Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

…#3232)

* chore: Update generation configuration at Wed Aug  6 02:42:05 UTC 2025

* chore: generate libraries at Wed Aug  6 02:42:36 UTC 2025

#3237)

* chore: Update generation configuration at Thu Aug  7 02:41:43 UTC 2025

* chore: generate libraries at Thu Aug  7 02:42:13 UTC 2025

* chore: Update generation configuration at Fri Aug  8 02:40:54 UTC 2025

* chore: Update generation configuration at Sat Aug  9 02:33:16 UTC 2025

* chore: Update generation configuration at Sun Aug 10 02:43:55 UTC 2025

* chore: Update generation configuration at Mon Aug 11 02:40:32 UTC 2025

#3243)

* chore: Update generation configuration at Tue Aug 12 02:31:47 UTC 2025

* chore: generate libraries at Tue Aug 12 02:32:20 UTC 2025

* chore: Update generation configuration at Wed Aug 13 02:32:37 UTC 2025

* chore: Update generation configuration at Thu Aug 14 02:35:24 UTC 2025

* chore: Update generation configuration at Fri Aug 15 02:34:26 UTC 2025

* chore: Update generation configuration at Sat Aug 16 02:30:38 UTC 2025

* chore: generate libraries at Sat Aug 16 02:31:07 UTC 2025

…66.0 (#3244)

…v3.52.0 (#3250)

#3253)

* chore: Update generation configuration at Wed Aug 20 02:29:59 UTC 2025

* chore: generate libraries at Wed Aug 20 02:30:32 UTC 2025

## Description
feat: *breaking behavior* rewrite Storage.blobAppendableUpload to be non-blocking and have improved throughput (#3231)

Rewrite internals of BlobAppendableUpload to provide non-blocking write calls, and it take advantage of grpc async message handling.

When `AppendableUploadWriteableByteChannel#write(ByteBuffer)` is called, an attempt will be made to enqueue the bytes in the outbound queue to GCS.
If there is only enough room to partially consume the bytes provided in the `ByteBuffer` the write call will return early specifying the number of bytes actually consumed.

As acknowledgements come in from gcs, enqueued messages will be evicted freeing space in the outbound queue. Thereby allowing more bytes to be consumed and enqueued.

Given appendable objects are still in private preview I can't quote any metrics here, however preliminary benchmarking of several million objects across a range of sizes show across the board throughput improvments.

Because the channel's write call is now non-blocking, if you want to block your application until the full buffer is consumed some new helper methods have been added in StorageChannelUtils to provide blocking behavior.

A new method `MinFlushSizeFlushPolicy#withMaxPendingBytes(long)` has been added to allow limiting the number of pending outbound bytes. The default values is 16MiB, but can be configured lower if necessary.

## Release Notes

BEGIN_COMMIT_OVERRIDE

BEGIN_NESTED_COMMIT
feat: *breaking behavior* rewrite Storage.blobAppendableUpload to be non-blocking and have improved throughput (#3231)
END_NESTED_COMMIT

BEGIN_NESTED_COMMIT
feat: add StorageChannelUtils to provide helper methods to perform blocking read/write to/from non-blocking channels (#3231)
END_NESTED_COMMIT

BEGIN_NESTED_COMMIT
feat: add MinFlushSizeFlushPolicy#withMaxPendingBytes(long) (#3231)
END_NESTED_COMMIT

BEGIN_NESTED_COMMIT
fix: update BlobAppendableUploadConfig and FlushPolicy.MinFlushSizeFlushPolicy to default to 4MiB minFlushSize and 16MiB maxPendingBytes (#3249)
END_NESTED_COMMIT

BEGIN_NESTED_COMMIT
fix: make FlushPolicy${Min,Max}FlushSizeFlushPolicy constructors private (#3217)
END_NESTED_COMMIT

END_COMMIMT_OVERRIDE

## Sub PRs
This PR is made of up the following PRs, in sequence
1. #3217
2. #3218 
3. #3219
4. #3220
5. #3221
6. #3222
7. #3223
8. #3224 
9. #3225 
10. #3226 
11. #3227 
12. #3228 
13. #3229 
14. #3230 
15. #3235 
16. #3236 
17. #3241
18. #3242
19. #3246
20. #3248
21. #3249
22. #3252

…zy RPCs such as reads & writes (#3255)

* Fixes for WriteChannel
* Fixes for RadChannel
* Fixes for BlobWriteSession
* Fixes for BlobReadSession
  `s$com.google.cloud.storage.Storage/readAs$com.google.cloud.storage.Storage/blobReadSession/readAs$g`
* Fixes for BlobAppendableUpload

Accidentally opened after some debugging in #3255

Allows blocking the invoking thread until the number of bytes acknowledged by GCS matches the number of written bytes prior to calling flush().

…o v1-rev20250815-2.0.0 (#3245)

* chore(main): release 2.56.0

* chore: generate libraries at Mon Aug 25 19:27:55 UTC 2025

---------

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
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