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[PATCH 4/5] inline lookup_replace_object() calls

From
Junio C Hamano <gitster@pobox.com>
Date
May 15, 2011, 19:54 UTC
Message-ID
<1305489294-14341-5-git-send-email-gitster@pobox.com>
In-Reply-To
<1305489294-14341-1-git-send-email-gitster@pobox.com>

In a repository without object replacement, lookup_replace_object() should be a no-op. Check the flag "read_replace_refs" on the side of the caller, and bypess a function call when we know we are not dealing with replacement.

Also, even when we are set up to replace objects, if we do not find any replacement defined, flip that flag off to avoid function call overhead for all the later object accesses.

As this change the semantics of the flag from "do we need read the replacement definition?" to "do we need to check with the lookup table?" the flag needs to be renamed later to something saner, e.g. "use_replace", when the codebase is calmer, but not now.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 cache.h          |   12 ++++++++++--
 environment.c    |    2 +-
 replace_object.c |    4 +++-
 3 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/cache.h b/cache.h
index a9ae100..c10a91d 100644
--- a/cache.h
+++ b/cache.h
@@ -756,10 +756,18 @@ char *strip_path_suffix(const char *path, const char *suffix);
 int daemon_avoid_alias(const char *path);
 int offset_1st_component(const char *path);
 
+/* object replacement */
+extern void *read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size);
+extern const unsigned char *do_lookup_replace_object(const unsigned char *sha1);
+static inline const unsigned char *lookup_replace_object(const unsigned char *sha1)
+{
+	if (!read_replace_refs)
+		return sha1;
+	return do_lookup_replace_object(sha1);
+}
+
 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 extern int sha1_object_info(const unsigned char *, unsigned long *);
-extern void *read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size);
-extern const unsigned char *lookup_replace_object(const unsigned char *sha1);
 extern int hash_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1);
 extern int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 extern int pretend_sha1_file(void *, unsigned long, enum object_type, unsigned char *);
diff --git a/environment.c b/environment.c
index 40185bc..9182820 100644
--- a/environment.c
+++ b/environment.c
@@ -42,7 +42,7 @@ const char *editor_program;
 const char *askpass_program;
 const char *excludes_file;
 enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
-int read_replace_refs = 1;
+int read_replace_refs = 1; /* NEEDSWORK: rename to use_replace_refs */
 enum eol eol = EOL_UNSET;
 enum safe_crlf safe_crlf = SAFE_CRLF_WARN;
 unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
diff --git a/replace_object.c b/replace_object.c
index 7c6c754..d0b1548 100644
--- a/replace_object.c
+++ b/replace_object.c
@@ -85,12 +85,14 @@ static void prepare_replace_object(void)
 
 	for_each_replace_ref(register_replace_ref, NULL);
 	replace_object_prepared = 1;
+	if (!replace_object_nr)
+		read_replace_refs = 0;
 }
 
 /* We allow "recursive" replacement. Only within reason, though */
 #define MAXREPLACEDEPTH 5
 
-const unsigned char *lookup_replace_object(const unsigned char *sha1)
+const unsigned char *do_lookup_replace_object(const unsigned char *sha1)
 {
 	int pos, depth = MAXREPLACEDEPTH;
 	const unsigned char *cur = sha1;
-- 
1.7.5.1.334.gdfd07
Previous: Junio C HamanoNext: Junio C Hamano
Message 5 of 6 in “Updates to replace-object API”
  1. 0/5 Updates to replace-object APIJunio C Hamano, May 15, 2011
  2. 1/5 Declare lookup_replace_object() in cache.h, not in commit.hJunio C Hamano, May 15, 2011
  3. 2/5 t6050: make sure we test not just commit replacementJunio C Hamano, May 15, 2011
  4. 3/5 read_sha1_file(): get rid of read_sha1_file_repl() madnessJunio C Hamano, May 15, 2011
  5. 4/5 inline lookup_replace_object() callsJunio C Hamano, May 15, 2011
  6. 5/5 read_sha1_file(): allow selective bypassing of replacement mechanismJunio C Hamano, May 15, 2011

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