(Ruby) Compress Large Binary File in Blocks

Compresses a large binary file in blocks. This example uses BeginCompressBytes, MoreCompressBytes, and EndCompressBytes.

Chilkat Ruby Downloads Ruby Library for Linux and MAC OS X

require 'chilkat'

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

facSrc = Chilkat::CkFileAccess.new()
facDest = Chilkat::CkFileAccess.new()

# Open a large binary file for reading.
success = facSrc.OpenForRead("qa_data/bmp/big.bmp")
if (success != true)
    print facSrc.lastErrorText() + "\n";
    exit
end

# If we compress in 64K chunks, find out how many blocks there will be.
blockSize = 65536
numBlocks = facSrc.GetNumBlocks(blockSize)

# Open an output file for the compressed data.
success = facDest.OpenForWrite("qa_data/bmp/compressedBmp.dat")
if (success != true)
    print facDest.lastErrorText() + "\n";
    exit
end

compress = Chilkat::CkCompression.new()
compress.put_Algorithm("deflate")

fileBytes = Chilkat::CkByteData.new()
compressedBytes = Chilkat::CkByteData.new()

i = 0
while i < numBlocks
    success = facSrc.ReadBlock(i,blockSize,fileBytes)
    if (i == 0)
        success = compress.BeginCompressBytes(fileBytes,compressedBytes)
    else
        success = compress.MoreCompressBytes(fileBytes,compressedBytes)
    end

    facDest.FileWrite(compressedBytes)

    i = i + 1
end

# At the very end, flush any remaining compressed bytes, if any.
success = compress.EndCompressBytes(compressedBytes)
facDest.FileWrite(compressedBytes)

facSrc.FileClose()
facDest.FileClose()

print "Finished compressing file." + "\n";