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7 commits

Author SHA1 Message Date
Martin Ågren 3bf97e1270 MyFirstObjectWalk: drop init_walken_defaults()
In a recent commit, we stopped calling `init_grep_defaults()` from this
function. Thus, by the end of the tutorial, we still haven't added any
contents to this function. Let's remove it for simplicity.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-30 13:55:54 -08:00
Martin Ågren 96313423a7 grep: use designated initializers for grep_defaults
In 15fabd1bbd ("builtin/grep.c: make configuration callback more
reusable", 2012-10-09), we learned to fill a `static struct grep_opt
grep_defaults` which we can use as a blueprint for other such structs.

At the time, we didn't consider designated initializers to be widely
useable, but these days, we do. (See, e.g., cbc0f81d96 ("strbuf: use
designated initializers in STRBUF_INIT", 2017-07-10).)

Use designated initializers to let the compiler set up the struct and so
that we don't need to remember to call `init_grep_defaults()`.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-21 14:50:33 -08:00
Martin Ågren 1d3878799f grep: don't set up a "default" repo for grep
`init_grep_defaults()` fills a `static struct grep_opt grep_defaults`.
This struct is then used by `grep_init()` as a blueprint for other such
structs. Notably, `grep_init()` takes a `struct repo *` and assigns it
into the target struct.

As a result, it is unnecessary for us to take a `struct repo *` in
`init_grep_defaults()` as well. We assign it into the default struct and
never look at it again. And in light of how we return early if we have
already set up the default struct, it's not just unnecessary, but is
also a bit confusing: If we are called twice and with different repos,
is it a bug or a feature that we ignore the second repo?

Drop the repo parameter for `init_grep_defaults()`.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-21 14:50:29 -08:00
Johannes Schindelin e3f53ce5bd MyFirstObjectWalk: remove unnecessary conditional statement
In the given example, `commit` cannot be `NULL` (because this is the
loop condition: if it was `NULL`, the loop body would not be entered at
all). It took this developer a moment or two to see that this is
therefore dead code.

Let's remove it, to avoid puzzling future readers.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-30 11:16:41 -07:00
Heba Waly 13aa9c8b70 cache: move doc to cache.h
Move the documentation from Documentation/technical/api-allocation-growing.txt
to cache.h as it's easier for the developers to find the usage
information beside the code instead of looking for it in another doc file.

Also documentation/technical/api-allocation-growing.txt is removed because the
information it has is now redundant and it'll be hard to keep it up to
date and synchronized with the documentation in the header file.

Signed-off-by: Heba Waly <heba.waly@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-18 15:21:29 +09:00
Heba Waly 301d595e72 revision: move doc to revision.h
Move the documentation from Documentation/technical/api-revision-walking.txt
to revision.h as it's easier for the developers to find the usage
information beside the code instead of looking for it in another doc file.

Also documentation/technical/api-revision-walking.txt is removed because the
information it has is now redundant and it'll be hard to keep it up to
date and synchronized with the documentation in the header file.

Signed-off-by: Heba Waly <heba.waly@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-18 15:21:28 +09:00
Emily Shaffer e0479fa073 documentation: add tutorial for object walking
Existing documentation on object walks seems to be primarily intended
as a reference for those already familiar with the procedure. This
tutorial attempts to give an entry-level guide to a couple of bare-bones
object walks so that new Git contributors can learn the concepts
without having to wade through options parsing or special casing.

The target audience is a Git contributor who is just getting started
with the concept of object walking. The goal is to prepare this
contributor to be able to understand and modify existing commands which
perform revision walks more easily, although it will also prepare
contributors to create new commands which perform walks.

The tutorial covers a basic overview of the structs involved during
object walk, setting up a basic commit walk, setting up a basic
all-object walk, and adding some configuration changes to both walk
types. It intentionally does not cover how to create new commands or
search for options from the command line or gitconfigs.

There is an associated patchset at
https://github.com/nasamuffin/git/tree/revwalk that contains a reference
implementation of the code generated by this tutorial.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-12 10:29:15 +09:00