Merge branch 'cc/split-index-config'

The experimental "split index" feature has gained a few
configuration variables to make it easier to use.

* cc/split-index-config: (22 commits)
  Documentation/git-update-index: explain splitIndex.*
  Documentation/config: add splitIndex.sharedIndexExpire
  read-cache: use freshen_shared_index() in read_index_from()
  read-cache: refactor read_index_from()
  t1700: test shared index file expiration
  read-cache: unlink old sharedindex files
  config: add git_config_get_expiry() from gc.c
  read-cache: touch shared index files when used
  sha1_file: make check_and_freshen_file() non static
  Documentation/config: add splitIndex.maxPercentChange
  t1700: add tests for splitIndex.maxPercentChange
  read-cache: regenerate shared index if necessary
  config: add git_config_get_max_percent_split_change()
  Documentation/git-update-index: talk about core.splitIndex config var
  Documentation/config: add information for core.splitIndex
  t1700: add tests for core.splitIndex
  update-index: warn in case of split-index incoherency
  read-cache: add and then use tweak_split_index()
  split-index: add {add,remove}_split_index() functions
  config: add git_config_get_split_index()
  ...

1 files changed, 29 insertions, 0 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 5e5c2ae5fb..eccc012672 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -334,6 +334,10 @@ core.trustctime::
 	crawlers and some backup systems).
 	See linkgit:git-update-index[1]. True by default.
 
+core.splitIndex::
+	If true, the split-index feature of the index will be used.
+	See linkgit:git-update-index[1]. False by default.
+
 core.untrackedCache::
 	Determines what to do about the untracked cache feature of the
 	index. It will be kept, if this variable is unset or set to
@@ -2850,6 +2854,31 @@ showbranch.default::
 	The default set of branches for linkgit:git-show-branch[1].
 	See linkgit:git-show-branch[1].
 
+splitIndex.maxPercentChange::
+	When the split index feature is used, this specifies the
+	percent of entries the split index can contain compared to the
+	total number of entries in both the split index and the shared
+	index before a new shared index is written.
+	The value should be between 0 and 100. If the value is 0 then
+	a new shared index is always written, if it is 100 a new
+	shared index is never written.
+	By default the value is 20, so a new shared index is written
+	if the number of entries in the split index would be greater
+	than 20 percent of the total number of entries.
+	See linkgit:git-update-index[1].
+
+splitIndex.sharedIndexExpire::
+	When the split index feature is used, shared index files that
+	were not modified since the time this variable specifies will
+	be removed when a new shared index file is created. The value
+	"now" expires all entries immediately, and "never" suppresses
+	expiration altogether.
+	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
+	either created based on it or read from it.
+	See linkgit:git-update-index[1].
+
 status.relativePaths::
 	By default, linkgit:git-status[1] shows paths relative to the
 	current directory. Setting this variable to `false` shows paths