Compression.zstdDecompress

Creates a flow that zstd-decompresses a stream of ByteStrings.

Compression operators

Dependency

The zstd operators use zstd-jni, an optional dependency of Pekko Streams that has to be added explicitly:

sbt

libraryDependencies += "com.github.luben" % "zstd-jni" % "1.5.7-25"

Maven

<dependencies>
  <dependency>
    <groupId>com.github.luben</groupId>
    <artifactId>zstd-jni</artifactId>
    <version>1.5.7-25</version>
  </dependency>
</dependencies>

Gradle

dependencies {
  implementation "com.github.luben:zstd-jni:1.5.7-25"
}

Signature

Compression.zstdDecompressCompression.zstdDecompress Compression.zstdDecompressCompression.zstdDecompress

Description

Creates a flow that zstd-decompresses a stream of ByteStrings. If the input is truncated or corrupt this operator fails with a com.github.luben.zstd.ZstdException.

The zstdDecompress(settings) overload takes a ZstdDecompressionSettingsZstdDecompressionSettings, which sets the maximum chunk size and, with withDictionary, a dictionary to decompress data that was compressed with one. It must be the same dictionary (including any offset and length) that was used for compression; the dictionary level only applies to compression and is ignored.

By default, zstd accepts frames with a window of up to 128 MiB (a window log of 27), and the decompressor allocates the window buffer from the frame header before any data is decompressed. When decompressing untrusted input, use withWindowLogMax to reject frames with a larger window, for example a window log of 23 (8 MiB), the limit that RFC 9659 sets for the HTTP zstd content-coding. withWindowLogMax requires zstd-jni 1.5.7-25 or later; with an older version, the operator fails when it is materialized.

Reactive Streams semantics