1 files changed, 57 insertions, 0 deletions
diff --git a/fbreader/src/formats/pdb/BitReader.cpp b/fbreader/src/formats/pdb/BitReader.cpp
new file mode 100644
index 0000000..551aaf3
--- /dev/null
+++ b/fbreader/src/formats/pdb/BitReader.cpp
@@ -0,0 +1,57 @@
+/*
+ * 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 <cstring>
+#include <string>
+
+#include "BitReader.h"
+
+BitReader::BitReader(const unsigned char* data, std::size_t size) : myOffset(0), myLength(size * 8) {
+	myData = new unsigned char[size + 4];
+	std::memcpy(myData, data, size);
+	std::memset(myData + size, 0x00, 4);
+}
+
+BitReader::~BitReader() {
+	delete[] myData;
+}
+
+unsigned long long BitReader::peek(std::size_t n) {
+	if (n > 32) {
+		return 0;
+	}
+	unsigned long long r = 0;
+	std::size_t g = 0;
+	while (g < n) {
+		r = (r << 8) | myData[(myOffset + g) >> 3]; 
+		g = g + 8 - ((myOffset+g) & 7);
+	}
+	unsigned long long mask = 1;
+	mask = (mask << n) - 1;
+	return (r >> (g - n)) & mask;
+}
+
+bool BitReader::eat(std::size_t n) {
+	myOffset += n;
+	return myOffset <= myLength;
+}
+
+std::size_t BitReader::left() const {
+	return myLength - myOffset;
+}