C
C
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 C Downloads
#include <C_CkXml.h>
#include <C_CkFileAccess.h>
#include <C_CkRest.h>
#include <C_CkAuthAws.h>
#include <C_CkStringBuilder.h>
#include <C_CkStream.h>
void ChilkatSample(void)
{
BOOL success;
HCkXml xmlInit;
const char *uploadId;
const char *fileToUploadPath;
int partSize;
HCkFileAccess fac;
int numParts;
const char *partsListFile;
HCkXml partsListXml;
HCkRest rest;
BOOL bTls;
int port;
BOOL bAutoReconnect;
HCkAuthAws authAws;
int partNumber;
HCkStringBuilder sbPartNumber;
BOOL bPartAlreadyUploaded;
int numUploadedParts;
HCkXml xRec0;
HCkXml foundRec;
HCkStream fileStream;
const char *responseStr;
const char *etag;
HCkXml xPart;
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) {
printf("Did not find the initiate.xml XML file.\n");
CkXml_Dispose(xmlInit);
return;
}
uploadId = CkXml_getChildContent(xmlInit,"UploadId");
printf("UploadId = %s\n",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);
printf("numParts = %d\n",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) {
CkXml_LoadXmlFile(partsListXml,partsListFile);
}
// 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)) {
printf("---- %d ----\n",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) {
// 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) {
bPartAlreadyUploaded = TRUE;
printf("Part %d was previously uploaded.\n",partNumber);
printf("%s\n",CkXml_getXml(foundRec));
CkXml_Dispose(foundRec);
}
CkXml_Dispose(xRec0);
}
// 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) {
printf("Uploading part %d ...\n",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) {
printf("%s\n",CkRest_lastErrorText(rest));
CkXml_Dispose(xmlInit);
CkFileAccess_Dispose(fac);
CkXml_Dispose(partsListXml);
CkRest_Dispose(rest);
CkAuthAws_Dispose(authAws);
CkStringBuilder_Dispose(sbPartNumber);
CkStream_Dispose(fileStream);
return;
}
if (CkRest_getResponseStatusCode(rest) != 200) {
// 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: %s\n",responseStr);
printf("---\n");
printf("LastRequestStartLine: %s\n",CkRest_lastRequestStartLine(rest));
printf("LastRequestHeader: %s\n",CkRest_lastRequestHeader(rest));
CkXml_Dispose(xmlInit);
CkFileAccess_Dispose(fac);
CkXml_Dispose(partsListXml);
CkRest_Dispose(rest);
CkAuthAws_Dispose(authAws);
CkStringBuilder_Dispose(sbPartNumber);
CkStream_Dispose(fileStream);
return;
}
// 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) {
printf("No ETag response header found!\n");
printf("response header: %s\n",CkRest_responseHeader(rest));
CkXml_Dispose(xmlInit);
CkFileAccess_Dispose(fac);
CkXml_Dispose(partsListXml);
CkRest_Dispose(rest);
CkAuthAws_Dispose(authAws);
CkStringBuilder_Dispose(sbPartNumber);
CkStream_Dispose(fileStream);
return;
}
// 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) {
printf("%s\n",CkXml_lastErrorText(partsListXml));
CkXml_Dispose(xmlInit);
CkFileAccess_Dispose(fac);
CkXml_Dispose(partsListXml);
CkRest_Dispose(rest);
CkAuthAws_Dispose(authAws);
CkStringBuilder_Dispose(sbPartNumber);
CkStream_Dispose(fileStream);
return;
}
printf("-- Part %d uploaded. ---------------------\n",partNumber);
}
partNumber = partNumber + 1;
}
printf("Finished. All parts uploaded.\n");
CkXml_Dispose(xmlInit);
CkFileAccess_Dispose(fac);
CkXml_Dispose(partsListXml);
CkRest_Dispose(rest);
CkAuthAws_Dispose(authAws);
CkStringBuilder_Dispose(sbPartNumber);
CkStream_Dispose(fileStream);
}