-/*******************************************************************************\r
- * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
- * in Industry THTH ry.\r
- * All rights reserved. This program and the accompanying materials\r
- * are made available under the terms of the Eclipse Public License v1.0\r
- * which accompanies this distribution, and is available at\r
- * http://www.eclipse.org/legal/epl-v10.html\r
- *\r
- * Contributors:\r
- * VTT Technical Research Centre of Finland - initial API and implementation\r
- *******************************************************************************/\r
-package org.simantics.db;\r
-\r
-import org.simantics.db.exception.DatabaseException;\r
-import org.simantics.db.exception.ExternalValueException;\r
-\r
-/**\r
- * This interface is for accessing external values of resources. External\r
- * values are values of resources which are stored outside the cluster of the\r
- * resource. These values support partial read and write.\r
- *\r
- * @author Kalle Kondelin\r
- */\r
-public interface ExternalValueSupport {\r
- /**\r
- * Removes the value from the resource. Also truncates the value to zero\r
- * length so that if the value is created again it does not have any content.\r
- *\r
- * @param graph to ensure that caller has write transaction.\r
- * @param resource which value is to be removed.\r
- * @throws DatabaseException\r
- */\r
- void removeValue(WriteGraph graph, Resource resource)\r
- throws DatabaseException;\r
- /**\r
- * Write some or all bytes of an external value.\r
- *\r
- * IMPLEMENTATION NOTE:\r
- * The current implementation for the value is a file and every transaction\r
- * you write the value the whole file is copied and then the modification\r
- * is applied.\r
- * If you write internal value or create external value you must write the\r
- * whole value because the value is not initialized.\r
- * If you write a value that is so big that server can't hold it in memory\r
- * during the commit you must split it in parts by using commitAndContinue\r
- * method.\r
- *\r
- * @param graph to ensure that caller has write transaction.\r
- * @param resource which value is modified.\r
- * @param offset from start of the value. Must be within [0, MAX_VALUE_SIZE).\r
- * MAX_VALUE_SIZE = (1<<58)-2. (1<<58)-1 reserved for special move message.\r
- * @param length of the modified segment i.e. number of bytes to write.\r
- * Must be positive. If zero then the value length is truncated to offset.\r
- * If offset + length is greater then MAX_VALUE_SIZE then the behavior is\r
- * undefined.\r
- * @param bytes to write. Must have at least length bytes.\r
- * @throws DatabaseException\r
- */\r
- void writeValue(WriteGraph graph, Resource resource, long offset, int length, byte[] bytes)\r
- throws DatabaseException;\r
- /**\r
- * If there is an old value moves it to current change set. This means that\r
- * old value is lost but space is saved. Must be called before first\r
- * writeValue call for given change set to have any effect.\r
- *\r
- * @param graph to ensure that caller has write transaction.\r
- * @param resource which value is to be modified i.e. the same value as\r
- * given to following writeValue(s).\r
- */\r
-// This breaks undo.\r
-// void moveValue(WriteGraph graph, Resource resource)\r
-// throws DatabaseException;\r
- /**\r
- * Sends commit message to server but does not end transaction. This\r
- * enables server to release memory used by writeValue requests.\r
- * Waits until most of the pending requests has been sent so that the\r
- * memory used by the pending requests does not grow unreasonably large.\r
- *\r
- * @param graph to ensure that caller has write transaction.\r
- * @param wtraits required by commit message. Usually the write request\r
- * which is calling this method.\r
- * @param resource which value is modified i.e. the same value as given to writeValue.\r
- */\r
-// This breaks undo.\r
-// void commitAndContinue(WriteGraph graph, WriteTraits wtraits, Resource resource)\r
-// throws DatabaseException;\r
- /**\r
- * Read some or all bytes of an external value.\r
- *\r
- * @param graph to ensure that caller has read transaction.\r
- * @param resource which value is to be read.\r
- * @param offset from start of the value. Must be within [0, valueSize).\r
- * @param length of the segment to read. Offset + length must be within [0, valueSize].\r
- * @return the bytes of the segment that was asked.\r
- * @throws DatabaseException\r
- */\r
- byte[] readValue(ReadGraph graph, Resource resource, long offset, int length)\r
- throws DatabaseException;\r
- /**\r
- * @param graph to ensure that caller has read transaction.\r
- * @param resource which value is to be read.\r
- * @return size of the value.\r
- * @throws DatabaseException\r
- * @throws ExternalValueException if the value is not external.\r
- */\r
- long getValueSize(ReadGraph graph, Resource resource)\r
- throws DatabaseException, ExternalValueException;\r
-\r
- /**\r
- * Wait until there is less than limit requests in outgoing request queue.\r
- *\r
- * @param limit value for requests in request queue. Must be greater than zero.\r
- * @return Number of requests left in request queue.\r
- * @throws DatabaseException\r
- */\r
- int wait4RequestsLess(int limit)\r
- throws DatabaseException;\r
-}\r
+/*******************************************************************************
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * in Industry THTH ry.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * VTT Technical Research Centre of Finland - initial API and implementation
+ *******************************************************************************/
+package org.simantics.db;
+
+import org.simantics.db.exception.DatabaseException;
+import org.simantics.db.exception.ExternalValueException;
+
+/**
+ * This interface is for accessing external values of resources. External
+ * values are values of resources which are stored outside the cluster of the
+ * resource. These values support partial read and write.
+ *
+ * @author Kalle Kondelin
+ */
+public interface ExternalValueSupport {
+ /**
+ * Removes the value from the resource. Also truncates the value to zero
+ * length so that if the value is created again it does not have any content.
+ *
+ * @param graph to ensure that caller has write transaction.
+ * @param resource which value is to be removed.
+ * @throws DatabaseException
+ */
+ void removeValue(WriteGraph graph, Resource resource)
+ throws DatabaseException;
+ /**
+ * Write some or all bytes of an external value.
+ *
+ * IMPLEMENTATION NOTE:
+ * The current implementation for the value is a file and every transaction
+ * you write the value the whole file is copied and then the modification
+ * is applied.
+ * If you write internal value or create external value you must write the
+ * whole value because the value is not initialized.
+ * If you write a value that is so big that server can't hold it in memory
+ * during the commit you must split it in parts by using commitAndContinue
+ * method.
+ *
+ * @param graph to ensure that caller has write transaction.
+ * @param resource which value is modified.
+ * @param offset from start of the value. Must be within [0, MAX_VALUE_SIZE).
+ * MAX_VALUE_SIZE = (1<<58)-2. (1<<58)-1 reserved for special move message.
+ * @param length of the modified segment i.e. number of bytes to write.
+ * Must be positive. If zero then the value length is truncated to offset.
+ * If offset + length is greater then MAX_VALUE_SIZE then the behavior is
+ * undefined.
+ * @param bytes to write. Must have at least length bytes.
+ * @throws DatabaseException
+ */
+ void writeValue(WriteGraph graph, Resource resource, long offset, int length, byte[] bytes)
+ throws DatabaseException;
+ /**
+ * If there is an old value moves it to current change set. This means that
+ * old value is lost but space is saved. Must be called before first
+ * writeValue call for given change set to have any effect.
+ *
+ * @param graph to ensure that caller has write transaction.
+ * @param resource which value is to be modified i.e. the same value as
+ * given to following writeValue(s).
+ */
+// This breaks undo.
+// void moveValue(WriteGraph graph, Resource resource)
+// throws DatabaseException;
+ /**
+ * Sends commit message to server but does not end transaction. This
+ * enables server to release memory used by writeValue requests.
+ * Waits until most of the pending requests has been sent so that the
+ * memory used by the pending requests does not grow unreasonably large.
+ *
+ * @param graph to ensure that caller has write transaction.
+ * @param wtraits required by commit message. Usually the write request
+ * which is calling this method.
+ * @param resource which value is modified i.e. the same value as given to writeValue.
+ */
+// This breaks undo.
+// void commitAndContinue(WriteGraph graph, WriteTraits wtraits, Resource resource)
+// throws DatabaseException;
+ /**
+ * Read some or all bytes of an external value.
+ *
+ * @param graph to ensure that caller has read transaction.
+ * @param resource which value is to be read.
+ * @param offset from start of the value. Must be within [0, valueSize).
+ * @param length of the segment to read. Offset + length must be within [0, valueSize].
+ * @return the bytes of the segment that was asked.
+ * @throws DatabaseException
+ */
+ byte[] readValue(ReadGraph graph, Resource resource, long offset, int length)
+ throws DatabaseException;
+ /**
+ * @param graph to ensure that caller has read transaction.
+ * @param resource which value is to be read.
+ * @return size of the value.
+ * @throws DatabaseException
+ * @throws ExternalValueException if the value is not external.
+ */
+ long getValueSize(ReadGraph graph, Resource resource)
+ throws DatabaseException, ExternalValueException;
+
+ /**
+ * Wait until there is less than limit requests in outgoing request queue.
+ *
+ * @param limit value for requests in request queue. Must be greater than zero.
+ * @return Number of requests left in request queue.
+ * @throws DatabaseException
+ */
+ int wait4RequestsLess(int limit)
+ throws DatabaseException;
+}
Code Review / simantics / platform.git / blobdiff