chris@1: /*
chris@1: * SONEWS News Server
chris@1: * see AUTHORS for the list of contributors
chris@1: *
chris@1: * This program is free software: you can redistribute it and/or modify
chris@1: * it under the terms of the GNU General Public License as published by
chris@1: * the Free Software Foundation, either version 3 of the License, or
chris@1: * (at your option) any later version.
chris@1: *
chris@1: * This program is distributed in the hope that it will be useful,
chris@1: * but WITHOUT ANY WARRANTY; without even the implied warranty of
chris@1: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
chris@1: * GNU General Public License for more details.
chris@1: *
chris@1: * You should have received a copy of the GNU General Public License
chris@1: * along with this program. If not, see .
chris@1: */
chris@1:
chris@1: package org.sonews.daemon.command;
chris@1:
chris@1: import java.io.IOException;
chris@1: import java.util.List;
chris@1: import org.sonews.util.Log;
chris@1: import org.sonews.daemon.NNTPConnection;
chris@3: import org.sonews.storage.Article;
chris@3: import org.sonews.storage.ArticleHead;
chris@3: import org.sonews.storage.Headers;
chris@3: import org.sonews.storage.StorageBackendException;
chris@1: import org.sonews.util.Pair;
chris@1:
chris@1: /**
chris@1: * Class handling the OVER/XOVER command.
chris@1: *
chris@1: * Description of the XOVER command:
chris@1: *
chris@1: * XOVER [range]
chris@1: *
chris@1: * The XOVER command returns information from the overview
chris@1: * database for the article(s) specified.
chris@1: *
chris@1: * The optional range argument may be any of the following:
chris@1: * an article number
chris@1: * an article number followed by a dash to indicate
chris@1: * all following
chris@1: * an article number followed by a dash followed by
chris@1: * another article number
chris@1: *
chris@1: * If no argument is specified, then information from the
chris@1: * current article is displayed. Successful responses start
chris@1: * with a 224 response followed by the overview information
chris@1: * for all matched messages. Once the output is complete, a
chris@1: * period is sent on a line by itself. If no argument is
chris@1: * specified, the information for the current article is
chris@1: * returned. A news group must have been selected earlier,
chris@1: * else a 412 error response is returned. If no articles are
chris@1: * in the range specified, a 420 error response is returned
chris@1: * by the server. A 502 response will be returned if the
chris@1: * client only has permission to transfer articles.
chris@1: *
chris@1: * Each line of output will be formatted with the article number,
chris@1: * followed by each of the headers in the overview database or the
chris@1: * article itself (when the data is not available in the overview
chris@1: * database) for that article separated by a tab character. The
chris@1: * sequence of fields must be in this order: subject, author,
chris@1: * date, message-id, references, byte count, and line count. Other
chris@1: * optional fields may follow line count. Other optional fields may
chris@1: * follow line count. These fields are specified by examining the
chris@1: * response to the LIST OVERVIEW.FMT command. Where no data exists,
chris@1: * a null field must be provided (i.e. the output will have two tab
chris@1: * characters adjacent to each other). Servers should not output
chris@1: * fields for articles that have been removed since the XOVER database
chris@1: * was created.
chris@1: *
chris@1: * The LIST OVERVIEW.FMT command should be implemented if XOVER
chris@1: * is implemented. A client can use LIST OVERVIEW.FMT to determine
chris@1: * what optional fields and in which order all fields will be
chris@1: * supplied by the XOVER command.
chris@1: *
chris@1: * Note that any tab and end-of-line characters in any header
chris@1: * data that is returned will be converted to a space character.
chris@1: *
chris@1: * Responses:
chris@1: *
chris@1: * 224 Overview information follows
chris@1: * 412 No news group current selected
chris@1: * 420 No article(s) selected
chris@1: * 502 no permission
chris@1: *
chris@1: * OVER defines additional responses:
chris@1: *
chris@1: * First form (message-id specified)
chris@1: * 224 Overview information follows (multi-line)
chris@1: * 430 No article with that message-id
chris@1: *
chris@1: * Second form (range specified)
chris@1: * 224 Overview information follows (multi-line)
chris@1: * 412 No newsgroup selected
chris@1: * 423 No articles in that range
chris@1: *
chris@1: * Third form (current article number used)
chris@1: * 224 Overview information follows (multi-line)
chris@1: * 412 No newsgroup selected
chris@1: * 420 Current article number is invalid
chris@1: *
chris@1: *
chris@1: * @author Christian Lins
chris@1: * @since sonews/0.5.0
chris@1: */
chris@3: public class OverCommand implements Command
chris@1: {
chris@1:
chris@3: public static final int MAX_LINES_PER_DBREQUEST = 200;
chris@3:
chris@3: @Override
chris@3: public String[] getSupportedCommandStrings()
chris@1: {
chris@3: return new String[]{"OVER", "XOVER"};
chris@1: }
chris@1:
chris@1: @Override
chris@1: public boolean hasFinished()
chris@1: {
chris@1: return true;
chris@1: }
chris@1:
chris@1: @Override
chris@3: public boolean isStateful()
chris@1: {
chris@3: return false;
chris@3: }
chris@3:
chris@3: @Override
chris@3: public void processLine(NNTPConnection conn, final String line, byte[] raw)
chris@3: throws IOException, StorageBackendException
chris@3: {
chris@3: if(conn.getCurrentChannel() == null)
chris@1: {
chris@3: conn.println("412 no newsgroup selected");
chris@1: }
chris@1: else
chris@1: {
chris@1: String[] command = line.split(" ");
chris@1:
chris@1: // If no parameter was specified, show information about
chris@1: // the currently selected article(s)
chris@1: if(command.length == 1)
chris@1: {
chris@3: final Article art = conn.getCurrentArticle();
chris@1: if(art == null)
chris@1: {
chris@3: conn.println("420 no article(s) selected");
chris@1: return;
chris@1: }
chris@1:
chris@3: conn.println(buildOverview(art, -1));
chris@1: }
chris@1: // otherwise print information about the specified range
chris@1: else
chris@1: {
chris@3: long artStart;
chris@3: long artEnd = conn.getCurrentChannel().getLastArticleNumber();
chris@1: String[] nums = command[1].split("-");
chris@1: if(nums.length >= 1)
chris@1: {
chris@1: try
chris@1: {
chris@1: artStart = Integer.parseInt(nums[0]);
chris@1: }
chris@1: catch(NumberFormatException e)
chris@1: {
chris@1: Log.msg(e.getMessage(), true);
chris@1: artStart = Integer.parseInt(command[1]);
chris@1: }
chris@1: }
chris@1: else
chris@1: {
chris@3: artStart = conn.getCurrentChannel().getFirstArticleNumber();
chris@1: }
chris@1:
chris@1: if(nums.length >=2)
chris@1: {
chris@1: try
chris@1: {
chris@1: artEnd = Integer.parseInt(nums[1]);
chris@1: }
chris@1: catch(NumberFormatException e)
chris@1: {
chris@1: e.printStackTrace();
chris@1: }
chris@1: }
chris@1:
chris@1: if(artStart > artEnd)
chris@1: {
chris@1: if(command[0].equalsIgnoreCase("OVER"))
chris@1: {
chris@3: conn.println("423 no articles in that range");
chris@1: }
chris@1: else
chris@1: {
chris@3: conn.println("224 (empty) overview information follows:");
chris@3: conn.println(".");
chris@1: }
chris@1: }
chris@1: else
chris@1: {
chris@3: for(long n = artStart; n <= artEnd; n += MAX_LINES_PER_DBREQUEST)
chris@1: {
chris@3: long nEnd = Math.min(n + MAX_LINES_PER_DBREQUEST - 1, artEnd);
chris@3: List> articleHeads = conn.getCurrentChannel()
chris@1: .getArticleHeads(n, nEnd);
chris@1: if(articleHeads.isEmpty() && n == artStart
chris@1: && command[0].equalsIgnoreCase("OVER"))
chris@1: {
chris@1: // This reply is only valid for OVER, not for XOVER command
chris@3: conn.println("423 no articles in that range");
chris@1: return;
chris@1: }
chris@1: else if(n == artStart)
chris@1: {
chris@1: // XOVER replies this although there is no data available
chris@3: conn.println("224 overview information follows");
chris@1: }
chris@1:
chris@1: for(Pair article : articleHeads)
chris@1: {
chris@1: String overview = buildOverview(article.getB(), article.getA());
chris@3: conn.println(overview);
chris@1: }
chris@1: } // for
chris@3: conn.println(".");
chris@1: }
chris@1: }
chris@1: }
chris@1: }
chris@1:
chris@1: private String buildOverview(ArticleHead art, long nr)
chris@1: {
chris@1: StringBuilder overview = new StringBuilder();
chris@1: overview.append(nr);
chris@1: overview.append('\t');
chris@1:
chris@1: String subject = art.getHeader(Headers.SUBJECT)[0];
chris@1: if("".equals(subject))
chris@1: {
chris@1: subject = "";
chris@1: }
chris@1: overview.append(escapeString(subject));
chris@1: overview.append('\t');
chris@1:
chris@1: overview.append(escapeString(art.getHeader(Headers.FROM)[0]));
chris@1: overview.append('\t');
chris@1: overview.append(escapeString(art.getHeader(Headers.DATE)[0]));
chris@1: overview.append('\t');
chris@1: overview.append(escapeString(art.getHeader(Headers.MESSAGE_ID)[0]));
chris@1: overview.append('\t');
chris@1: overview.append(escapeString(art.getHeader(Headers.REFERENCES)[0]));
chris@1: overview.append('\t');
chris@1:
chris@1: String bytes = art.getHeader(Headers.BYTES)[0];
chris@1: if("".equals(bytes))
chris@1: {
chris@1: bytes = "0";
chris@1: }
chris@1: overview.append(escapeString(bytes));
chris@1: overview.append('\t');
chris@1:
chris@1: String lines = art.getHeader(Headers.LINES)[0];
chris@1: if("".equals(lines))
chris@1: {
chris@1: lines = "0";
chris@1: }
chris@1: overview.append(escapeString(lines));
chris@1: overview.append('\t');
chris@1: overview.append(escapeString(art.getHeader(Headers.XREF)[0]));
chris@1:
chris@1: // Remove trailing tabs if some data is empty
chris@1: return overview.toString().trim();
chris@1: }
chris@1:
chris@1: private String escapeString(String str)
chris@1: {
chris@1: String nstr = str.replace("\r", "");
chris@1: nstr = nstr.replace('\n', ' ');
chris@1: nstr = nstr.replace('\t', ' ');
chris@1: return nstr.trim();
chris@1: }
chris@1:
chris@1: }