homework-jianmu/source/libs/tdb/src/db/tdbPage.c

107 lines
2.3 KiB
C

/*
* Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
*
* This program is free software: you can use, redistribute, and/or modify
* it under the terms of the GNU Affero General Public License, version 3
* or later ("AGPL"), as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "tdbInt.h"
static int tdbPageAllocate(SPage *pPage, int size, SCell **ppCell);
int tdbPageCreate(int pageSize, SPage **ppPage, void *(*xMalloc)(void *, size_t), void *arg) {
SPage *pPage;
u8 *ptr;
int size;
ASSERT(TDB_IS_PGSIZE_VLD(pageSize));
*ppPage = NULL;
size = pageSize + sizeof(*pPage);
ptr = (u8 *)((*xMalloc)(arg, size));
if (pPage == NULL) {
return -1;
}
memset(ptr, 0, size);
pPage = (SPage *)(ptr + pageSize);
pPage->pData = ptr;
pPage->pageSize = pageSize;
if (pageSize < 65536) {
pPage->szOffset = 2;
} else {
pPage->szOffset = 3;
}
TDB_INIT_PAGE_LOCK(pPage);
/* TODO */
*ppPage = pPage;
return 0;
}
int tdbPageDestroy(SPage *pPage, void (*xFree)(void *arg, void *ptr), void *arg) {
u8 *ptr;
ptr = pPage->pData;
(*xFree)(arg, ptr);
return 0;
}
int tdbPageInsertCell(SPage *pPage, int idx, SCell *pCell, int szCell) {
int ret;
SCell *pTarget;
if (pPage->nOverflow || szCell + pPage->szOffset > pPage->nFree) {
// TODO
} else {
ret = tdbPageAllocate(pPage, szCell, &pTarget);
if (ret < 0) {
return -1;
}
}
return 0;
}
int tdbPageDropCell(SPage *pPage, int idx) {
// TODO
return 0;
}
static int tdbPageAllocate(SPage *pPage, int size, SCell **ppCell) {
SCell *pCell;
ASSERT(pPage->nFree > size + pPage->szOffset);
if (pPage->pFreeEnd - pPage->pFreeStart > size + pPage->szOffset) {
pPage->pFreeEnd -= size;
pPage->pFreeStart += pPage->szOffset;
pCell = pPage->pFreeEnd;
} else {
}
return 0;
}
static int tdbPageFree(SPage *pPage, int idx, SCell *pCell, int size) {
// TODO
return 0;
}
static int tdbPageDefragment(SPage *pPage) {
// TODO
return 0;
}