From: git@jeffhostetler.com
To: git@vger.kernel.org
Cc: gitster@pobox.com, peff@peff.net,
Jeff Hostetler <jeffhost@microsoft.com>
Subject: [PATCH v4 2/4] read-cache: add strcmp_offset function
Date: Tue, 4 Apr 2017 21:08:45 +0000 [thread overview]
Message-ID: <20170404210847.50860-3-git@jeffhostetler.com> (raw)
In-Reply-To: <20170404210847.50860-1-git@jeffhostetler.com>
From: Jeff Hostetler <jeffhost@microsoft.com>
Add strcmp_offset() function to also return the offset of the
first change.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
cache.h | 1 +
read-cache.c | 29 +++++++++++++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/cache.h b/cache.h
index 80b6372..4d82490 100644
--- a/cache.h
+++ b/cache.h
@@ -574,6 +574,7 @@ extern int write_locked_index(struct index_state *, struct lock_file *lock, unsi
extern int discard_index(struct index_state *);
extern int unmerged_index(const struct index_state *);
extern int verify_path(const char *path);
+extern int strcmp_offset(const char *s1_in, const char *s2_in, int *first_change);
extern int index_dir_exists(struct index_state *istate, const char *name, int namelen);
extern void adjust_dirname_case(struct index_state *istate, char *name);
extern struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int igncase);
diff --git a/read-cache.c b/read-cache.c
index 9054369..b3fc77d 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -887,6 +887,35 @@ static int has_file_name(struct index_state *istate,
return retval;
}
+
+/*
+ * Like strcmp(), but also return the offset of the first change.
+ */
+int strcmp_offset(const char *s1_in, const char *s2_in, int *first_change)
+{
+ const unsigned char *s1 = (const unsigned char *)s1_in;
+ const unsigned char *s2 = (const unsigned char *)s2_in;
+ int diff = 0;
+ int k;
+
+ *first_change = 0;
+ for (k=0; s1[k]; k++)
+ if ((diff = (s1[k] - s2[k])))
+ goto found_it;
+ if (!s2[k])
+ return 0;
+ diff = -1;
+
+found_it:
+ *first_change = k;
+ if (diff > 0)
+ return 1;
+ else if (diff < 0)
+ return -1;
+ else
+ return 0;
+}
+
/*
* Do we have another file with a pathname that is a proper
* subset of the name we're trying to add?
--
2.9.3
next prev parent reply other threads:[~2017-04-04 21:09 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-04 21:08 [PATCH v4 0/4] read-cache: speed up add_index_entry git
2017-04-04 21:08 ` [PATCH v4 1/4] p0004-read-tree: perf test to time read-tree git
2017-04-04 21:08 ` git [this message]
2017-04-04 21:08 ` [PATCH v4 3/4] test-strcmp-offset: created test for strcmp_offset git
2017-04-04 21:08 ` [PATCH v4 4/4] read-cache: speed up add_index_entry during checkout git
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