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Upload File in Blocks (with Content-MD5 header) and Commit the Block List

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Demonstrates how to upload a file in blocks and then commit the block list. This example includes a Content-MD5 header for each block.

Chilkat C Downloads

C
#include <C_CkRest.h>
#include <C_CkAuthAzureStorage.h>
#include <C_CkXml.h>
#include <C_CkFileAccess.h>
#include <C_CkCrypt2.h>
#include <C_CkStringBuilder.h>
#include <C_CkBinData.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkRest rest;
    BOOL bTls;
    int port;
    BOOL bAutoReconnect;
    HCkAuthAzureStorage azAuth;
    HCkXml xml;
    HCkFileAccess fac;
    int blockSize;
    int numBlocks;
    HCkCrypt2 crypt;
    HCkStringBuilder sbResponseBody;
    HCkStringBuilder uriPath;
    const char *blockId;
    HCkBinData dataBlock;
    const char *contentMd5;
    int i;
    const char *xmlStr;
    const char *responseStr;

    success = FALSE;

    // Azure Blob Service Example: Upload a file in blocks, and then commit the block list.
    // See also: https://msdn.microsoft.com/en-us/library/azure/dd135726.aspx

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

    rest = CkRest_Create();

    // Connect to the Azure Storage Blob Service
    bTls = TRUE;
    port = 443;
    bAutoReconnect = TRUE;
    // In this example, the storage account name is "chilkat".
    success = CkRest_Connect(rest,"chilkat.blob.core.windows.net",port,bTls,bAutoReconnect);
    if (success != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        return;
    }

    // Provide Azure Cloud credentials for the REST call.
    azAuth = CkAuthAzureStorage_Create();
    CkAuthAzureStorage_putAccessKey(azAuth,"AZURE_ACCESS_KEY");
    // The account name used here should match the 1st part of the domain passed in the call to Connect (above).
    CkAuthAzureStorage_putAccount(azAuth,"chilkat");
    CkAuthAzureStorage_putScheme(azAuth,"SharedKey");
    CkAuthAzureStorage_putService(azAuth,"Blob");
    // This causes the "x-ms-version: 2021-08-06" header to be automatically added.
    CkAuthAzureStorage_putXMsVersion(azAuth,"2021-08-06");
    success = CkRest_SetAuthAzureStorage(rest,azAuth);

    // Note: The application does not need to explicitly set the following
    // headers: Content-Length, x-ms-date, Authorization.  These headers
    // are automatically set by Chilkat.

    // As the blocks are uploaded, we'll keep an XML block list for the subsequent commit..
    xml = CkXml_Create();
    CkXml_putTag(xml,"BlockList");

    // Any type of file can be uploaded in this way.  It can a text file, binary file, anything...
    // This example will upload an XML file that is approximately 275K in size.  It can be downloaded
    // at http://www.chilkatsoft.com/hamlet.xml
    fac = CkFileAccess_Create();
    success = CkFileAccess_OpenForRead(fac,"qa_data/xml/hamlet.xml");
    // Assuming success for the example..

    // We'll upload in 16K blocks (normally a program would upload in larger block sizes than this,
    // but this is just an example...)
    blockSize = 16384;

    // How many 16K blocks?  (Including 1 for the last partial block)
    numBlocks = CkFileAccess_GetNumBlocks(fac,blockSize);

    crypt = CkCrypt2_Create();
    CkCrypt2_putHashAlgorithm(crypt,"md5");

    sbResponseBody = CkStringBuilder_Create();
    uriPath = CkStringBuilder_Create();

    dataBlock = CkBinData_Create();

    i = 0;
    while (i < numBlocks) {

        CkBinData_Clear(dataBlock);
        success = CkFileAccess_ReadBlockBd(fac,i,blockSize,dataBlock);
        if (success == FALSE) {
            printf("%s\n",CkFileAccess_lastErrorText(fac));
            CkRest_Dispose(rest);
            CkAuthAzureStorage_Dispose(azAuth);
            CkXml_Dispose(xml);
            CkFileAccess_Dispose(fac);
            CkCrypt2_Dispose(crypt);
            CkStringBuilder_Dispose(sbResponseBody);
            CkStringBuilder_Dispose(uriPath);
            CkBinData_Dispose(dataBlock);
            return;
        }

        // Generate a base64 block ID.  
        // (Chilkat provides a helper method named GenBlockId to make this easy)
        // A pre-base64 encoded block ID length of 4 is sufficient in this case because
        // this file certainly won't have more than 99,999 blocks..
        blockId = CkFileAccess_genBlockId(fac,i,4,"base64");

        // Add this blockId to the list of blocks to be committed.
        CkXml_NewChild2(xml,"Latest",blockId);

        // Build the URI path
        CkStringBuilder_Clear(uriPath);
        success = CkStringBuilder_Append(uriPath,"/mycontainer/hamlet.xml?comp=block&blockId=");
        success = CkStringBuilder_Append(uriPath,blockId);

        contentMd5 = CkCrypt2_hashBdENC(crypt,dataBlock);
        CkRest_AddHeader(rest,"Content-MD5",contentMd5);

        // Upload this block..
        CkStringBuilder_Clear(sbResponseBody);
        success = CkRest_FullRequestBd(rest,"PUT",CkStringBuilder_getAsString(uriPath),dataBlock,sbResponseBody);
        if (success == FALSE) {
            printf("%s\n",CkRest_lastErrorText(rest));
            CkRest_Dispose(rest);
            CkAuthAzureStorage_Dispose(azAuth);
            CkXml_Dispose(xml);
            CkFileAccess_Dispose(fac);
            CkCrypt2_Dispose(crypt);
            CkStringBuilder_Dispose(sbResponseBody);
            CkStringBuilder_Dispose(uriPath);
            CkBinData_Dispose(dataBlock);
            return;
        }

        // Verify that we received a 201 status code.
        if (CkRest_getResponseStatusCode(rest) != 201) {
            // Examine the request/response to see what happened.
            printf("response status code = %d\n",CkRest_getResponseStatusCode(rest));
            printf("response status text = %s\n",CkRest_responseStatusText(rest));
            printf("response header: %s\n",CkRest_responseHeader(rest));
            printf("response body (if any): %s\n",CkStringBuilder_getAsString(sbResponseBody));
            printf("---\n");
            printf("LastRequestStartLine: %s\n",CkRest_lastRequestStartLine(rest));
            printf("LastRequestHeader: %s\n",CkRest_lastRequestHeader(rest));
            CkRest_Dispose(rest);
            CkAuthAzureStorage_Dispose(azAuth);
            CkXml_Dispose(xml);
            CkFileAccess_Dispose(fac);
            CkCrypt2_Dispose(crypt);
            CkStringBuilder_Dispose(sbResponseBody);
            CkStringBuilder_Dispose(uriPath);
            CkBinData_Dispose(dataBlock);
            return;
        }

        i = i + 1;
    }

    CkFileAccess_FileClose(fac);

    // Now commit the blocks.
    // Let's have a look at the XML that will commit the blocks:
    xmlStr = CkXml_getXml(xml);
    printf("%s\n",xmlStr);

    // The XML will look like this:

    // <?xml version="1.0" encoding="utf-8" ?>
    // <BlockList>
    //     <Latest>MDAwMA==</Latest>
    //     <Latest>MDAwMQ==</Latest>
    //     <Latest>MDAwMg==</Latest>
    //     <Latest>MDAwMw==</Latest>
    //     <Latest>MDAwNA==</Latest>
    //     <Latest>MDAwNQ==</Latest>
    //     <Latest>MDAwNg==</Latest>
    //     <Latest>MDAwNw==</Latest>
    //     <Latest>MDAwOA==</Latest>
    //     <Latest>MDAwOQ==</Latest>
    //     <Latest>MDAxMA==</Latest>
    //     <Latest>MDAxMQ==</Latest>
    //     <Latest>MDAxMg==</Latest>
    //     <Latest>MDAxMw==</Latest>
    //     <Latest>MDAxNA==</Latest>
    //     <Latest>MDAxNQ==</Latest>
    //     <Latest>MDAxNg==</Latest>
    //     <Latest>MDAxNw==</Latest>
    // </BlockList>

    // --------------------------------------------------------------------------
    // IMPORTANT: Remove the Content-MD5 header previously set in the loop above.
    // --------------------------------------------------------------------------
    CkRest_RemoveHeader(rest,"Content-MD5");

    // Send the PUT Block List...
    responseStr = CkRest_fullRequestString(rest,"PUT","/mycontainer/hamlet.xml?comp=blocklist",xmlStr);
    if (CkRest_getLastMethodSuccess(rest) != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        CkAuthAzureStorage_Dispose(azAuth);
        CkXml_Dispose(xml);
        CkFileAccess_Dispose(fac);
        CkCrypt2_Dispose(crypt);
        CkStringBuilder_Dispose(sbResponseBody);
        CkStringBuilder_Dispose(uriPath);
        CkBinData_Dispose(dataBlock);
        return;
    }

    // When successful, the Azure Storage service will respond with a 201 response status code,
    // with no response body.

    if (CkRest_getResponseStatusCode(rest) != 201) {
        // Examine the request/response to see what happened.
        printf("response status code = %d\n",CkRest_getResponseStatusCode(rest));
        printf("response status text = %s\n",CkRest_responseStatusText(rest));
        printf("response header: %s\n",CkRest_responseHeader(rest));
        printf("response body (if any): %s\n",responseStr);
        printf("---\n");
        printf("LastRequestStartLine: %s\n",CkRest_lastRequestStartLine(rest));
        printf("LastRequestHeader: %s\n",CkRest_lastRequestHeader(rest));
        CkRest_Dispose(rest);
        CkAuthAzureStorage_Dispose(azAuth);
        CkXml_Dispose(xml);
        CkFileAccess_Dispose(fac);
        CkCrypt2_Dispose(crypt);
        CkStringBuilder_Dispose(sbResponseBody);
        CkStringBuilder_Dispose(uriPath);
        CkBinData_Dispose(dataBlock);
        return;
    }

    printf("Success.\n");


    CkRest_Dispose(rest);
    CkAuthAzureStorage_Dispose(azAuth);
    CkXml_Dispose(xml);
    CkFileAccess_Dispose(fac);
    CkCrypt2_Dispose(crypt);
    CkStringBuilder_Dispose(sbResponseBody);
    CkStringBuilder_Dispose(uriPath);
    CkBinData_Dispose(dataBlock);

    }