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

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 Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoRest.h>
#import <CkoAuthAzureStorage.h>
#import <CkoXml.h>
#import <CkoFileAccess.h>
#import <CkoCrypt2.h>
#import <CkoStringBuilder.h>
#import <NSString.h>
#import <CkoBinData.h>

// 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.

CkoRest *rest = [[CkoRest alloc] init];

// Connect to the Azure Storage Blob Service
BOOL bTls = YES;
int port = 443;
BOOL bAutoReconnect = YES;
// In this example, the storage account name is "chilkat".
BOOL success = [rest Connect: @"chilkat.blob.core.windows.net" port: [NSNumber numberWithInt: port] tls: bTls autoReconnect: bAutoReconnect];
if (success != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

// Provide Azure Cloud credentials for the REST call.
CkoAuthAzureStorage *azAuth = [[CkoAuthAzureStorage alloc] init];
azAuth.AccessKey = @"AZURE_ACCESS_KEY";
// The account name used here should match the 1st part of the domain passed in the call to Connect (above).
azAuth.Account = @"chilkat";
azAuth.Scheme = @"SharedKey";
azAuth.Service = @"Blob";
// This causes the "x-ms-version: 2021-08-06" header to be automatically added.
azAuth.XMsVersion = @"2021-08-06";
success = [rest SetAuthAzureStorage: 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..
CkoXml *xml = [[CkoXml alloc] init];
xml.Tag = @"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
CkoFileAccess *fac = [[CkoFileAccess alloc] init];
success = [fac OpenForRead: @"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...)
int blockSize = 16384;

// How many 16K blocks?  (Including 1 for the last partial block)
int numBlocks = [[fac GetNumBlocks: [NSNumber numberWithInt: blockSize]] intValue];

CkoCrypt2 *crypt = [[CkoCrypt2 alloc] init];
crypt.HashAlgorithm = @"md5";

CkoStringBuilder *sbResponseBody = [[CkoStringBuilder alloc] init];
CkoStringBuilder *uriPath = [[CkoStringBuilder alloc] init];
NSString *blockId = 0;
CkoBinData *dataBlock = [[CkoBinData alloc] init];
NSString *contentMd5 = 0;
int i = 0;
while (i < numBlocks) {

    [dataBlock Clear];
    success = [fac ReadBlockBd: [NSNumber numberWithInt: i] blockSize: [NSNumber numberWithInt: blockSize] bd: dataBlock];
    if (success == NO) {
        NSLog(@"%@",fac.LastErrorText);
        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 = [fac GenBlockId: [NSNumber numberWithInt: i] length: [NSNumber numberWithInt: 4] encoding: @"base64"];

    // Add this blockId to the list of blocks to be committed.
    [xml NewChild2: @"Latest" content: blockId];

    // Build the URI path
    [uriPath Clear];
    success = [uriPath Append: @"/mycontainer/hamlet.xml?comp=block&blockId="];
    success = [uriPath Append: blockId];

    contentMd5 = [crypt HashBdENC: dataBlock];
    [rest AddHeader: @"Content-MD5" value: contentMd5];

    // Upload this block..
    [sbResponseBody Clear];
    success = [rest FullRequestBd: @"PUT" uriPath: [uriPath GetAsString] binData: dataBlock responseBody: sbResponseBody];
    if (success == NO) {
        NSLog(@"%@",rest.LastErrorText);
        return;
    }

    // Verify that we received a 201 status code.
    if ([rest.ResponseStatusCode intValue] != 201) {
        // Examine the request/response to see what happened.
        NSLog(@"%@%d",@"response status code = ",[rest.ResponseStatusCode intValue]);
        NSLog(@"%@%@",@"response status text = ",rest.ResponseStatusText);
        NSLog(@"%@%@",@"response header: ",rest.ResponseHeader);
        NSLog(@"%@%@",@"response body (if any): ",[sbResponseBody GetAsString]);
        NSLog(@"%@",@"---");
        NSLog(@"%@%@",@"LastRequestStartLine: ",rest.LastRequestStartLine);
        NSLog(@"%@%@",@"LastRequestHeader: ",rest.LastRequestHeader);
        return;
    }

    i = i + 1;
}

[fac FileClose];

// Now commit the blocks.
// Let's have a look at the XML that will commit the blocks:
NSString *xmlStr = [xml GetXml];
NSLog(@"%@",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.
// --------------------------------------------------------------------------
[rest RemoveHeader: @"Content-MD5"];

// Send the PUT Block List...
NSString *responseStr = [rest FullRequestString: @"PUT" uriPath: @"/mycontainer/hamlet.xml?comp=blocklist" bodyText: xmlStr];
if (rest.LastMethodSuccess != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

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

if ([rest.ResponseStatusCode intValue] != 201) {
    // Examine the request/response to see what happened.
    NSLog(@"%@%d",@"response status code = ",[rest.ResponseStatusCode intValue]);
    NSLog(@"%@%@",@"response status text = ",rest.ResponseStatusText);
    NSLog(@"%@%@",@"response header: ",rest.ResponseHeader);
    NSLog(@"%@%@",@"response body (if any): ",responseStr);
    NSLog(@"%@",@"---");
    NSLog(@"%@%@",@"LastRequestStartLine: ",rest.LastRequestStartLine);
    NSLog(@"%@%@",@"LastRequestHeader: ",rest.LastRequestHeader);
    return;
}

NSLog(@"%@",@"Success.");