[PATCH 2/2] index-v4: document the entry format

From

Junio C Hamano <gitster@pobox.com>

Date

Apr 27, 2012, 23:02 UTC

Message-ID

<xmqqpqas93sa.fsf_-_@junio.mtv.corp.google.com>

In-Reply-To

<xmqqzk9w93zu.fsf@junio.mtv.corp.google.com>

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/technical/index-format.txt |   13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Documentation/technical/index-format.txt b/Documentation/technical/index-format.txt
index 8930b3f..9d25b30 100644
--- a/Documentation/technical/index-format.txt
+++ b/Documentation/technical/index-format.txt
@@ -113,9 +113,22 @@ GIT index format
     are encoded in 7-bit ASCII and the encoding cannot contain a NUL
     byte (iow, this is a UNIX pathname).
 
+  (Version 4) In version 4, the entry path name is prefix-compressed
+    relative to the path name for the previous entry (the very first
+    entry is encoded as if the path name for the previous entry is an
+    empty string).  At the beginning of an entry, an integer N in the
+    variable width encoding (the same encoding as the offset is encoded
+    for OFS_DELTA pack entries; see pack-format.txt) is stored, followed
+    by a NUL-terminated string S.  Removing N bytes from the end of the
+    path name for the previous entry, and replacing it with the string S
+    yields the path name for this entry.
+
   1-8 nul bytes as necessary to pad the entry to a multiple of eight bytes
   while keeping the name NUL-terminated.
 
+  (Version 4) In version 4, the padding after the pathname does not
+  exist.
+
 == Extensions
 
 === Cached tree

-- 
1.7.10.526.gb0571