Tcl

Compress Text Feed to Binary

See more Compression Examples

This example receives incoming text data in chunks, compresses as a stream, and accumulates the compressed binary data. Tcl

load ./chilkat.dll

set success 0

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

set bdCompressed [new_CkBinData]

set compress [new_CkCompression]

CkCompression_put_Algorithm $compress "deflate"
CkCompression_put_Charset $compress "utf-8"

set sbUncompressedChunk [new_CkStringBuilder]

CkCompression_put_FirstChunk $compress 1
CkCompression_put_LastChunk $compress 0

for {set i 0} {$i <= 24} {incr i} {
    if {$i == 24} then {
        CkCompression_put_LastChunk $compress 1
    }

    CkStringBuilder_Clear $sbUncompressedChunk
    CkStringBuilder_AppendInt $sbUncompressedChunk $i
    CkStringBuilder_Append $sbUncompressedChunk ": This is a line of data to be compressed...\r\n"

    CkCompression_CompressSb $compress $sbUncompressedChunk $bdCompressed

    CkCompression_put_FirstChunk $compress 0
}

# Show the compressed data in hex format:
puts "The hex encoded compressed text:"
puts [CkBinData_getEncoded $bdCompressed hex]

# Now decompress in one call.  It is important to set both FirstChunk and LastChunk = 1
set bdDecompressed [new_CkBinData]

CkCompression_put_FirstChunk $compress 1
CkCompression_put_LastChunk $compress 1
set success [CkCompression_DecompressBd2 $compress $bdCompressed $bdDecompressed]
if {$success == 0} then {
    puts [CkCompression_lastErrorText $compress]
    delete_CkBinData $bdCompressed
    delete_CkCompression $compress
    delete_CkStringBuilder $sbUncompressedChunk
    delete_CkBinData $bdDecompressed
    exit
}

set originalText [CkBinData_getString $bdDecompressed "utf-8"]
puts "$originalText"

delete_CkBinData $bdCompressed
delete_CkCompression $compress
delete_CkStringBuilder $sbUncompressedChunk
delete_CkBinData $bdDecompressed