mirror of
https://github.com/ilyakooo0/urbit.git
synced 2024-11-24 10:33:22 +03:00
121 lines
3.6 KiB
C
121 lines
3.6 KiB
C
/* include/n/h.h
|
|
**
|
|
** This file is in the public domain.
|
|
*/
|
|
/** Data structures.
|
|
**/
|
|
/** Straightforward implementation of the classic Bagwell
|
|
*** HAMT (hash array mapped trie), using a mug hash.
|
|
***
|
|
*** Because a mug is 31 bits, the root table is 64 wide.
|
|
*** Thereupon 5 bits each are warm for each layer. The
|
|
*** final leaf is simply a linear search.
|
|
***
|
|
*** We store an extra "freshly warm" bit for a simple
|
|
*** clock-algorithm reclamation policy, not yet implemented.
|
|
*** Search "clock algorithm" to figure it out.
|
|
**/
|
|
/* u3h_slot: map slot.
|
|
**
|
|
** Either a key-value cell or a loom offset, decoded as a pointer
|
|
** to a u3h_node. Matches the u3_noun format - coordinate with
|
|
** meme.h. The top two bits are:
|
|
**
|
|
** 00 - empty (in the root table only)
|
|
** 01 - table
|
|
** 02 - entry, stale
|
|
** 03 - entry, fresh
|
|
*/
|
|
typedef c3_w u3h_slot;
|
|
|
|
/* u3h_node: map node.
|
|
*/
|
|
typedef struct {
|
|
c3_w map_w;
|
|
u3h_slot sot_w[0];
|
|
} u3h_node;
|
|
|
|
/* u3h_root: hash root table, with future-proof clock.
|
|
*/
|
|
typedef struct {
|
|
c3_w clk_w;
|
|
u3h_slot sot_w[64];
|
|
} u3h_root;
|
|
|
|
/* u3h_buck: bottom bucket.
|
|
*/
|
|
typedef struct {
|
|
c3_w len_w;
|
|
u3_noun kev[0];
|
|
} u3h_buck;
|
|
|
|
/** HAMT macros.
|
|
***
|
|
*** Coordinate with u3_noun definition!
|
|
**/
|
|
/* u3h_slot_is_null(): yes iff slot is empty
|
|
** u3h_slot_is_noun(): yes iff slot contains a key/value cell
|
|
** u3h_slot_is_node(): yes iff slot contains a subtable/bucket
|
|
** u3h_slot_is_warm(): yes iff fresh bit is set
|
|
** u3h_slot_to_node(): slot to node pointer
|
|
** u3h_node_to_slot(): node pointer to slot
|
|
** u3h_slot_to_noun(): slot to cell
|
|
** u3h_noun_to_slot(): cell to slot
|
|
*/
|
|
# define u3h_slot_is_null(sot) ((0 == ((sot) >> 30)) ? c3y : c3n)
|
|
# define u3h_slot_is_node(sot) ((1 == ((sot) >> 30)) ? c3y : c3n)
|
|
# define u3h_slot_is_noun(sot) ((1 == ((sot) >> 31)) ? c3y : c3n)
|
|
# define u3h_slot_is_warm(sot) (((sot) & 0x40000000) ? c3y : c3n)
|
|
# define u3h_slot_to_node(sot) (u3a_into((sot) & 0x3fffffff))
|
|
# define u3h_node_to_slot(ptr) (u3a_outa(ptr) | 0x40000000)
|
|
# define u3h_slot_to_noun(sot) (0x40000000 | (sot))
|
|
# define u3h_noun_to_slot(som) (som)
|
|
# define u3h_noun_be_warm(sot) ((sot) | 0x40000000)
|
|
# define u3h_noun_be_cold(sot) ((sot) & ~0x40000000)
|
|
|
|
|
|
/** Functions.
|
|
***
|
|
*** Needs: delete and merge functions; clock reclamation function.
|
|
**/
|
|
/* u3h_new(): create hashtable.
|
|
*/
|
|
u3p(u3h_root)
|
|
u3h_new(void);
|
|
|
|
/* u3h_put(): insert in hashtable.
|
|
**
|
|
** `key` is RETAINED; `val` is transferred.
|
|
*/
|
|
void
|
|
u3h_put(u3p(u3h_root) har_p, u3_noun key, u3_noun val);
|
|
|
|
/* u3h_get(): read from hashtable.
|
|
**
|
|
** `key` is RETAINED.
|
|
*/
|
|
u3_weak
|
|
u3h_get(u3p(u3h_root) har_p, u3_noun key);
|
|
|
|
/* u3h_gut(): read from hashtable, unifying key nouns.
|
|
**
|
|
** `key` is RETAINED.
|
|
*/
|
|
u3_weak
|
|
u3h_gut(u3p(u3h_root) har_p, u3_noun key);
|
|
|
|
/* u3h_free(): free hashtable.
|
|
*/
|
|
void
|
|
u3h_free(u3p(u3h_root) har_p);
|
|
|
|
/* u3h_mark(): mark hashtable for gc.
|
|
*/
|
|
void
|
|
u3h_mark(u3p(u3h_root) har_p);
|
|
|
|
/* u3h_walk(): traverse hashtable with key, value fn; RETAINS.
|
|
*/
|
|
void
|
|
u3h_walk(u3p(u3h_root) har_p, void (*fun_f)(u3_noun));
|