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Commit Graph

44 Commits

Author SHA1 Message Date
Zdenek Kabelac
3a9689652d radix_tree: add radix_tree_values
To more easily adopt radix_tree over existing code base, add
abstraction over 'radix_tree_iterate' which basically builds
an array of all traversed values, and then it's just easy to
go over all array elements.

TODO: code should be converted to use  radix_tree_iterate()
directly as it's more efficient.

Note: it can be possibly to rewrite recursive _iterate() usage
to linear travesal, not sure whether it's worth the effort
as conversion to 'radix_itree_iterator' is relatively simple.
2024-06-03 15:30:05 +02:00
Zdenek Kabelac
1813d0d186 radix_tree: add radix_tree_lookup/insert_ptr
Add simple 'wrapper' inline functions to insert or return ptr lookup value.
(So the user doesn't need to deal with 'union radix_value' locally and
also it makes easier to translage some lvm2 functions to use radix_tree).

Note: If the stored 'value' would NULL, it cannot be recognized
from a case of 'not found'. So usable only when 'values' stored with
tree are not NULL.
2024-06-03 15:30:05 +02:00
Zdenek Kabelac
b77edc337a radix_tree: constify _iterate
Use nodes as const.
Swap order of arguments.
2024-06-03 15:30:05 +02:00
Zdenek Kabelac
1e2a3445d9 radix_tree: debug updates
Some updates to _dump()  debugging function so the printed result
can be more easily examined by human.

Also print 'prefix' as string when all chars are printable.

Add 'simple' variant of _dump also to 'simple' version of radix tree
(which is however normally not compiled).
2024-06-03 15:30:05 +02:00
Zdenek Kabelac
88681f05f1 radix_tree: api change
Instead of using 'key state & key end' uint8_t* switch to use
void* key, & size_t keylen.  This allows easier adaptation with
lvm code base with way too much casting with every use of function.

Also correctly mark const buffers to avoid compiled warnings and
casting.

Adapt the only bcache user ATM for API change.

Adapt unit test to match changed API.
2024-06-03 15:30:05 +02:00
Zdenek Kabelac
5731d06bc5 radix_tree: indent
Some minor indent changes to more easily read code.
2024-06-03 15:30:05 +02:00
Zdenek Kabelac
5d573cc91d const: array of const values 2024-05-08 01:55:20 +02:00
Zdenek Kabelac
9eafd44734 gcc: use more zero length arrays
Define last array struct member with zero size.
2021-09-22 17:18:50 +02:00
Zdenek Kabelac
ff21723512 hash: replace hash with better function
Add Bob Jenkins hash function to get better working hash function,
which does genarate way less colisions (especially with similar
strings).

For a comparision also a kernel function used in DM kernel is include.
While it's better then our existing one, it's still far worse,
then Bob Jenkins hash.
2021-03-08 15:33:15 +01:00
Zdenek Kabelac
d602837b91 hash: speed up hash tables
Enhance hash perfomance by remembering the computed
hash value for the hashed node - this allows to speedup
lookup of nodes with the hash collision when
different keys map to the same masked hash value.

For the easier use 'num_slots' become 'mask_slots',
so we only add '1' in rare case of need of the original
num_slots value.

Also add statistic counters for hashes and print stats in
debug build (-DDEBUG) on hash wiping.
(so badly performing hash can be optimized.)
2021-03-08 15:33:15 +01:00
Zdenek Kabelac
84679d254f hash: use unsigned size
There is not much point in using 64bit hash size, since we hash
with way less bits anyway. So keep size 32bit.
2021-03-08 15:33:15 +01:00
Zdenek Kabelac
1ff1e86deb cleanup: better expressing passing key arg to _hash 2020-09-01 17:57:50 +02:00
Zdenek Kabelac
85e2c7e14d cov: explicitely ignore function result 2020-09-01 17:57:50 +02:00
Zdenek Kabelac
fd96f1014b gcc: zero-sized array to fexlible array C99
Switch remaining zero sized struct to flexible arrays to be C99
complient.

These simple rules should apply:

- The incomplete array type must be the last element within the structure.
- There cannot be an array of structures that contain a flexible array member.
- Structures that contain a flexible array member cannot be used as a member of another structure.
- The structure must contain at least one named member in addition to the flexible array member.

Although some of the code pieces should be still improved.
2020-09-01 17:57:50 +02:00
Zdenek Kabelac
deb5160181 list: use container_of
Reuse macro
2020-05-20 16:01:20 +02:00
Zdenek Kabelac
b3fa71fbd8 libdm: fix dm_list pointer arithmentic for new gcc 10 optimization 2020-03-05 17:38:55 +01:00
Zdenek Kabelac
18aa541ca2 configure: avoid repeative inclusion of configure.h
Since configure.h is a generated header and it's missing traditional
ifdefs preambule - it can be included & parsed multiple times.
Normally compiler is fine when defines have same value and there is
no warning - yet we don't need to parse this several times
and by adding -include  directive we can ensure every file
in the package is rightly compile with configure.h as the
first header file.
2018-12-21 19:19:50 +01:00
Zdenek Kabelac
0b19387dae headers: use configure.h as 1st. header
Ensure configure.h is always 1st. included header.
Maybe we could eventually introduce gcc -include option, but for now
this better uses dependency tracking.

Also move _REENTRANT and _GNU_SOURCE into configure.h so it
doesn't need to be present in various source files.
This ensures consistent compilation of headers like stdio.h since
it may produce different declaration.
2018-12-14 15:09:13 +01:00
Zdenek Kabelac
1aac59f82a gcc: avoid shadowing index
Some older headers were declaring 'index' so avoid its usage.
/usr/include/string.h:489: warning: shadowed declaration is here
2018-12-01 01:06:51 +01:00
Zdenek Kabelac
9238b972c5 cov: mark warning as expected one 2018-11-03 16:10:32 +01:00
Zdenek Kabelac
c7789daec0 cov: overflow before widen
Evaluate as 64bit arithmetic (instead of doing 32bit mults which can
in this case purely teoretically overflow).
2018-11-03 16:10:31 +01:00
Zdenek Kabelac
30b1b57506 cov: add at least ASSERT
Seems lot of code here can't handle failing allocation.
Meanwhile before bigger fix put in asserts in place.
2018-10-15 17:49:44 +02:00
Zdenek Kabelac
eed8715e1d cov: fix missing null allocation check 2018-10-15 17:49:44 +02:00
Joe Thornber
bb17302084 [radix-tree] tidy up _degrade_to_n48
Shouldn't be any functional changes.
2018-09-20 14:28:47 +01:00
Joe Thornber
ebd2d7773f [radix-tree] Fix bug in _degrade_to_n16
Values were getting shuffled
2018-09-20 14:20:16 +01:00
Joe Thornber
0ac7913c6a [radix-tree] Fix bug in _dump
Values in an n48 were not being printed in the correct order.
2018-09-20 14:18:57 +01:00
Joe Thornber
abe2210c26 [radix-tree] Add some extra checks to is_well_formed() 2018-09-20 14:18:10 +01:00
Joe Thornber
4d964133e2 [radix-tree] alternative radix-tree implementation.
Sacrifices performance for simplicity, meant only for verification of
the real adaptive implementation.
2018-09-11 13:12:07 +01:00
Joe Thornber
8b05f1f230 radix-tree: Fix bug in remove_prefix()
Accidental decrement of the nr entries when a n256 didn't have the
entry in the first place.
2018-08-20 15:23:40 +01:00
Joe Thornber
254e5c5d11 radix-tree: squash a pointer arithmetic warning 2018-06-21 17:41:56 +01:00
Joe Thornber
72e2e92f4c radix-tree: fix bug when erasing elts in remove_prefix
_erase_elt() now zeroes the last element of the array (ie. sets to
UNSET).  Previously remove() was doing this, but not remove_prefix().
2018-06-21 17:10:05 +01:00
Joe Thornber
40c1f7889f radix-tree: More debugging of remove
There's now a pretty printer called radix_tree_dump()

n4, n16, and n48 weren't UNSETting the last entry after
sliding values down.
2018-06-21 09:49:43 +01:00
Joe Thornber
20b9746c5d radix-tree: FIx various bugs to do with removal
Add radix_tree_is_well_formed() which does some sanity checking
of the tree.

Call the above a lot in the unit tests.

Fix revealed bugs.
2018-06-21 09:49:08 +01:00
Joe Thornber
61e67e51e1 device_mapper: move hash.[hc] to base/data-struct 2018-06-08 13:54:19 +01:00
Joe Thornber
88ae928ca3 base: Move list to base/data-struct 2018-06-08 11:24:18 +01:00
Joe Thornber
06c789eda1 radix-tree: fix some bugs in remove_prefix and iterate
These weren't working if the prefix key was part of a prefix_chain.
2018-05-30 14:21:27 +01:00
Joe Thornber
1924426ad1 radix-tree: radix_tree_iterate() 2018-05-29 17:58:58 +01:00
Joe Thornber
c2a8bbed3b radix-tree: radix_tree_remove_prefix() 2018-05-29 13:25:59 +01:00
Joe Thornber
9b41efae82 radix-tree: call the value dtr when removing an entry. 2018-05-29 11:23:36 +01:00
Joe Thornber
0181c77e3f Merge branch '2018-05-29-radix-tree-iterate' into 2018-05-23-radix-tree-remove 2018-05-29 11:04:32 +01:00
Joe Thornber
033df741e2 data-struct/radix-tree: pass the value dtr into create.
Rather than having to pass it into every method that removes items.
2018-05-29 11:03:10 +01:00
Joe Thornber
b7fd8ac8eb radix_tree: add remove method 2018-05-23 12:48:06 +01:00
Joe Thornber
30a4c7988e radix-tree: remove some unneccessary includes 2018-05-11 09:46:34 +01:00
Joe Thornber
576dd1fc41 radix-tree: First drop of radix tree.
An implementation of an adaptive radix tree.  Has the following nice
properties:

  - At least as fast as the hash table
  - Uses less memory
  - You don't need to give an expected size when you create
  - It scales nicely (ie. no large reallocations like the hash table).
  - You can iterate the keys in lexicographical order.

Only insert and lookup are implemented so far.  Plus there's a lot
more performance to come.
2018-05-11 06:10:01 +01:00