When we call lookup_commit, lookup_tree, etc, the logic goes
something like:
1. Look for an existing object struct. If we don't have
one, allocate and return a new one.
2. Double check that any object we have is the expected
type (and complain and return NULL otherwise).
3. Convert an object with type OBJ_NONE (from a prior
call to lookup_unknown_object) to the expected type.
We can encapsulate steps 2 and 3 in a helper function which
checks whether we have the expected object type, converts
OBJ_NONE as appropriate, and returns the object.
Not only does this shorten the code, but it also provides
one central location for converting OBJ_NONE objects into
objects of other types. Future patches will use that to
enforce type-specific invariants.
Since this is a refactoring, we would want it to behave
exactly as the current code. It takes a little reasoning to
see that this is the case:
- for lookup_{commit,tree,etc} functions, we are just
pulling steps 2 and 3 into a function that does the same
thing.
- for the call in peel_object, we currently only do step 3
(but we want to consolidate it with the others, as
mentioned above). However, step 2 is a noop here, as the
surrounding conditional makes sure we have OBJ_NONE
(which we want to keep to avoid an extraneous call to
sha1_object_info).
- for the call in lookup_commit_reference_gently, we are
currently doing step 2 but not step 3. However, step 3
is a noop here. The object we got will have just come
from deref_tag, which must have figured out the type for
each object in order to know when to stop peeling.
Therefore the type will never be OBJ_NONE.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
blob.c | 9 +--------
commit.c | 19 ++-----------------
object.c | 17 +++++++++++++++++
object.h | 2 ++
refs.c | 3 +--
tag.c | 9 +--------
tree.c | 9 +--------
7 files changed, 25 insertions(+), 43 deletions(-)
diff --git a/blob.c b/blob.c
index 5720a38..1fcb8e4 100644
--- a/blob.c
+++ b/blob.c
@@ -8,14 +8,7 @@ struct blob *lookup_blob(const unsigned char *sha1)
struct object *obj = lookup_object(sha1);
if (!obj)
return create_object(sha1, alloc_blob_node());
- if (!obj->type)
- obj->type = OBJ_BLOB;
- if (obj->type != OBJ_BLOB) {
- error("Object %s is a %s, not a blob",
- sha1_to_hex(sha1), typename(obj->type));
- return NULL;
- }
- return (struct blob *) obj;
+ return object_as_type(obj, OBJ_BLOB, 0);
}
int parse_blob_buffer(struct blob *item, void *buffer, unsigned long size)
diff --git a/commit.c b/commit.c
index 21ed310..dd638de 100644
--- a/commit.c
+++ b/commit.c
@@ -18,19 +18,6 @@ int save_commit_buffer = 1;
const char *commit_type = "commit";
-static struct commit *check_commit(struct object *obj,
- const unsigned char *sha1,
- int quiet)
-{
- if (obj->type != OBJ_COMMIT) {
- if (!quiet)
- error("Object %s is a %s, not a commit",
- sha1_to_hex(sha1), typename(obj->type));
- return NULL;
- }
- return (struct commit *) obj;
-}
-
struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
int quiet)
{
@@ -38,7 +25,7 @@ struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
if (!obj)
return NULL;
- return check_commit(obj, sha1, quiet);
+ return object_as_type(obj, OBJ_COMMIT, quiet);
}
struct commit *lookup_commit_reference(const unsigned char *sha1)
@@ -65,9 +52,7 @@ struct commit *lookup_commit(const unsigned char *sha1)
struct commit *c = alloc_commit_node();
return create_object(sha1, c);
}
- if (!obj->type)
- obj->type = OBJ_COMMIT;
- return check_commit(obj, sha1, 0);
+ return object_as_type(obj, OBJ_COMMIT, 0);
}
struct commit *lookup_commit_reference_by_name(const char *name)
diff --git a/object.c b/object.c
index 472aa8d..b2319f6 100644
--- a/object.c
+++ b/object.c
@@ -158,6 +158,23 @@ void *create_object(const unsigned char *sha1, void *o)
return obj;
}
+void *object_as_type(struct object *obj, enum object_type type, int quiet)
+{
+ if (obj->type == type)
+ return obj;
+ else if (obj->type == OBJ_NONE) {
+ obj->type = type;
+ return obj;
+ }
+ else {
+ if (!quiet)
+ error("object %s is a %s, not a %s",
+ sha1_to_hex(obj->sha1),
+ typename(obj->type), typename(type));
+ return NULL;
+ }
+}
+
struct object *lookup_unknown_object(const unsigned char *sha1)
{
struct object *obj = lookup_object(sha1);
diff --git a/object.h b/object.h
index 8020ace..5e8d8ee 100644
--- a/object.h
+++ b/object.h
@@ -81,6 +81,8 @@ struct object *lookup_object(const unsigned char *sha1);
extern void *create_object(const unsigned char *sha1, void *obj);
+void *object_as_type(struct object *obj, enum object_type type, int quiet);
+
/*
* Returns the object, having parsed it to find out what it is.
*
diff --git a/refs.c b/refs.c
index 20e2bf1..5a18e2d 100644
--- a/refs.c
+++ b/refs.c
@@ -1729,9 +1729,8 @@ static enum peel_status peel_object(const unsigned char *name, unsigned char *sh
if (o->type == OBJ_NONE) {
int type = sha1_object_info(name, NULL);
- if (type < 0)
+ if (type < 0 || !object_as_type(o, type, 0))
return PEEL_INVALID;
- o->type = type;
}
if (o->type != OBJ_TAG)
diff --git a/tag.c b/tag.c
index 79552c7..82d841b 100644
--- a/tag.c
+++ b/tag.c
@@ -41,14 +41,7 @@ struct tag *lookup_tag(const unsigned char *sha1)
struct object *obj = lookup_object(sha1);
if (!obj)
return create_object(sha1, alloc_tag_node());
- if (!obj->type)
- obj->type = OBJ_TAG;
- if (obj->type != OBJ_TAG) {
- error("Object %s is a %s, not a tag",
- sha1_to_hex(sha1), typename(obj->type));
- return NULL;
- }
- return (struct tag *) obj;
+ return object_as_type(obj, OBJ_TAG, 0);
}
static unsigned long parse_tag_date(const char *buf, const char *tail)
diff --git a/tree.c b/tree.c
index ed66575..bb02c1c 100644
--- a/tree.c
+++ b/tree.c
@@ -184,14 +184,7 @@ struct tree *lookup_tree(const unsigned char *sha1)
struct object *obj = lookup_object(sha1);
if (!obj)
return create_object(sha1, alloc_tree_node());
- if (!obj->type)
- obj->type = OBJ_TREE;
- if (obj->type != OBJ_TREE) {
- error("Object %s is a %s, not a tree",
- sha1_to_hex(sha1), typename(obj->type));
- return NULL;
- }
- return (struct tree *) obj;
+ return object_as_type(obj, OBJ_TREE, 0);
}
int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
--
2.0.0.566.gfe3e6b2
--
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