sysproperties.java

非常棒的java数据库

/*
 * Copyright 2004-2008 H2 Group. Licensed under the H2 License, Version 1.0
 * (http://h2database.com/html/license.html).
 * Initial Developer: H2 Group
 */
package org.h2.constant;

import org.h2.engine.Constants;
import org.h2.message.TraceSystem;

/**
 * The constants defined in this class are initialized from system properties.
 * Those properties can be set when starting the virtual machine:
 * <pre>
 * java -Dh2.baseDir=/temp
 * </pre>
 * They can be set within the application, but this must be done before loading
 * any classes of this database (before loading the JDBC driver):
 * <pre>
 * System.setProperty(&quot;h2.baseDir&quot;, &quot;/temp&quot;);
 * </pre>
 */
public class SysProperties {

    /**
     * INTERNAL
     */
    public static final String H2_MAX_QUERY_TIMEOUT = "h2.maxQueryTimeout";

    /**
     * INTERNAL
     */
    public static final String H2_LOG_DELETE_DELAY = "h2.logDeleteDelay";

    /**
     * INTERNAL
     */
    public static final String H2_COLLATOR_CACHE_SIZE = "h2.collatorCacheSize";

    /**
     * System property <code>file.encoding</code> (default: Cp1252).<br />
     * It is usually set by the system and is the default encoding used for the
     * RunScript and CSV tool.
     */
    public static final String FILE_ENCODING = getStringSetting("file.encoding", "Cp1252");

    /**
     * System property <code>file.separator</code> (default: /).<br />
     * It is usually set by the system, and used to build absolute file names.
     */
    public static final String FILE_SEPARATOR = getStringSetting("file.separator", "/");

    /**
     * System property <code>line.separator</code> (default: \n).<br />
     * It is usually set by the system, and used by the script and trace tools.
     */
    public static final String LINE_SEPARATOR = getStringSetting("line.separator", "\n");

    /**
     * System property <code>user.home</code> (default: empty string).<br />
     * It is usually set by the system, and used as a replacement for ~ in file
     * names.
     */
    public static final String USER_HOME = getStringSetting("user.home", "");

    /**
     * System property <code>h2.aliasColumnName</code> (default: false).<br />
     * When enabled, aliased columns (as in SELECT ID AS I FROM TEST) return the
     * real table and column name in ResultSetMetaData.getTableName() and
     * getColumnName(). This is disabled by default for compatibility with other
     * databases (HSQLDB, Apache Derby, PostgreSQL, some version of MySQL).
     */
    // TODO change in version 1.1
    public static final boolean ALIAS_COLUMN_NAME = getBooleanSetting("h2.aliasColumnName", false);

    /**
     * System property <code>h2.allowBigDecimalExtensions</code> (default:
     * false).<br />
     * When enabled, classes that extend BigDecimal are supported in
     * PreparedStatement.setBigDecimal.
     */
    public static final boolean ALLOW_BIG_DECIMAL_EXTENSIONS = getBooleanSetting("h2.allowBigDecimalExtensions", false);

    /**
     * System property <code>h2.allowedClasses</code> (default: *).<br />
     * Comma separated list of class names or prefixes.
     */
    public static final String ALLOWED_CLASSES = getStringSetting("h2.allowedClasses", "*");

    /**
     * System property <code>h2.bindAddress</code> (default: *).<br />
     * Comma separated list of class names or prefixes.
     */
    public static final String BIND_ADDRESS = getStringSetting("h2.bindAddress", null);

    /**
     * System property <code>h2.cacheSizeDefault</code> (default: 16384).<br />
     * The default cache size in KB.
     */
    public static final int CACHE_SIZE_DEFAULT = getIntSetting("h2.cacheSizeDefault", 16 * 1024);

    /**
     * System property <code>h2.cacheSizeIndexShift</code> (default: 3).<br />
     * How many time the cache size value is divided by two to get the index
     * cache size. The index cache size is calculated like this: cacheSize >>
     * cacheSizeIndexShift.
     */
    public static final int CACHE_SIZE_INDEX_SHIFT = getIntSetting("h2.cacheSizeIndexShift", 3);

    /**
     * INTERNAL
     */
    public static final int CACHE_SIZE_INDEX_DEFAULT = CACHE_SIZE_DEFAULT >> CACHE_SIZE_INDEX_SHIFT;

    /**
     * System property <code>h2.check</code> (default: true).<br />
     * Assertions in the database engine.
     */
    public static final boolean CHECK = getBooleanSetting("h2.check", true);

    /**
     * System property <code>h2.check2</code> (default: true).<br />
     * Additional assertions in the database engine.
     */
    public static final boolean CHECK2 = getBooleanSetting("h2.check2", false);

    /**
     * System property <code>h2.clientTraceDirectory</code> (default:
     * trace.db/).<br />
     * Directory where the trace files of the JDBC client are stored (only for
     * client / server).
     */
    public static final String CLIENT_TRACE_DIRECTORY = getStringSetting("h2.clientTraceDirectory", "trace.db/");

    /**
     * System property <code>h2.defaultMaxOperationMemory</code> (default:
     * 100000).<br />
     * The default for the setting MAX_OPERATION_MEMORY.
     */
    public static final int DEFAULT_MAX_OPERATION_MEMORY = getIntSetting("h2.defaultMaxOperationMemory", 100000);

    /**
     * System property <code>h2.dataSourceTraceLevel</code> (default: 1).<br />
     * The trace level of the data source implementation. Default is 1 for
     * error.
     */
    public static final int DATASOURCE_TRACE_LEVEL = getIntSetting("h2.dataSourceTraceLevel", TraceSystem.ERROR);

    /**
     * System property <code>h2.defaultMaxMemoryUndo</code> (default: 100000).<br />
     * The default value for the MAX_MEMORY_UNDO setting.
     */
    public static final int DEFAULT_MAX_MEMORY_UNDO = getIntSetting("h2.defaultMaxMemoryUndo", 100000);

    /**
     * System property <code>h2.defaultLockMode</code> (default: 3).<br />
     * The default value for the LOCK_MODE setting.
     */
    public static final int DEFAULT_LOCK_MODE = getIntSetting("h2.defaultLockMode", Constants.LOCK_MODE_READ_COMMITTED);

    /**
     * System property <code>h2.emergencySpaceInitial</code> (default: 262144).<br />
     * Size of 'reserve' file to detect disk full problems early.
     */
    public static final int EMERGENCY_SPACE_INITIAL = getIntSetting("h2.emergencySpaceInitial", 256 * 1024);

    /**
     * System property <code>h2.emergencySpaceMin</code> (default: 65536).<br />
     * Minimum size of 'reserve' file.
     */
    public static final int EMERGENCY_SPACE_MIN = getIntSetting("h2.emergencySpaceMin", 64 * 1024);

    /**
     * System property <code>h2.lobCloseBetweenReads</code> (default: false).<br />
     * Close LOB files between read operations.
     */
    public static boolean lobCloseBetweenReads = getBooleanSetting("h2.lobCloseBetweenReads", false);

    /**
     * System property <code>h2.lobFilesInDirectories</code> (default: false).<br />
     * Store LOB files in subdirectories.
     */
    // TODO change in version 1.1
    // TODO: when removing this property, also remove 
    // DataHandler.allocateObjectId, createTempFile it
    public static final boolean LOB_FILES_IN_DIRECTORIES = getBooleanSetting("h2.lobFilesInDirectories", false);

    /**
     * System property <code>h2.lobFilesPerDirectory</code> (default: 256).<br />
     * Maximum number of LOB files per directory.
     */
    public static final int LOB_FILES_PER_DIRECTORY = getIntSetting("h2.lobFilesPerDirectory", 256);

    /**
     * System property <code>h2.logAllErrors</code> (default: false).<br />
     * Write stack traces of any kind of error to a file.
     */
    public static final boolean LOG_ALL_ERRORS = getBooleanSetting("h2.logAllErrors", false);

    /**
     * System property <code>h2.logAllErrorsFile</code> (default:
     * h2errors.txt).<br />
     * File name to log errors.
     */
    public static final String LOG_ALL_ERRORS_FILE = getStringSetting("h2.logAllErrorsFile", "h2errors.txt");

    /**
     * System property <code>h2.maxFileRetry</code> (default: 16).<br />
     * Number of times to retry file delete and rename.
     */
    public static final int MAX_FILE_RETRY = Math.max(1, getIntSetting("h2.maxFileRetry", 16));

    /**
     * System property <code>h2.maxMemoryRowsDistinct</code> (default:
     * Integer.MAX_VALUE).<br />
     * The maximum number of rows kept in-memory for SELECT DISTINCT queries. If
     * more than this number of rows are in a result set, a temporary table is
     * used.
     */
    public static final int MAX_MEMORY_ROWS_DISTINCT = getIntSetting("h2.maxMemoryRowsDistinct", Integer.MAX_VALUE);

    /**
     * System property <code>h2.maxQueryTimeout</code> (default: 0).<br />
     * The maximum timeout of a query. The default is 0, meaning no limit.
     */
    public static final int MAX_QUERY_TIMEOUT = getIntSetting(H2_MAX_QUERY_TIMEOUT, 0);

    /**
     * System property <code>h2.minColumnNameMap</code> (default: 3).<br />
     * The minimum number of columns where a hash table is created when result set
     * methods with column name (instead of column index) parameter are called.
     */
    public static final int MIN_COLUMN_NAME_MAP = getIntSetting("h2.minColumnNameMap", 3);

    /**
     * System property <code>h2.minWriteDelay</code> (default: 5).<br />
     * The minimum write delay that causes commits to be delayed.
     */
    public static final int MIN_WRITE_DELAY = getIntSetting("h2.minWriteDelay", 5);

    /**
     * System property <code>h2.objectCache</code> (default: true).<br />
     * Cache commonly used objects (integers, strings).
     */
    public static final boolean OBJECT_CACHE = getBooleanSetting("h2.objectCache", true);