1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/org/sonews/daemon/command/OverCommand.java Sun Aug 29 17:28:58 2010 +0200
1.3 @@ -0,0 +1,294 @@
1.4 +/*
1.5 + * SONEWS News Server
1.6 + * see AUTHORS for the list of contributors
1.7 + *
1.8 + * This program is free software: you can redistribute it and/or modify
1.9 + * it under the terms of the GNU General Public License as published by
1.10 + * the Free Software Foundation, either version 3 of the License, or
1.11 + * (at your option) any later version.
1.12 + *
1.13 + * This program is distributed in the hope that it will be useful,
1.14 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
1.15 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1.16 + * GNU General Public License for more details.
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License
1.19 + * along with this program. If not, see <http://www.gnu.org/licenses/>.
1.20 + */
1.21 +
1.22 +package org.sonews.daemon.command;
1.23 +
1.24 +import java.io.IOException;
1.25 +import java.util.List;
1.26 +import org.sonews.util.Log;
1.27 +import org.sonews.daemon.NNTPConnection;
1.28 +import org.sonews.storage.Article;
1.29 +import org.sonews.storage.ArticleHead;
1.30 +import org.sonews.storage.Headers;
1.31 +import org.sonews.storage.StorageBackendException;
1.32 +import org.sonews.util.Pair;
1.33 +
1.34 +/**
1.35 + * Class handling the OVER/XOVER command.
1.36 + *
1.37 + * Description of the XOVER command:
1.38 + * <pre>
1.39 + * XOVER [range]
1.40 + *
1.41 + * The XOVER command returns information from the overview
1.42 + * database for the article(s) specified.
1.43 + *
1.44 + * The optional range argument may be any of the following:
1.45 + * an article number
1.46 + * an article number followed by a dash to indicate
1.47 + * all following
1.48 + * an article number followed by a dash followed by
1.49 + * another article number
1.50 + *
1.51 + * If no argument is specified, then information from the
1.52 + * current article is displayed. Successful responses start
1.53 + * with a 224 response followed by the overview information
1.54 + * for all matched messages. Once the output is complete, a
1.55 + * period is sent on a line by itself. If no argument is
1.56 + * specified, the information for the current article is
1.57 + * returned. A news group must have been selected earlier,
1.58 + * else a 412 error response is returned. If no articles are
1.59 + * in the range specified, a 420 error response is returned
1.60 + * by the server. A 502 response will be returned if the
1.61 + * client only has permission to transfer articles.
1.62 + *
1.63 + * Each line of output will be formatted with the article number,
1.64 + * followed by each of the headers in the overview database or the
1.65 + * article itself (when the data is not available in the overview
1.66 + * database) for that article separated by a tab character. The
1.67 + * sequence of fields must be in this order: subject, author,
1.68 + * date, message-id, references, byte count, and line count. Other
1.69 + * optional fields may follow line count. Other optional fields may
1.70 + * follow line count. These fields are specified by examining the
1.71 + * response to the LIST OVERVIEW.FMT command. Where no data exists,
1.72 + * a null field must be provided (i.e. the output will have two tab
1.73 + * characters adjacent to each other). Servers should not output
1.74 + * fields for articles that have been removed since the XOVER database
1.75 + * was created.
1.76 + *
1.77 + * The LIST OVERVIEW.FMT command should be implemented if XOVER
1.78 + * is implemented. A client can use LIST OVERVIEW.FMT to determine
1.79 + * what optional fields and in which order all fields will be
1.80 + * supplied by the XOVER command.
1.81 + *
1.82 + * Note that any tab and end-of-line characters in any header
1.83 + * data that is returned will be converted to a space character.
1.84 + *
1.85 + * Responses:
1.86 + *
1.87 + * 224 Overview information follows
1.88 + * 412 No news group current selected
1.89 + * 420 No article(s) selected
1.90 + * 502 no permission
1.91 + *
1.92 + * OVER defines additional responses:
1.93 + *
1.94 + * First form (message-id specified)
1.95 + * 224 Overview information follows (multi-line)
1.96 + * 430 No article with that message-id
1.97 + *
1.98 + * Second form (range specified)
1.99 + * 224 Overview information follows (multi-line)
1.100 + * 412 No newsgroup selected
1.101 + * 423 No articles in that range
1.102 + *
1.103 + * Third form (current article number used)
1.104 + * 224 Overview information follows (multi-line)
1.105 + * 412 No newsgroup selected
1.106 + * 420 Current article number is invalid
1.107 + *
1.108 + * </pre>
1.109 + * @author Christian Lins
1.110 + * @since sonews/0.5.0
1.111 + */
1.112 +public class OverCommand implements Command
1.113 +{
1.114 +
1.115 + public static final int MAX_LINES_PER_DBREQUEST = 200;
1.116 +
1.117 + @Override
1.118 + public String[] getSupportedCommandStrings()
1.119 + {
1.120 + return new String[]{"OVER", "XOVER"};
1.121 + }
1.122 +
1.123 + @Override
1.124 + public boolean hasFinished()
1.125 + {
1.126 + return true;
1.127 + }
1.128 +
1.129 + @Override
1.130 + public String impliedCapability()
1.131 + {
1.132 + return null;
1.133 + }
1.134 +
1.135 + @Override
1.136 + public boolean isStateful()
1.137 + {
1.138 + return false;
1.139 + }
1.140 +
1.141 + @Override
1.142 + public void processLine(NNTPConnection conn, final String line, byte[] raw)
1.143 + throws IOException, StorageBackendException
1.144 + {
1.145 + if(conn.getCurrentChannel() == null)
1.146 + {
1.147 + conn.println("412 no newsgroup selected");
1.148 + }
1.149 + else
1.150 + {
1.151 + String[] command = line.split(" ");
1.152 +
1.153 + // If no parameter was specified, show information about
1.154 + // the currently selected article(s)
1.155 + if(command.length == 1)
1.156 + {
1.157 + final Article art = conn.getCurrentArticle();
1.158 + if(art == null)
1.159 + {
1.160 + conn.println("420 no article(s) selected");
1.161 + return;
1.162 + }
1.163 +
1.164 + conn.println(buildOverview(art, -1));
1.165 + }
1.166 + // otherwise print information about the specified range
1.167 + else
1.168 + {
1.169 + long artStart;
1.170 + long artEnd = conn.getCurrentChannel().getLastArticleNumber();
1.171 + String[] nums = command[1].split("-");
1.172 + if(nums.length >= 1)
1.173 + {
1.174 + try
1.175 + {
1.176 + artStart = Integer.parseInt(nums[0]);
1.177 + }
1.178 + catch(NumberFormatException e)
1.179 + {
1.180 + Log.get().info(e.getMessage());
1.181 + artStart = Integer.parseInt(command[1]);
1.182 + }
1.183 + }
1.184 + else
1.185 + {
1.186 + artStart = conn.getCurrentChannel().getFirstArticleNumber();
1.187 + }
1.188 +
1.189 + if(nums.length >=2)
1.190 + {
1.191 + try
1.192 + {
1.193 + artEnd = Integer.parseInt(nums[1]);
1.194 + }
1.195 + catch(NumberFormatException e)
1.196 + {
1.197 + e.printStackTrace();
1.198 + }
1.199 + }
1.200 +
1.201 + if(artStart > artEnd)
1.202 + {
1.203 + if(command[0].equalsIgnoreCase("OVER"))
1.204 + {
1.205 + conn.println("423 no articles in that range");
1.206 + }
1.207 + else
1.208 + {
1.209 + conn.println("224 (empty) overview information follows:");
1.210 + conn.println(".");
1.211 + }
1.212 + }
1.213 + else
1.214 + {
1.215 + for(long n = artStart; n <= artEnd; n += MAX_LINES_PER_DBREQUEST)
1.216 + {
1.217 + long nEnd = Math.min(n + MAX_LINES_PER_DBREQUEST - 1, artEnd);
1.218 + List<Pair<Long, ArticleHead>> articleHeads = conn.getCurrentChannel()
1.219 + .getArticleHeads(n, nEnd);
1.220 + if(articleHeads.isEmpty() && n == artStart
1.221 + && command[0].equalsIgnoreCase("OVER"))
1.222 + {
1.223 + // This reply is only valid for OVER, not for XOVER command
1.224 + conn.println("423 no articles in that range");
1.225 + return;
1.226 + }
1.227 + else if(n == artStart)
1.228 + {
1.229 + // XOVER replies this although there is no data available
1.230 + conn.println("224 overview information follows");
1.231 + }
1.232 +
1.233 + for(Pair<Long, ArticleHead> article : articleHeads)
1.234 + {
1.235 + String overview = buildOverview(article.getB(), article.getA());
1.236 + conn.println(overview);
1.237 + }
1.238 + } // for
1.239 + conn.println(".");
1.240 + }
1.241 + }
1.242 + }
1.243 + }
1.244 +
1.245 + private String buildOverview(ArticleHead art, long nr)
1.246 + {
1.247 + StringBuilder overview = new StringBuilder();
1.248 + overview.append(nr);
1.249 + overview.append('\t');
1.250 +
1.251 + String subject = art.getHeader(Headers.SUBJECT)[0];
1.252 + if("".equals(subject))
1.253 + {
1.254 + subject = "<empty>";
1.255 + }
1.256 + overview.append(escapeString(subject));
1.257 + overview.append('\t');
1.258 +
1.259 + overview.append(escapeString(art.getHeader(Headers.FROM)[0]));
1.260 + overview.append('\t');
1.261 + overview.append(escapeString(art.getHeader(Headers.DATE)[0]));
1.262 + overview.append('\t');
1.263 + overview.append(escapeString(art.getHeader(Headers.MESSAGE_ID)[0]));
1.264 + overview.append('\t');
1.265 + overview.append(escapeString(art.getHeader(Headers.REFERENCES)[0]));
1.266 + overview.append('\t');
1.267 +
1.268 + String bytes = art.getHeader(Headers.BYTES)[0];
1.269 + if("".equals(bytes))
1.270 + {
1.271 + bytes = "0";
1.272 + }
1.273 + overview.append(escapeString(bytes));
1.274 + overview.append('\t');
1.275 +
1.276 + String lines = art.getHeader(Headers.LINES)[0];
1.277 + if("".equals(lines))
1.278 + {
1.279 + lines = "0";
1.280 + }
1.281 + overview.append(escapeString(lines));
1.282 + overview.append('\t');
1.283 + overview.append(escapeString(art.getHeader(Headers.XREF)[0]));
1.284 +
1.285 + // Remove trailing tabs if some data is empty
1.286 + return overview.toString().trim();
1.287 + }
1.288 +
1.289 + private String escapeString(String str)
1.290 + {
1.291 + String nstr = str.replace("\r", "");
1.292 + nstr = nstr.replace('\n', ' ');
1.293 + nstr = nstr.replace('\t', ' ');
1.294 + return nstr.trim();
1.295 + }
1.296 +
1.297 +}