diff options
Diffstat (limited to 'source/com/c2kernel/persistency/TransactionManager.java')
| -rw-r--r-- | source/com/c2kernel/persistency/TransactionManager.java | 324 |
1 files changed, 0 insertions, 324 deletions
diff --git a/source/com/c2kernel/persistency/TransactionManager.java b/source/com/c2kernel/persistency/TransactionManager.java deleted file mode 100644 index d2679a8..0000000 --- a/source/com/c2kernel/persistency/TransactionManager.java +++ /dev/null @@ -1,324 +0,0 @@ -package com.c2kernel.persistency;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-
-import com.c2kernel.common.ObjectNotFoundException;
-import com.c2kernel.entity.C2KLocalObject;
-import com.c2kernel.entity.agent.JobList;
-import com.c2kernel.events.History;
-import com.c2kernel.utils.Logger;
-
-public class TransactionManager {
-
- HashMap<Integer, Object> locks;
- HashMap<Object, ArrayList<TransactionEntry>> pendingTransactions;
- ClusterStorageManager storage;
-
- public TransactionManager() throws ClusterStorageException {
- storage = new ClusterStorageManager();
- locks = new HashMap<Integer, Object>();
- pendingTransactions = new HashMap<Object, ArrayList<TransactionEntry>>();
- }
-
- public boolean hasPendingTransactions()
- {
- return pendingTransactions.size() > 0;
- }
-
- public ClusterStorageManager getDb() {
- return storage;
- }
-
- public void close() {
- if (pendingTransactions.size() != 0) {
- Logger.error("There were pending transactions on shutdown. All changes were lost.");
- dumpPendingTransactions(0);
- }
- Logger.msg("Transaction Manager: Closing storages");
- storage.close();
- }
-
- public String[] getClusterContents(int sysKey, String path) throws ClusterStorageException {
- if (path.startsWith("/") && path.length() > 1) path = path.substring(1);
- return storage.getClusterContents(new Integer(sysKey), path);
- }
-
- /**
- * Public get method. Required a 'locker' object for a transaction key.
- * Checks the transaction table first to see if the caller has uncommitted changes
- */
- public C2KLocalObject get(int sysKey, String path, Object locker)
- throws ClusterStorageException,
- ObjectNotFoundException {
- if (path.startsWith("/") && path.length() > 1) path = path.substring(1);
-
- // deal out top level remote maps, if transactions aren't needed
- if (path.indexOf('/') == -1) {
- if (path.equals(ClusterStorage.HISTORY) && locker != null)
- return new History(sysKey, locker);
- if (path.equals(ClusterStorage.JOB) && locker != null)
- return new JobList(sysKey, locker);
- }
-
- Integer sysKeyIntObj = new Integer(sysKey);
- // check to see if the locker has been modifying this cluster
- synchronized(locks) {
- if (locks.containsKey(sysKeyIntObj) && locks.get(sysKeyIntObj).equals(locker)) {
- ArrayList<TransactionEntry> lockerTransaction = pendingTransactions.get(locker);
- for (TransactionEntry thisEntry : lockerTransaction) {
- if (sysKey == thisEntry.sysKey.intValue() && path.equals(thisEntry.getPath())) {
- if (thisEntry.obj == null)
- throw new ClusterStorageException("ClusterStorageManager.get() - Cluster " + path + " has been deleted in " + sysKey +
- " but not yet committed");
- return thisEntry.obj;
- }
- }
- }
- }
- return storage.get(sysKeyIntObj, path);
- }
-
- /**
- * Public put method. Manages the transaction table keyed by the object 'locker'.
- * If this object is null, transaction support is bypassed (so long as no lock exists on that object).
- */
- public void put(int sysKey, C2KLocalObject obj, Object locker) throws ClusterStorageException {
- Integer sysKeyIntObj = new Integer(sysKey);
- ArrayList<TransactionEntry> lockerTransaction;
- String path = ClusterStorage.getPath(obj);
-
- synchronized(locks) {
- // look to see if this object is already locked
- if (locks.containsKey(sysKeyIntObj)) {
- // if it's this locker, get the transaction list
- Object thisLocker = locks.get(sysKeyIntObj);
- if (thisLocker.equals(locker)) // retrieve the transaction list
- lockerTransaction = pendingTransactions.get(locker);
- else // locked by someone else
- throw new ClusterStorageException("ClusterStorageManager.get() - Access denied: Object " + sysKeyIntObj +
- " has been locked for writing by " + thisLocker);
- }
- else { // either we are the locker, or there is no locker
- if (locker == null) { // non-locking put/delete
- storage.put(sysKeyIntObj, obj);
- return;
- }
- else {// initialise the transaction
- locks.put(sysKeyIntObj, locker);
- lockerTransaction = new ArrayList<TransactionEntry>();
- pendingTransactions.put(locker, lockerTransaction);
- }
- }
-
- // create the new entry in the transaction table
- TransactionEntry newEntry = new TransactionEntry(sysKeyIntObj, path, obj);
- /* equals() in TransactionEntry only compares sysKey and path, so we can use
- * contains() in ArrayList to looks for preexisting entries for this cluster
- * and overwrite them.
- */
- if (lockerTransaction.contains(newEntry))
- lockerTransaction.remove(newEntry);
- lockerTransaction.add(newEntry);
- }
- }
-
- /** Public delete method. Uses the put method, with null as the object value.
- */
- public void remove(int sysKey, String path, Object locker) throws ClusterStorageException {
- Integer sysKeyIntObj = new Integer(sysKey);
- ArrayList<TransactionEntry> lockerTransaction;
- synchronized(locks) {
- // look to see if this object is already locked
- if (locks.containsKey(sysKeyIntObj)) {
- // if it's this locker, get the transaction list
- Object thisLocker = locks.get(sysKeyIntObj);
- if (thisLocker.equals(locker)) // retrieve the transaction list
- lockerTransaction = pendingTransactions.get(locker);
- else // locked by someone else
- throw new ClusterStorageException("ClusterStorageManager.get() - Access denied: Object " + sysKeyIntObj +
- " has been locked for writing by " + thisLocker);
- }
- else { // either we are the locker, or there is no locker
- if (locker == null) { // non-locking put/delete
- storage.remove(sysKeyIntObj, path);
- return;
- }
- else {// initialise the transaction
- locks.put(sysKeyIntObj, locker);
- lockerTransaction = new ArrayList<TransactionEntry>();
- pendingTransactions.put(locker, lockerTransaction);
- }
- }
-
- // create the new entry in the transaction table
- TransactionEntry newEntry = new TransactionEntry(sysKeyIntObj, path, null);
- /* equals() in TransactionEntry only compares sysKey and path, so we can use
- * contains() in ArrayList to looks for preexisting entries for this cluster
- * and overwrite them.
- */
- if (lockerTransaction.contains(newEntry))
- lockerTransaction.remove(newEntry);
- lockerTransaction.add(newEntry);
- }
- }
-
- /**
- * Removes all child objects from the given path
- *
- * @param sysKey - entity to delete from
- * @param path - root path to delete
- * @param locker - locking object
- *
- * @throws ClusterStorageException - when deleting fails
- */
- public void removeCluster(int sysKey, String path, Object locker) throws ClusterStorageException {
-
- String[] children = getClusterContents(sysKey, path);
- for (String element : children)
- removeCluster(sysKey, path+(path.length()>0?"/":"")+element, locker);
- if (children.length==0 && path.indexOf("/") > -1)
- remove(sysKey, path, locker);
-
- }
- /**
- * Writes all pending changes to the backends.
- */
- public void commit(Object locker) {
- synchronized(locks) {
- ArrayList<TransactionEntry> lockerTransactions = pendingTransactions.get(locker);
- HashMap<TransactionEntry, Exception> exceptions = new HashMap<TransactionEntry, Exception>();
- // quit if no transactions are present;
- if (lockerTransactions == null) return;
- for (TransactionEntry thisEntry : lockerTransactions) {
- try {
- if (thisEntry.obj == null)
- storage.remove(thisEntry.sysKey, thisEntry.path);
- else
- storage.put(thisEntry.sysKey, thisEntry.obj);
- locks.remove(thisEntry.sysKey);
- } catch (Exception e) {
- exceptions.put(thisEntry, e);
- }
- }
- pendingTransactions.remove(locker);
- if (exceptions.size() > 0) { // oh dear
- Logger.error("TransactionManager.commit() - Problems during transaction commit of locker "+locker.toString()+". Database may be in an inconsistent state.");
- for (TransactionEntry entry : exceptions.keySet()) {
- Exception ex = exceptions.get(entry);
- Logger.msg(entry.toString());
- Logger.error(ex);
- }
- dumpPendingTransactions(0);
- Logger.die("Database failure");
- }
-
- }
- }
-
- /**
- * Rolls back all changes sent in the name of 'locker' and unlocks the sysKeys
- */
- public void abort(Object locker) {
- synchronized(locks) {
- if (locks.containsValue(locker)) {
- for (Integer thisKey : locks.keySet()) {
- if (locks.get(thisKey).equals(locker))
- locks.remove(thisKey);
- }
- }
- pendingTransactions.remove(locker);
- }
- }
-
- public void clearCache(int sysKey, String path) {
- if (sysKey == -1)
- storage.clearCache();
- else if (path == null)
- storage.clearCache(new Integer(sysKey));
- else
- storage.clearCache(new Integer(sysKey), path);
-
- }
-
- public void dumpPendingTransactions(int logLevel) {
- Logger.msg(logLevel, "================");
- Logger.msg(logLevel, "Transaction dump");
- Logger.msg(logLevel, "Locked Items:");
- if (locks.size() == 0)
- Logger.msg(logLevel, " None");
- else
- for (Integer thisKey : locks.keySet()) {
- Object locker = locks.get(thisKey);
- Logger.msg(logLevel, " "+thisKey+" locked by "+locker);
- }
-
- Logger.msg(logLevel, "Open transactions:");
- if (pendingTransactions.size() == 0)
- Logger.msg(logLevel, " None");
- else
- for (Object thisLocker : pendingTransactions.keySet()) {
- Logger.msg(logLevel, " Transaction owner:"+thisLocker);
- ArrayList<TransactionEntry> entries = pendingTransactions.get(thisLocker);
- for (TransactionEntry thisEntry : entries) {
- Logger.msg(logLevel, " "+thisEntry.toString());
- }
- }
- }
-
- /** Used in the transaction table to store details of a put until commit
- */
- class TransactionEntry {
- public Integer sysKey;
- public String path;
- public C2KLocalObject obj;
- public TransactionEntry(Integer sysKey, String path, C2KLocalObject obj) {
- this.sysKey = sysKey;
- this.path = path;
- this.obj = obj;
- }
-
- public String getPath() {
- return ClusterStorage.getPath(obj);
- }
-
- @Override
- public String toString() {
- StringBuffer report = new StringBuffer();
- if (obj == null)
- report.append("Delete");
- else
- report.append("Put "+obj.getClass().getName());
- report.append(" at ").append(path).append(" in ").append(sysKey);
- return report.toString();
-
- }
- /**
- * @see java.lang.Object#hashCode()
- */
- @Override
- public int hashCode() {
- return sysKey.hashCode()*getPath().hashCode();
- }
-
- /**
- * @see java.lang.Object#equals(java.lang.Object)
- */
- @Override
- public boolean equals(Object other) {
- if (other instanceof TransactionEntry)
- return hashCode() == ((TransactionEntry)other).hashCode();
- return false;
- }
-
- }
-
- public Object query(String id, Object query) throws ClusterStorageException {
- return storage.query(id, query);
- }
-
- public String queryToXML(String id, String query, boolean genericFormat) throws ClusterStorageException {
- return storage.queryToXML(id, query, genericFormat);
- }
-
-}
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