Added torrent support

The BEncode parser is loosely based on this:
https://github.com/jif/Bencode/blob/master/bencode.cpp

Not perfect, but enough to display all the essential data in the shiny
new TorrentDisplay dialog.

1 files changed, 103 insertions, 0 deletions

diff --git a/torrentparser.cpp b/torrentparser.cpp
new file mode 100644
index 0000000..fc59233
--- /dev/null
+++ b/torrentparser.cpp
@@ -0,0 +1,103 @@
+#include <QFile>
+
+#include "torrentparser.h"
+
+TorrentParser::TorrentParser(const QString file, QObject *parent) : QObject(parent), mFile(file), mPos(0), mOk(true) {}
+
+const QList<QVariant> TorrentParser::parse(){
+    QFile f(mFile);
+    QList<QVariant> retval;
+    if(f.size() > 4*1024*1024){ //this is an arbitray value
+        mLastError = tr("File is too big!");
+        return retval;
+    }
+    f.open(QIODevice::ReadOnly);
+    mData = f.readAll();
+    f.close();
+    while(mPos < mData.size()){
+        retval << parseObject();
+    }
+    return retval;
+}
+
+const QVariant TorrentParser::parseObject(){
+    QChar cur = mData.at(mPos);
+    if(cur == 'i'){
+        return parseInt();
+    }
+    if(cur == 'l'){
+        return parseList();
+    }
+    if(cur == 'd'){
+        return parseDict();
+    }
+    if(cur.isNumber()){
+        return parseString();
+    }
+    ++mPos;
+    return QVariant();
+}
+
+const QByteArray TorrentParser::parseString(){
+    int lenlen = mData.indexOf(':', mPos) - mPos;
+    if(lenlen <= 0){
+        mOk = false;
+        return QByteArray();
+    }
+    int len = mData.mid(mPos, lenlen).toInt();
+    if(mPos + len > mData.size()){
+        mOk = false;
+        return QByteArray();
+    }
+    mPos = mPos + lenlen + 1;
+    QByteArray retval = mData.mid(mPos, len);
+    mPos += len;
+    return retval;
+}
+
+int TorrentParser::parseInt(){
+    if(mData.at(mPos) != 'i'){
+        return 0;
+    }
+    ++mPos;
+    int len = mData.indexOf('e', mPos) - mPos;
+    if(len <= 0){
+        return 0;
+    }
+    int retval = mData.mid(mPos, len).toInt();
+    mPos = mPos + len + 1;
+    return retval;
+}
+
+const QList<QVariant> TorrentParser::parseList(){
+    if(mData.at(mPos) != 'l'){
+        return QList<QVariant>();
+    }
+    ++mPos;
+    QList<QVariant> retval;
+    while(mData.at(mPos) != 'e'){
+        retval.append(parseObject());
+    }
+    ++mPos;
+    return retval;
+}
+
+
+
+const QHash<QString,QVariant> TorrentParser::parseDict(){
+    QHash<QString,QVariant> retval;
+    if(mData.at(mPos) != 'd'){
+        return retval;
+    }
+    ++mPos;
+    while(mData.at(mPos) != 'e'){
+        QString key = parseString();
+        QVariant value = parseObject();
+        if(key.isEmpty() || value.isNull()){
+            return retval;
+        }
+        retval.insert(key, value);
+    }
+    ++mPos;
+    return retval;
+}