delta/git.git/name-hash.c, branch sb/parse-options-codeformat

hashmap: add simplified hashmap_get_from_hash() API

2014-07-07T20:56:35+00:00

Hashmap entries are typically looked up by just a key. The hashmap_get()
API expects an initialized entry structure instead, to support compound
keys. This flexibility is currently only needed by find_dir_entry() in
name-hash.c (and compat/win32/fscache.c in the msysgit fork). All other
(currently five) call sites of hashmap_get() have to set up a near emtpy
entry structure, resulting in duplicate code like this:

  struct hashmap_entry keyentry;
  hashmap_entry_init(&keyentry, hash(key));
  return hashmap_get(map, &keyentry, key);

Add a hashmap_get_from_hash() API that allows hashmap lookups by just
specifying the key and its hash code, i.e.:

  return hashmap_get_from_hash(map, hash(key), key);

Signed-off-by: Karsten Blees 
Signed-off-by: Junio C Hamano

name-hash.c: replace cache_name_compare() with memcmp(3)

2014-06-20T17:08:10+00:00

The same_name() private function wants a quick-and-exact check to
see if they two names are byte-for-byte identical first and then
fall back to the slow path.  Use memcmp(3) for the former to make it
clear that we do not want any "name" specific comparison.

Signed-off-by: Jeremiah Mahler 
Signed-off-by: Junio C Hamano

name-hash: retire unused index_name_exists()

2014-02-24T23:26:33+00:00

db5360f3f496 (name-hash: refactor polymorphic index_name_exists();
2013-09-17) split index_name_exists() into index_file_exists() and
index_dir_exists() but retained index_name_exists() as a thin wrapper
to avoid disturbing possible in-flight topics. Since this change
landed in 'master' some time ago and there are no in-flight topics
referencing index_name_exists(), retire it.

Signed-off-by: Eric Sunshine 
Signed-off-by: Junio C Hamano

name-hash.c: remove cache entries instead of marking them CE_UNHASHED

2013-11-18T21:04:24+00:00

The new hashmap implementation supports remove, so really remove unused
cache entries from the name hashmap instead of just marking them.

The CE_UNHASHED flag and CE_STATE_MASK are no longer needed.

Keep the CE_HASHED flag to prevent adding entries twice.

Signed-off-by: Karsten Blees 
Signed-off-by: Junio C Hamano

name-hash.c: use new hash map implementation for cache entries

2013-11-18T21:04:24+00:00

Note: the "ce->next = NULL;" in unpack-trees.c::do_add_entry can safely be
removed, as ce->next (now ce->ent.next) is always properly initialized in
name-hash.c::hash_index_entry.

Signed-off-by: Karsten Blees 
Signed-off-by: Junio C Hamano

name-hash.c: remove unreferenced directory entries

2013-11-18T21:04:24+00:00

The new hashmap implementation supports remove, so remove and free
directory entries that are no longer referenced by active cache entries.

Signed-off-by: Karsten Blees 
Signed-off-by: Junio C Hamano

name-hash.c: use new hash map implementation for directories

2013-11-18T21:04:23+00:00

Signed-off-by: Karsten Blees 
Signed-off-by: Junio C Hamano

name-hash: stop storing trailing '/' on paths in index_state.dir_hash

2013-09-17T17:08:07+00:00

When 5102c617 (Add case insensitivity support for directories when using
git status, 2010-10-03) added directories to the name-hash there was
only a single hash table in which both real cache entries and leading
directory prefixes were registered. To distinguish between the two types
of entries, directories were stored with a trailing '/'.

2092678c (name-hash.c: fix endless loop with core.ignorecase=true,
2013-02-28), however, moved directories to a separate hash table
(index_state.dir_hash) but retained the (now) redundant trailing '/',
thus callers continue to bear the burden of ensuring the slash's
presence before searching the index for a directory. Eliminate this
redundancy by storing paths in the dir-hash without the trailing '/'.

An important benefit of this change is that it eliminates undocumented
and dangerous behavior of dir.c:directory_exists_in_index_icase() in
which it assumes not only that it can validly access one character
beyond the end of its incoming directory argument, but also that that
character will unconditionally be a '/'. This perilous behavior was
"tolerated" because the string passed in by its lone caller always had a
'/' in that position, however, things broke [1] when 2eac2a4c (ls-files
-k: a directory only can be killed if the index has a non-directory,
2013-08-15) added a new caller which failed to respect the undocumented
assumption.

[1]: http://thread.gmane.org/gmane.comp.version-control.git/232727

Signed-off-by: Eric Sunshine 
Signed-off-by: Junio C Hamano

name-hash: refactor polymorphic index_name_exists()

2013-09-17T17:07:13+00:00

Depending upon the absence or presence of a trailing '/' on the incoming
pathname, index_name_exists() checks either if a file is present in the
index or if a directory is represented within the index. Each caller
explicitly chooses the mode of operation by adding or removing a
trailing '/' before invoking index_name_exists().

Since these two modes of operations are disjoint and have no code in
common (one searches index_state.name_hash; the other dir_hash), they
can be represented more naturally as distinct functions: one to search
for a file, and one for a directory.

Splitting index searching into two functions relieves callers of the
artificial burden of having to add or remove a slash to select the mode
of operation; instead they just call the desired function. A subsequent
patch will take advantage of this benefit in order to eliminate the
requirement that the incoming pathname for a directory search must have
a trailing slash.

(In order to avoid disturbing in-flight topics, index_name_exists() is
retained as a thin wrapper dispatching either to index_dir_exists() or
index_file_exists().)

Signed-off-by: Eric Sunshine 
Signed-off-by: Junio C Hamano

Merge branch 'kb/name-hash'

2013-04-01T15:59:53+00:00

The code to keep track of what directory names are known to Git on
platforms with case insensitive filesystems can get confused upon
a hash collision between these pathnames and looped forever.

* kb/name-hash:
  name-hash.c: fix endless loop with core.ignorecase=true