(C) Azure File Service: Upload Large File

Sample code to upload a large file to a directory in a share in the Azure File Service. A file is uploaded by first creating the file in the Azure share and then writing ranges of bytes to the file. Azure imposes a 4MB limit for each PUT to write a range. Files larger than 4MB need to be uploaded by making multiple "Put Range" calls. This example uploads a large file requiring multiple "Put Range" calls.

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#include <C_CkRest.h>
#include <C_CkFileAccess.h>
#include <C_CkAuthAzureStorage.h>
#include <C_CkStringBuilder.h>
#include <C_CkBinData.h>

void ChilkatSample(void)
    {
    HCkRest rest;
    BOOL bTls;
    int port;
    BOOL bAutoReconnect;
    BOOL success;
    const char *localFilePath;
    HCkFileAccess fac;
    int szLocalFile;
    HCkAuthAzureStorage azAuth;
    HCkStringBuilder sbFileSize;
    const char *responseStr;
    HCkStringBuilder sbRange;
    HCkStringBuilder sbResponseBody;
    HCkBinData bdFileData;
    int numBytesLeft;
    int curIndex;
    int chunkSize;

    // Azure File Service Example: Upload a large file.  
    // See:  https://docs.microsoft.com/en-us/rest/api/storageservices/create-share
    // also see: https://docs.microsoft.com/en-us/rest/api/storageservices/put-range

    // 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.file.core.windows.net",port,bTls,bAutoReconnect);
    if (success != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        return;
    }

    // This example will upload a larger file.
    localFilePath = "qa_data/zips/somethingBig.zip";
    fac = CkFileAccess_Create();
    // Note: The FileSize method returns a signed 32-bit integer.  If the file is potentially larger than 2GB, call FileSizeStr instead to return
    // the size of the file as a string, then convert to an integer value.
    szLocalFile = CkFileAccess_FileSize(fac,localFilePath);
    if (szLocalFile < 0) {
        printf("%s\n",CkFileAccess_lastErrorText(fac));
        CkRest_Dispose(rest);
        CkFileAccess_Dispose(fac);
        return;
    }

    // Provide Azure Cloud credentials for the REST calls.
    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,"File");
    // This causes the "x-ms-version: 2020-08-04" header to be automatically added.
    CkAuthAzureStorage_putXMsVersion(azAuth,"2020-08-04");
    success = CkRest_SetAuthAzureStorage(rest,azAuth);

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

    // However, a few additional headers are required for the "Create File" operation:
    CkRest_AddHeader(rest,"x-ms-type","file");

    // This required header specifies the final size of the file (or the maximum size it can be).
    sbFileSize = CkStringBuilder_Create();
    CkStringBuilder_AppendInt(sbFileSize,szLocalFile);
    CkRest_AddHeader(rest,"x-ms-content-length",CkStringBuilder_getAsString(sbFileSize));

    // Send a PUT request to create the file (or replace the file if it already exists).
    // This will initialize the file in the Azure file storage.  To upload content, we'll need
    // to do the "Put Range" operation one or more times.

    // The following will create the file "somethingBig.zip" in the share "pip"
    responseStr = CkRest_fullRequestNoBody(rest,"PUT","/pip/somethingBig.zip");
    if (CkRest_getLastMethodSuccess(rest) != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        CkFileAccess_Dispose(fac);
        CkAuthAzureStorage_Dispose(azAuth);
        CkStringBuilder_Dispose(sbFileSize);
        return;
    }

    // When successful, the Azure File Service will respond with a 201 (Created) response status code,
    // with no XML response body.  If an error response is returned, there will be an XML 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);
        CkFileAccess_Dispose(fac);
        CkAuthAzureStorage_Dispose(azAuth);
        CkStringBuilder_Dispose(sbFileSize);
        return;
    }

    printf("Successfully created somethingBig.zip\n");

    // --------------------------------------------------------------------------------
    // Upload the file data...

    // Make sure the headers from the "Create File" operation are removed.
    CkRest_ClearAllHeaders(rest);

    // The x-ms-write header is required for each "Put Range" request.
    CkRest_AddHeader(rest,"x-ms-write","update");

    sbRange = CkStringBuilder_Create();
    sbResponseBody = CkStringBuilder_Create();
    bdFileData = CkBinData_Create();

    // Open the file.  We'll be reading and uploading in chunks..
    success = CkFileAccess_OpenForRead(fac,localFilePath);
    if (success != TRUE) {
        printf("%s\n",CkFileAccess_lastErrorText(fac));
        CkRest_Dispose(rest);
        CkFileAccess_Dispose(fac);
        CkAuthAzureStorage_Dispose(azAuth);
        CkStringBuilder_Dispose(sbFileSize);
        CkStringBuilder_Dispose(sbRange);
        CkStringBuilder_Dispose(sbResponseBody);
        CkBinData_Dispose(bdFileData);
        return;
    }

    numBytesLeft = szLocalFile;
    curIndex = 0;
    while (numBytesLeft > 0) {

        chunkSize = numBytesLeft;
        // Azure allows for 4MB max chunks  (4 x 1024 x 1024 = 4194304)
        if (chunkSize > 4194304) {
            chunkSize = 4194304;
        }

        // The only tricky part here is to correctly add the x-ms-range header.
        // It will be formatted like this:
        // x-ms-range: bytes=0-759623
        CkStringBuilder_Clear(sbRange);
        CkStringBuilder_Append(sbRange,"bytes=");
        CkStringBuilder_AppendInt(sbRange,curIndex);
        CkStringBuilder_Append(sbRange,"-");
        CkStringBuilder_AppendInt(sbRange,curIndex + chunkSize - 1);

        // This replaces the header if it already exists..
        CkRest_AddHeader(rest,"x-ms-range",CkStringBuilder_getAsString(sbRange));

        // Read the next chunk from the local file.
        CkBinData_Clear(bdFileData);
        success = CkFileAccess_FileReadBd(fac,chunkSize,bdFileData);

        success = CkRest_FullRequestBd(rest,"PUT","/pip/somethingBig.zip?comp=range",bdFileData,sbResponseBody);
        if (success != TRUE) {
            // This would indicate a failure where no response was received.
            printf("%s\n",CkRest_lastErrorText(rest));
            CkRest_Dispose(rest);
            CkFileAccess_Dispose(fac);
            CkAuthAzureStorage_Dispose(azAuth);
            CkStringBuilder_Dispose(sbFileSize);
            CkStringBuilder_Dispose(sbRange);
            CkStringBuilder_Dispose(sbResponseBody);
            CkBinData_Dispose(bdFileData);
            return;
        }

        // A 201 response indicates the chunk was uploaded.
        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);
            CkFileAccess_Dispose(fac);
            CkAuthAzureStorage_Dispose(azAuth);
            CkStringBuilder_Dispose(sbFileSize);
            CkStringBuilder_Dispose(sbRange);
            CkStringBuilder_Dispose(sbResponseBody);
            CkBinData_Dispose(bdFileData);
            return;
        }

        printf("Uploaded chunk from %d to %d\n",curIndex,curIndex + chunkSize - 1);

        curIndex = curIndex + chunkSize;
        numBytesLeft = numBytesLeft - chunkSize;
    }

    CkFileAccess_FileClose(fac);

    printf("success.\n");


    CkRest_Dispose(rest);
    CkFileAccess_Dispose(fac);
    CkAuthAzureStorage_Dispose(azAuth);
    CkStringBuilder_Dispose(sbFileSize);
    CkStringBuilder_Dispose(sbRange);
    CkStringBuilder_Dispose(sbResponseBody);
    CkBinData_Dispose(bdFileData);

    }