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>
Update the index format documentation to mention the v4 format.
* nd/doc-index-format:
update-index: list supported idx versions and their features
read-cache.c: use INDEX_FORMAT_{LB,UB} in verify_hdr()
index-format.txt: mention of v4 is missing in some places
In the earlier days, we used to spell the name of the system as GIT,
to simulate as if it were typeset with capital G and IT in small
caps. Later we stopped doing so at around 1.6.5 days.
Let's stop doing so throughout the documentation. The name to refer
to the whole system (and the concept it embodies) is "Git"; the
command end-users type is "git". And document this in the coding
guideline.
Signed-off-by: Thomas Ackermann <th.acker@arcor.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A cache-tree entry with a negative entry count is considered invalid
by the current Git; it records that we do not know the object name
of a tree that would result by writing the directory covered by the
cache-tree as a tree object.
Clarify that any entry with a negative entry count is invalid, but
the implementations must write -1 there. This way, we can later
decide to allow writers to use negative values other than -1 to
encode optional information on such invalidated entries without
harming interoperability; we do not know what will be encoded and
how, so we keep these other negative values as reserved for now.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These were not originally meant for asciidoc, but they are already
so close. Mark them up in asciidoc.
Signed-off-by: Thomas Ackermann <th.acker@arcor.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the entry_count is -1, the tree is invalidated and therefore has
not associated hash (or object name). Explicitly state that the next
entry starts after the newline.
Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* Clarify "string of unsigned bytes";
* Blob has two variants (regular file vs symlink), not (blob vs symlink);
* Clarify permission mode bits;
* Clarify ce_namelen() "too long to fit in the length field" case;
* Clarify "." etc are forbidden as path components;
* Match the description with the internal wording "cache-tree";
* All types of extension begin with signature and length as explained in
the first part. Don't repeat the "length" part in the description of
each extension (can be mistaken as if there is a separate 32-bit size
field inside the extension), but state what the signature for each
extension is.
* Don't say "Extension tag", as we have said "Extension signature" in the
first part---be consistent;
* Clarify the invalidation of cache-tree entries;
* Correct description on subtree_nr field in the cache-tree;
* Clarify the order of entries in cache-tree;
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This bases on the original work by Robin Rosenberg.
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
