miegl/glorytun
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Simplify the db by merging size and mask

Browse Source
This commit is contained in:
angt
2015-12-24 13:13:43 +01:00
parent 597c586657
commit cf022af4a9
1 changed files with 24 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
src/db.c
View File

@@ -7,8 +7,7 @@
struct node { struct node {
uint8_t *child[2]; uint8_t *child[2];
uint8_t size; uint32_t point;
uint8_t mask;
}; };
_pure_ _pure_
@@ -39,17 +38,19 @@ static inline size_t db_cmp (const uint8_t *a, const uint8_t *b)
} }
_pure_ _pure_
static inline int db_dir (struct node *node, const uint8_t *data, const size_t size) static inline int db_dir (const uint32_t point, uint8_t *data, const size_t size)
{ {
if (node->size>=size) const size_t pos = point>>8;
if (pos>=size)
return 0; return 0;
return (node->mask|data[node->size])==255; return ((point|data[pos])&255)==255;
} }
uint8_t *db_search (uint8_t **p, uint8_t *data) uint8_t *db_search (uint8_t **p, uint8_t *data)
{ {
if (!*p) if _0_(!*p)
return NULL; return NULL;
uint8_t *r = *p; uint8_t *r = *p;
@@ -57,7 +58,7 @@ uint8_t *db_search (uint8_t **p, uint8_t *data)
while (CBIT(r)) { while (CBIT(r)) {
struct node *node = CBIT_NODE(r); struct node *node = CBIT_NODE(r);
r = node->child[db_dir(node, data, size)]; r = node->child[db_dir(node->point, data, size)];
} }
if (!db_cmp(r, data)) if (!db_cmp(r, data))
@@ -68,52 +69,50 @@ uint8_t *db_search (uint8_t **p, uint8_t *data)
uint8_t *db_insert (uint8_t **p, uint8_t *data) uint8_t *db_insert (uint8_t **p, uint8_t *data)
{ {
if (CBIT(data)) if _0_(CBIT(data))
return NULL; return NULL;
if (!*p) { if _0_(!*p) {
*p = data; *p = data;
return data; return data;
} }
uint8_t *r = *p; uint8_t *r = *p;
size_t data_size = db_size(data); size_t size = db_size(data);
while (CBIT(r)) { while (CBIT(r)) {
struct node *node = CBIT_NODE(r); struct node *node = CBIT_NODE(r);
r = node->child[db_dir(node, data, data_size)]; r = node->child[db_dir(node->point, data, size)];
} }
const size_t diff = db_cmp(r, data); const size_t diff = db_cmp(r, data);
if (!diff) if _0_(!diff)
return r; return r;
const uint8_t size = diff-1; const size_t pos = diff-1;
const uint8_t mask = ~((1u<<31)>>CLZ(r[size]^data[size])); const uint8_t mask = ~((1u<<31)>>CLZ(r[pos]^data[pos]));
const size_t point = (pos<<8)|mask;
while (CBIT(*p)) { while (CBIT(*p)) {
struct node *node = CBIT_NODE(*p); struct node *node = CBIT_NODE(*p);
if ((node->size>size) || if (node->point>point)
(node->size==size && node->mask>mask)) {
break; break;
}
p = node->child+db_dir(node, data, data_size); p = node->child+db_dir(node->point, data, size);
} }
struct node *node = malloc(sizeof(struct node)); struct node *node = malloc(sizeof(struct node));
if (!node) if _0_(!node)
return NULL; return NULL;
const int dir = (mask|r[size])==255; const int dir = (mask|r[pos])==255;
node->child[dir] = *p; node->child[dir] = *p;
node->child[1-dir] = data; node->child[1-dir] = data;
node->size = size; node->point = point;
node->mask = mask;
*p = CBIT_PTR(node); *p = CBIT_PTR(node);
@@ -122,7 +121,7 @@ uint8_t *db_insert (uint8_t **p, uint8_t *data)
uint8_t *db_remove (uint8_t **p, uint8_t *data) uint8_t *db_remove (uint8_t **p, uint8_t *data)
{ {
if (!*p) if _0_(!*p)
return NULL; return NULL;
const size_t size = db_size(data); const size_t size = db_size(data);
@@ -134,11 +133,11 @@ uint8_t *db_remove (uint8_t **p, uint8_t *data)
while (CBIT(*p)) { while (CBIT(*p)) {
p_old = p; p_old = p;
node = CBIT_NODE(*p); node = CBIT_NODE(*p);
dir = db_dir(node, data, size); dir = db_dir(node->point, data, size);
p = node->child+dir; p = node->child+dir;
} }
if (db_cmp(data, *p)) if _0_(db_cmp(data, *p))
return NULL; return NULL;
uint8_t *r = *p; uint8_t *r = *p;