src/com/bytezone/diskbrowser/prodos/write/FileWriter.java

@@ -5,9 +5,6 @@ import static com.bytezone.diskbrowser.prodos.ProdosConstants.SAPLING;
 import static com.bytezone.diskbrowser.prodos.ProdosConstants.SEEDLING;
 import static com.bytezone.diskbrowser.prodos.ProdosConstants.TREE;
 
-// Assumptions:
-// - file does not already exist
-// - disk has no interleave
 // -----------------------------------------------------------------------------------//
 public class FileWriter
 // -----------------------------------------------------------------------------------//
@@ -40,7 +37,8 @@ public class FileWriter
 
     while (dataPtr < this.eof)
     {
-      int actualBlockNo = register (dataPtr / BLOCK_SIZE);
+      int actualBlockNo = allocateNextBlock ();
+      map (dataPtr / BLOCK_SIZE, actualBlockNo);
 
       int bufferPtr = actualBlockNo * BLOCK_SIZE;
       int transfer = Math.min (remaining, BLOCK_SIZE);
@@ -55,7 +53,8 @@ public class FileWriter
   }
 
   // ---------------------------------------------------------------------------------//
-  void writeRecord (int recordNo, byte[] dataBuffer, int recordLength) throws DiskFullException
+  void writeRecord (int recordNo, byte[] dataBuffer, int recordLength)
+      throws DiskFullException
   // ---------------------------------------------------------------------------------//
   {
     assert recordLength > 0;
@@ -104,8 +103,8 @@ public class FileWriter
     switch (storageType)
     {
       case TREE:
-        actualBlockNo =
-            masterIndexBlock.get (logicalBlockNo / 0x100).getPosition (logicalBlockNo % 0x100);
+        actualBlockNo = masterIndexBlock.get (logicalBlockNo / 0x100)
+            .getPosition (logicalBlockNo % 0x100);
         break;
 
       case SAPLING:
@@ -120,7 +119,10 @@ public class FileWriter
     }
 
     if (actualBlockNo == 0)
-      actualBlockNo = register (logicalBlockNo);
+    {
+      actualBlockNo = allocateNextBlock ();
+      map (logicalBlockNo, actualBlockNo);
+    }
 
     return actualBlockNo;
   }
@@ -136,17 +138,14 @@ public class FileWriter
   }
 
   // ---------------------------------------------------------------------------------//
-  private int register (int logicalBlockNo) throws DiskFullException
+  private void map (int logicalBlockNo, int actualBlockNo) throws DiskFullException
   // ---------------------------------------------------------------------------------//
   {
-    int nextBlockNo = allocateNextBlock ();
-
     if (logicalBlockNo >= 0x100)                       // potential TREE
     {
       if (storageType != TREE)
       {
-        masterIndexBlock = new MasterIndexBlock (nextBlockNo);
-        nextBlockNo = allocateNextBlock ();
+        masterIndexBlock = new MasterIndexBlock (allocateNextBlock ());
 
         if (storageType == SAPLING)                   // sapling -> tree
         {
@@ -154,9 +153,7 @@ public class FileWriter
         }
         else if (storageType == SEEDLING)             // seedling -> sapling -> tree
         {
-          indexBlock = new IndexBlock (nextBlockNo);
-          nextBlockNo = allocateNextBlock ();
-
+          indexBlock = new IndexBlock (allocateNextBlock ());
           indexBlock.setPosition (0, keyPointer);
           masterIndexBlock.set (0, indexBlock);
         }
@@ -166,51 +163,48 @@ public class FileWriter
         indexBlock = null;
       }
 
-      getIndexBlock (logicalBlockNo / 0x100).setPosition (logicalBlockNo % 0x100, nextBlockNo);
+      getIndexBlock (logicalBlockNo / 0x100).setPosition (logicalBlockNo % 0x100,
+          actualBlockNo);
     }
     else if (logicalBlockNo > 0)                      // potential SAPLING
     {
       if (storageType == TREE)                        // already a tree
       {
-        getIndexBlock (0).setPosition (logicalBlockNo, nextBlockNo);
+        getIndexBlock (0).setPosition (logicalBlockNo, actualBlockNo);
       }
       else if (storageType == SAPLING)                // already a sapling
       {
-        indexBlock.setPosition (logicalBlockNo, nextBlockNo);
+        indexBlock.setPosition (logicalBlockNo, actualBlockNo);
       }
       else                                            // new file or already a seedling
       {
-        indexBlock = new IndexBlock (nextBlockNo);
-        nextBlockNo = allocateNextBlock ();
-
+        indexBlock = new IndexBlock (allocateNextBlock ());
         if (storageType == SEEDLING)                  // seedling -> sapling
           indexBlock.setPosition (0, keyPointer);
 
         keyPointer = indexBlock.blockNo;
         storageType = SAPLING;
-        indexBlock.setPosition (logicalBlockNo, nextBlockNo);
+        indexBlock.setPosition (logicalBlockNo, actualBlockNo);
       }
     }
     else if (logicalBlockNo == 0)                     // potential SEEDLING
     {
       if (storageType == TREE)                        // already a tree
       {
-        getIndexBlock (0).setPosition (0, nextBlockNo);
+        getIndexBlock (0).setPosition (0, actualBlockNo);
       }
       else if (storageType == SAPLING)                // already a sapling
       {
-        indexBlock.setPosition (0, nextBlockNo);
+        indexBlock.setPosition (0, actualBlockNo);
       }
       else
       {
-        keyPointer = nextBlockNo;
+        keyPointer = actualBlockNo;
         storageType = SEEDLING;
       }
     }
     else
       System.out.println ("Error: " + logicalBlockNo);
-
-    return nextBlockNo;
   }
 
   // ---------------------------------------------------------------------------------//