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:
cli@37: public static final int MAX_LINES_PER_DBREQUEST = 200;
chris@3:
cli@37: @Override
cli@37: public String[] getSupportedCommandStrings()
cli@37: {
cli@37: return new String[] {"OVER", "XOVER"};
cli@37: }
chris@1:
cli@37: @Override
cli@37: public boolean hasFinished()
cli@37: {
cli@37: return true;
cli@37: }
chris@1:
cli@37: @Override
cli@37: public String impliedCapability()
cli@37: {
cli@37: return null;
cli@37: }
cli@20:
cli@37: @Override
cli@37: public boolean isStateful()
cli@37: {
cli@37: return false;
cli@37: }
chris@3:
cli@37: @Override
cli@37: public void processLine(NNTPConnection conn, final String line, byte[] raw)
cli@37: throws IOException, StorageBackendException
cli@37: {
cli@37: if (conn.getCurrentChannel() == null) {
cli@37: conn.println("412 no newsgroup selected");
cli@37: } else {
cli@37: String[] command = line.split(" ");
chris@1:
cli@37: // If no parameter was specified, show information about
cli@37: // the currently selected article(s)
cli@37: if (command.length == 1) {
cli@37: final Article art = conn.getCurrentArticle();
cli@37: if (art == null) {
cli@37: conn.println("420 no article(s) selected");
cli@37: return;
cli@37: }
chris@1:
cli@37: conn.println(buildOverview(art, -1));
cli@37: } // otherwise print information about the specified range
cli@37: else {
cli@37: long artStart;
cli@37: long artEnd = conn.getCurrentChannel().getLastArticleNumber();
cli@37: String[] nums = command[1].split("-");
cli@37: if (nums.length >= 1) {
cli@37: try {
cli@37: artStart = Integer.parseInt(nums[0]);
cli@37: } catch (NumberFormatException e) {
cli@37: Log.get().info(e.getMessage());
cli@37: artStart = Integer.parseInt(command[1]);
cli@37: }
cli@37: } else {
cli@37: artStart = conn.getCurrentChannel().getFirstArticleNumber();
cli@37: }
chris@1:
cli@37: if (nums.length >= 2) {
cli@37: try {
cli@37: artEnd = Integer.parseInt(nums[1]);
cli@37: } catch (NumberFormatException e) {
cli@37: e.printStackTrace();
cli@37: }
cli@37: }
chris@1:
cli@37: if (artStart > artEnd) {
cli@37: if (command[0].equalsIgnoreCase("OVER")) {
cli@37: conn.println("423 no articles in that range");
cli@37: } else {
cli@37: conn.println("224 (empty) overview information follows:");
cli@37: conn.println(".");
cli@37: }
cli@37: } else {
cli@37: for (long n = artStart; n <= artEnd; n += MAX_LINES_PER_DBREQUEST) {
cli@37: long nEnd = Math.min(n + MAX_LINES_PER_DBREQUEST - 1, artEnd);
cli@37: List> articleHeads = conn.getCurrentChannel().getArticleHeads(n, nEnd);
cli@37: if (articleHeads.isEmpty() && n == artStart
cli@37: && command[0].equalsIgnoreCase("OVER")) {
cli@37: // This reply is only valid for OVER, not for XOVER command
cli@37: conn.println("423 no articles in that range");
cli@37: return;
cli@37: } else if (n == artStart) {
cli@37: // XOVER replies this although there is no data available
cli@37: conn.println("224 overview information follows");
cli@37: }
chris@1:
cli@37: for (Pair article : articleHeads) {
cli@37: String overview = buildOverview(article.getB(), article.getA());
cli@37: conn.println(overview);
cli@37: }
cli@37: } // for
cli@37: conn.println(".");
cli@37: }
cli@37: }
cli@37: }
cli@37: }
chris@1:
cli@37: private String buildOverview(ArticleHead art, long nr)
cli@37: {
cli@37: StringBuilder overview = new StringBuilder();
cli@37: overview.append(nr);
cli@37: overview.append('\t');
chris@1:
cli@37: String subject = art.getHeader(Headers.SUBJECT)[0];
cli@37: if ("".equals(subject)) {
cli@37: subject = "";
cli@37: }
cli@37: overview.append(escapeString(subject));
cli@37: overview.append('\t');
chris@1:
cli@37: overview.append(escapeString(art.getHeader(Headers.FROM)[0]));
cli@37: overview.append('\t');
cli@37: overview.append(escapeString(art.getHeader(Headers.DATE)[0]));
cli@37: overview.append('\t');
cli@37: overview.append(escapeString(art.getHeader(Headers.MESSAGE_ID)[0]));
cli@37: overview.append('\t');
cli@37: overview.append(escapeString(art.getHeader(Headers.REFERENCES)[0]));
cli@37: overview.append('\t');
chris@1:
cli@37: String bytes = art.getHeader(Headers.BYTES)[0];
cli@37: if ("".equals(bytes)) {
cli@37: bytes = "0";
cli@37: }
cli@37: overview.append(escapeString(bytes));
cli@37: overview.append('\t');
chris@1:
cli@37: String lines = art.getHeader(Headers.LINES)[0];
cli@37: if ("".equals(lines)) {
cli@37: lines = "0";
cli@37: }
cli@37: overview.append(escapeString(lines));
cli@37: overview.append('\t');
cli@37: overview.append(escapeString(art.getHeader(Headers.XREF)[0]));
cli@37:
cli@37: // Remove trailing tabs if some data is empty
cli@37: return overview.toString().trim();
cli@37: }
cli@37:
cli@37: private String escapeString(String str)
cli@37: {
cli@37: String nstr = str.replace("\r", "");
cli@37: nstr = nstr.replace('\n', ' ');
cli@37: nstr = nstr.replace('\t', ' ');
cli@37: return nstr.trim();
cli@37: }
chris@1: }