--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FastBitDecoder.cpp	Mon Sep 10 21:31:10 2012 +0200
@@ -0,0 +1,103 @@
+#include "FastBitDecoder.hpp"
+
+#include "BitDecoder.hpp"
+
+#include <QtCore/QDebug>
+
+#include <cassert>
+
+unsigned char FastBitDecoder::getPaddedChar(const QBitArray& bits, uint offset)
+{
+  unsigned char retVal = 0;
+  size_t n = std::min(8u, bits.size() - offset);
+  for (size_t i = 0; i < n; ++i) {
+    retVal |= (bits.testBit(i + offset) ? 1 : 0) << (7 - i) ;
+  }
+  return retVal;
+}
+
+QBitArray FastBitDecoder::removeFirst(const QBitArray& bits)
+{
+  size_t N = bits.size();
+  assert(N - 8 > 0);
+  size_t n = N - 8;
+  QBitArray retVal(n);
+  for (size_t i = 0; i < n; ++i) {
+    retVal.setBit(i, bits.at(i + 8));
+  }
+  return retVal;
+}
+
+
+void FastBitDecoder::fill()
+{
+  for (size_t i = 0; i < N; ++i) {
+    if (decoder[i] != 0) {
+      decoder[i]->fill();
+    }
+    else if (data[i] == 0) {
+      assert(data[i - 1]);
+      data[i] = data[i - 1];
+      numBits[i] = numBits[i - 1];
+    }
+  }
+}
+
+void FastBitDecoder::blank()
+{
+  for (size_t i = 0; i < N; ++i) {
+    decoder[i] = 0;
+    data[i] = 0;
+    numBits[i] = 0;
+  }
+}
+
+FastBitDecoder::FastBitDecoder()
+{
+  blank();
+}
+
+
+FastBitDecoder::FastBitDecoder(const QMap<QString, QBitArray>& encoder)
+{
+  blank();
+  for(QMap<QString, QBitArray>::const_iterator it =  encoder.begin();
+      it != encoder.end(); ++it) {
+    insert(it.value(), it.key());
+  }
+  fill();
+}
+
+
+void FastBitDecoder::insert(const QBitArray& key, const QString& value)
+{
+  unsigned char l = getPaddedChar(key);
+  if (key.size() <= 8) {
+    data[l] = new QString(value);
+    numBits[l] = key.size();
+  }
+  else {
+    if (!decoder[l])
+      decoder[l] = new FastBitDecoder();
+    decoder[l]->insert(removeFirst(key), value);
+    numBits[l] = 8;
+  }  
+}
+
+
+uint FastBitDecoder::decode(QString& resString, const QBitArray& bits, uint offset) const
+{
+  unsigned char l = getPaddedChar(bits, offset);
+  if (data[l]) {
+    resString.append(*data[l]);
+    return numBits[l];
+  }
+  else {
+    return decoder[l]->decode(resString, bits, offset + 8) + 8;
+  }
+}
+
+QString FastBitDecoder::decode(const QString& bits) const
+{
+  return decode(BitDecoder::bitsFromString(bits));
+}