1 files changed, 111 insertions, 0 deletions
diff --git a/fbreader/src/formats/chm/BitStream.h b/fbreader/src/formats/chm/BitStream.h
new file mode 100644
index 0000000..80c1e25
--- /dev/null
+++ b/fbreader/src/formats/chm/BitStream.h
@@ -0,0 +1,111 @@
+/*
+ * 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.
+ */
+
+#ifndef __BITSTREAM_H__
+#define __BITSTREAM_H__
+
+#include <string>
+
+class BitStream {
+
+public:
+	static const int BufferSize;
+
+public:
+	BitStream();
+	void setData(const std::string &data);
+	void reset();
+	unsigned int peek(unsigned char length);
+	void remove(unsigned char length);
+	unsigned int get(unsigned char length);
+	unsigned int bytesLeft() const;
+
+	unsigned int get4BytesDirect();
+	bool getBytesDirect(unsigned char *buffer, unsigned int length);
+
+private:
+	bool ensure(unsigned char length);
+
+private:
+	unsigned int myBuffer;
+	unsigned char myBitCounter;
+	const unsigned char *myByteStream;
+	const unsigned char *myByteStreamEnd;
+
+private:
+	BitStream(const BitStream&);
+	const BitStream &operator = (const BitStream&);
+};
+
+inline BitStream::BitStream() : myBuffer(0), myBitCounter(0) {
+}
+
+inline void BitStream::setData(const std::string &data) {
+	myByteStream = (const unsigned char*)data.data();
+	myByteStreamEnd = myByteStream + data.length();
+	myBuffer = 0;
+	myBitCounter = 0;
+}
+
+inline void BitStream::reset() {
+	myByteStream -= myBitCounter / 8;
+	myBuffer = 0;
+	myBitCounter = 0;
+}
+
+inline bool BitStream::ensure(unsigned char length) {
+	while ((myBitCounter < length) && (bytesLeft() >= 2)) {
+		myBuffer |= ((myByteStream[1] << 8) | myByteStream[0]) << (BitStream::BufferSize - 16 - myBitCounter);
+		myBitCounter += 16;
+		myByteStream += 2;
+	}
+	return myBitCounter >= length;
+}
+
+inline unsigned int BitStream::peek(unsigned char length) {
+	ensure(length);
+	return (length > 0) ? (myBuffer >> (BufferSize - length)) : 0;
+}
+
+inline void BitStream::remove(unsigned char length) {
+	if (ensure(length)) {
+		myBuffer <<= length;
+		myBitCounter -= length;
+	}
+}
+
+inline unsigned int BitStream::get(unsigned char length) {
+	unsigned int bits;
+	if (length > 16) {
+		bits = peek(length - 16) << 16;
+		remove(length - 16);
+		bits += peek(16);
+		remove(16);
+	} else {
+		bits = peek(length);
+		remove(length);
+	}
+	return bits;
+}
+
+inline unsigned int BitStream::bytesLeft() const {
+	return myByteStreamEnd - myByteStream;
+}
+
+#endif /* __BITSTREAM_H__ */