multiindex.java

来自「jsr170接口的java实现。是个apache的开源项目。」· Java 代码 · 共 1,855 行 · 第 1/5 页

         *
         * @param transactionId the id of the transaction that is committed.
         */
        Commit(long transactionId) {
            super(transactionId, Action.TYPE_COMMIT);
        }

        /**
         * Creates a new Commit action.
         *
         * @param transactionId the id of the transaction that executes this
         *                      action.
         * @param arguments     ignored by this method.
         * @return the Commit action.
         */
        static Commit fromString(long transactionId, String arguments) {
            return new Commit(transactionId);
        }

        /**
         * Touches the last flush time (sets it to the current time).
         *
         * @inheritDoc
         */
        public void execute(MultiIndex index) throws IOException {
            index.lastFlushTime = System.currentTimeMillis();
        }

        /**
         * @inheritDoc
         */
        public String toString() {
            return Long.toString(getTransactionId()) + ' ' + Action.COMMIT;
        }
    }

    /**
     * Creates an new sub index but does not add it to the active persistent index
     * list.
     */
    private static class CreateIndex extends Action {

        /**
         * The name of the index to add.
         */
        private String indexName;

        /**
         * Indicates if the index is forced to be created. That is, existing
         * index data is deleted.
         */
        private final boolean create;

        /**
         * Creates a new CreateIndex action.
         *
         * @param transactionId the id of the transaction that executes this
         *                      action.
         * @param indexName     the name of the index to add, or <code>null</code>
         *                      if an index with a new name should be created.
         * @param create        if <code>true</code> existing index data is
         *                      overwritten.
         */
        CreateIndex(long transactionId, String indexName, boolean create) {
            super(transactionId, Action.TYPE_CREATE_INDEX);
            this.indexName = indexName;
            this.create = create;
        }

        /**
         * Creates a new CreateIndex action.
         *
         * @param transactionId the id of the transaction that executes this
         *                      action.
         * @param arguments     the name of the index to create.
         * @return the AddIndex action.
         * @throws IllegalArgumentException if the arguments are malformed.
         */
        static CreateIndex fromString(long transactionId, String arguments) {
            // when created from String, this action is executed as redo action
            // -> don't create index, simply open it.
            return new CreateIndex(transactionId, arguments, false);
        }

        /**
         * Creates a new index.
         *
         * @inheritDoc
         */
        public void execute(MultiIndex index) throws IOException {
            PersistentIndex idx = index.getOrCreateIndex(indexName, create);
            indexName = idx.getName();
        }

        /**
         * @inheritDoc
         */
        public void undo(MultiIndex index) throws IOException {
            if (index.hasIndex(indexName)) {
                PersistentIndex idx = index.getOrCreateIndex(indexName, false);
                idx.close();
                index.deleteIndex(idx);
            }
        }

        /**
         * @inheritDoc
         */
        public String toString() {
            StringBuffer logLine = new StringBuffer();
            logLine.append(Long.toString(getTransactionId()));
            logLine.append(' ');
            logLine.append(Action.CREATE_INDEX);
            logLine.append(' ');
            logLine.append(indexName);
            return logLine.toString();
        }

        /**
         * Returns the index name that has been created. If this method is called
         * before {@link #execute(MultiIndex)} it will return <code>null</code>.
         *
         * @return the name of the index that has been created.
         */
        String getIndexName() {
            return indexName;
        }
    }

    /**
     * Closes and deletes an index that is no longer in use.
     */
    private static class DeleteIndex extends Action {

        /**
         * The name of the index to add.
         */
        private String indexName;

        /**
         * Creates a new DeleteIndex action.
         *
         * @param transactionId the id of the transaction that executes this
         *                      action.
         * @param indexName     the name of the index to delete.
         */
        DeleteIndex(long transactionId, String indexName) {
            super(transactionId, Action.TYPE_DELETE_INDEX);
            this.indexName = indexName;
        }

        /**
         * Creates a new DeleteIndex action.
         *
         * @param transactionId the id of the transaction that executes this
         *                      action.
         * @param arguments     the name of the index to delete.
         * @return the DeleteIndex action.
         * @throws IllegalArgumentException if the arguments are malformed.
         */
        static DeleteIndex fromString(long transactionId, String arguments) {
            return new DeleteIndex(transactionId, arguments);
        }

        /**
         * Removes a sub index from <code>index</code>.
         *
         * @inheritDoc
         */
        public void execute(MultiIndex index) throws IOException {
            // get index if it exists
            for (Iterator it = index.indexes.iterator(); it.hasNext();) {
                PersistentIndex idx = (PersistentIndex) it.next();
                if (idx.getName().equals(indexName)) {
                    idx.close();
                    index.deleteIndex(idx);
                    break;
                }
            }
        }

        /**
         * @inheritDoc
         */
        public String toString() {
            StringBuffer logLine = new StringBuffer();
            logLine.append(Long.toString(getTransactionId()));
            logLine.append(' ');
            logLine.append(Action.DELETE_INDEX);
            logLine.append(' ');
            logLine.append(indexName);
            return logLine.toString();
        }
    }

    /**
     * Deletes a node from the index.
     */
    private static class DeleteNode extends Action {

        /**
         * The maximum length of a DeleteNode String.
         */
        private static final int ENTRY_LENGTH = Long.toString(Long.MAX_VALUE).length()
                + Action.DELETE_NODE.length()
                + Constants.UUID_FORMATTED_LENGTH
                + 2;

        /**
         * The uuid of the node to remove.
         */
        private final UUID uuid;

        /**
         * Creates a new DeleteNode action.
         *
         * @param transactionId the id of the transaction that executes this action.
         * @param uuid the uuid of the node to delete.
         */
        DeleteNode(long transactionId, UUID uuid) {
            super(transactionId, Action.TYPE_DELETE_NODE);
            this.uuid = uuid;
        }

        /**
         * Creates a new DeleteNode action.
         *
         * @param transactionId the id of the transaction that executes this
         *                      action.
         * @param arguments     the uuid of the node to delete.
         * @return the DeleteNode action.
         * @throws IllegalArgumentException if the arguments are malformed. Not a
         *                                  UUID.
         */
        static DeleteNode fromString(long transactionId, String arguments) {
            // simple length check
            if (arguments.length() != Constants.UUID_FORMATTED_LENGTH) {
                throw new IllegalArgumentException("arguments is not a uuid");
            }
            return new DeleteNode(transactionId, UUID.fromString(arguments));
        }

        /**
         * Deletes a node from the index.
         *
         * @inheritDoc
         */
        public void execute(MultiIndex index) throws IOException {
            String uuidString = uuid.toString();
            // check if indexing queue is still working on
            // this node from a previous update
            Document doc = index.indexingQueue.removeDocument(uuidString);
            if (doc != null) {
                Util.disposeDocument(doc);
            }
            Term idTerm = new Term(FieldNames.UUID, uuidString);
            // if the document cannot be deleted from the volatile index
            // delete it from one of the persistent indexes.
            int num = index.volatileIndex.removeDocument(idTerm);
            if (num == 0) {
                for (int i = index.indexes.size() - 1; i >= 0; i--) {
                    // only look in registered indexes
                    PersistentIndex idx = (PersistentIndex) index.indexes.get(i);
                    if (index.indexNames.contains(idx.getName())) {
                        num = idx.removeDocument(idTerm);
                        if (num > 0) {
                            return;
                        }
                    }
                }
            }
        }

        /**
         * @inheritDoc
         */
        public String toString() {
            StringBuffer logLine = new StringBuffer(ENTRY_LENGTH);
            logLine.append(Long.toString(getTransactionId()));
            logLine.append(' ');
            logLine.append(Action.DELETE_NODE);
            logLine.append(' ');
            logLine.append(uuid);
            return logLine.toString();
        }
    }

    /**
     * Starts a transaction.
     */
    private static class Start extends Action {

        /**
         * Creates a new Start transaction action.
         *
         * @param transactionId the id of the transaction that started.
         */
        Start(long transactionId) {
            super(transactionId, Action.TYPE_START);
        }

        /**
         * Creates a new Start action.
         *
         * @param transactionId the id of the transaction that executes this
         *                      action.
         * @param arguments     ignored by this method.
         * @return the Start action.
         */
        static Start fromString(long transactionId, String arguments) {
            return new Start(transactionId);
        }

        /**
         * Sets the current transaction id on <code>index</code>.
         *
         * @inheritDoc
         */
        public void execute(MultiIndex index) throws IOException {
            index.currentTransactionId = getTransactionId();
        }

        /**
         * @inheritDoc
         */
        public String toString() {
            return Long.toString(getTransactionId()) + ' ' + Action.START;
        }
    }

    /**
     * Commits the volatile index to disk.
     */
    private static class VolatileCommit extends Action {

        /**
         * The name of the target index to commit to.
         */
        private final String targetIndex;

        /**
         * Creates a new VolatileCommit action.
         *
         * @param transactionId the id of the transaction that executes this action.
         */
        VolatileCommit(long transactionId, String targetIndex) {
            super(transactionId, Action.TYPE_VOLATILE_COMMIT);
            this.targetIndex = targetIndex;
        }

        /**
         * Creates a new VolatileCommit action.
         *
         * @param transactionId the id of the transaction that executes this
         *                      action.
         * @param arguments     ignored by this implementation.
         * @return the VolatileCommit action.
         */
        static VolatileCommit fromString(long transactionId, String arguments) {
            return new VolatileCommit(transactionId, arguments);
        }

        /**
         * Commits the volatile index to disk.
         *
         * @inheritDoc
         */
        public void execute(MultiIndex index) throws IOException {
            VolatileIndex volatileIndex = index.getVolatileIndex();
            PersistentIndex persistentIndex = index.getOrCreateIndex(targetIndex, true);
            persistentIndex.copyIndex(volati