"Fossies" - the Fresh Open Source Software Archive  

Source code changes of the file "vendor/github.com/klauspost/compress/zstd/README.md" between
buildah-1.11.2.tar.gz and buildah-1.11.3.tar.gz

About: Buildah is a tool that facilitates building Open Container Initiative (OCI) container images.

README.md  (buildah-1.11.2):README.md  (buildah-1.11.3)
skipping to change at line 36 skipping to change at line 36
### Status: ### Status:
BETA - there may still be subtle bugs, but a wide variety of content has been te sted. BETA - there may still be subtle bugs, but a wide variety of content has been te sted.
There may still be implementation specific stuff in regards to error handling th at could lead to edge cases. There may still be implementation specific stuff in regards to error handling th at could lead to edge cases.
For now, a high speed (fastest) and medium-fast (default) compressor has been im plemented. For now, a high speed (fastest) and medium-fast (default) compressor has been im plemented.
The "Fastest" compression ratio is roughly equivalent to zstd level 1. The "Fastest" compression ratio is roughly equivalent to zstd level 1.
The "Default" compression ration is roughly equivalent to zstd level 3 (default) . The "Default" compression ration is roughly equivalent to zstd level 3 (default) .
In terms of speed, it is typically 2x as fast as the stdlib deflate/gzip in its In terms of speed, it is typically 2x as fast as the stdlib deflate/gzip in its
fastest mode. The compression ratio compared to stdlib is around level 3, but us fastest mode.
ually 3x as fast. The compression ratio compared to stdlib is around level 3, but usually 3x as fa
st.
Compared to cgo zstd, the speed is around level 3 (default), but compression sli ghtly worse, between level 1&2. Compared to cgo zstd, the speed is around level 3 (default), but compression sli ghtly worse, between level 1&2.
### Usage ### Usage
An Encoder can be used for either compressing a stream via the An Encoder can be used for either compressing a stream via the
`io.WriteCloser` interface supported by the Encoder or as multiple independent `io.WriteCloser` interface supported by the Encoder or as multiple independent
tasks via the `EncodeAll` function. tasks via the `EncodeAll` function.
Smaller encodes are encouraged to use the EncodeAll function. Smaller encodes are encouraged to use the EncodeAll function.
Use `NewWriter` to create a new instance that can be used for both. Use `NewWriter` to create a new instance that can be used for both.
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silesia.tar gzstd 1 211947520 80007735 2515 80.37 silesia.tar gzstd 1 211947520 80007735 2515 80.37
silesia.tar gzstd 3 211947520 73133380 4259 47.45 silesia.tar gzstd 3 211947520 73133380 4259 47.45
silesia.tar zstd 1 211947520 73513991 933 216.64 silesia.tar zstd 1 211947520 73513991 933 216.64
silesia.tar zstd 3 211947520 66793301 1377 146.79 silesia.tar zstd 3 211947520 66793301 1377 146.79
``` ```
### Converters ### Converters
As part of the development process a *Snappy* -> *Zstandard* converter was also built. As part of the development process a *Snappy* -> *Zstandard* converter was also built.
This can convert a *framed* [Snappy Stream](https://godoc.org/github.com/golang/ This can convert a *framed* [Snappy Stream](https://godoc.org/github.com/golang/
snappy#Writer) to a zstd stream. Note that a single block is not framed. snappy#Writer) to a zstd stream.
Note that a single block is not framed.
Conversion is done by converting the stream directly from Snappy without interme diate full decoding. Conversion is done by converting the stream directly from Snappy without interme diate full decoding.
Therefore the compression ratio is much less than what can be done by a full dec ompression Therefore the compression ratio is much less than what can be done by a full dec ompression
and compression, and a faulty Snappy stream may lead to a faulty Zstandard strea m without and compression, and a faulty Snappy stream may lead to a faulty Zstandard strea m without
any errors being generated. any errors being generated.
No CRC value is being generated and not all CRC values of the Snappy stream are checked. No CRC value is being generated and not all CRC values of the Snappy stream are checked.
However, it provides really fast re-compression of Snappy streams. However, it provides really fast re-compression of Snappy streams.
``` ```
BenchmarkSnappy_ConvertSilesia-8 1 1156001600 ns/op 183.35 MB/s BenchmarkSnappy_ConvertSilesia-8 1 1156001600 ns/op 183.35 MB/s
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