TempleOSCDV3.11.ISO

Kernel/BlkDev/DskCache.CPP

@@ -0,0 +1,145 @@
+U0 DskCacheInit(I64 size_in_U8s)
+{
+  CCacheBlk *tempc;
+  I64 i,cnt;
+
+  while (LBts(&sys_semas[SYS_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++) {
+      tempc=blkdev.cache_base+i;
+      QueIns(tempc,blkdev.cache_ctrl->last_lru);
+      tempc->next_hash=tempc->last_hash=tempc;
+      tempc->dv=NULL;
+      tempc->blk=0;
+    }
+
+    blkdev.cache_hash_table=AMAlloc(DSK_CACHE_HASH_SIZE*sizeof(U8 *)*2);
+    for (i=0;i<DSK_CACHE_HASH_SIZE;i++) {
+      tempc=blkdev.cache_hash_table(U8 *)+i*sizeof(U8 *)*2
+	    -offset(CCacheBlk.next_hash);
+      tempc->next_hash=tempc->last_hash=tempc;
+    }
+  }
+  LBtr(&sys_semas[SYS_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 *tempc)
+{
+  QueRem(tempc);
+  tempc->next_hash->last_hash=tempc->last_hash;
+  tempc->last_hash->next_hash=tempc->next_hash;
+}
+
+U0 DskCacheQueIns(CCacheBlk *tempc)
+{
+  CCacheBlk *temp_n,*temp_l;
+  QueIns(tempc,blkdev.cache_ctrl->last_lru);
+  temp_l=DskCacheHash(tempc->blk);
+  temp_n=temp_l->next_hash;
+  tempc->last_hash=temp_l;
+  tempc->next_hash=temp_n;
+  temp_l->next_hash=temp_n->last_hash=tempc;
+}
+
+CCacheBlk *DskCacheFind(CDrv *dv,I64 blk)
+{
+  CCacheBlk *tempc,*tempc1=DskCacheHash(blk);
+  tempc=tempc1->next_hash;
+  while (tempc!=tempc1) {
+    if (tempc->dv==dv && tempc->blk==blk)
+      return tempc;
+    tempc=tempc->next_hash;
+  }
+  return NULL;
+}
+
+U0 DskCacheAdd(CDrv *dv,U8 *buf, I64 blk, I64 cnt)
+{
+  CCacheBlk *tempc;
+  if (blkdev.cache_base) {
+    while (LBts(&sys_semas[SYS_SEMA_DSK_CACHE],0))
+      Yield;
+    while (cnt-->0) {
+      if (!(tempc=DskCacheFind(dv,blk)))
+	tempc=blkdev.cache_ctrl->next_lru;
+      DskCacheQueRem(tempc);
+      MemCpy(&tempc->body,buf,BLK_SIZE);
+      tempc->dv=dv;
+      tempc->blk=blk;
+      DskCacheQueIns(tempc);
+      blk++;
+      buf+=BLK_SIZE;
+    }
+    LBtr(&sys_semas[SYS_SEMA_DSK_CACHE],0);
+  }
+}
+
+U0 DskCacheInvalidate2(CDrv *dv)
+{
+  CCacheBlk *tempc,*tempc1;
+  if (blkdev.cache_base) {
+    while (LBts(&sys_semas[SYS_SEMA_DSK_CACHE],0))
+      Yield;
+    tempc=blkdev.cache_ctrl->last_lru;
+    while (tempc!=blkdev.cache_ctrl) {
+      tempc1=tempc->last_lru;
+      if (tempc->dv==dv) {
+	DskCacheQueRem(tempc);
+	tempc->dv=NULL;
+	tempc->blk=0;
+	tempc->next_hash=tempc->last_hash=tempc;
+	QueIns(tempc,blkdev.cache_ctrl->last_lru);
+      }
+      tempc=tempc1;
+    }
+    LBtr(&sys_semas[SYS_SEMA_DSK_CACHE],0);
+  }
+}
+
+U0 RCache(CDrv *dv,U8 **_buf, I64 *_blk, I64 *_cnt)
+{
+  CCacheBlk *tempc;
+  if (blkdev.cache_base) {
+    while (LBts(&sys_semas[SYS_SEMA_DSK_CACHE],0))
+      Yield;
+//fetch leading blks from cache
+    while (*_cnt>0) {
+      if (tempc=DskCacheFind(dv,*_blk)) {
+	MemCpy(*_buf,&tempc->body,BLK_SIZE);
+	*_cnt-=1;
+	*_buf+=BLK_SIZE;
+	*_blk+=1;
+      } else
+	break;
+    }
+//fetch trailing blks from cache
+    while (*_cnt>0) {
+      if (tempc=DskCacheFind(dv,*_blk+*_cnt-1)) {
+	MemCpy(*_buf+(*_cnt-1)<<BLK_SIZE_BITS,&tempc->body,BLK_SIZE);
+	*_cnt-=1;
+      } else
+	break;
+    }
+    LBtr(&sys_semas[SYS_SEMA_DSK_CACHE],0);
+  }
+}