Initial (manual) import

2017-01-22 20:26:44 +01:00
1 parent f39611c506
commit 895fe109de
@@ -0,0 +1,151 @@
+I64 ClusterNumNext(CDrv *dv,I64 c,I64 cnt=1)
+{//Return next cnt'th cluster in chain.
+  Bool unlock;
+  DrvChk(dv);
+  if (cnt<=0) return c;
+  try {
+    unlock=DrvLock(dv);
+    switch (dv->fs_type) {
+      case FSt_ISO9660:
+      case FSt_REDSEA:
+	c+=cnt;
+	break;
+      case FSt_FAT32:
+	while (cnt-->0 && 0<c<0x0FFFFFF8) {
+	  DrvFATBlkSet(dv,c);
+	  c=dv->cur_fat_blk[c & (BLK_SIZE/4-1)];
+	}
+	if (!(0<c<0x0FFFFFF8))
+	  c=INVALID_CLUSTER;
+	break;
+      default:
+	throw('Drv');
+    }
+    if (unlock)
+      DrvUnlock(dv);
+  } catch
+    if (unlock)
+      DrvUnlock(dv);
+  return c;
+}
+
+I64 Cluster2Blk(CDrv *dv,I64 c)
+{//Drv cluster num to blk num.
+  DrvChk(dv);
+  switch (dv->fs_type) {
+    case FSt_REDSEA:
+      return c;
+    case FSt_ISO9660:
+    case FSt_FAT32:
+      return dv->data_area+c*dv->spc;
+    default:
+      throw('Drv');
+  }
+}
+
+I64 RClustersBlks(CDrv *dv,U8 *buf,I64 c,I64 blks)
+{//Accepts blk count, so padding on last cluster is not read.
+  I64 i;
+  Bool unlock;
+  DrvChk(dv);
+  if (blks<=0) return c;
+  try {
+    unlock=DrvLock(dv);
+    switch (dv->fs_type) {
+      case FSt_ISO9660:
+	RBlks(dv,buf,dv->data_area+c*dv->spc,blks);
+	c+=(blks+dv->spc-1)/dv->spc;
+	break;
+      case FSt_REDSEA:
+	RBlks(dv,buf,c,blks);
+	c+=blks;
+	break;
+      case FSt_FAT32:
+	while (blks && 0<c<0x0FFFFFF8) {
+	  i=blks;
+	  if (i>dv->spc)
+	    i=dv->spc;
+	  RBlks(dv,buf,dv->data_area+c*dv->spc,i);
+	  buf+=i<<BLK_SIZE_BITS;
+	  c=ClusterNumNext(dv,c,1);
+	  blks-=i;
+	}
+	if (blks)
+	  throw('Drv');
+	break;
+      default:
+	throw('Drv');
+    }
+    if (unlock)
+      DrvUnlock(dv);
+  } catch
+    if (unlock)
+      DrvUnlock(dv);
+  return c;
+}
+
+I64 RClusters(CDrv *dv,U8 *buf,I64 c,I64 cnt)
+{//Read cluster cnt from drv to buf.
+  return RClustersBlks(dv,buf,c,cnt*dv->spc);
+}
+
+I64 WClustersBlks(CDrv *dv,U8 *buf,I64 c,I64 blks)
+{//Accepts blk count, so padding on last cluster is not written.
+  I64 i;
+  Bool unlock;
+  DrvChk(dv);
+  if (blks<=0) return c;
+  try {
+    unlock=DrvLock(dv);
+    switch (dv->fs_type) {
+      case FSt_REDSEA:
+	WBlks(dv,buf,c,blks);
+	c=0;
+	break;
+      case FSt_FAT32:
+	while (blks) {
+	  if (!(0<c<0x0FFFFFF8))
+	    throw('Drv');
+	  i=blks;
+	  if (i>dv->spc)
+	    i=dv->spc;
+	  WBlks(dv,buf,dv->data_area+c*dv->spc,i);
+	  buf+=i<<BLK_SIZE_BITS;
+	  c=ClusterNumNext(dv,c);
+	  blks-=i;
+	}
+	break;
+      default:
+	throw('Drv');
+    }
+    if (unlock)
+      DrvUnlock(dv);
+  } catch
+    if (unlock)
+      DrvUnlock(dv);
+  return c;
+}
+
+I64 WClusters(CDrv *dv,U8 *buf,I64 c,I64 cnt)
+{//Write cluster cnt from buf to drv.
+  return WClustersBlks(dv,buf,c,cnt*dv->spc);
+}
+
+I64 ClustersAlloc(CDrv *dv,I64 c=0,I64 cnt=1,Bool contiguous=FALSE)
+{//Alloc cluster cnt into chain.
+//c=0 means first cluster in chain
+  DrvChk(dv);
+  if (cnt<=0) return c;
+  switch (dv->fs_type) {
+    case FSt_REDSEA:
+      return RedSeaAllocClusters(dv,cnt);
+    case FSt_FAT32:
+      if (contiguous) {
+	if (c) throw('File');
+	return FAT32AllocContiguousClusters(dv,cnt);
+      } else
+	return FAT32AllocClusters(dv,c,cnt);
+    default:
+      throw('Drv');
+  }
+}