Re: [Tarantool-patches] [PATCH v3 1/4] vclock: add an ability to set individual clock components

[Serge Petrenko <sergepetrenko@tarantool.org>]

> 23 марта 2020 г., в 19:37, Konstantin Osipov <kostja.osipov@gmail.com> написал(а):
> 
> * Serge Petrenko <sergepetrenko@tarantool.org> [20/03/23 19:23]:
>> This is needed to 'hide' 0-th vclock component in replication responses.
> 
> I think the name should reflect the magic that happens in this
> function.
> 
> How about vclock_reset()?

No problem, fixed.

> 
>> 
>> Follow-up #3186
>> Prerequisite #4114
>> ---
>> src/box/vclock.c | 15 +++++++++++++++
>> src/box/vclock.h | 11 +++++++++++
>> 2 files changed, 26 insertions(+)
>> 
>> diff --git a/src/box/vclock.c b/src/box/vclock.c
>> index 90ae27591..302c0438d 100644
>> --- a/src/box/vclock.c
>> +++ b/src/box/vclock.c
>> @@ -37,6 +37,21 @@
>> #include "diag.h"
>> #include "tt_static.h"
>> 
>> +void
>> +vclock_set(struct vclock *vclock, uint32_t replica_id, int64_t lsn)
>> +{
>> +	assert(lsn >= 0);
>> +	assert(replica_id < VCLOCK_MAX);
>> +	vclock->signature -= vclock_get(vclock, replica_id);
>> +	if (lsn == 0) {
>> +		vclock->map &= ~(1 << replica_id);
>> +		return;
>> +	}
> 
>> +	vclock->lsn[replica_id] = lsn;
>> +	vclock->map |= 1 << replica_id;
>> +	vclock->signature += lsn;
>> +}
>> +
>> int64_t
>> vclock_follow(struct vclock *vclock, uint32_t replica_id, int64_t lsn)
>> {
>> diff --git a/src/box/vclock.h b/src/box/vclock.h
>> index 79e5a1bc0..7dc69015f 100644
>> --- a/src/box/vclock.h
>> +++ b/src/box/vclock.h
>> @@ -211,6 +211,17 @@ vclock_calc_sum(const struct vclock *vclock)
>> 	return sum;
>> }
>> 
>> +/**
>> + * Set vclock component represented by replica id to the desired
>> + * value.
> 
> Why is it necessary and how is it used? Should be in this comment. 
> The use case is still not very clear from the commit comment.
> 

I amended both the commit message and the comment. Please see v4

>> + *
>> + * @param vclock Vector clock.
>> + * @param replica_id Replica identifier.
>> + * @param lsn Lsn to set
>> + */
>> +void
>> +vclock_set(struct vclock *vclock, uint32_t replica_id, int64_t lsn);
>> +
>> static inline int64_t
>> vclock_sum(const struct vclock *vclock)
> 
> -- 
> Konstantin Osipov, Moscow, Russia
> https://scylladb.com


--
Serge Petrenko
sergepetrenko@tarantool.org