diff mbox series

[v2] refs: make explicit that ref_iterator_peel returns boolean

Message ID pull.1006.v2.git.git.1621438289354.gitgitgadget@gmail.com (mailing list archive)
State Accepted
Commit 617480d75bdca266d4549e4047452c633ddb7a52
Headers show
Series [v2] refs: make explicit that ref_iterator_peel returns boolean | expand

Commit Message

Han-Wen Nienhuys May 19, 2021, 3:31 p.m. UTC 
From: Han-Wen Nienhuys <hanwen@google.com>

Use -1 as error return value throughout.

This removes spurious differences in the GIT_TRACE_REFS output, depending on the
ref storage backend active.

Before, the cached ref_iterator (but only that iterator!) would return
peel_object() output directly. No callers relied on the peel_status values
beyond success/failure. All calls to these functions go through
peel_iterated_oid(), which returns peel_object() as a fallback, but also
squashing the error values.

The iteration interface already passes REF_ISSYMREF and REF_ISBROKEN through the
flags argument, so the additional error values in enum peel_status provide no
value.

The ref iteration interface provides a separate peel() function because certain
formats (eg. packed-refs and reftable) can store the peeled object next to the
tag SHA1. Passing the peeled SHA1 as an optional argument to each_ref_fn maps
more naturally to the implementation of ref databases. Changing the code in this
way is left for a future refactoring.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
---
    refs: ref_iterator_peel returns boolean, rather than peel_status
    
    v2: expand commit message.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1006%2Fhanwen%2Fpeel_return-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1006/hanwen/peel_return-v2
Pull-Request: https://github.com/git/git/pull/1006

Range-diff vs v1:

 1:  241e0ad1954b ! 1:  f1dc6c2d7fea refs: ref_iterator_peel returns boolean, rather than peel_status
     @@ Metadata
      Author: Han-Wen Nienhuys <hanwen@google.com>
      
       ## Commit message ##
     -    refs: ref_iterator_peel returns boolean, rather than peel_status
     +    refs: make explicit that ref_iterator_peel returns boolean
      
     -    Before, the cached ref_iterator would return peel_object() output directly. This
     -    led to spurious differences in the GIT_TRACE_REFS output, depending on the ref
     -    storage backend active.
     +    Use -1 as error return value throughout.
     +
     +    This removes spurious differences in the GIT_TRACE_REFS output, depending on the
     +    ref storage backend active.
     +
     +    Before, the cached ref_iterator (but only that iterator!) would return
     +    peel_object() output directly. No callers relied on the peel_status values
     +    beyond success/failure. All calls to these functions go through
     +    peel_iterated_oid(), which returns peel_object() as a fallback, but also
     +    squashing the error values.
     +
     +    The iteration interface already passes REF_ISSYMREF and REF_ISBROKEN through the
     +    flags argument, so the additional error values in enum peel_status provide no
     +    value.
     +
     +    The ref iteration interface provides a separate peel() function because certain
     +    formats (eg. packed-refs and reftable) can store the peeled object next to the
     +    tag SHA1. Passing the peeled SHA1 as an optional argument to each_ref_fn maps
     +    more naturally to the implementation of ref databases. Changing the code in this
     +    way is left for a future refactoring.
      
          Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
      
     @@ refs.c: int peel_iterated_oid(const struct object_id *base, struct object_id *pe
       		return ref_iterator_peel(current_ref_iter, peeled);
       
      -	return peel_object(base, peeled);
     -+	return !!peel_object(base, peeled);
     ++	return peel_object(base, peeled) ? -1 : 0;
       }
       
       int refs_create_symref(struct ref_store *refs,
      
     + ## refs/packed-backend.c ##
     +@@ refs/packed-backend.c: static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator,
     + 	} else if ((iter->base.flags & (REF_ISBROKEN | REF_ISSYMREF))) {
     + 		return -1;
     + 	} else {
     +-		return !!peel_object(&iter->oid, peeled);
     ++		return peel_object(&iter->oid, peeled) ? -1 : 0;
     + 	}
     + }
     + 
     +
       ## refs/ref-cache.c ##
      @@ refs/ref-cache.c: static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator)
       static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator,
       				   struct object_id *peeled)
       {
      -	return peel_object(ref_iterator->oid, peeled);
     -+	return !!peel_object(ref_iterator->oid, peeled);
     ++	return peel_object(ref_iterator->oid, peeled) ? -1 : 0;
       }
       
       static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator)
     @@ refs/refs-internal.h: void base_ref_iterator_free(struct ref_iterator *iter);
       typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
       
      +/*
     -+ * Peels the current ref, returning 0 for success.
     ++ * Peels the current ref, returning 0 for success or -1 for failure.
      + */
       typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
       				 struct object_id *peeled);


 refs.c                | 2 +-
 refs/packed-backend.c | 2 +-
 refs/ref-cache.c      | 2 +-
 refs/refs-internal.h  | 3 +++
 4 files changed, 6 insertions(+), 3 deletions(-)


base-commit: bf949ade81106fbda068c1fdb2c6fd1cb1babe7e

Comments

Junio C Hamano May 19, 2021, 10:58 p.m. UTC | #1 
"Han-Wen Nienhuys via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: Han-Wen Nienhuys <hanwen@google.com>
>
> Use -1 as error return value throughout.

So this corresponds to the bottommost step in the series that is
queued as hn/reftable, with the difference at the end of this
message.

Do you want me to replace that single step with this version and
rebuild the remainder of the topic on top?

Thanks.


diff --git c/refs.c w/refs.c
index 7292c80a26..3b3478a2f1 100644
--- c/refs.c
+++ w/refs.c
@@ -2020,7 +2020,7 @@ int peel_iterated_oid(const struct object_id *base, struct object_id *peeled)
 	     oideq(current_ref_iter->oid, base)))
 		return ref_iterator_peel(current_ref_iter, peeled);
 
-	return !!peel_object(base, peeled);
+	return peel_object(base, peeled) ? -1 : 0;
 }
 
 int refs_create_symref(struct ref_store *refs,
diff --git c/refs/packed-backend.c w/refs/packed-backend.c
index dfecdbc1db..66cb90c79e 100644
--- c/refs/packed-backend.c
+++ w/refs/packed-backend.c
@@ -889,7 +889,7 @@ static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator,
 	} else if ((iter->base.flags & (REF_ISBROKEN | REF_ISSYMREF))) {
 		return -1;
 	} else {
-		return !!peel_object(&iter->oid, peeled);
+		return peel_object(&iter->oid, peeled) ? -1 : 0;
 	}
 }
 
diff --git c/refs/ref-cache.c w/refs/ref-cache.c
index 703a12959e..49d732f6db 100644
--- c/refs/ref-cache.c
+++ w/refs/ref-cache.c
@@ -491,7 +491,7 @@ static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator)
 static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator,
 				   struct object_id *peeled)
 {
-	return !!peel_object(ref_iterator->oid, peeled);
+	return peel_object(ref_iterator->oid, peeled) ? -1 : 0;
 }
 
 static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator)
diff --git c/refs/refs-internal.h w/refs/refs-internal.h
index 7b427b58f6..2bdabf7b4a 100644
--- c/refs/refs-internal.h
+++ w/refs/refs-internal.h
@@ -454,7 +454,7 @@ void base_ref_iterator_free(struct ref_iterator *iter);
 typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
 
 /*
- * Peels the current ref, returning 0 for success.
+ * Peels the current ref, returning 0 for success or -1 for failure.
  */
 typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
 				 struct object_id *peeled);
Han-Wen Nienhuys May 20, 2021, 9:04 a.m. UTC | #2 
On Thu, May 20, 2021 at 12:58 AM Junio C Hamano <gitster@pobox.com> wrote:
> > Use -1 as error return value throughout.
>
> So this corresponds to the bottommost step in the series that is
> queued as hn/reftable, with the difference at the end of this
> message.
>
> Do you want me to replace that single step with this version and
> rebuild the remainder of the topic on top?

Yes.

I'm hoping this can graduate soon, so the hn/reftable topic becomes
smaller (I don't know what that means for your organization of the
seen branch).
Han-Wen Nienhuys July 6, 2021, 6:09 p.m. UTC | #3 
On Thu, May 20, 2021 at 11:04 AM Han-Wen Nienhuys <hanwen@google.com> wrote:
> > So this corresponds to the bottommost step in the series that is
> > queued as hn/reftable, with the difference at the end of this
> > message.
> >
> > Do you want me to replace that single step with this version and
> > rebuild the remainder of the topic on top?
>
> Yes.
>
> I'm hoping this can graduate soon, so the hn/reftable topic becomes
> smaller (I don't know what that means for your organization of the
> seen branch).

Any update on this? This wasn't queued for next, but I believe it should be.
Junio C Hamano July 6, 2021, 7:54 p.m. UTC | #4 
Han-Wen Nienhuys <hanwen@google.com> writes:

> On Thu, May 20, 2021 at 11:04 AM Han-Wen Nienhuys <hanwen@google.com> wrote:
>> > So this corresponds to the bottommost step in the series that is
>> > queued as hn/reftable, with the difference at the end of this
>> > message.
>> >
>> > Do you want me to replace that single step with this version and
>> > rebuild the remainder of the topic on top?
>>
>> Yes.
>>
>> I'm hoping this can graduate soon, so the hn/reftable topic becomes
>> smaller (I don't know what that means for your organization of the
>> seen branch).
>
> Any update on this? This wasn't queued for next, but I believe it should be.

Sorry, I thought you meant you wanted to fix up the bottommost
commit in that series, which I think was already done at 617480d7
(refs: make explicit that ref_iterator_peel returns boolean,
2021-05-19), and did not realize that you wanted a separate single
patch topic for this step, on top of which the remainder of the
other topic builds.

Will do.  Thanks.
diff mbox series

Patch

diff --git a/refs.c b/refs.c
index 8c9490235ea6..8b9f7c3a80a0 100644
--- a/refs.c
+++ b/refs.c
@@ -2010,7 +2010,7 @@  int peel_iterated_oid(const struct object_id *base, struct object_id *peeled)
 	     oideq(current_ref_iter->oid, base)))
 		return ref_iterator_peel(current_ref_iter, peeled);
 
-	return peel_object(base, peeled);
+	return peel_object(base, peeled) ? -1 : 0;
 }
 
 int refs_create_symref(struct ref_store *refs,
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index dfecdbc1db60..66cb90c79ee0 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -889,7 +889,7 @@  static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator,
 	} else if ((iter->base.flags & (REF_ISBROKEN | REF_ISSYMREF))) {
 		return -1;
 	} else {
-		return !!peel_object(&iter->oid, peeled);
+		return peel_object(&iter->oid, peeled) ? -1 : 0;
 	}
 }
 
diff --git a/refs/ref-cache.c b/refs/ref-cache.c
index 46f1e5428433..49d732f6db96 100644
--- a/refs/ref-cache.c
+++ b/refs/ref-cache.c
@@ -491,7 +491,7 @@  static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator)
 static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator,
 				   struct object_id *peeled)
 {
-	return peel_object(ref_iterator->oid, peeled);
+	return peel_object(ref_iterator->oid, peeled) ? -1 : 0;
 }
 
 static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator)
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 467f4b3c936d..3155708345fc 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -453,6 +453,9 @@  void base_ref_iterator_free(struct ref_iterator *iter);
  */
 typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
 
+/*
+ * Peels the current ref, returning 0 for success or -1 for failure.
+ */
 typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
 				 struct object_id *peeled);