Function ZSTD_initLegacyStream

freebsd/contrib/openzfs/module/zstd/lib/zstd.c:24092–24147

MEM_STATIC size_t ZSTD_initLegacyStream(void** legacyContext, U32 prevVersion, U32 newVersion,
                                        const void* dict, size_t dictSize)
{
    DEBUGLOG(5, "ZSTD_initLegacyStream for v0.%u", newVersion);
    if (prevVersion != newVersion) ZSTD_freeLegacyStreamContext(*legacyContext, prevVersion);
    switch(newVersion)
    {
        default :
        case 1 :
        case 2 :
        case 3 :
            (void)dict; (void)dictSize;
            return 0;
#if (ZSTD_LEGACY_SUPPORT <= 4)
        case 4 :
        {
            ZBUFFv04_DCtx* dctx = (prevVersion != newVersion) ? ZBUFFv04_createDCtx() : (ZBUFFv04_DCtx*)*legacyContext;
            if (dctx==NULL) return ERROR(memory_allocation);
            ZBUFFv04_decompressInit(dctx);
            ZBUFFv04_decompressWithDictionary(dctx, dict, dictSize);
            *legacyContext = dctx;
            return 0;
        }
#endif
#if (ZSTD_LEGACY_SUPPORT <= 5)
        case 5 :
        {
            ZBUFFv05_DCtx* dctx = (prevVersion != newVersion) ? ZBUFFv05_createDCtx() : (ZBUFFv05_DCtx*)*legacyContext;
            if (dctx==NULL) return ERROR(memory_allocation);
            ZBUFFv05_decompressInitDictionary(dctx, dict, dictSize);
            *legacyContext = dctx;
            return 0;
        }
#endif
#if (ZSTD_LEGACY_SUPPORT <= 6)
        case 6 :
        {
            ZBUFFv06_DCtx* dctx = (prevVersion != newVersion) ? ZBUFFv06_createDCtx() : (ZBUFFv06_DCtx*)*legacyContext;
            if (dctx==NULL) return ERROR(memory_allocation);
            ZBUFFv06_decompressInitDictionary(dctx, dict, dictSize);
            *legacyContext = dctx;
            return 0;
        }
#endif
#if (ZSTD_LEGACY_SUPPORT <= 7)
        case 7 :
        {
            ZBUFFv07_DCtx* dctx = (prevVersion != newVersion) ? ZBUFFv07_createDCtx() : (ZBUFFv07_DCtx*)*legacyContext;
            if (dctx==NULL) return ERROR(memory_allocation);
            ZBUFFv07_decompressInitDictionary(dctx, dict, dictSize);
            *legacyContext = dctx;
            return 0;
        }
#endif
    }
}