[PATCH v2 00/15] index-helper, watchman

In this version:

I removed the statistics since they're not really a core part of the series and we can always add them later.

I added a little more testing.

I merged the untracked cache/watchman mashup into the relevant patches. Hopefully I didn't screw it up -- I got into the rebase weeds here and took a while to get out. I wish I were better at rebasing.

I moved the index-helper to a named-pipe based IPC mechanism instead of a signal-based one. I don't actualy know much about named pipes other than what I learned while writing this, so someone with clue should probably take a peek.

The index-helper pid files was kind of a hassle -- there was a lot of mechanism involved in making sure that they were in fact pointing to a live index-helper process. With named pipes, we don't really need them: if a live index-helper is running, it can simply be instructed to die, and if it's not, then the pipe can be safely removed and a new index-helper started.

Because there is no longer a pid file for index-helper, index-helper has no way to let git know that it should wait for a watchman update reply when poked. I worked around this by making the waiting configurable, and giving a sensible default. Note that in the no-watchman case, the wait will be short even if misconfigured, because the daemon can immediately send an "OK" message.

I updated some commit messages, following Junio and Duy's suggestions.

Johannes Schindelin said that he would work on the Windows side, so I've dropped the Windows bits (including one patch). Since I don't know anything about Windows, it's probably for the best that I'm not coding for it.

I eliminated the ability to start up an index-helper when there was already one running because I don't see why you would want to do that, and because it would lead to multiple readers on the same named pipe, which has undefined behavior. Just kill the old one if you're done with it.

David Turner (7):
  read-cache: invalidate untracked cache data when reading WAMA
  unpack-trees: preserve index extensions
  index-helper: kill mode
  index-helper: don't run if already running
  index-helper: autorun mode
  index-helper: optionally automatically run
  read-cache: config for waiting for index-helper

Nguyễn Thái Ngọc Duy (10):
  read-cache.c: fix constness of verify_hdr()
  read-cache: allow to keep mmap'd memory after reading
  index-helper: new daemon for caching index and related stuff
  index-helper: add --strict
  daemonize(): set a flag before exiting the main process
  index-helper: add --detach
  read-cache: add watchman 'WAMA' extension
  Add watchman support to reduce index refresh cost
  index-helper: use watchman to avoid refreshing index with lstat()
  update-index: enable/disable watchman support

 .gitignore                         |   1 +
 Documentation/git-index-helper.txt |  64 ++++++
 Makefile                           |  21 ++
 builtin/gc.c                       |   2 +-
 builtin/update-index.c             |  11 +
 cache.h                            |  18 +-
 config.c                           |  10 +
 config.mak.uname                   |   1 +
 configure.ac                       |   8 +
 daemon.c                           |   2 +-
 dir.c                              |  23 +-
 dir.h                              |   6 +
 environment.c                      |   8 +
 git-compat-util.h                  |   1 +
 git.c                              |  35 ++-
 index-helper.c                     | 439 +++++++++++++++++++++++++++++++++++
 read-cache.c                       | 455 +++++++++++++++++++++++++++++++++++--
 setup.c                            |   4 +-
 shm.c                              |  67 ++++++
 shm.h                              |  23 ++
 t/t7063-status-untracked-cache.sh  |  23 ++
 t/t7900-index-helper.sh            |  60 +++++
 t/test-lib-functions.sh            |   4 +
 unpack-trees.c                     |   1 +
 watchman-support.c                 | 134 +++++++++++
 watchman-support.h                 |   7 +
 26 files changed, 1406 insertions(+), 22 deletions(-)
 create mode 100644 Documentation/git-index-helper.txt
 create mode 100644 index-helper.c
 create mode 100644 shm.c
 create mode 100644 shm.h
 create mode 100755 t/t7900-index-helper.sh
 create mode 100644 watchman-support.c
 create mode 100644 watchman-support.h