1 files changed, 60 insertions, 0 deletions
diff --git a/fbreader/src/formats/chm/HuffmanDecoder.cpp b/fbreader/src/formats/chm/HuffmanDecoder.cpp
new file mode 100644
index 0000000..db8718f
--- /dev/null
+++ b/fbreader/src/formats/chm/HuffmanDecoder.cpp
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2004-2012 Geometer Plus <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <algorithm>
+
+#include "HuffmanDecoder.h"
+
+HuffmanDecoder::HuffmanDecoder() : myMaxBitsNumber(0) {
+}
+
+void HuffmanDecoder::reset() {
+	CodeLengths.clear();
+}
+
+bool HuffmanDecoder::buildTable() {
+	myMaxBitsNumber = 0;
+	for (unsigned short symbol = 0; symbol < CodeLengths.size(); symbol++) {
+		myMaxBitsNumber = std::max(CodeLengths[symbol], myMaxBitsNumber);
+	}
+	if (myMaxBitsNumber > 16) {
+		return false;
+	}
+
+	unsigned int tableSize = 1 << myMaxBitsNumber;
+	mySymbols.clear();
+	mySymbols.reserve(tableSize);
+
+	for (unsigned char i = 1; i <= myMaxBitsNumber; ++i) {
+		for (unsigned short symbol = 0; symbol < CodeLengths.size(); symbol++) {
+			if (CodeLengths[symbol] == i) {
+				mySymbols.insert(mySymbols.end(), 1 << (myMaxBitsNumber - i), symbol);
+				if (mySymbols.size() > tableSize) {
+					return false;
+				}
+			}
+		}
+	}
+
+	if (mySymbols.size() < tableSize) {
+		mySymbols.insert(mySymbols.end(), tableSize - mySymbols.size(), 0);
+	}
+
+	return true;
+}