Reserve 2 bits out of EB_EXPIRE_TIME_MAX for possible future use #13331
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@tezc, rdb.c relies on |
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tezc
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…is#13331) Reserve 2 bits out of hash-field expiration time (`EB_EXPIRE_TIME_MAX`) for possible future lightweight indexing/categorizing of fields. It can be achieved by hacking HFE as follows: ``` HPEXPIREAT key [ 2^47 + USER_INDEX ] FIELDS numfields field [field …] ``` Redis will also need to expose kind of `HEXPIRESCAN` and `HEXPIRECOUNT` for this idea. Yet to be better defined. `HFE_MAX_ABS_TIME_MSEC` constraint must be enforced only at API level. Internally, the expiration time can be up to `EB_EXPIRE_TIME_MAX` for future readiness.
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Reserve 2 bits out of hash-field expiration time (
#define HFE_MAX_ABS_TIME_MSEC (EB_EXPIRE_TIME_MAX >> 2)) for possible future lightweight indexing/categorizing of fields. It can be achieved by hacking HFE as follows:Redis will also need to expose kind of
HEXPIRESCANandHEXPIRECOUNTfor this idea. Yet to be better defined.HFE_MAX_ABS_TIME_MSECconstraint must be enforced only at API level. Internally, the expiration time can be up toEB_EXPIRE_TIME_MAXfor future readiness.