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Start to reintroduce backpointers in skiplist. 

Also need an non-nullptr end node now.
This commit is contained in:
Max Neunhoeffer 2014-09-16 00:17:04 +02:00
parent 7e44fa03d0
commit c57569a27c
2 changed files with 32 additions and 4 deletions
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26
lib/Basics/skip-list.cpp
View File

@ -87,6 +87,7 @@ static TRI_skiplist_node_t* SkipListAllocNode (TRI_skiplist_t* sl,
TRI_Free(TRI_UNKNOWN_MEM_ZONE, newNode);
return nullptr;
}
newNode->prev = nullptr;
sl->_memoryUsed += sizeof(TRI_skiplist_node_t) +
sizeof(TRI_skiplist_node_t*) * newNode->height;
@ -291,15 +292,26 @@ TRI_skiplist_t* TRI_InitSkipList (TRI_skiplist_cmp_elm_elm_t cmp_elm_elm,
sl->_memoryUsed = sizeof(TRI_skiplist_t);
sl->start = SkipListAllocNode(sl, TRI_SKIPLIST_MAX_HEIGHT);
if (nullptr == sl->start) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE,sl);
return nullptr;
}
sl->end = SkipListAllocNode(sl, 1);
if (nullptr == sl->end) {
SkipListFreeNnode(sl, sl->start);
TRI_Free(TRI_UNKNOWN_MEM_ZONE, sl);
return nullptr;
}
sl->start->height = 1;
sl->start->next[0] = nullptr;
sl->start->next[0] = sl->end;
sl->start->prev = nullptr;
sl->end->height = 1;
sl->end->next[0] = nullptr;
sl->end->prev = start;
sl->cmp_elm_elm = cmp_elm_elm;
sl->cmp_key_elm = cmp_key_elm;
@ -343,7 +355,15 @@ TRI_skiplist_node_t* TRI_SkipListStartNode (TRI_skiplist_t* sl) {
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return the successor node or nullptr if last node
/// @brief return the end node
////////////////////////////////////////////////////////////////////////////////
TRI_skiplist_node_t* TRI_SkipListEndNode (TRI_skiplist_t* sl) {
return sl->end;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return the successor node or sl->end if last node
////////////////////////////////////////////////////////////////////////////////
TRI_skiplist_node_t* TRI_SkipListNextNode (TRI_skiplist_node_t* node) {

10
lib/Basics/skip-list.h
View File

@ -49,8 +49,9 @@
typedef struct TRI_skiplist_node_s {
struct TRI_skiplist_node_s** next;
int height;
struct TRI_skiplist_node_s* prev;
void *doc;
int height;
} TRI_skiplist_node_t;
////////////////////////////////////////////////////////////////////////////////
@ -96,6 +97,7 @@ typedef void (*TRI_skiplist_free_func_t)(void*);
typedef struct TRI_skiplist_s {
TRI_skiplist_node_t* start;
TRI_skiplist_node_t* end;
TRI_skiplist_cmp_elm_elm_t cmp_elm_elm;
TRI_skiplist_cmp_key_elm_t cmp_key_elm;
void* cmpdata; // will be the first argument
@ -139,6 +141,12 @@ void TRI_FreeSkipList (TRI_skiplist_t* sl);
TRI_skiplist_node_t* TRI_SkipListStartNode (TRI_skiplist_t* sl);
////////////////////////////////////////////////////////////////////////////////
/// @brief return the end node
////////////////////////////////////////////////////////////////////////////////
TRI_skiplist_node_t* TRI_SkipListEndNode (TRI_skiplist_t* sl);
////////////////////////////////////////////////////////////////////////////////
/// @brief return the successor node or NULL if last node
////////////////////////////////////////////////////////////////////////////////