[libzstd] Fix decompression dictionary bugs and clean up initialization#1580
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Bugs: * `ZSTD_DCtx_refPrefix()` didn't clear the dictionary after the first use. Fix and add a test case. * `ZSTD_DCtx_reset()` always cleared the dictionary. Fix and add a test case. * After calling `ZSTD_resetDStream()` you could no longer load a dictionary, since the stage was set to `zdss_loadHeader`. Fix and add a test case. Cleanup: * Make `ZSTD_initDStream*()` and `ZSTD_resetDStream()` wrap the new advanced API, and add test cases. * Document the equivalent of these functions in the advanced API and document the unstable functions as deprecated.
Cyan4973
reviewed
Apr 10, 2019
| int ddictIsCold; /* if == 1 : dictionary is "new" for working context, and presumed "cold" (not in cpu cache) */ | ||
| int dictUsesRemaining; /* if == 1 : dictionary should be used once. | ||
| * if == 0 : dictionary should be forgotten now. | ||
| * if < 0 : dictionary should be used indefinitely. */ |
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minor : while it works, it nonetheless feels strange to declare a member dictUsesRemaining to actually mean "use indefinitely when value is negative".
Would it be clearer to have an enum, with typically 3 values, for example use_indefinitely, use_once, do_no_longer_use ?
Contributor
|
These are very good points, I just have a minor comment regarding clarity of one internal mechanism. |
Cyan4973
approved these changes
Apr 10, 2019
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Bugs:
ZSTD_DCtx_refPrefix()didn't clear the dictionary after the firstuse. Fix and add a test case.
ZSTD_DCtx_reset()always cleared the dictionary. Fix and add a testcase.
ZSTD_resetDStream()you could no longer load adictionary, since the stage was set to
zdss_loadHeader. Fix and adda test case.
Cleanup:
ZSTD_initDStream*()andZSTD_resetDStream()wrap the newadvanced API, and add test cases.
document the unstable functions as deprecated.