[PATCH v2 6/6] fsmonitor: add a sample query-fsmonitor hook script for Watchman

[Ben Peart <peartben@gmail.com>]

This hook script integrates the new fsmonitor capabilities of git with
the cross platform Watchman file watching service. To use the script:

Download and install Watchman from https://facebook.github.io/watchman/
and instruct Watchman to watch your working directory for changes
('watchman watch-project /usr/src/git').

Rename the sample integration hook from query-fsmonitor.sample to
query-fsmonitor.

Configure git to use the extension ('git config core.fsmonitor true')
and optionally turn on the untracked cache for optimal performance
('git config core.untrackedcache true').

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 templates/hooks--query-fsmonitor.sample | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 templates/hooks--query-fsmonitor.sample

diff --git a/templates/hooks--query-fsmonitor.sample b/templates/hooks--query-fsmonitor.sample
new file mode 100644
index 0000000000..4bd22f21d8
--- /dev/null
+++ b/templates/hooks--query-fsmonitor.sample
@@ -0,0 +1,27 @@
+#!/bin/sh
+#
+# An example hook script to integrate Watchman
+# (https://facebook.github.io/watchman/) with git to provide fast
+# git status.
+#
+# The hook is passed a time_t formatted as a string and outputs to
+# stdout all files that have been modified since the given time.
+# Paths must be relative to the root of the working tree and
+# separated by a single NUL.
+#
+# To enable this hook, rename this file to "query-fsmonitor"
+
+# Convert unix style paths to escaped Windows style paths
+case "$(uname -s)" in
+MINGW*|MSYS_NT*)
+  GIT_WORK_TREE="$(cygpath -aw "$PWD" | sed 's,\\,\\\\,g')"
+  ;;
+*)
+  GIT_WORK_TREE="$PWD"
+  ;;
+esac
+
+# Query Watchman for all the changes since the requested time
+echo "[\"query\", \"$GIT_WORK_TREE\", {\"since\": $1, \"fields\":[\"name\"]}]" | \
+watchman -j | \
+perl -e 'use JSON::PP; my $o = JSON::PP->new->utf8->decode(join("", <>)); die "Watchman: $o->{'error'}.\nFalling back to scanning...\n" if defined($o->{"error"}); print(join("\0", @{$o->{"files"}}));'
-- 
2.13.0.windows.1.6.g4597375fc3