--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/servlet3/src/main/java/digilib/servlet/Scaler.java	Tue Apr 26 20:24:31 2011 +0200
@@ -0,0 +1,345 @@
+package digilib.servlet;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+
+import javax.servlet.AsyncContext;
+import javax.servlet.ServletConfig;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.apache.log4j.Logger;
+
+import digilib.auth.AuthOpException;
+import digilib.auth.AuthOps;
+import digilib.image.DocuImage;
+import digilib.image.ImageJobDescription;
+import digilib.image.ImageOpException;
+import digilib.io.DocuDirCache;
+import digilib.io.DocuDirectory;
+import digilib.io.ImageInput;
+import digilib.util.DigilibJobCenter;
+
+@WebServlet(name="Scaler", urlPatterns={"/Scaler", "/servlet/Scaler/*"}, asyncSupported=true)
+public class Scaler extends HttpServlet {
+
+    private static final long serialVersionUID = 5289386646192471549L;
+
+    /** digilib servlet version (for all components) */
+    public static final String version = "2.0b1";
+
+    /** servlet error codes */
+    public static enum Error {UNKNOWN, AUTH, FILE, IMAGE};
+    
+    /** type of error message */
+    public static enum ErrMsg {IMAGE, TEXT, CODE};
+    
+    /** default error message type */
+    public static ErrMsg defaultErrMsgType = ErrMsg.IMAGE;
+    
+    /** logger for accounting requests */
+    protected static Logger accountlog = Logger.getLogger("account.request");
+
+    /** gengeral logger for this class */
+    protected static Logger logger = Logger.getLogger("digilib.scaler");
+
+    /** logger for authentication related */
+    protected static Logger authlog = Logger.getLogger("digilib.auth");
+
+    /** DocuDirCache instance */
+    protected DocuDirCache dirCache;
+
+    /** Image executor */
+    protected DigilibJobCenter<DocuImage> imageJobCenter;
+
+    /** authentication error image file */
+    public static File denyImgFile;
+
+    /** image error image file */
+    public static File errorImgFile;
+
+    /** not found error image file */
+    public static File notfoundImgFile;
+
+    /** send files as is? */
+    protected boolean sendFileAllowed = true;
+
+    /** DigilibConfiguration instance */
+    protected DigilibConfiguration dlConfig;
+
+    /** use authorization database */
+    protected boolean useAuthorization = true;
+
+    /** AuthOps instance */
+    protected AuthOps authOp;
+
+    /**
+     * Initialisation on first run.
+     * 
+     * @throws ServletException
+     * 
+     * @see javax.servlet.Servlet#init(javax.servlet.ServletConfig)
+     */
+    public void init(ServletConfig config) throws ServletException {
+        super.init(config);
+
+        System.out
+                .println("***** Digital Image Library Image Scaler Servlet (version "
+                        + version + ") *****");
+        // say hello in the log file
+        logger.info("***** Digital Image Library Image Scaler Servlet (version "
+                + version + ") *****");
+
+        // get our ServletContext
+        ServletContext context = config.getServletContext();
+        // see if there is a Configuration instance
+        dlConfig = (DigilibConfiguration) context.getAttribute("digilib.servlet.configuration");
+        if (dlConfig == null) {
+            // no Configuration
+            throw new ServletException("No Configuration!");
+        }
+        // set our AuthOps
+        useAuthorization = dlConfig.getAsBoolean("use-authorization");
+        authOp = (AuthOps) dlConfig.getValue("servlet.auth.op");
+
+        // DocuDirCache instance
+        dirCache = (DocuDirCache) dlConfig.getValue("servlet.dir.cache");
+
+        // Executor
+        imageJobCenter = (DigilibJobCenter<DocuImage>) dlConfig
+                .getValue("servlet.worker.imageexecutor");
+
+        denyImgFile = ServletOps.getFile(
+                (File) dlConfig.getValue("denied-image"), context);
+        errorImgFile = ServletOps.getFile(
+                (File) dlConfig.getValue("error-image"), context);
+        notfoundImgFile = ServletOps.getFile(
+                (File) dlConfig.getValue("notfound-image"), context);
+        sendFileAllowed = dlConfig.getAsBoolean("sendfile-allowed");
+        try {
+            defaultErrMsgType = ErrMsg.valueOf(dlConfig.getAsString("default-errmsg-type"));
+        } catch (Exception e) {
+            // nothing to do
+        }
+    }
+
+    /**
+     * Returns modification time relevant to the request for caching.
+     * 
+     * @see javax.servlet.http.HttpServlet#getLastModified(javax.servlet.http.HttpServletRequest)
+     */
+    public long getLastModified(HttpServletRequest request) {
+        accountlog.debug("GetLastModified from " + request.getRemoteAddr()
+                + " for " + request.getQueryString());
+        long mtime = -1;
+        try {
+            // create new digilib request
+            DigilibServletRequest dlReq = new DigilibServletRequest(request);
+            DocuDirectory dd = dirCache.getDirectory(dlReq.getFilePath());
+            if (dd != null) {
+                mtime = dd.getDirMTime() / 1000 * 1000;
+            }
+        } catch (Exception e) {
+            logger.error("error in getLastModified: " + e.getMessage());
+        }
+        logger.debug("  returns " + mtime);
+        return mtime;
+    }
+
+    /* (non-Javadoc)
+     * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
+     */
+    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException {
+        accountlog.info("GET from " + request.getRemoteAddr());
+        this.processRequest(request, response);
+    }
+
+
+    /* (non-Javadoc)
+     * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
+     */
+    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException {
+        accountlog.info("POST from " + request.getRemoteAddr());
+        this.processRequest(request, response);
+    }
+    
+
+	protected void doHead(HttpServletRequest req, HttpServletResponse resp)
+			throws ServletException, IOException {
+		logger.debug("HEAD from "+req.getRemoteAddr());
+		super.doHead(req, resp);
+	}
+
+	protected void doOptions(HttpServletRequest req, HttpServletResponse resp)
+			throws ServletException, IOException {
+		logger.debug("OPTIONS from "+req.getRemoteAddr());
+		super.doOptions(req, resp);
+	}
+
+	/** Service this request using the response.
+     * @param request
+     * @param response
+     * @throws ServletException 
+     */
+    public void processRequest(HttpServletRequest request,
+            HttpServletResponse response) throws ServletException {
+
+        if (dlConfig == null) {
+            logger.error("ERROR: No Configuration!");
+            throw new ServletException("NO VALID digilib CONFIGURATION!");
+        }
+
+        accountlog.debug("request: " + request.getQueryString());
+        logger.debug("request: " + request.getQueryString());
+        logger.debug("headers: " + ServletOps.headersToString(request));
+        //logger.debug("response:"+ response + " committed=" + response.isCommitted());
+        final long startTime = System.currentTimeMillis();
+
+        // parse request
+        DigilibServletRequest dlRequest = new DigilibServletRequest(request);
+        // extract the job information
+        final ImageJobDescription jobTicket = ImageJobDescription.getInstance(dlRequest, dlConfig);
+
+        // type of error reporting
+        ErrMsg errMsgType = defaultErrMsgType;
+        if (dlRequest.hasOption("errimg")) {
+            errMsgType = ErrMsg.IMAGE;
+        } else if (dlRequest.hasOption("errtxt")) {
+        	errMsgType = ErrMsg.TEXT;
+        } else if (dlRequest.hasOption("errcode")) {
+        	errMsgType = ErrMsg.CODE;
+        }
+        
+        try {
+        	/*
+        	 *  check if we can fast-track without scaling
+        	 */
+            ImageInput fileToLoad = (ImageInput) jobTicket.getInput();
+
+            // check permissions
+            if (useAuthorization) {
+                // get a list of required roles (empty if no restrictions)
+                List<String> rolesRequired = authOp.rolesForPath(
+                        jobTicket.getFilePath(), request);
+                if (rolesRequired != null) {
+                    authlog.debug("Role required: " + rolesRequired);
+                    authlog.debug("User: " + request.getRemoteUser());
+                    // is the current request/user authorized?
+                    if (!authOp.isRoleAuthorized(rolesRequired, request)) {
+                        // send deny answer and abort
+                        throw new AuthOpException();
+                    }
+                }
+            }
+
+            // if requested, send image as a file
+            if (sendFileAllowed && jobTicket.getSendAsFile()) {
+                String mt = null;
+                if (jobTicket.hasOption("rawfile")) {
+                    mt = "application/octet-stream";
+                }
+                logger.debug("Sending RAW File as is.");
+                ServletOps.sendFile(fileToLoad.getFile(), mt, null, response, logger);
+                logger.info("Done in " + (System.currentTimeMillis() - startTime) + "ms");
+                return;
+            }
+
+            // if possible, send the image without actually having to transform it
+            if (! jobTicket.isTransformRequired()) {
+                logger.debug("Sending File as is.");
+                ServletOps.sendFile(fileToLoad.getFile(), null, null, response, logger);
+                logger.info("Done in " + (System.currentTimeMillis() - startTime) + "ms");
+                return;
+            }
+
+            // check load of workers
+            if (imageJobCenter.isBusy()) {
+                logger.error("Servlet overloaded!");
+                response.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
+                return;
+            }
+            
+            // worker job is done asynchronously
+            AsyncContext asyncCtx = request.startAsync(request, response); 
+            // create job
+            AsyncServletWorker job = new AsyncServletWorker(dlConfig, jobTicket, asyncCtx, errMsgType, startTime);
+            // submit job
+            imageJobCenter.submit(job);
+            // we're done for now
+
+        } catch (ImageOpException e) {
+            logger.error(e.getClass() + ": " + e.getMessage());
+            digilibError(errMsgType, Error.IMAGE, null, response);
+        } catch (IOException e) {
+            logger.error(e.getClass() + ": " + e.getMessage());
+            digilibError(errMsgType, Error.FILE, null, response);
+        } catch (AuthOpException e) {
+            logger.error(e.getClass() + ": " + e.getMessage());
+            digilibError(errMsgType, Error.AUTH, null, response);
+        } catch (Exception e) {
+            logger.error("Other Exception: ", e);
+            // TODO: should we rethrow or swallow?
+            //throw new ServletException(e);
+        }
+    }
+
+    /**
+     * Sends an error to the client as text or image.
+     * 
+     * @param type
+     * @param error
+     * @param msg
+     * @param response
+     */
+    public static void digilibError(ErrMsg type, Error error, String msg,
+            HttpServletResponse response) {
+        try {
+            File img = null;
+            int status = 0;
+            if (error == Error.AUTH) {
+                if (msg == null) {
+                    msg = "ERROR: Unauthorized access!";
+                }
+                img = denyImgFile;
+                status = HttpServletResponse.SC_FORBIDDEN;
+            } else if (error == Error.FILE) {
+                if (msg == null) {
+                    msg = "ERROR: Image file not found!";
+                }
+                img = notfoundImgFile;
+                status = HttpServletResponse.SC_NOT_FOUND;
+            } else {
+                if (msg == null) {
+                    msg = "ERROR: Other image error!";
+                }
+                img = errorImgFile;
+                status = HttpServletResponse.SC_BAD_REQUEST;
+            }
+            if (response.isCommitted()) {
+                // response already committed
+                logger.warn("Response committed for error "+msg);
+            }
+            if (type == ErrMsg.TEXT) {
+                ServletOps.htmlMessage(msg, response);
+            } else if (type == ErrMsg.CODE) {
+                response.sendError(status, msg);
+            } else if (img != null) {
+                // default: image
+                ServletOps.sendFile(img, null, null, response, logger);
+            }
+        } catch (Exception e) {
+            logger.error("Error sending error!", e);
+        }
+
+    }
+
+    public static String getVersion() {
+        return version;
+    }
+
+}