Huffman compression/decompression

Simple compression/decompression tool, uses Huffman algorithm to compress and to decompress files.

The compression process:

• going over the the file and reads it byte by byte, calculating how many appearances there are for each of the 2^(byte size) different bytes possible and saves it.
• after creating the histogram of bytes it builds the tree which will be used to convert each byte to Huffman code.
• creates a new file which will store the compressed information.
• saves the histogram (sizeof(int) * 2^(byte size)) in the beginning of the file.
• reads one byte at a time from the input file, and translates each byte to unique code (0's and 1's) to a buffer (size of buffer is 1 byte), only after the buffer is filled the program writes the data from buffer to the output file.

The decompression process:

• reads the first (sizeof(int) * 2^(byte size)) and restores the histogram of the original file.
• builds the translation tree from the histogram to translate the Huffman code to the correct bytes.
• reads one byte at a time from the input file and for each byte:
  • getting one bit from the byte
  • according to the bit value (0 or 1) going left or right in the translation tree.
  • if a leaf was reached then we found a translation from code to original byte, we write the corresponding byte and deduce 1 from our histogram.
  • if we reached a leaf and the corresponding byte in the histogram is 0, then we just read the 0's we filled our last byte with in the compression and the process is ended.

how to use

to compress:

./Huffman.exe -c [file_path]

this will generate [file_name].huf file which is the compressed file.

to decompress:

./Huffman.exe -d [compressed_file_path]

this will generate [decompressed_file] file which is the decompressed file.