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more TDB

This commit is contained in:
Hongze Cheng 2022-02-07 09:38:13 +00:00
parent f3d1bd4340
commit 24fe6cb2df
1 changed files with 22 additions and 2 deletions
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24
source/libs/tdb/src/db/pgcache.c
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@ -20,6 +20,7 @@ struct SPage {
frame_id_t frameid; // frame id
SPgListNode freeNode; // for SPgCache.freeList
SPgListNode pghtNode; // for pght
SPgListNode lruNode; // for LRU
uint8_t * pData; // real data
};
@ -31,6 +32,7 @@ struct SPgCache {
int32_t npage;
SPage * pages;
SPgList freeList;
SPgList lru;
struct {
int32_t nbucket;
SPgList *buckets;
@ -38,6 +40,7 @@ struct SPgCache {
};
static void pgCachePinPage(SPage *pPage);
static void pgCacheUnpinPage(SPage *pPage);
int pgCacheCreate(SPgCache **ppPgCache, pgsize_t pgSize, int32_t npage) {
SPgCache *pPgCache;
@ -144,12 +147,29 @@ SPage *pgCacheFetch(SPgCache *pPgCache, pgid_t pgid) {
}
if (pPage) {
// Page is found, pin the page (TODO) and return the page
// Page is found, pin the page and return the page
pgCachePinPage(pPage);
return pPage;
}
// TODO
// 2. Check the free list
pPage = TD_DLIST_HEAD(&(pPgCache->freeList));
if (pPage) {
TD_DLIST_POP_WITH_FIELD(&(pPgCache->freeList), pPage, freeNode);
pgCachePinPage(pPage);
return pPage;
}
// 3. Try to recycle a page from the LRU list
pPage = TD_DLIST_HEAD(&(pPgCache->lru));
if (pPage) {
TD_DLIST_POP_WITH_FIELD(&(pPgCache->lru), pPage, lruNode);
// TODO: remove from the hash table
pgCachePinPage(pPage);
return pPage;
}
// 4. If a memory allocator is set, try to allocate from the allocator (TODO)
return NULL;
}