Reading from a StreamStore now throws an IOException if the underlying data doesn't exist.

h2/src/main/org/h2/mvstore/DataUtils.java

@@ -72,7 +72,12 @@ public class DataUtils {
      * available.
      */
     public static final int ERROR_CHUNK_NOT_FOUND = 9;
-
+    
+    /**
+     * The block in the stream store was not found.
+     */
+    public static final int ERROR_BLOCK_NOT_FOUND = 50;
+    
     /**
      * The transaction store is corrupt.
      */
@@ -781,7 +786,15 @@ public class DataUtils {
         return e;
     }
 
-    private static String formatMessage(int errorCode, String message,
+    /**
+     * Format an error message.
+     * 
+     * @param errorCode the error code
+     * @param message the message
+     * @param arguments the arguments
+     * @return the formatted message
+     */
+    public static String formatMessage(int errorCode, String message,
             Object... arguments) {
         // convert arguments to strings, to avoid locale specific formatting
         for (int i = 0; i < arguments.length; i++) {

h2/src/main/org/h2/mvstore/StreamStore.java

@@ -344,7 +344,13 @@ public class StreamStore {
      * @return the block
      */
     byte[] getBlock(long key) {
-        return map.get(key);
+        byte[] data = map.get(key);
+        if (data == null) {
+            throw DataUtils.newIllegalStateException(
+                    DataUtils.ERROR_BLOCK_NOT_FOUND, 
+                    "Block {0} not found",  key);
+        }
+        return data;
     }
 
     /**
@@ -367,7 +373,7 @@ public class StreamStore {
         }
 
         @Override
-        public int read() {
+        public int read() throws IOException {
             byte[] buffer = oneByteBuffer;
             if (buffer == null) {
                 buffer = oneByteBuffer = new byte[1];
@@ -405,13 +411,21 @@ public class StreamStore {
         }
 
         @Override
-        public int read(byte[] b, int off, int len) {
+        public int read(byte[] b, int off, int len) throws IOException {
             if (len <= 0) {
                 return 0;
             }
             while (true) {
                 if (buffer == null) {
-                    buffer = nextBuffer();
+                    try {
+                        buffer = nextBuffer();
+                    } catch (IllegalStateException e) {
+                        String msg = DataUtils.formatMessage(
+                                DataUtils.ERROR_BLOCK_NOT_FOUND, 
+                                "Block not found in id {0}", 
+                                Arrays.toString(idBuffer.array()));
+                        throw new IOException(msg, e);
+                    }
                     if (buffer == null) {
                         return -1;
                     }

h2/src/test/org/h2/test/store/TestStreamStore.java

@@ -14,6 +14,8 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Random;
 import java.util.concurrent.atomic.AtomicInteger;
+
+import org.h2.mvstore.DataUtils;
 import org.h2.mvstore.MVMap;
 import org.h2.mvstore.MVStore;
 import org.h2.mvstore.StreamStore;
@@ -41,6 +43,7 @@ public class TestStreamStore extends TestBase {
     public void test() throws IOException {
         FileUtils.deleteRecursive(getBaseDir(), true);
         FileUtils.createDirectories(getBaseDir());
+        testIOException();
         testSaveCount();
         testExceptionDuringStore();
         testReadCount();
@@ -52,6 +55,25 @@ public class TestStreamStore extends TestBase {
         testWithFullMap();
         testLoop();
     }
+    
+    private void testIOException() throws IOException {
+        HashMap<Long, byte[]> map = New.hashMap();
+        StreamStore s = new StreamStore(map);
+        byte[] id = s.put(new ByteArrayInputStream(new byte[1024 * 1024]));
+        InputStream in = s.get(id);
+        map.clear();
+        try {
+            while (true) {
+                if (in.read() < 0) {
+                    break;
+                }
+            }
+            fail();
+        } catch (IOException e) {
+            assertEquals(DataUtils.ERROR_BLOCK_NOT_FOUND, 
+                    DataUtils.getErrorCode(e.getMessage()));
+        }
+    }
 
     private void testSaveCount() throws IOException {
         String fileName = getBaseDir() + "/testSaveCount.h3";