This includes the core.fastindex setting, the update-index additions,
and the fastindex index extension.
Signed-off-by: Ben Peart <benpe...@microsoft.com>
---
Documentation/config.txt | 8 ++++++++
Documentation/git-update-index.txt | 11 +++++++++++
Documentation/technical/index-format.txt | 26 ++++++++++++++++++++++++++
3 files changed, 45 insertions(+)
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 5f0d62753d..269ff97c8c 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -868,6 +868,14 @@ relatively high IO latencies. When enabled, Git will do
the
index comparison to the filesystem data in parallel, allowing
overlapping IO's. Defaults to true.
+core.fastIndex::
+ Enable parallel index loading
++
+This can speed up operations like 'git diff' and 'git status' especially
+when the index is very large. When enabled, Git will do the index
+loading from the on disk format to the in-memory format in parallel.
+Defaults to false.
+
core.createObject::
You can set this to 'link', in which case a hardlink followed by
a delete of the source are used to make sure that object creation
diff --git a/Documentation/git-update-index.txt
b/Documentation/git-update-index.txt
index 75c7dd9dea..7ffd285c94 100644
--- a/Documentation/git-update-index.txt
+++ b/Documentation/git-update-index.txt
@@ -19,6 +19,7 @@ SYNOPSIS
[--ignore-submodules]
[--[no-]split-index]
[--[no-|test-|force-]untracked-cache]
+ [--[no-]fastindex]
[--really-refresh] [--unresolve] [--again | -g]
[--info-only] [--index-info]
[-z] [--stdin] [--index-version <n>]
@@ -201,6 +202,16 @@ will remove the intended effect of the option.
`--untracked-cache` used to imply `--test-untracked-cache` but
this option would enable the extension unconditionally.
+--fastindex::
+--no-fastindex::
+ Enable or disable the fast index feature. These options
+ take effect whatever the value of the `core.fastindex`
+ configuration variable (see linkgit:git-config[1]). But a warning
+ is emitted when the change goes against the configured value, as
+ the configured value will take effect next time the index is
+ read and this will remove the intended effect of the option.
+
+
\--::
Do not interpret any more arguments as options.
diff --git a/Documentation/technical/index-format.txt
b/Documentation/technical/index-format.txt
index ade0b0c445..e37b4cf874 100644
--- a/Documentation/technical/index-format.txt
+++ b/Documentation/technical/index-format.txt
@@ -295,3 +295,29 @@ The remaining data of each directory block is grouped by
type:
in the previous ewah bitmap.
- One NUL.
+
+== Index Entry Offset Table
+
+ The Index Entry Offset Table (IEOT) is used to help address the CPU
+ cost of loading the index by enabling multi-threading the process of
+ converting cache entries from the on-disk format to the in-memory format.
+ Because it must be able to be loaded before the variable length cache
+ entries and other index extensions, this extension must be written last.
+ The signature for this extension is { 'I', 'E', 'O', 'T' }.
+
+ The extension consists of:
+
+ - 32-bit version (currently 1)
+
+ - A number of index offset entries each consisting of:
+
+ - 32-bit offset from the begining of the file to the first cache entry
+ in this block of entries.
+
+ - 32-bit count of cache entries in this block
+
+ - 32-bit version (currently 1)
+
+ - 32-bit size of the extension
+
+ - 4-byte extension signature
--
2.15.0.windows.1
