(C) Unzip Binary File to Stream

Demonstrates how to unzip a large binary file to a stream to allow the application to process the uncompressed bytes chunk by chunk.

Note: This example requires Chilkat v11.0.0 or greater.

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#include <C_CkZip.h>
#include <C_CkZipEntry.h>
#include <C_CkStream.h>
#include <C_CkTask.h>
#include <C_CkFileAccess.h>
#include <C_CkBinData.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkZip zip;
    HCkZipEntry entry;
    HCkStream dataStream;
    HCkTask unzipTask;
    HCkFileAccess fac;
    HCkBinData bd;

    success = FALSE;

    // This requires the Chilkat Zip API to have been previously unlocked.
    // See Unlock Chilkat Zip for sample code.

    zip = CkZip_Create();

    // First open a .zip.
    success = CkZip_OpenZip(zip,"qa_data/zips/big.zip");
    if (success == FALSE) {
        printf("%s\n",CkZip_lastErrorText(zip));
        CkZip_Dispose(zip);
        return;
    }

    // Get the entry to be unzipped to a stream..
    entry = CkZipEntry_Create();
    success = CkZip_EntryAt(zip,0,entry);
    if (success == FALSE) {
        printf("%s\n",CkZip_lastErrorText(zip));
        CkZip_Dispose(zip);
        CkZipEntry_Dispose(entry);
        return;
    }

    dataStream = CkStream_Create();

    unzipTask = CkZipEntry_UnzipToStreamAsync(entry,dataStream);
    if (CkZipEntry_getLastMethodSuccess(entry) != TRUE) {
        printf("%s\n",CkZipEntry_lastErrorText(entry));
        CkZip_Dispose(zip);
        CkZipEntry_Dispose(entry);
        CkStream_Dispose(dataStream);
        return;
    }

    // Start the background unzip thread.
    CkTask_Run(unzipTask);

    // We'll read the uncompressed data chunk-by-chunk and write to an output file.
    fac = CkFileAccess_Create();
    success = CkFileAccess_OpenForWrite(fac,"qa_output/out.dat");
    if (success != TRUE) {
        printf("%s\n",CkFileAccess_lastErrorText(fac));
        CkZip_Dispose(zip);
        CkZipEntry_Dispose(entry);
        CkStream_Dispose(dataStream);
        CkFileAccess_Dispose(fac);
        return;
    }

    // Read the stream.  (this is reading the unzipped file data)
    bd = CkBinData_Create();
    while (CkStream_getEndOfStream(dataStream) != TRUE) {
        // Get the next chunk of decompressed bytes.
        CkStream_ReadBd(dataStream,bd);
        // Do something with it..
        // In this simple example, we'll just write to the file.
        CkFileAccess_FileWriteBd(fac,bd,0,0);
        // Clear for the next read.
        CkBinData_Clear(bd);
    }

    CkFileAccess_FileClose(fac);

    CkTask_Dispose(unzipTask);
    printf("Success.\n");


    CkZip_Dispose(zip);
    CkZipEntry_Dispose(entry);
    CkStream_Dispose(dataStream);
    CkFileAccess_Dispose(fac);
    CkBinData_Dispose(bd);

    }