zstd: Improve memory usage on small streaming encodes

[klauspost]

Very small streams will use EncodeAll internally when closing and no header has been written.

This will pull a new encoder from the async buffer.

Instead re-use the stream encoder.

Before:

BenchmarkMem/flush-32         	    1359	    837989 ns/op	 7376959 B/op	     109 allocs/op
BenchmarkMem/no-flush-32      	     129	   8884753 ns/op	112044489 B/op	     254 allocs/op

After:

BenchmarkMem/flush-32         	    1254	    922593 ns/op	 7376966 B/op	     109 allocs/op
BenchmarkMem/no-flush-32      	    1488	    841270 ns/op	 7374164 B/op	      29 allocs/op

Test is pretty much worst case, but shows the issue nicely.

Summary by CodeRabbit

• New Features

  • Upgraded Go version to 1.22.0 for improved performance and compatibility.
  • Introduced new test functions to assess memory usage and performance during encoding.

• Bug Fixes

  • Enhanced debug output control to reduce unnecessary logs during normal operations.

• Refactor

  • Refactored encoding methods for better resource management and code organization.

• Tests

  • Added tests for memory usage and performance metrics in the encoding process.

[klauspost]

@coderabbitai review

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Walkthrough

Walkthrough

The changes encompass updates to several Go modules within the github.com/klauspost/compress repository. The go.mod files have been modified to upgrade the Go version and dependencies, while the source code files have seen enhancements in debugging output control and resource management in encoding processes. New test functions have been added to evaluate memory usage during encoding, improving the overall testing framework.

Changes

File(s)	Change Summary
huff0/_generate/go.mod	Updated Go version to 1.22.0, toolchain to go1.22.4, and modified several dependencies.
s2/cmd/_s2sx/go.mod	Updated Go version to 1.21 and added toolchain version go1.22.4.
zstd/_generate/go.mod	Updated Go version to 1.22.0, toolchain to go1.22.4, and modified several dependencies.
zstd/blockdec.go	Added conditional debug print statement in prepareSequences function.
zstd/encoder.go	Refactored EncodeAll method for better resource management and added new encodeAll method.
zstd/framedec.go	Wrapped debug print statement in reset function with a conditional check for debugDecoder.
zstd/zstd_test.go	Added TestWriterMemUsage for memory usage testing, along with helper functions for benchmarks.

Suggested reviewers

• klauspost
• coderabbitai

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