[PATCH v5 22/22] Documentation/git-update-index: explain splitIndex.*
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
Documentation/config.txt | 2 +-
Documentation/git-update-index.txt | 37 +++++++++++++++++++++++++++++--------
2 files changed, 30 insertions(+), 9 deletions(-)
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 2afd5d982b..24ed9c476d 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -2873,7 +2873,7 @@ splitIndex.sharedIndexExpire::
The default value is "2.weeks.ago".
Note that a shared index file is considered modified (for the
purpose of expiration) each time a new split-index file is
- created based on it.
+ either created based on it or read from it.
See linkgit:git-update-index[1].
status.relativePaths::
diff --git a/Documentation/git-update-index.txt b/Documentation/git-update-index.txt
index e091b2a409..1579abf3c3 100644
--- a/Documentation/git-update-index.txt
+++ b/Documentation/git-update-index.txt
@@ -163,14 +163,10 @@ may not support it yet.
--split-index::
--no-split-index::
- Enable or disable split index mode. If enabled, the index is
- split into two files, $GIT_DIR/index and $GIT_DIR/sharedindex.<SHA-1>.
- Changes are accumulated in $GIT_DIR/index while the shared
- index file contains all index entries stays unchanged. If
- split-index mode is already enabled and `--split-index` is
- given again, all changes in $GIT_DIR/index are pushed back to
- the shared index file. This mode is designed for very large
- indexes that take a significant amount of time to read or write.
+ Enable or disable split index mode. If split-index mode is
+ already enabled and `--split-index` is given again, all
+ changes in $GIT_DIR/index are pushed back to the shared index
+ file.
+
These options take effect whatever the value of the `core.splitIndex`
configuration variable (see linkgit:git-config[1]). But a warning is
@@ -394,6 +390,31 @@ Although this bit looks similar to assume-unchanged bit, its goal is
different from assume-unchanged bit's. Skip-worktree also takes
precedence over assume-unchanged bit when both are set.
+Split index
+-----------
+
+This mode is designed for repositories with very large indexes, and
+aims at reducing the time it takes to repeatedly write these indexes.
+
+In this mode, the index is split into two files, $GIT_DIR/index and
+$GIT_DIR/sharedindex.<SHA-1>. Changes are accumulated in
+$GIT_DIR/index, the split index, while the shared index file contains
+all index entries and stays unchanged.
+
+All changes in the split index are pushed back to the shared index
+file when the number of entries in the split index reaches a level
+specified by the splitIndex.maxPercentChange config variable (see
+linkgit:git-config[1]).
+
+Each time a new shared index file is created, the old shared index
+files are deleted if their modification time is older than what is
+specified by the splitIndex.sharedIndexExpire config variable (see
+linkgit:git-config[1]).
+
+To avoid deleting a shared index file that is still used, its
+modification time is updated to the current time everytime a new split
+index based on the shared index file is either created or read from.
+
Untracked cache
---------------
--
2.12.0.206.g74921e51d6.dirty
Christian Couder <christian.couder@gmail.com>