/python-zipfile-module-doesnt-seem-to-be-compressing-my-files#:~:text=This%20is%20because%20ZipFile%20requires,the%20method%20to%20be%20zipfile.

Source https://stackoverflow.com/questions/71277957

QUESTION

Cannot extract the contents of a TGZ file using F# and SharpZipLib

Asked 2022-Feb-22 at 01:50

I am learning F# and Deedle. I am trying to extract the contents of this TGZ File using SharpZipLib. I downloaded the TGZ to my local drive. I think I am close because out1 works, but out2 errs. I am sure the code could be written better with pipe forwarding or composition, but it first needs to work. Does anyone have any ideas?

...

ANSWER

Answered 2022-Feb-22 at 01:44

Does this help?

https://stackoverflow.com/a/52200001/1594263

Looks like you should be using CreateInputTarArchive(). I modified your example to use CreateInputTarArchive(), and it worked for me.

BTW you're just assigning a function to out1, you're not actually calling ListContents().

Source https://stackoverflow.com/questions/71214631

QUESTION

Nested zip contents listing

Asked 2022-Feb-17 at 23:04

I've been working on a little side project of listing files compressed in nested zip files. I've cooked up a script that does just that, but only if the depth of zip files is known. In in example below the zip file has additional zips in it and then anthoer in one of them.

...

ANSWER

Answered 2022-Feb-17 at 18:26

Here you have a little example of how recursion would look like, basically, you loop over the .Entries property of ZipFile and check if the extension of each item is .zip, if it is, then you pass that entry to your function.

EDIT: Un-deleting this answer mainly to show how this could be approached using a recursive function, my previous answer was inaccurate. I was using [ZipFile]::OpenRead(..) to read the nested .zip files which seemed to work correctly on Linux (.NET Core) however it clearly does not work when using Windows PowerShell. The correct approach would be to use [ZipArchive]::new($nestedZip.Open()) as Sage Pourpre's helpful answer shows.

Source https://stackoverflow.com/questions/71157138

QUESTION

Compress output raster and parallelize gdalwarp from R

Asked 2022-Feb-09 at 21:10

I would like to include -co options to compress output raster using gdalwarp from gdalUtilities in R.

I have tried some options (commented in the code), but I have not been successful in generating the compressed raster.

...

ANSWER

Answered 2022-Feb-09 at 21:10

1 - COMPRESSION

Please find the solution for the problem of file compression. To be honest, I have already been confronted with the same problem as you and, at the time, I was racking my brains... to finally find the solution which is quite simple (once we know it!): you must not put any spaces (i.e. "COMPRESS=DEFLATE" and not "COMPRESS = DEFLATE")

So, please find below a small reprex.

Reprex

Source https://stackoverflow.com/questions/71052310

QUESTION

How to convert ZIP to GZIP in python, in-memory (AWS Lambda)

Asked 2022-Feb-08 at 04:08

I have managed to convert zip files to gzip, using AWS lambda's local storage /tmp. The problem is that this storage maxes out at 500Mb.

...

ANSWER

Answered 2022-Feb-07 at 18:06

This should do as you ask:

Source https://stackoverflow.com/questions/71022156

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install dedupfs

You can download it from GitHub.
You can use dedupfs like any standard Python library. You will need to make sure that you have a development environment consisting of a Python distribution including header files, a compiler, pip, and git installed. Make sure that your pip, setuptools, and wheel are up to date. When using pip it is generally recommended to install packages in a virtual environment to avoid changes to the system.

Support

If you have questions, bug reports, suggestions, etc. the author can be contacted at peter@peterodding.com. The latest version of DedupFS is available at http://peterodding.com/code/dedupfs/ and http://github.com/xolox/dedupfs.

Find more information at: