(PureBasic) Decompress Gzip Data In-Place Using BinData

See more Gzip Examples

This example demonstrates how to use the UncompressBd method to decompress Gzip data stored in a BinData object.

The compressed .gz file is first loaded into memory. The UncompressBd method then decompresses the data in-place, meaning the original compressed bytes in the BinData object are replaced with the uncompressed data.

After decompression, the example writes the resulting data to a file. This approach is useful when working entirely in memory before saving or further processing the uncompressed data.

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IncludeFile "CkGzip.pb"
IncludeFile "CkBinData.pb"

Procedure ChilkatExample()

    success.i = 0

    ; This example demonstrates how to decompress Gzip data stored in a BinData object.
    ; The decompression is done in-place, replacing the compressed data with the original data.

    gzip.i = CkGzip::ckCreate()
    If gzip.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    bd.i = CkBinData::ckCreate()
    If bd.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Load a .gz file into BinData:
    success = CkBinData::ckLoadFile(bd,"example.txt.gz")
    If success = 0
        Debug CkBinData::ckLastErrorText(bd)
        CkGzip::ckDispose(gzip)
        CkBinData::ckDispose(bd)
        ProcedureReturn
    EndIf

    Debug "Compressed size (bytes): " + Str(CkBinData::ckNumBytes(bd))

    ; Uncompress the data in-place:
    success = CkGzip::ckUncompressBd(gzip,bd)
    If success = 0
        Debug CkGzip::ckLastErrorText(gzip)
        CkGzip::ckDispose(gzip)
        CkBinData::ckDispose(bd)
        ProcedureReturn
    EndIf

    Debug "Decompressed size (bytes): " + Str(CkBinData::ckNumBytes(bd))

    ; Save the uncompressed data to a file:
    success = CkBinData::ckWriteFile(bd,"example.txt")
    If success = 0
        Debug CkBinData::ckLastErrorText(bd)
        CkGzip::ckDispose(gzip)
        CkBinData::ckDispose(bd)
        ProcedureReturn
    EndIf

    Debug "File successfully uncompressed to example.txt"


    CkGzip::ckDispose(gzip)
    CkBinData::ckDispose(bd)


    ProcedureReturn
EndProcedure