[pbs-devel] [PATCH proxmox-backup v3 0/5] improve compression throughput

[Dominik Csapak]

in my tests (against current master) it improved the throughput if
the source/target storage is fast enough (tmpfs -> tmpfs):

Type                master (MiB/s)   with my patches (MiB/s)
.img file           ~614             ~767
pxar one big file   ~657             ~807
pxar small files    ~576             ~627

(these results are also in the relevant commit message)

It would be great, if someone else can cross check my results here.
Note: the the pxar code being faster than the img code seems to stem
from better multithreading pipelining in that code or in tokio (pxar
codepath scales more directly with more cores than the .img codepath)

changes from v2:
* use zstd_safe instead of zstd so we have access to the underlying
  error code
* add test for the error code handling since that's not part of the
  public zstd api, only an implementation detail (albeit one that's
  not likely to change soon)
* seperated the tests for the decode(encode()) roundtrip so a failure
  can more easily assigned to a specific codepath

changes from v1:
* reorder patches so that the data blob writer removal is the first one
* add tests for DataBlob that we can decode what we encoded
  (to see that my patches don't mess up the chunk generation)
* add new patch to cleanup the `encode` function a bit

Dominik Csapak (5):
  remove data blob writer
  datastore: test DataBlob encode/decode roundtrip
  datastore: data blob: add helper and test for checking zstd_safe error
    code
  datastore: data blob: increase compression throughput
  datastore: DataBlob encode: simplify code

 Cargo.toml                            |   1 +
 pbs-datastore/Cargo.toml              |   1 +
 pbs-datastore/src/data_blob.rs        | 193 ++++++++++++++++-------
 pbs-datastore/src/data_blob_writer.rs | 212 --------------------------
 pbs-datastore/src/lib.rs              |   2 -
 tests/blob_writer.rs                  | 105 -------------
 6 files changed, 144 insertions(+), 370 deletions(-)
 delete mode 100644 pbs-datastore/src/data_blob_writer.rs
 delete mode 100644 tests/blob_writer.rs

-- 
2.39.2