Re: [PATCH v3 05/11] commit-graph: return 64-bit generation number

> "Abhishek Kumar via GitGitGadget" <gitgitgadget@gmail.com> writes:
> 
> > From: Abhishek Kumar <abhishekkumar8222@gmail.com>
> >
> > In a preparatory step, let's return timestamp_t values from
> > commit_graph_generation(), use timestamp_t for local variables
> 
> All right, this is all good.
> 
> > and define GENERATION_NUMBER_INFINITY as (2 ^ 63 - 1) instead.
> 
> This needs more detailed examination.  There are two similar constants,
> GENERATION_NUMBER_INFINITY and GENERATION_NUMBER_MAX.  The former is
> used for newest commits outside the commit-graph, while the latter is
> maximum number that commits in the commit-graph can have (because of the
> storage limitations).  We therefore need GENERATION_NUMBER_INFINITY
> to be larger than GENERATION_NUMBER_MAX, and it is (and was).
> 
> The GENERATION_NUMBER_INFINITY is because of the above requirement
> traditionally taken as maximum value that can be represented in the data
> type used to store commit's generation number _in memory_, but it can be
> less.  For timestamp_t the maximum value that can be represented
> is (2 ^ 63 - 1).
> 
> All right then.
> 
> >

> 
> The commit message says nothing about the new symbolic constant
> GENERATION_NUMBER_V1_INFINITY, though.
> 
> I'm not sure it is even needed (see comments below).