view release on metacpan or  search on metacpan

unqlite/unqlite.c  view on Meta::CPAN

	/* Acquire a writer lock */
	rc = pPage->pHash->pIo->xWrite(pPage->pRaw);
	if( rc != UNQLITE_OK ){
		return rc;
	}
	/* Offset of the first cell */
	SyBigEndianPack16(zRaw,0);
	zRaw += 2;
	/* Offset of the first free block */
	pHeader->iFree = L_HASH_PAGE_HDR_SZ;
	SyBigEndianPack16(zRaw,L_HASH_PAGE_HDR_SZ);
	zRaw += 2;
	/* Slave page number */
	SyBigEndianPack64(zRaw,0);
	zRaw += 8;
	/* Fill the free block */
	SyBigEndianPack16(zRaw,0); /* Offset of the next free block */
	zRaw += 2;
	nByte = (sxu16)L_HASH_MX_FREE_SPACE(pPage->pHash->iPageSize);
	SyBigEndianPack16(zRaw,nByte);
	pPage->nFree = nByte;
	/* Do not add this page to the hot dirty list */
	pPage->pHash->pIo->xDontMkHot(pPage->pRaw);
	return UNQLITE_OK;
}
/* Forward declaration */
static int lhSlaveStore(
	lhpage *pPage,
	const void *pKey,sxu32 nKeyLen,
	const void *pData,unqlite_int64 nDataLen,
	sxu32 nHash
	);
/*
 * Store a cell and its payload in a given page.
 */
static int lhStoreCell(
	lhpage *pPage, /* Target page */
	const void *pKey,sxu32 nKeyLen, /* Payload: Key */
	const void *pData,unqlite_int64 nDataLen, /* Payload: Data */
	sxu32 nHash, /* Hash of the key */
	int auto_append /* Auto append a slave page if full */
	)
{
	lhash_kv_engine *pEngine = pPage->pHash;
	int iNeedOvfl = 0; /* Need overflow page for this cell and its payload*/
	lhcell *pCell;
	sxu16 nOfft;
	int rc;
	/* Acquire a writer lock on this page first */
	rc = pEngine->pIo->xWrite(pPage->pRaw);
	if( rc != UNQLITE_OK ){
		return rc;
	}
	/* Check for a free block  */
	rc = lhAllocateSpace(pPage,L_HASH_CELL_SZ+nKeyLen+nDataLen,&nOfft);
	if( rc != UNQLITE_OK ){
		/* Check for a free block to hold a single cell only (without payload) */
		rc = lhAllocateSpace(pPage,L_HASH_CELL_SZ,&nOfft);
		if( rc != UNQLITE_OK ){
			if( !auto_append ){
				/* A split must be done */
				return UNQLITE_FULL;
			}else{
				/* Store this record in a slave page */
				rc = lhSlaveStore(pPage,pKey,nKeyLen,pData,nDataLen,nHash);
				return rc;
			}
		}
		iNeedOvfl = 1;
	}
	/* Allocate a new cell instance */
	pCell = lhNewCell(pEngine,pPage);
	if( pCell == 0 ){
		pEngine->pIo->xErr(pEngine->pIo->pHandle,"KV store is running out of memory");
		return UNQLITE_NOMEM;
	}
	/* Fill-in the structure */
	pCell->iStart = nOfft;
	pCell->nKey = nKeyLen;
	pCell->nData = (sxu64)nDataLen;
	pCell->nHash = nHash;
	if( nKeyLen < 262144 /* 256 KB */ ){
		/* Keep the key in-memory for fast lookup */
		SyBlobAppend(&pCell->sKey,pKey,nKeyLen);
	}
	/* Link the cell */
	rc = lhInstallCell(pCell);
	if( rc != UNQLITE_OK ){
		return rc;
	}
	/* Write the payload */
	if( iNeedOvfl ){
		rc = lhCellWriteOvflPayload(pCell,pKey,nKeyLen,pData,nDataLen,(const void *)0);
		if( rc != UNQLITE_OK ){
			lhCellDiscard(pCell);
			return rc;
		}
	}else{
		lhCellWriteLocalPayload(pCell,pKey,nKeyLen,pData,nDataLen);
	}
	/* Finally, Write the cell header */
	lhCellWriteHeader(pCell);
	/* All done */
	return UNQLITE_OK;
}
/*
 * Find a slave page capable of hosting the given amount.
 */
static int lhFindSlavePage(lhpage *pPage,sxu64 nAmount,sxu16 *pOfft,lhpage **ppSlave)
{
	lhash_kv_engine *pEngine = pPage->pHash;
	lhpage *pMaster = pPage->pMaster;
	lhpage *pSlave = pMaster->pSlave;
	unqlite_page *pRaw;
	lhpage *pNew;
	sxu16 iOfft;
	sxi32 i;
	int rc;
	/* Look for an already attached slave page */
	for( i = 0 ; i < pMaster->iSlave ; ++i ){
		/* Find a free chunk big enough */