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

247 lines
7.7 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"
typedef struct __attribute__((__packed__)) {
u8 szCell[2];
u8 nxOffset[2];
} SFreeCell;
typedef struct __attribute__((__packed__)) {
u8 szCell[3];
u8 nxOffset[3];
} SFreeCellL;
/* For small page */
#define TDB_SPAGE_FREE_CELL_SIZE_PTR(PCELL) (((SFreeCell *)(PCELL))->szCell)
#define TDB_SPAGE_FREE_CELL_NXOFFSET_PTR(PCELL) (((SFreeCell *)(PCELL))->nxOffset)
#define TDB_SPAGE_FREE_CELL_SIZE(PCELL) ((u16 *)TDB_SPAGE_FREE_CELL_SIZE_PTR(PCELL))[0]
#define TDB_SPAGE_FREE_CELL_NXOFFSET(PCELL) ((u16 *)TDB_SPAGE_FREE_CELL_NXOFFSET_PTR(PCELL))[0]
#define TDB_SPAGE_FREE_CELL_SIZE_SET(PCELL, SIZE) (TDB_SPAGE_FREE_CELL_SIZE(PCELL) = (SIZE))
#define TDB_SPAGE_FREE_CELL_NXOFFSET_SET(PCELL, OFFSET) (TDB_SPAGE_FREE_CELL_NXOFFSET(PCELL) = (OFFSET))
/* For large page */
#define TDB_LPAGE_FREE_CELL_SIZE_PTR(PCELL) (((SFreeCellL *)(PCELL))->szCell)
#define TDB_LPAGE_FREE_CELL_NXOFFSET_PTR(PCELL) (((SFreeCellL *)(PCELL))->nxOffset)
#define TDB_LPAGE_FREE_CELL_SIZE(PCELL) TDB_GET_U24(TDB_LPAGE_FREE_CELL_SIZE_PTR(PCELL))
#define TDB_LPAGE_FREE_CELL_NXOFFSET(PCELL) TDB_GET_U24(TDB_LPAGE_FREE_CELL_NXOFFSET_PTR(PCELL))
#define TDB_LPAGE_FREE_CELL_SIZE_SET(PCELL, SIZE) TDB_PUT_U24(TDB_LPAGE_FREE_CELL_SIZE_PTR(PCELL), SIZE)
#define TDB_LPAGE_FREE_CELL_NXOFFSET_SET(PCELL, OFFSET) TDB_PUT_U24(TDB_LPAGE_FREE_CELL_NXOFFSET_PTR(PCELL), OFFSET)
/* For page */
#define TDB_PAGE_FREE_CELL_SIZE_PTR(PPAGE, PCELL) \
(TDB_IS_LARGE_PAGE(pPage) ? TDB_LPAGE_FREE_CELL_SIZE_PTR(PCELL) : TDB_SPAGE_FREE_CELL_SIZE_PTR(PCELL))
#define TDB_PAGE_FREE_CELL_NXOFFSET_PTR(PPAGE, PCELL) \
(TDB_IS_LARGE_PAGE(pPage) ? TDB_LPAGE_FREE_CELL_NXOFFSET_PTR(PCELL) : TDB_SPAGE_FREE_CELL_NXOFFSET_PTR(PCELL))
#define TDB_PAGE_FREE_CELL_SIZE(PPAGE, PCELL) \
(TDB_IS_LARGE_PAGE(pPage) ? TDB_LPAGE_FREE_CELL_SIZE(PCELL) : TDB_SPAGE_FREE_CELL_SIZE(PCELL))
#define TDB_PAGE_FREE_CELL_NXOFFSET(PPAGE, PCELL) \
(TDB_IS_LARGE_PAGE(pPage) ? TDB_LPAGE_FREE_CELL_NXOFFSET(PCELL) : TDB_SPAGE_FREE_CELL_NXOFFSET(PCELL))
#define TDB_PAGE_FREE_CELL_SIZE_SET(PPAGE, PCELL, SIZE) \
do { \
if (TDB_IS_LARGE_PAGE(PPAGE)) { \
TDB_LPAGE_FREE_CELL_SIZE_SET(PCELL, SIZE); \
} else { \
TDB_SPAGE_FREE_CELL_SIZE_SET(PCELL, SIZE); \
} \
} while (0)
#define TDB_PAGE_FREE_CELL_NXOFFSET_SET(PPAGE, PCELL, OFFSET) \
do { \
if (TDB_IS_LARGE_PAGE(PPAGE)) { \
TDB_LPAGE_FREE_CELL_NXOFFSET_SET(PCELL, OFFSET); \
} else { \
TDB_SPAGE_FREE_CELL_NXOFFSET_SET(PCELL, OFFSET); \
} \
} while (0)
static int tdbPageAllocate(SPage *pPage, int size, SCell **ppCell);
static int tdbPageDefragment(SPage *pPage);
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;
pPage->szPageHdr = sizeof(SPageHdr);
pPage->szFreeCell = sizeof(SFreeCell);
} else {
pPage->szOffset = 3;
pPage->szPageHdr = sizeof(SPageHdrL);
pPage->szFreeCell = sizeof(SFreeCellL);
}
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: Page is full
ASSERT(0);
} else {
ret = tdbPageAllocate(pPage, szCell, &pTarget);
if (ret < 0) {
return -1;
}
memcpy(pTarget, pCell, szCell);
// TODO: memmove();
TDB_PAGE_CELL_OFFSET_AT_SET(pPage, idx, pCell - pPage->pData);
TDB_PAGE_NCELLS_SET(pPage, TDB_PAGE_NCELLS(pPage) + 1);
}
return 0;
}
int tdbPageDropCell(SPage *pPage, int idx) {
// TODO
return 0;
}
static int tdbPageAllocate(SPage *pPage, int size, SCell **ppCell) {
SCell *pCell;
SFreeCell *pFreeCell;
u8 *pOffset;
int ret;
ASSERT(pPage->nFree > size + pPage->szOffset);
pCell = NULL;
*ppCell = NULL;
// 1. Try to allocate from the free space area
if (pPage->pFreeEnd - pPage->pFreeStart > size + pPage->szOffset) {
pPage->pFreeEnd -= size;
pPage->pFreeStart += pPage->szOffset;
pCell = pPage->pFreeEnd;
}
// 2. Try to allocate from the page free list
if ((pCell == NULL) && (pPage->pFreeEnd - pPage->pFreeStart >= pPage->szOffset) && TDB_PAGE_FCELL(pPage)) {
int szCell;
int nxOffset;
pCell = pPage->pData + TDB_PAGE_FCELL(pPage);
pOffset = TDB_IS_LARGE_PAGE(pPage) ? ((SPageHdrL *)(pPage->pPageHdr))[0].fCell
: (u8 *)&(((SPageHdr *)(pPage->pPageHdr))[0].fCell);
szCell = TDB_PAGE_FREE_CELL_SIZE(pPage, pCell);
nxOffset = TDB_PAGE_FREE_CELL_NXOFFSET(pPage, pCell);
for (;;) {
// Find a cell
if (szCell >= size) {
if (szCell - size >= pPage->szFreeCell) {
SCell *pTmpCell = pCell + size;
TDB_PAGE_FREE_CELL_SIZE_SET(pPage, pTmpCell, szCell - size);
TDB_PAGE_FREE_CELL_NXOFFSET_SET(pPage, pTmpCell, nxOffset);
// TODO: *pOffset = pTmpCell - pPage->pData;
} else {
TDB_PAGE_NFREE_SET(pPage, TDB_PAGE_NFREE(pPage) + szCell - size);
// TODO: *pOffset = nxOffset;
}
break;
}
// Not find a cell yet
if (nxOffset > 0) {
pCell = pPage->pData + nxOffset;
pOffset = TDB_PAGE_FREE_CELL_NXOFFSET_PTR(pPage, pCell);
szCell = TDB_PAGE_FREE_CELL_SIZE(pPage, pCell);
nxOffset = TDB_PAGE_FREE_CELL_NXOFFSET(pPage, pCell);
continue;
} else {
pCell = NULL;
break;
}
}
if (pCell) {
pPage->pFreeStart = pPage->pFreeStart + pPage->szOffset;
}
}
// 3. Try to dfragment and allocate again
if (pCell == NULL) {
ret = tdbPageDefragment(pPage);
if (ret < 0) {
return -1;
}
ASSERT(pPage->pFreeEnd - pPage->pFreeStart > size + pPage->szOffset);
ASSERT(pPage->nFree == pPage->pFreeEnd - pPage->pFreeStart);
// Allocate from the free space area again
pPage->pFreeEnd -= size;
pPage->pFreeStart += pPage->szOffset;
pCell = pPage->pFreeEnd;
}
ASSERT(pCell != NULL);
pPage->nFree = pPage->nFree - size - pPage->szOffset;
*ppCell = pCell;
return 0;
}
static int tdbPageFree(SPage *pPage, int idx, SCell *pCell, int size) {
// TODO
return 0;
}
static int tdbPageDefragment(SPage *pPage) {
// TODO
ASSERT(0);
return 0;
}