package org.opendaylight.controller.cluster.raft;
+import akka.japi.Procedure;
import java.util.List;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
/**
* Represents the ReplicatedLog that needs to be kept in sync by the RaftActor
*/
public interface ReplicatedLog {
+ long NO_MAX_SIZE = -1;
+
/**
- * Get a replicated log entry at the specified index
+ * Return the replicated log entry at the specified index.
*
* @param index the index of the log entry
- * @return the ReplicatedLogEntry at index. null if index less than 0 or
+ * @return the ReplicatedLogEntry if found, otherwise null if the adjusted index less than 0 or
* greater than the size of the in-memory journal.
*/
- ReplicatedLogEntry get(long index);
-
+ @Nullable ReplicatedLogEntry get(long index);
/**
- * Get the last replicated log entry
- *
- * @return
+ * Return the last replicated log entry in the log or null of not found.
*/
- ReplicatedLogEntry last();
+ @Nullable ReplicatedLogEntry last();
/**
- *
- * @return
+ * Return the index of the last entry in the log or -1 if the log is empty.
*/
long lastIndex();
/**
- *
- * @return
+ * Return the term of the last entry in the log or -1 if the log is empty.
*/
long lastTerm();
/**
- * To be called when we need to remove entries from the in-memory log.
- * This method will remove all entries >= index. This method should be used
- * during recovery to appropriately trim the log based on persisted
- * information
+ * Removes entries from the in-memory log starting at the given index.
*
- * @param index the index of the log entry
+ * @param index the index of the first log entry to remove
+ * @return the adjusted index of the first log entry removed or -1 if the log entry is not found.
*/
- void removeFrom(long index);
-
+ long removeFrom(long index);
/**
- * To be called when we need to remove entries from the in-memory log and we
- * need that information persisted to disk. This method will remove all
- * entries >= index.
+ * Removes entries from the in-memory log a nd the persisted log starting at the given index.
* <p>
* The persisted information would then be used during recovery to properly
* reconstruct the state of the in-memory replicated log
*
- * @param index the index of the log entry
+ * @param index the index of the first log entry to remove
+ * @return
*/
- void removeFromAndPersist(long index);
+ boolean removeFromAndPersist(long index);
/**
- * Append an entry to the log
- * @param replicatedLogEntry
+ * Appends an entry to the log.
+ *
+ * @param replicatedLogEntry the entry to append
+ * @return true if the entry was successfully appended, false otherwise. An entry can fail to append if
+ * the index is already included in the log.
*/
- void append(ReplicatedLogEntry replicatedLogEntry);
+ boolean append(ReplicatedLogEntry replicatedLogEntry);
/**
+ * Optimization method to increase the capacity of the journal log prior to appending entries.
*
- * @param replicatedLogEntry
+ * @param amount the amount to increase by
+ */
+ void increaseJournalLogCapacity(int amount);
+
+ /**
+ * Appends an entry to the in-memory log and persists it as well.
+ *
+ * @param replicatedLogEntry the entry to append
*/
void appendAndPersist(final ReplicatedLogEntry replicatedLogEntry);
+ void appendAndPersist(ReplicatedLogEntry replicatedLogEntry, Procedure<ReplicatedLogEntry> callback);
+
/**
+ * Returns a list of log entries starting from the given index to the end of the log.
*
- * @param index the index of the log entry
+ * @param index the index of the first log entry to get.
+ * @return the List of entries
*/
- List<ReplicatedLogEntry> getFrom(long index);
+ @Nonnull List<ReplicatedLogEntry> getFrom(long index);
+ /**
+ * Returns a list of log entries starting from the given index up to the given maximum of entries or
+ * the given maximum accumulated size, whichever comes first.
+ *
+ * @param index the index of the first log entry to get
+ * @param maxEntries the maximum number of entries to get
+ * @param maxDataSize the maximum accumulated size of the log entries to get
+ * @return the List of entries meeting the criteria.
+ */
+ @Nonnull List<ReplicatedLogEntry> getFrom(long index, int maxEntries, long maxDataSize);
/**
*
- * @return
+ * @return the number of entries in the journal
*/
long size();
*/
boolean isInSnapshot(long index);
- /**
- * Get the snapshot
- *
- * @return an object representing the snapshot if it exists. null otherwise
- */
- Object getSnapshot();
-
/**
* Get the index of the snapshot
*
* otherwise
*/
long getSnapshotTerm();
+
+ /**
+ * sets the snapshot index in the replicated log
+ * @param snapshotIndex
+ */
+ void setSnapshotIndex(long snapshotIndex);
+
+ /**
+ * sets snapshot term
+ * @param snapshotTerm
+ */
+ void setSnapshotTerm(long snapshotTerm);
+
+ /**
+ * Clears the journal entries with startIndex(inclusive) and endIndex (exclusive)
+ * @param startIndex
+ * @param endIndex
+ */
+ void clear(int startIndex, int endIndex);
+
+ /**
+ * Handles all the bookkeeping in order to perform a rollback in the
+ * event of SaveSnapshotFailure
+ * @param snapshotCapturedIndex
+ * @param snapshotCapturedTerm
+ */
+ void snapshotPreCommit(long snapshotCapturedIndex, long snapshotCapturedTerm);
+
+ /**
+ * Sets the Replicated log to state after snapshot success.
+ */
+ void snapshotCommit();
+
+ /**
+ * Restores the replicated log to a state in the event of a save snapshot failure
+ */
+ void snapshotRollback();
+
+ /**
+ * Size of the data in the log (in bytes)
+ */
+ int dataSize();
+
+ /**
+ * We decide if snapshot need to be captured based on the count/memory consumed.
+ * @param replicatedLogEntry
+ */
+ void captureSnapshotIfReady(ReplicatedLogEntry replicatedLogEntry);
+
}
Code Review / controller.git / blobdiff