--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/huffman/bitwriter.h Fri May 15 20:13:36 2015 +0300
@@ -0,0 +1,109 @@
+/*
+ * skulltag::BitWriter class - Enables writing arbitrary bit lengths of data.
+ *
+ * Copyright 2009 Timothy Landers
+ * email: code.vortexcortex@gmail.com
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef _BIT_WRITER_VERSION
+#define _BIT_WRITER_VERSION 1
+
+/** Prevents naming convention problems via encapsulation. */
+namespace skulltag { // scope limitation
+
+/** BitWriter - Allows writing of varying amounts of bits to a char buffer. <br>
+ * Very usefull for outputting variable bit length encodings such as Huffman. */
+
+ class BitWriter {
+ int bufferBits; /**< intermediary buffer of bits. */
+ int bitsLeft; /**< number of bits left in the buffer. */
+ unsigned char * currentByte; /**< position in memory the next char will be stored. */
+ int bytesAvailable; /**< amount of available space left in the output buffer in bytes. Excludes the contents of bufferBits. */
+ int bitsAvailable; /**< amount of available space left in the output buffer in bits. Includes the contents of bufferBits. */
+ int maximumBytes; /**< total amount of bytes that can be written to the output buffer. */
+ static int mask[]; /**< maps a number of bits to a bit mask containing as many bits. */
+ static int intSize; /**< number of chars in an int. */
+public:
+
+ /** Creates a new BitWriter. */
+ BitWriter();
+
+ /** Creates a new BitWriter.
+ * @param output Destination that bits will be written to.
+ * @param max Maximum number of chars to output. */
+ BitWriter( unsigned char * const output, int const &max );
+
+ /** Appends a char worth of bits to the buffer.
+ * @param bits the bits to append.
+ * @return true if successful, false if an error occurs. */
+ bool put( unsigned char const &bits );
+
+ /** Appends a short worth of bits to the buffer.
+ * @param bits the bits to append.
+ * @return true if successful, false otherwise.
+ * @return true if successful, false if an error occurs. */
+ bool put( short const &bits );
+
+ /** Appends an int worth of bits to the buffer.
+ * @param bits the bits to append.
+ * @return true if successful, false if an error occurs. */
+ bool put( int const &bits );
+
+ /** Appends a specified number of bits from an int to the buffer.
+ * @param bits the bits to append. <br>
+ * The bits should be stored in the least significant portion of the int.
+ * @param count the number of bits to append.
+ * @return true if successful, false if an error occurs. */
+ bool put( int const &bits, int count );
+
+ /** Appends multiple chars from a buffer to this BitWriter.
+ * @param inputBuffer pointer to char data
+ * @param count number of chars to read
+ * @return true if successful, false if an error occurs. */
+ bool put( unsigned char const * const inputBuffer, int count );
+
+ /** Sets the output buffer that bytes will be written to.
+ * @param output Destination that bits will be written to.
+ * @param max Maximum number of chars to output.
+ * @return true if successful, false if an error occurs. */
+ bool outputBuffer( unsigned char * const output, int const &max );
+
+ /** Writes any full chars of data stored in this BitWriter to the output char buffer.
+ * @return true if successful, false if an error occurs. */
+ bool flush();
+
+ /** Flushes this BitWriter then outputs any partial chars by padding them with zeros. <br>
+ * After calling finish() all other calls to update the BitWriter will fail until a buffer is set via outputBuffer().
+ * @param bytesWritten out: the number of bytes written to the output buffer.
+ * @param paddingBits out: the number of padding bits used in the final byte of output.
+ * @return true if successful, false if an error occurs. */
+ bool finish( int &bytesWritten, int &paddingBits );
+
+ private:
+
+ /** Initializes this BitWriter. */
+ void init();
+
+ };
+
+}
+#endif
+