# PassThroughConfiguration.java

    /*
    *  Copyright (c) 2005-2010, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
    *
    *  WSO2 Inc. licenses this file to you under the Apache License,
    *  Version 2.0 (the "License"); you may not use this file except
    *  in compliance with the License.
    *  You may obtain a copy of the License at
    *
    *    http://www.apache.org/licenses/LICENSE-2.0
    *
    * Unless required by applicable law or agreed to in writing,
    * software distributed under the License is distributed on an
    * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    * KIND, either express or implied.  See the License for the
    * specific language governing permissions and limitations
    * under the License.
    */

    package org.apache.synapse.transport.passthru.config;

    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.apache.http.params.HttpConnectionParams;
    import org.apache.synapse.transport.passthru.PassThroughConstants;

    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.Properties;

    /**
     * This class encapsulates pass-through http transport tuning configurations specified via a
     * configurations file or system properties.
     */
    public class PassThroughConfiguration {

        /**
         * Default tuning parameter values
         */
        private static final int DEFAULT_WORKER_POOL_SIZE_CORE       = 40;
        private static final int DEFAULT_WORKER_POOL_SIZE_MAX        = 200;
        private static final int DEFAULT_WORKER_THREAD_KEEPALIVE_SEC = 60;
        private static final int DEFAULT_WORKER_POOL_QUEUE_LENGTH    = -1;
        private static final int DEFAULT_IO_BUFFER_SIZE              = 8 * 1024;
        private static final int DEFAULT_IO_THREADS_PER_REACTOR      =
                                                             Runtime.getRuntime().availableProcessors();
        private static final int DEFAULT_MAX_ACTIVE_CON = -1;
        private static final int DEFAULT_LISTENER_SHUTDOWN_WAIT_TIME = 0;
        private static final int DEFAULT_CONNECTION_GRACE_TIME = 10000;
        private Boolean isKeepAliveDisabled = null;

        //additional rest dispatch handlers
        private static final String REST_DISPATCHER_SERVICE="rest.dispatcher.service";
        // URI configurations that determine if it requires custom rest dispatcher
        private static final String REST_URI_API_REGEX = "rest_uri_api_regex";
        private static final String REST_URI_PROXY_REGEX = "rest_uri_proxy_regex";
        // properties which are allowed to be directly pass through from request context to response context explicitly
        private static final String ALLOWED_RESPONSE_PROPERTIES = "allowed_response_properties";

        /** Reverse proxy mode is enabled or not */
        private Boolean reverseProxyMode = null;

        /** Default Synapse service name */
        private String passThroughDefaultServiceName = null;

        private static final Log log = LogFactory.getLog(PassThroughConfiguration.class);

        private static PassThroughConfiguration _instance = new PassThroughConfiguration();

        private Properties props;

        private PassThroughConfiguration() {
            try {
                props = loadProperties("passthru-http.properties");
            } catch (Exception ignored) {}
        }

        public static PassThroughConfiguration getInstance() {
            return _instance;
        }

        public int getWorkerPoolCoreSize() {
            return getIntProperty(PassThroughConfigPNames.WORKER_POOL_SIZE_CORE,
                    DEFAULT_WORKER_POOL_SIZE_CORE);
        }

        public int getWorkerPoolMaxSize() {
            return getIntProperty(PassThroughConfigPNames.WORKER_POOL_SIZE_MAX,
                    DEFAULT_WORKER_POOL_SIZE_MAX);
        }

        public int getWorkerThreadKeepaliveSec() {
            return getIntProperty(PassThroughConfigPNames.WORKER_THREAD_KEEP_ALIVE_SEC,
                    DEFAULT_WORKER_THREAD_KEEPALIVE_SEC);
        }

        public int getWorkerPoolQueueLen() {
            return getIntProperty(PassThroughConfigPNames.WORKER_POOL_QUEUE_LENGTH,
                    DEFAULT_WORKER_POOL_QUEUE_LENGTH);
        }

        public int getIOThreadsPerReactor() {
            return getIntProperty(PassThroughConfigPNames.IO_THREADS_PER_REACTOR,
                    DEFAULT_IO_THREADS_PER_REACTOR);
        }

        public int getIOBufferSize() {
            return getIntProperty(PassThroughConfigPNames.IO_BUFFER_SIZE,
                    DEFAULT_IO_BUFFER_SIZE);
        }

        public boolean isKeepAliveDisabled() {
            if (isKeepAliveDisabled == null) {
                isKeepAliveDisabled = getBooleanProperty(PassThroughConfigPNames.DISABLE_KEEPALIVE, false);
            }
            return isKeepAliveDisabled.booleanValue();
        }

        public int getMaxActiveConnections() {
            return getIntProperty(PassThroughConfigPNames.C_MAX_ACTIVE, DEFAULT_MAX_ACTIVE_CON);
        }
        public int getListenerShutdownWaitTime() {
            return getIntProperty(PassThroughConfigPNames.TRANSPORT_LISTENER_SHUTDOWN_WAIT_TIME_SEC,
                    DEFAULT_LISTENER_SHUTDOWN_WAIT_TIME)*1000;
        }

        public boolean isPreserveUserAgentHeader() {
            return getBooleanProperty(PassThroughConfigPNames.USER_AGENT_HEADER_PRESERVE, false);
        }

        public boolean isPreserveServerHeader() {
            return getBooleanProperty(PassThroughConfigPNames.SERVER_HEADER_PRESERVE, false);
        }

        public boolean isForcedXmlMessageValidationEnabled() {
            return getBooleanProperty(PassThroughConstants.FORCE_XML_MESSAGE_VALIDATION, false);
        }

        public boolean isForcedJSONMessageValidationEnabled() {
            return getBooleanProperty(PassThroughConstants.FORCE_JSON_MESSAGE_VALIDATION, false);
        }

        public String getPreserveHttpHeaders() {
            return getStringProperty(PassThroughConfigPNames.HTTP_HEADERS_PRESERVE, "");
        }

        public String getResponsePreseveHttpHeaders() {
            return getStringProperty(PassThroughConfigPNames.HTTP_RESPONSE_HEADERS_PRESERVE, "");
        }

        public int getConnectionIdleTime() {

            int idleTime;
            // Giving higher priority for grace time if it is configured, than for the configured idle time
            if (isIntPropertyConfigured(PassThroughConfigPNames.CONNECTION_GRACE_TIME)) {
                idleTime = getIdleTimeFromGraceTime();
            } else {
                // Setting idle time if it is configured, if not, using the default grace time to calculate idle time
                idleTime = getIntProperty(PassThroughConfigPNames.CONNECTION_IDLE_TIME, getIdleTimeFromGraceTime());
            }

            if (idleTime < 0) {
                return 0;
            }
            return idleTime;
        }
        public int getMaximumConnectionLifespan() {
            return getIntProperty(PassThroughConfigPNames.MAXIMUM_CONNECTION_LIFESPAN, Integer.MAX_VALUE);
        }
        public int getConnectionGraceTime() {
            return getIntProperty(PassThroughConfigPNames.CONNECTION_GRACE_TIME, DEFAULT_CONNECTION_GRACE_TIME);
        }

        /**
         * For the default value, grace time is reduced to avoid connection being used at the moment it is being closed
         * @return default connection idle time
         */
        private int getIdleTimeFromGraceTime(){
            return getIntProperty(HttpConnectionParams.SO_TIMEOUT, 60000) - getConnectionGraceTime();
        }

        public String getCorrelationHeaderName() {
            return getStringProperty(PassThroughConfigPNames.CORRELATION_HEADER_NAME_PROPERTY,
                    PassThroughConstants.CORRELATION_DEFAULT_HEADER);
        }

        /**
         * Loads the properties from a given property file path
         *
         * @param filePath Path of the property file
         * @return Properties loaded from given file
         */
        private static Properties loadProperties(String filePath) {

        	 Properties properties = new Properties();
             ClassLoader cl = Thread.currentThread().getContextClassLoader();

             if (log.isDebugEnabled()) {
                 log.debug("Loading the file '" + filePath + "' from classpath");
             }

             InputStream in  = null;

             //if we reach to this assume that the we may have to looking to the customer provided external location for the
             //given properties
     		if (System.getProperty(PassThroughConstants.CONF_LOCATION) != null) {
     			try {
     				in = new FileInputStream(System.getProperty(PassThroughConstants.CONF_LOCATION) + File.separator + filePath);
     			} catch (FileNotFoundException e) {
     				String msg = "Error loading properties from a file at from the System defined location: " + filePath;
     				log.warn(msg);
     			}
     		}

             if (in == null) {
             	in = cl.getResourceAsStream(filePath);
                 if (log.isDebugEnabled()) {
                     log.debug("Unable to load file  '" + filePath + "'");
                 }

                 filePath = "conf" + File.separatorChar + filePath;
                 if (log.isDebugEnabled()) {
                     log.debug("Loading the file '" + filePath + "'");
                 }

                 in = cl.getResourceAsStream(filePath);
                 if (in == null) {
                     if (log.isDebugEnabled()) {
                         log.debug("Unable to load file  '" + filePath + "'");
                     }
                 }
             }
             if (in != null) {
                 try {
                     properties.load(in);
                 } catch (IOException e) {
                     String msg = "Error loading properties from a file at : " + filePath;
                     log.error(msg, e);
                 }
             }
             return properties;
        }

        /**
         * Get an int property that tunes pass-through http transport. Prefer system properties
         *
         * @param name name of the system/config property
         * @param def  default value to return if the property is not set
         * @return the value of the property to be used
         */
        public Integer getIntProperty(String name, Integer def) {
            String val = System.getProperty(name);
            if (val == null) {
                val = props.getProperty(name);
            }

            if (val != null) {
                int intVal;
                try {
                    intVal = Integer.valueOf(val);
                } catch (NumberFormatException e) {
                    log.warn("Invalid pass-through http tuning property value. " + name +
                            " must be an integer");
                    return def;
                }
                if (log.isDebugEnabled()) {
                    log.debug("Using pass-through http tuning parameter : " + name + " = " + val);
                }
                return intVal;
            }

            return def;
        }

        /**
         * Return true if user has configured an int property that tunes pass-through http transport
         * @param name  name of the system/config property
         * @return      true if property is configured
         */
        private boolean isIntPropertyConfigured(String name) {

            String val = System.getProperty(name);
            if (val == null) {
                val = props.getProperty(name);
            }

            if (val != null) {
                try {
                    Integer.parseInt(val);
                } catch (NumberFormatException e) {
                    log.warn("Incorrect pass-through http tuning property value. " + name +
                            " must be an integer");
                    return false;
                }
                if (log.isDebugEnabled()) {
                    log.debug("Using configured pass-through http tuning property value for : " + name);
                }
                return true;
            }

            return false;
        }

        /**
         * Get an int property that tunes pass-through http transport. Prefer system properties
         *
         * @param name name of the system/config property
         * @return the value of the property, null if the property is not found
         */
        public Integer getIntProperty(String name) {
            return getIntProperty(name, null);
        }

        /**
         * Get a boolean property that tunes pass-through http transport. Prefer system properties
         *
         * @param name name of the system/config property
         * @param def  default value to return if the property is not set
         * @return the value of the property to be used
         */
        public Boolean getBooleanProperty(String name, Boolean def) {
            String val = System.getProperty(name);
            if (val == null) {
                val = props.getProperty(name);
            }

            if (val != null) {
                if (log.isDebugEnabled()) {
                    log.debug("Using pass-through http tuning parameter : " + name + " = " + val);
                }
                return Boolean.valueOf(val);
            }

            return def;
        }

        /**
         * Get a Boolean property that tunes pass-through http transport. Prefer system properties
         *
         * @param name name of the system/config property
         * @return the value of the property, null if the property is not found
         */
        public Boolean getBooleanProperty(String name) {
            return getBooleanProperty(name, null);
        }

        /**
         * Get a String property that tunes pass-through http transport. Prefer system properties
         *
         * @param name name of the system/config property
         * @param def  default value to return if the property is not set
         * @return the value of the property to be used
         */
        public String getStringProperty(String name, String def) {
            String val = System.getProperty(name);
            if (val == null) {
                val = props.getProperty(name);
            }

            return val == null ? def : val;
        }

        public String getRESTDispatchService() {
            return getStringProperty(REST_DISPATCHER_SERVICE,"");
        }

        public String getRestUriApiRegex() {
            return getStringProperty(REST_URI_API_REGEX, "");
        }

        public String getRestUriProxyRegex() {
            return getStringProperty(REST_URI_PROXY_REGEX, "");
        }

        public boolean isListeningIOReactorShared(){
            return getBooleanProperty(PassThroughConfigPNames.HTTP_LISTENING_IO_REACTOR_SHARING_ENABLE, false);
        }

        public String getAllowedResponseProperties() {
            return getStringProperty(ALLOWED_RESPONSE_PROPERTIES, null);
        }

        /**
         * Check for reverse proxy mode
         *
         * @return whether reverse proxy mode is enabled
         */
        public boolean isReverseProxyMode() {
            if (reverseProxyMode == null) {
                reverseProxyMode = Boolean.parseBoolean(System.getProperty("reverseProxyMode"));
            }
            return reverseProxyMode;
        }

        /**
         * Get the default synapse service name
         *
         * @return default synapse service name
         */
        public String getPassThroughDefaultServiceName() {
            if (passThroughDefaultServiceName == null) {
                passThroughDefaultServiceName = getStringProperty("passthru.default.service", "__SynapseService");
            }
            return passThroughDefaultServiceName;
        }
    }