(Tcl) Compress Text Feed to Binary

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

The purpose is to demonstrate the BeginCompressString, MoreCompressString, and EndCompressString methods.

Chilkat Tcl Extension Downloads Chilkat Tcl Extension Downloads

load ./chilkat.dll

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

set compressedData [new_CkBinData]

set compressedBytes [new_CkByteData]

set compress [new_CkCompression]

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

set sbIndex [new_CkStringBuilder]

for {set i 0} {$i <= 24} {incr i} {
    # Note: It is possible (and normal) for a BeginCompress* or MoreCompress* method to return
    # an empty string (or 0 bytes).  When this happens, the input data is not lost.  It will be flushed
    # in a subsequent call.
    [CkStringBuilder_Clear $sbIndex]
    [CkStringBuilder_AppendInt $sbIndex $i]
    if {[expr $i == 0]} then {
        set success [CkCompression_BeginCompressString $compress [CkStringBuilder_getAsString $sbIndex] $compressedBytes]
    }     else {
        set success [CkCompression_MoreCompressString $compress [CkStringBuilder_getAsString $sbIndex] $compressedBytes]
    }

    [CkBinData_AppendBinary $compressedData $compressedBytes]
    set success [CkCompression_MoreCompressString $compress ": This is a line of data to be compressed...\r\n" $compressedBytes]
    [CkBinData_AppendBinary $compressedData $compressedBytes]
}

# Flush any remaining output.
set success [CkCompression_EndCompressString $compress $compressedBytes]
CkBinData_AppendBinary $compressedData $compressedBytes

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

# Now decompress in one call:
set success [CkBinData_GetBinary $compressedData $compressedBytes]
set originalText [CkCompression_decompressString $compress $compressedBytes]
puts "$originalText"

delete_CkBinData $compressedData
delete_CkByteData $compressedBytes
delete_CkCompression $compress
delete_CkStringBuilder $sbIndex