Delphi DLL
Delphi DLL
S3 Upload the Parts for a Multipart Upload
See more Amazon S3 (new) Examples
This example uploads a large file in parts. The multipart upload needs to have been first initiated prior to uploading the parts.See http://docs.aws.amazon.com/AmazonS3/latest/API/mpUploadUploadPart.html for more information about uploading parts.
Chilkat Delphi DLL Downloads
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, AuthAws, FileAccess, Stream, StringBuilder, Xml, Rest;
...
procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
xmlInit: HCkXml;
uploadId: PWideChar;
fileToUploadPath: PWideChar;
partSize: Integer;
fac: HCkFileAccess;
numParts: Integer;
partsListFile: PWideChar;
partsListXml: HCkXml;
rest: HCkRest;
bTls: Boolean;
port: Integer;
bAutoReconnect: Boolean;
authAws: HCkAuthAws;
partNumber: Integer;
sbPartNumber: HCkStringBuilder;
bPartAlreadyUploaded: Boolean;
numUploadedParts: Integer;
xRec0: HCkXml;
foundRec: HCkXml;
fileStream: HCkStream;
responseStr: PWideChar;
etag: PWideChar;
xPart: HCkXml;
begin
success := False;
// In the 1st step for uploading a large file, the multipart upload was initiated
// as shown here: Initiate Multipart Upload
// Other S3 Multipart Upload Examples:
// Complete Multipart Upload
// Abort Multipart Upload
// List Parts
// When we initiated the multipart upload, we saved the XML response to a file. This
// XML response contains the UploadId. We'll begin by loading that XML and getting
// the Upload ID.
xmlInit := CkXml_Create();
success := CkXml_LoadXmlFile(xmlInit,'s3_multipart_uploads/initiate.xml');
if (success <> True) then
begin
Memo1.Lines.Add('Did not find the initiate.xml XML file.');
Exit;
end;
uploadId := CkXml__getChildContent(xmlInit,'UploadId');
Memo1.Lines.Add('UploadId = ' + uploadId);
// When uploading parts, we need to keep an XML record of each part number
// and its corresponding ETag, which is received in the response for each part.
// There can be up to 10000 parts, numbered 1 to 10000.
// After all parts have been uploaded, the final step will be to complete
// the multipart upload (see Complete Multipart Upload)
// In this example, the large file we want to upload is somethingBig.zip
fileToUploadPath := 's3_multipart_uploads/somethingBig.zip';
// The minimum allowed part size is 5MB (5242880 bytes). The last part can be smaller because
// it will contain the remainder of the file. (This minimum is enforced by the AWS service.)
// We'll use the minimum allowed part size for this example.
partSize := 5242880;
// Let's use Chilkat's FileAccess API to examine the file to be uploaded. We'll get the size
// of the file and find out how many parts will be needed, including the final "partial" part.
fac := CkFileAccess_Create();
CkFileAccess_OpenForRead(fac,fileToUploadPath);
// How many parts will there be if each part is 5242880 bytes?
numParts := CkFileAccess_GetNumBlocks(fac,partSize);
Memo1.Lines.Add('numParts = ' + IntToStr(numParts));
CkFileAccess_FileClose(fac);
// Imagine that we may be running this for the 1st time, or maybe we already
// attempted to upload parts, and something failed. Maybe there was a network problem
// the resulted in not all parts getting uploaded. We'll write this code so that if run again,
// it will upload whatever parts haven't yet been uploaded.
// We'll keep a partsList.xml file to record the parts that have already been successfully
// uploaded. If this file does not yet exist, we'll create it..
partsListFile := 's3_multipart_uploads/partsList.xml';
partsListXml := CkXml_Create();
if (CkFileAccess_FileExists(fac,partsListFile) = True) then
begin
CkXml_LoadXmlFile(partsListXml,partsListFile);
end;
// Make sure the top-level tag is "CompleteMultipartUpload"
CkXml_putTag(partsListXml,'CompleteMultipartUpload');
// --------------------------------------
// Before entering the loop to upload parts,
// setup the REST object with AWS authentication,
// and make the initial connection.
rest := CkRest_Create();
// Connect to the Amazon AWS REST server.
bTls := True;
port := 443;
bAutoReconnect := True;
success := CkRest_Connect(rest,'s3.amazonaws.com',port,bTls,bAutoReconnect);
// ----------------------------------------------------------------------------
// Important: For buckets created in regions outside us-east-1,
// there are three important changes that need to be made.
// See Working with S3 Buckets in Non-us-east-1 Regions for the details.
// ----------------------------------------------------------------------------
// Provide AWS credentials for the REST call.
authAws := CkAuthAws_Create();
CkAuthAws_putAccessKey(authAws,'AWS_ACCESS_KEY');
CkAuthAws_putSecretKey(authAws,'AWS_SECRET_KEY');
CkAuthAws_putServiceName(authAws,'s3');
success := CkRest_SetAuthAws(rest,authAws);
// Set the bucket name via the HOST header.
// In this case, the bucket name is "chilkat100".
CkRest_putHost(rest,'chilkat100.s3.amazonaws.com');
// --------------------------------------
partNumber := 1;
sbPartNumber := CkStringBuilder_Create();
while (partNumber <= numParts) do
begin
Memo1.Lines.Add('---- ' + IntToStr(partNumber) + ' ----');
// This cumbersome way of converting an integer to a string is because
// Chilkat examples are written in a script that is converted to many programming languages.
// At this time, the translator does not have integer-to-string code generation capability..
CkStringBuilder_Clear(sbPartNumber);
CkStringBuilder_AppendInt(sbPartNumber,partNumber);
bPartAlreadyUploaded := False;
// If there are no children, then the XML is empty and no parts have yet been uploaded.
numUploadedParts := CkXml_getNumChildren(partsListXml);
if (numUploadedParts > 0) then
begin
// If some parts have been uploaded, check to see if this particular part was already upload.
// If so, then it can be skipped.
// Position ourselves at the 1st record.
xRec0 := CkXml_GetChild(partsListXml,0);
foundRec := CkXml_FindNextRecord(xRec0,'PartNumber',CkStringBuilder__getAsString(sbPartNumber));
if (CkXml_getLastMethodSuccess(xRec0) = True) then
begin
bPartAlreadyUploaded := True;
Memo1.Lines.Add('Part ' + IntToStr(partNumber) + ' was previously uploaded.');
Memo1.Lines.Add(CkXml__getXml(foundRec));
CkXml_Dispose(foundRec);
end;
CkXml_Dispose(xRec0);
end;
// If this part was not already uploaded, we need to upload.
// Also update the partsListXml and save as each part is successfully uploaded.
if (bPartAlreadyUploaded = False) then
begin
Memo1.Lines.Add('Uploading part ' + IntToStr(partNumber) + ' ...');
// Setup the stream source for the large file to be uploaded..
fileStream := CkStream_Create();
CkStream_putSourceFile(fileStream,fileToUploadPath);
// The Chilkat Stream API has features to make uploading a parts
// of a file easy. Indicate the part size by setting the SourceFilePartSize
// property.
CkStream_putSourceFilePartSize(fileStream,partSize);
// Our HTTP start line to upload a part will look like this:
// PUT /ObjectName?partNumber=PartNumber&uploadId=UploadId HTTP/1.1
// Set the query params. We'll need partNumber and uploadId.
// Make sure the query params from previous iterations are clear.
CkRest_ClearAllQueryParams(rest);
CkRest_AddQueryParam(rest,'partNumber',CkStringBuilder__getAsString(sbPartNumber));
CkRest_AddQueryParam(rest,'uploadId',uploadId);
// Upload this particular file part.
// Tell the fileStream which part is being uploaded.
// Our partNumber is 1-based (the 1st part is at index 1), but the fileStream's SourceFilePart
// property is 0-based. Therefore we use partNumber-1.
CkStream_putSourceFilePart(fileStream,partNumber - 1);
// Because the SourceFilePart and SourceFilePartSize properties are set, the stream will
// will provide just that part of the file.
responseStr := CkRest__fullRequestStream(rest,'PUT','/somethingBig.zip',fileStream);
if (CkRest_getLastMethodSuccess(rest) <> True) then
begin
Memo1.Lines.Add(CkRest__lastErrorText(rest));
Exit;
end;
if (CkRest_getResponseStatusCode(rest) <> 200) then
begin
// Examine the request/response to see what happened.
Memo1.Lines.Add('response status code = ' + IntToStr(CkRest_getResponseStatusCode(rest)));
Memo1.Lines.Add('response status text = ' + CkRest__responseStatusText(rest));
Memo1.Lines.Add('response header: ' + CkRest__responseHeader(rest));
Memo1.Lines.Add('response body: ' + responseStr);
Memo1.Lines.Add('---');
Memo1.Lines.Add('LastRequestStartLine: ' + CkRest__lastRequestStartLine(rest));
Memo1.Lines.Add('LastRequestHeader: ' + CkRest__lastRequestHeader(rest));
Exit;
end;
// OK, this part was uploaded..
// The response will have a 0-length body. The only information we need is the
// ETag response header field.
etag := CkRest__responseHdrByName(rest,'ETag');
// It should be present, but just in case there was no ETag header...
if (CkRest_getLastMethodSuccess(rest) <> True) then
begin
Memo1.Lines.Add('No ETag response header found!');
Memo1.Lines.Add('response header: ' + CkRest__responseHeader(rest));
Exit;
end;
// We need to add record to the partsListXml.
// The record will look like this:
// <Part>
// <PartNumber>PartNumber</PartNumber>
// <ETag>ETag</ETag>
// </Part>
xPart := CkXml_NewChild(partsListXml,'Part','');
CkXml_NewChildInt2(xPart,'PartNumber',partNumber);
CkXml_NewChild2(xPart,'ETag',etag);
CkXml_Dispose(xPart);
success := CkXml_SaveXml(partsListXml,partsListFile);
if (success <> True) then
begin
Memo1.Lines.Add(CkXml__lastErrorText(partsListXml));
Exit;
end;
Memo1.Lines.Add('-- Part ' + IntToStr(partNumber) + ' uploaded. ---------------------');
end;
partNumber := partNumber + 1;
end;
Memo1.Lines.Add('Finished. All parts uploaded.');
CkXml_Dispose(xmlInit);
CkFileAccess_Dispose(fac);
CkXml_Dispose(partsListXml);
CkRest_Dispose(rest);
CkAuthAws_Dispose(authAws);
CkStringBuilder_Dispose(sbPartNumber);
CkStream_Dispose(fileStream);
end;