Xbase++

Compress and Decompress Hex String

See more Compression Examples

Imagine we have data represented as a hex string. This example demonstrates how to decode, compress, and re-encode to a smaller hex string representing the compressed data. An even better choice is to re-encode to a more compact encoding such as base64.

Note: This example requires Chilkat v9.5.0.66 or greater.

Xbase++

LOCAL nSuccess
LOCAL cStrHex
LOCAL oCompress
LOCAL oBinDat
LOCAL cCompressedHex
LOCAL cCompressedBase64
LOCAL cDecompressedHex

nSuccess := 0

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

cStrHex := "54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A0D0A"

oCompress := CreateObject("Chilkat.Compression")
oCompress:Algorithm := "deflate"

oBinDat := CreateObject("Chilkat.BinData")
//  Load the hex string into a BinData object.
//  This decodes the hexidecimal. The decoded bytes will be contained in the BinData.
oBinDat:AppendEncoded(cStrHex, "hex")

//  Compress the BinData.
oCompress:CompressBd(oBinDat)

//  Get the compressed data in hex format:
cCompressedHex := oBinDat:GetEncoded("hex")
? "compressed hex:"
? cCompressedHex

//  The compressed hex is: 0BC94855282CCD4CCE56482ACA2FCF5348CBAF50C82ACD2D484D51C82F4B2D522801CAE72456552AA4E4A7EBF172850C61E5BC5C00

//  Even better, get the compressed data in base64 format:
//  (base64url and modbase64 are other valid choices...)
cCompressedBase64 := oBinDat:GetEncoded("base64")
? "compressed base64:"
? cCompressedBase64

//  The compressed base64 is: C8lIVSgszUzOVkgqyi/PU0jLr1DIKs0tSE1RyC9LLVIoAcrnJFZVKqTkp+vxcoUMYeW8XAA=

//  Now decompress:
oBinDat:Clear()
oBinDat:AppendEncoded(cCompressedHex, "hex")
oCompress:DecompressBd(oBinDat)

cDecompressedHex := oBinDat:GetEncoded("hex")
? "decompressed hex:"
? cDecompressedHex

//  The output is the original hex string:
//  54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A0D0A

oCompress:destroy()
oBinDat:destroy()