[bugfix] Do not overflow integer size bound of Journal file

Author: adamretter

src/org/exist/storage/journal/Journal.java

@@ -163,11 +163,6 @@ public final class Journal {
      */
     private int currentFile = 0;
 
-    /**
-     * used to keep track of the current position in the file
-     */
-    private int inFilePos = 0;
-
     /**
      * temp buffer
      */
@@ -291,8 +286,18 @@ public synchronized void writeToLog(final Loggable entry) throws JournalExceptio
         if (required > currentBuffer.remaining()) {
             flushToLog(false);
         }
-        currentLsn = Lsn.create(currentFile, inFilePos + currentBuffer.position() + 1);
+
+        try {
+            final long offset = channel.position();
+            if (offset > Integer.MAX_VALUE) {
+                throw new JournalException("Journal can only write log files of less that 2GB");
+            }
+            currentLsn = Lsn.create(currentFile, ((int)(channel.position() &0x7FFFFFFF)) + currentBuffer.position() + 1);
+        } catch (final IOException e) {
+            throw new JournalException("Unable to create LSN for: " + entry.dump());
+        }
         entry.setLsn(currentLsn);
+
         try {
             currentBuffer.put(entry.getLogType());
             currentBuffer.putLong(entry.getTransactionId());
@@ -365,7 +370,6 @@ private void flushBuffer() {
                         channel.write(currentBuffer);
                     }
 
-                    inFilePos += size;
                     lastLsnWritten = currentLsn;
                 }
             } catch (final IOException e) {
@@ -479,7 +483,6 @@ public void switchFiles() throws LogException {
                 throw new LogException("Failed to open new journal: " + file.toAbsolutePath().toString(), e);
             }
         }
-        inFilePos = 0;
     }
 
     /**

src/org/exist/storage/journal/JournalReader.java

@@ -113,8 +113,8 @@ Loggable previousEntry() throws LogException {
             // go back two bytes and read the back-link of the last entry
             fc.position(fc.position() - LOG_ENTRY_BACK_LINK_LEN);
             header.clear().limit(LOG_ENTRY_BACK_LINK_LEN);
-            final int bytes = fc.read(header);
-            if (bytes < LOG_ENTRY_BACK_LINK_LEN) {
+            final int read = fc.read(header);
+            if (read != LOG_ENTRY_BACK_LINK_LEN) {
                 throw new LogException("Unable to read journal entry back-link!");
             }
             header.flip();
@@ -159,17 +159,21 @@ Loggable lastEntry() throws LogException {
     private @Nullable
     Loggable readEntry() throws LogException {
         try {
-            final long lsn = Lsn.create(fileNumber, (int) fc.position() + 1);
+            final long offset = fc.position();
+            if (offset > Integer.MAX_VALUE) {
+                throw new LogException("Journal can only read log files of less that 2GB");
+            }
+            final long lsn = Lsn.create(fileNumber, ((int)(offset & 0x7FFFFFFF)) + 1);
 
             // read the entry header
             header.clear();
-            int bytes = fc.read(header);
-            if (bytes <= 0) {
+            int read = fc.read(header);
+            if (read <= 0) {
                 return null;
             }
-            if (bytes < LOG_ENTRY_HEADER_LEN) {
+            if (read != LOG_ENTRY_HEADER_LEN) {
                 throw new LogException("Incomplete journal entry header found, expected  "
-                        + LOG_ENTRY_HEADER_LEN + " bytes, but found " + bytes + " bytes");
+                        + LOG_ENTRY_HEADER_LEN + " bytes, but found " + read + " bytes");
             }
             header.flip();
 
@@ -192,8 +196,8 @@ Loggable readEntry() throws LogException {
                 payload = ByteBuffer.allocate(size + LOG_ENTRY_BACK_LINK_LEN);
             }
             payload.clear().limit(size + LOG_ENTRY_BACK_LINK_LEN);
-            bytes = fc.read(payload);
-            if (bytes < size + LOG_ENTRY_BACK_LINK_LEN) {
+            read = fc.read(payload);
+            if (read < size + LOG_ENTRY_BACK_LINK_LEN) {
                 throw new LogException("Incomplete log entry found!");
             }
             payload.flip();