add derive(Serialize, Deserialize) to DecompressorOxide

[dishmaker]

Fixes

• DecompressorOxide: Serialize state with serde #165
• derive(Serialize) state: Fsm vs AsyncSeek bearcove/rc-zip#99

I know this PR will not be merged, but it proves that state saving is actually possible!

Entire DecompressorOxide state compresses into only 356 bytes, for simple test case.

partial read len=32768
save at in_pos=11729
[miniz_oxide/tests/test_serde.rs:57:5] decompressor_state_msgpack.len() = 11824
[miniz_oxide/tests/test_serde.rs:58:5] decompressor_state_compressed.len() = 356
resume at in_pos=11729

So fast-seekable zip files are possible 😄

[oyvindln]

Could you leave leave the black_box change out of this PR? I would like to evaluate that separately.

I think adding a serde feature could be fine if there is a use for it though I would prefer if it's not enabled by default. Is it also possible to only enable the rmp_serde dev dependency conditionally?

[oyvindln]

Thanks for fixing the test part and splitting up the changes - will look over this and try to get it sorted when I have some time

[dishmaker]

Sorry for my ignorance.
There are better ways to achieve random access in zlib files. But not in zstd files.

[oyvindln]

Ah okay - just took me some days to get around to this - would have been fine with adding serde support if it was useful otherwise.

[grant-h]

I'm currently working on a similar project to enable random access seekable ZIP files. I'm currently resorting maintaining a serde remote copy of the DecompressorOxide type. Would love to see this added and gated behind a feature flag to enable snapshot/restore of state.