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

        /**
         * Action identifier in redo log for add node action.
         */
        static final String ADD_NODE = "ADD";

        /**
         * Action type for add node action.
         */
        public static final int TYPE_ADD_NODE = 1;

        /**
         * Action identifier in redo log for node delete action.
         */
        static final String DELETE_NODE = "DEL";

        /**
         * Action type for delete node action.
         */
        public static final int TYPE_DELETE_NODE = 2;

        /**
         * Action identifier in redo log for transaction commit action.
         */
        static final String COMMIT = "COM";

        /**
         * Action type for commit action.
         */
        public static final int TYPE_COMMIT = 3;

        /**
         * Action identifier in redo log for volatile index commit action.
         */
        static final String VOLATILE_COMMIT = "VOL_COM";

        /**
         * Action type for volatile index commit action.
         */
        public static final int TYPE_VOLATILE_COMMIT = 4;

        /**
         * Action identifier in redo log for index create action.
         */
        static final String CREATE_INDEX = "CRE_IDX";

        /**
         * Action type for create index action.
         */
        public static final int TYPE_CREATE_INDEX = 5;

        /**
         * Action identifier in redo log for index add action.
         */
        static final String ADD_INDEX = "ADD_IDX";

        /**
         * Action type for add index action.
         */
        public static final int TYPE_ADD_INDEX = 6;

        /**
         * Action identifier in redo log for delete index action.
         */
        static final String DELETE_INDEX = "DEL_IDX";

        /**
         * Action type for delete index action.
         */
        public static final int TYPE_DELETE_INDEX = 7;

        /**
         * Transaction identifier for internal actions like volatile index
         * commit triggered by timer thread.
         */
        static final long INTERNAL_TRANSACTION = -1;

        /**
         * Transaction identifier for internal action that replaces indexs.
         */
        static final long INTERNAL_TRANS_REPL_INDEXES = -2;

        /**
         * The id of the transaction that executed this action.
         */
        private final long transactionId;

        /**
         * The action type.
         */
        private final int type;

        /**
         * Creates a new <code>Action</code>.
         *
         * @param transactionId the id of the transaction that executed this
         *                      action.
         * @param type          the action type.
         */
        Action(long transactionId, int type) {
            this.transactionId = transactionId;
            this.type = type;
        }

        /**
         * Returns the transaction id for this <code>Action</code>.
         *
         * @return the transaction id for this <code>Action</code>.
         */
        long getTransactionId() {
            return transactionId;
        }

        /**
         * Returns the action type.
         *
         * @return the action type.
         */
        int getType() {
            return type;
        }

        /**
         * Executes this action on the <code>index</code>.
         *
         * @param index the index where to execute the action.
         * @throws IOException         if the action fails due to some I/O error in
         *                             the index or some other error.
         */
        public abstract void execute(MultiIndex index) throws IOException;

        /**
         * Executes the inverse operation of this action. That is, does an undo
         * of this action. This default implementation does nothing, but returns
         * silently.
         *
         * @param index the index where to undo the action.
         * @throws IOException if the action cannot be undone.
         */
        public void undo(MultiIndex index) throws IOException {
        }

        /**
         * Returns a <code>String</code> representation of this action that can be
         * written to the {@link RedoLog}.
         *
         * @return a <code>String</code> representation of this action.
         */
        public abstract String toString();

        /**
         * Parses an line in the redo log and created an {@link Action}.
         *
         * @param line the line from the redo log.
         * @return an <code>Action</code>.
         * @throws IllegalArgumentException if the line is malformed.
         */
        static Action fromString(String line) throws IllegalArgumentException {
            int endTransIdx = line.indexOf(' ');
            if (endTransIdx == -1) {
                throw new IllegalArgumentException(line);
            }
            long transactionId;
            try {
                transactionId = Long.parseLong(line.substring(0, endTransIdx));
            } catch (NumberFormatException e) {
                throw new IllegalArgumentException(line);
            }
            int endActionIdx = line.indexOf(' ', endTransIdx + 1);
            if (endActionIdx == -1) {
                // action does not have arguments
                endActionIdx = line.length();
            }
            String actionLabel = line.substring(endTransIdx + 1, endActionIdx);
            String arguments = "";
            if (endActionIdx + 1 <= line.length()) {
                arguments = line.substring(endActionIdx + 1);
            }
            Action a;
            if (actionLabel.equals(Action.ADD_NODE)) {
                a = AddNode.fromString(transactionId, arguments);
            } else if (actionLabel.equals(Action.ADD_INDEX)) {
                a = AddIndex.fromString(transactionId, arguments);
            } else if (actionLabel.equals(Action.COMMIT)) {
                a = Commit.fromString(transactionId, arguments);
            } else if (actionLabel.equals(Action.CREATE_INDEX)) {
                a = CreateIndex.fromString(transactionId, arguments);
            } else if (actionLabel.equals(Action.DELETE_INDEX)) {
                a = DeleteIndex.fromString(transactionId, arguments);
            } else if (actionLabel.equals(Action.DELETE_NODE)) {
                a = DeleteNode.fromString(transactionId, arguments);
            } else if (actionLabel.equals(Action.START)) {
                a = Start.fromString(transactionId, arguments);
            } else if (actionLabel.equals(Action.VOLATILE_COMMIT)) {
                a = VolatileCommit.fromString(transactionId, arguments);
            } else {
                throw new IllegalArgumentException(line);
            }
            return a;
        }
    }

    /**
     * Adds an index to the MultiIndex's active persistent index list.
     */
    private static class AddIndex extends Action {

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

        /**
         * Creates a new AddIndex 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.
         */
        AddIndex(long transactionId, String indexName) {
            super(transactionId, Action.TYPE_ADD_INDEX);
            this.indexName = indexName;
        }

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

        /**
         * Adds a sub index to <code>index</code>.
         *
         * @inheritDoc
         */
        public void execute(MultiIndex index) throws IOException {
            PersistentIndex idx = index.getOrCreateIndex(indexName, false);
            if (!index.indexNames.contains(indexName)) {
                index.indexNames.addName(indexName);
                // now that the index is in the active list let the merger know about it
                index.merger.indexAdded(indexName, idx.getNumDocuments());
            }
        }

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

    /**
     * Adds a node to the index.
     */
    private static class AddNode extends Action {

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

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

        /**
         * The document to add to the index, or <code>null</code> if not available.
         */
        private Document doc;

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

        /**
         * Creates a new AddNode action.
         *
         * @param transactionId the id of the transaction that executes this action.
         * @param doc the document to add.
         */
        AddNode(long transactionId, Document doc) {
            this(transactionId, UUID.fromString(doc.get(FieldNames.UUID)));
            this.doc = doc;
        }

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

        /**
         * Adds a node to the index.
         *
         * @inheritDoc
         */
        public void execute(MultiIndex index) throws IOException {
            if (doc == null) {
                try {
                    doc = index.createDocument(new NodeId(uuid));
                } catch (RepositoryException e) {
                    // node does not exist anymore
                    log.debug(e.getMessage());
                }
            }
            if (doc != null) {
                index.volatileIndex.addDocument(doc);
            }
        }

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

    /**
     * Commits a transaction.
     */
    private static class Commit extends Action {

        /**
         * Creates a new Commit action.