Граф коммитов

10 Коммитов

Автор SHA1 Сообщение Дата
brian m. carlson 2182abd94b split-index: convert struct split_index to object_id
Convert the base_sha1 member of struct split_index to use struct
object_id and rename it base_oid.  Include cache.h to make the structure
visible.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-02 13:59:50 +09:00
Brandon Williams 75b7b971ae split-index: rename 'new' variables
Rename C++ keyword in order to bring the codebase closer to being able
to be compiled with a C++ compiler.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-22 10:08:05 -08:00
Junio C Hamano 64719b115d Revert "split-index: add and use unshare_split_index()"
This reverts commit f9d7abec2ad2f9eb3d8873169cc28c34273df082;
see public-inbox.org/git/CAP8UFD0bOfzY-_hBDKddOcJdPUpP2KEVaX_SrCgvAMYAHtseiQ@mail.gmail.com
2017-06-24 12:02:39 -07:00
Nguyễn Thái Ngọc Duy f9d7abec2a split-index: add and use unshare_split_index()
When split-index is being used, we have two cache_entry arrays in
index_state->cache[] and index_state->split_index->base->cache[].

index_state->cache[] may share the same entries with base->cache[] so
we can quickly determine what entries are shared. This makes memory
management tricky, we can't free base->cache[] until we know
index_state->cache[] does not point to any of those entries.

unshare_split_index() is added for this purpose, to find shared
entries and either duplicate them in index_state->cache[], or discard
them. Either way it should be safe to free base->cache[] after
unshare_split_index().

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 10:50:20 +09:00
Christian Couder cef4fc7ebe split-index: add {add,remove}_split_index() functions
Also use the functions in cmd_update_index() in
builtin/update-index.c.

These functions will be used in a following commit to tweak
our use of the split-index feature depending on the setting
of a configuration variable.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-01 13:24:21 -08:00
Nguyễn Thái Ngọc Duy 76b07b37a3 split-index: the reading part
CE_REMOVE'd entries are removed here because only parts of the code
base (unpack_trees in fact) test this bit when they look for the
presence of an entry. Leaving them may confuse the code ignores this
bit and expects to see a real entry.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13 11:49:40 -07:00
Nguyễn Thái Ngọc Duy 96a1d8d34c split-index: the writing part
prepare_to_write_split_index() does the major work, classifying
deleted, updated and added entries. write_link_extension() then just
writes it down.

An observation is, deleting an entry, then adding it back is recorded
as "entry X is deleted, entry X is added", not "entry X is replaced".
This is simpler, with small overhead: a replaced entry is stored
without its path, a new entry is store with its path.

A note about unpack_trees() and the deduplication code inside
prepare_to_write_split_index(). Usually tracking updated/removed
entries via read-cache API is enough. unpack_trees() manipulates the
index in a different way: it throws the entire source index out,
builds up a new one, copying/duplicating entries (using dup_entry)
from the source index over if necessary, then returns the new index.

A naive solution would be marking the entire source index "deleted"
and add their duplicates as new. That could bring $GIT_DIR/index back
to the original size. So we try harder and memcmp() between the
original and the duplicate to see if it needs updating.

We could avoid memcmp() too, by avoiding duplicating the original
entry in dup_entry(). The performance gain this way is within noise
level and it complicates unpack-trees.c. So memcmp() is the preferred
way to deal with deduplication.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13 11:49:40 -07:00
Nguyễn Thái Ngọc Duy 078a58e825 read-cache: mark updated entries for split index
The large part of this patch just follows CE_ENTRY_CHANGED
marks. replace_index_entry() is updated to update
split_index->base->cache[] as well so base->cache[] does not reference
to a freed entry.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13 11:49:40 -07:00
Nguyễn Thái Ngọc Duy 045113a53e read-cache: save deleted entries in split index
Entries that belong to the base index should not be freed. Mark
CE_REMOVE to track them.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13 11:49:40 -07:00
Nguyễn Thái Ngọc Duy 5fc2fc8fa2 read-cache: split-index mode
This split-index mode is designed to keep write cost proportional to
the number of changes the user has made, not the size of the work
tree. (Read cost is another matter, to be dealt separately.)

This mode stores index info in a pair of $GIT_DIR/index and
$GIT_DIR/sharedindex.<SHA-1>. sharedindex is large and unchanged over
time while "index" is smaller and updated often. Format details are in
index-format.txt, although not everything is implemented in this
patch.

Shared indexes are not automatically removed, because it's unclear if
the shared index is needed by any (even temporary) indexes by just
looking at it. After a while you'll collect stale shared indexes. The
good news is one shared index is useable for long, until
$GIT_DIR/index becomes too big and sluggish that the new shared index
must be created.

The safest way to clean shared indexes is to turn off split index
mode, so shared files are all garbage, delete them all, then turn on
split index mode again.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13 11:49:39 -07:00