Introduce `git_oid_from_string`, `git_oid_from_prefix`, and
`git_oid_from_raw`, all of which take a `git_oid_t` that indicates what
type of OID should be parsed (SHA1 or SHA256).
This allows users to continue to use `git_oid_fromstr` without any code
changes, while remaining in a SHA1 world.
Note that these are not perfect analogs to the `fromstr` APIs.
* `git_oid_from_string` now takes a NUL terminated string, instead of
allowing for non-NUL terminated strings. Adding a NUL check feels like
an important safety consideration for C strings.
* `git_oid_from_prefix` should be used for an OID substring and length.
Previous usages of `git_oid_fromstr` with non-NUL terminated strings
should move to `git_oid_from_prefix` with the hexsize for the given OID
type.
The information about the type of a revision spec is not information
about the parser. Name it accordingly, so that `git_revparse_mode_t`
is now `git_revspec_t`. Deprecate the old name.
Inside of our networking example code, we have a git2 executable
that acts as an entry point to all the different network
examples. As such, it is kind of the same like the normal git(1)
executable in that it simply arbitrates to the respective
subcommands.
Let's extend this approach and merge all examples into a single
standalone lg2 executable. Instead of building an executable
for all the existing examples we have, we now bundle them all
inside of the lg2 one and let them be callable via subcommands.
In the process, we can get rid of duplicated library
initialization, deinitialization and repository discovery code.
Instead of having each subcommand handle these on its own, we
simply do it inside of the single main function now.
This describes their purpose better, as we now initialize ssl and some
other global stuff in there. Calling the init function is not something
which has been optional for a while now.
This demonstrates parts of the interface for specifying revisions that
Git users are familiar with from 'git rev-list', 'git log', and other
Git commands. A similar query interface is used in out-of-core
command-line programs that browse a Git repo (like 'tig'), and may be
useful for an 'advanced search' interface in GUI or web applications.
In this version, we parse all the query modifiers we can support with
the existing logic in revwalk: basic include/exclude commits, and the
ordering flags. More logic will be required to support '--grep',
'--author', the pickaxe '-S', etc.
Signed-off-by: Greg Price <price@mit.edu>
