diff mbox series

[v2,4/8] repository: add repo reference to index_state

Message ID a0d89d7a9731adeee4e2a432843b2f4a9c232dc4.1611320639.git.gitgitgadget@gmail.com (mailing list archive)
State Superseded
Headers show
Series More index cleanups | expand

Commit Message

Derrick Stolee Jan. 22, 2021, 1:03 p.m. UTC 
From: Derrick Stolee <dstolee@microsoft.com>

It will be helpful to add behavior to index operations that might
trigger an object lookup. Since each index belongs to a specific
repository, add a 'repo' pointer to struct index_state that allows
access to this repository.

This will prevent future changes from needing to pass an additional
'struct repository *repo' parameter and instead rely only on the 'struct
index_state *istate' parameter.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 cache.h      | 1 +
 repository.c | 4 ++++
 2 files changed, 5 insertions(+)

Comments

Junio C Hamano Jan. 22, 2021, 7:23 p.m. UTC | #1 
"Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: Derrick Stolee <dstolee@microsoft.com>
>
> It will be helpful to add behavior to index operations that might
> trigger an object lookup. Since each index belongs to a specific
> repository, add a 'repo' pointer to struct index_state that allows
> access to this repository.
>
> This will prevent future changes from needing to pass an additional
> 'struct repository *repo' parameter and instead rely only on the 'struct
> index_state *istate' parameter.
>
> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
> ---

I think this makes sense, but shouldn't we insist on these
bidirectional links to point at each other?  Otherwise we cannot
simplify the function signatures safely later.  That is ...

> +	/* Complete the double-reference */
> +	if (!repo->index->repo)
> +		repo->index->repo = repo;
> +

	else if (repo->index->repo != repo)
		BUG("the repo->index instance does not belong to the repo???");

... a check like this?

>  	return read_index_from(repo->index, repo->index_file, repo->gitdir);
>  }
diff mbox series

Patch

diff --git a/cache.h b/cache.h
index 71097657489..f9c7a603841 100644
--- a/cache.h
+++ b/cache.h
@@ -328,6 +328,7 @@  struct index_state {
 	struct ewah_bitmap *fsmonitor_dirty;
 	struct mem_pool *ce_mem_pool;
 	struct progress *progress;
+	struct repository *repo;
 };
 
 /* Name hashing */
diff --git a/repository.c b/repository.c
index a4174ddb062..67a4c1da2d9 100644
--- a/repository.c
+++ b/repository.c
@@ -264,6 +264,10 @@  int repo_read_index(struct repository *repo)
 	if (!repo->index)
 		repo->index = xcalloc(1, sizeof(*repo->index));
 
+	/* Complete the double-reference */
+	if (!repo->index->repo)
+		repo->index->repo = repo;
+
 	return read_index_from(repo->index, repo->index_file, repo->gitdir);
 }