U0 DskCacheInit(I64 size_in_U8s)
{
CCacheBlk *tmpc;
I64 i,cnt;
while (LBts(&sys_semas[SEMA_DSK_CACHE],0))
Yield;
Free(blkdev.cache_ctrl);
Free(blkdev.cache_base);
Free(blkdev.cache_hash_table);
if (size_in_U8s<0x2000) {
blkdev.cache_ctrl=NULL;
blkdev.cache_base=NULL;
blkdev.cache_hash_table=NULL;
} else {
blkdev.cache_ctrl=ACAlloc(offset(CCacheBlk.body));
blkdev.cache_base=AMAlloc(size_in_U8s);
QueInit(blkdev.cache_ctrl);
cnt=MSize(blkdev.cache_base)/sizeof(CCacheBlk);
blkdev.cache_size=cnt*BLK_SIZE;
for (i=0;i<cnt;i++) {
tmpc=blkdev.cache_base+i;
QueIns(tmpc,blkdev.cache_ctrl->last_lru);
tmpc->next_hash=tmpc->last_hash=tmpc;
tmpc->dv=NULL;
tmpc->blk=0;
}
blkdev.cache_hash_table=AMAlloc(DSK_CACHE_HASH_SIZE*sizeof(U8 *)*2);
for (i=0;i<DSK_CACHE_HASH_SIZE;i++) {
tmpc=blkdev.cache_hash_table(U8 *)+i*sizeof(U8 *)*2
-offset(CCacheBlk.next_hash);
tmpc->next_hash=tmpc->last_hash=tmpc;
}
}
LBtr(&sys_semas[SEMA_DSK_CACHE],0);
}
I64 DskCacheHash(I64 blk)
{
I64 i=blk & (DSK_CACHE_HASH_SIZE-1);
return blkdev.cache_hash_table(U8 *)+i<<4-offset(CCacheBlk.next_hash);
}
U0 DskCacheQueRem(CCacheBlk *tmpc)
{
QueRem(tmpc);
tmpc->next_hash->last_hash=tmpc->last_hash;
tmpc->last_hash->next_hash=tmpc->next_hash;
}
U0 DskCacheQueIns(CCacheBlk *tmpc)
{
CCacheBlk *tmp_n,*tmp_l;
QueIns(tmpc,blkdev.cache_ctrl->last_lru);
tmp_l=DskCacheHash(tmpc->blk);
tmp_n=tmp_l->next_hash;
tmpc->last_hash=tmp_l;
tmpc->next_hash=tmp_n;
tmp_l->next_hash=tmp_n->last_hash=tmpc;
}
CCacheBlk *DskCacheFind(CDrv *dv,I64 blk)
{
CCacheBlk *tmpc,*tmpc1=DskCacheHash(blk);
tmpc=tmpc1->next_hash;
while (tmpc!=tmpc1) {
if (tmpc->dv==dv && tmpc->blk==blk)
return tmpc;
tmpc=tmpc->next_hash;
}
return NULL;
}
U0 DskCacheAdd(CDrv *dv,U8 *buf, I64 blk, I64 cnt)
{
CCacheBlk *tmpc;
if (blkdev.cache_base) {
while (LBts(&sys_semas[SEMA_DSK_CACHE],0))
Yield;
while (cnt-->0) {
if (!(tmpc=DskCacheFind(dv,blk)))
tmpc=blkdev.cache_ctrl->next_lru;
DskCacheQueRem(tmpc);
MemCpy(&tmpc->body,buf,BLK_SIZE);
tmpc->dv=dv;
tmpc->blk=blk;
DskCacheQueIns(tmpc);
blk++;
buf+=BLK_SIZE;
}
LBtr(&sys_semas[SEMA_DSK_CACHE],0);
}
}
U0 DskCacheInvalidate2(CDrv *dv)
{
CCacheBlk *tmpc,*tmpc1;
if (blkdev.cache_base) {
while (LBts(&sys_semas[SEMA_DSK_CACHE],0))
Yield;
tmpc=blkdev.cache_ctrl->last_lru;
while (tmpc!=blkdev.cache_ctrl) {
tmpc1=tmpc->last_lru;
if (tmpc->dv==dv) {
DskCacheQueRem(tmpc);
tmpc->dv=NULL;
tmpc->blk=0;
tmpc->next_hash=tmpc->last_hash=tmpc;
QueIns(tmpc,blkdev.cache_ctrl->last_lru);
}
tmpc=tmpc1;
}
LBtr(&sys_semas[SEMA_DSK_CACHE],0);
}
}
U0 RCache(CDrv *dv,U8 **_buf, I64 *_blk, I64 *_cnt)
{
CCacheBlk *tmpc;
if (blkdev.cache_base) {
while (LBts(&sys_semas[SEMA_DSK_CACHE],0))
Yield;
//fetch leading blks from cache
while (*_cnt>0) {
if (tmpc=DskCacheFind(dv,*_blk)) {
MemCpy(*_buf,&tmpc->body,BLK_SIZE);
*_cnt-=1;
*_buf+=BLK_SIZE;
*_blk+=1;
} else
break;
}
//fetch trailing blks from cache
while (*_cnt>0) {
if (tmpc=DskCacheFind(dv,*_blk+*_cnt-1)) {
MemCpy(*_buf+(*_cnt-1)<<BLK_SIZE_BITS,&tmpc->body,BLK_SIZE);
*_cnt-=1;
} else
break;
}
LBtr(&sys_semas[SEMA_DSK_CACHE],0);
}
}