[PATCH v3 02/11] builtin/cat-file: introduce function to report object status

From: Patrick Steinhardt <ps@pks.im>
Date: Apr 2, 2025, 11:13 UTC
Message-ID: <20250402-pks-cat-file-object-type-filter-v3-2-4da6bb21871c@pks.im>
In-Reply-To: <20250402-pks-cat-file-object-type-filter-v3-0-4da6bb21871c@pks.im>

We have multiple callsites that report the status of an object, for example when the objec tis missing or its name is ambiguous. We're about to add a couple more such callsites to report on "excluded" objects.

Prepare for this by introducing a new function `report_object_status()` that encapsulates the functionality.

Note that this function also flushes stdout, which is a requirement so that request-response style batched modes can learn about the status before proceeding to the next object. We already flush correctly at all existing callsites, even though the flush in `batch_one_object()` only comes after the switch statement. That flush is now redundant, and we could in theory deduplicate it by moving it into all branches that don't use `report_object_status()`. But that doesn't quite feel sensible:

  - The duplicate flush should ultimately just be a no-op for us and
    thus shouldn't impact performance significantly.

  - By keeping the flush in `report_object_status()` we ensure that all
    future callers get semantics correct.

So let's just be pragmatic and live with the duplicated flush.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 builtin/cat-file.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index b158b3acef9..1261a3ce352 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -455,6 +455,16 @@ static void print_default_format(struct strbuf *scratch, struct expand_data *dat
 		    (uintmax_t)data->size, opt->output_delim);
 }
 
+static void report_object_status(struct batch_options *opt,
+				 const char *obj_name,
+				 const struct object_id *oid,
+				 const char *status)
+{
+	printf("%s %s%c", obj_name ? obj_name : oid_to_hex(oid),
+	       status, opt->output_delim);
+	fflush(stdout);
+}
+
 /*
  * If "pack" is non-NULL, then "offset" is the byte offset within the pack from
  * which the object may be accessed (though note that we may also rely on
@@ -481,9 +491,7 @@ static void batch_object_write(const char *obj_name,
 						       &data->oid, &data->info,
 						       OBJECT_INFO_LOOKUP_REPLACE);
 		if (ret < 0) {
-			printf("%s missing%c",
-			       obj_name ? obj_name : oid_to_hex(&data->oid), opt->output_delim);
-			fflush(stdout);
+			report_object_status(opt, obj_name, &data->oid, "missing");
 			return;
 		}
 
@@ -535,10 +543,10 @@ static void batch_one_object(const char *obj_name,
 	if (result != FOUND) {
 		switch (result) {
 		case MISSING_OBJECT:
-			printf("%s missing%c", obj_name, opt->output_delim);
+			report_object_status(opt, obj_name, &data->oid, "missing");
 			break;
 		case SHORT_NAME_AMBIGUOUS:
-			printf("%s ambiguous%c", obj_name, opt->output_delim);
+			report_object_status(opt, obj_name, &data->oid, "ambiguous");
 			break;
 		case DANGLING_SYMLINK:
 			printf("dangling %"PRIuMAX"%c%s%c",

-- 
2.49.0.604.gff1f9ca942.dirty