Node.js
Node.js
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 Node.js Downloads
NODEJS_PRELUDE
function chilkatExample() {
var 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.
var xmlInit = new chilkat.Xml();
success = xmlInit.LoadXmlFile("s3_multipart_uploads/initiate.xml");
if (success !== true) {
console.log("Did not find the initiate.xml XML file.");
return;
}
var uploadId = xmlInit.GetChildContent("UploadId");
console.log("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
var 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.
var 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.
var fac = new chilkat.FileAccess();
fac.OpenForRead(fileToUploadPath);
// How many parts will there be if each part is 5242880 bytes?
var numParts = fac.GetNumBlocks(partSize);
console.log("numParts = " + numParts);
fac.FileClose();
// 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..
var partsListFile = "s3_multipart_uploads/partsList.xml";
var partsListXml = new chilkat.Xml();
if (fac.FileExists(partsListFile) == true) {
partsListXml.LoadXmlFile(partsListFile);
}
// Make sure the top-level tag is "CompleteMultipartUpload"
partsListXml.Tag = "CompleteMultipartUpload";
// --------------------------------------
// Before entering the loop to upload parts,
// setup the REST object with AWS authentication,
// and make the initial connection.
var rest = new chilkat.Rest();
// Connect to the Amazon AWS REST server.
var bTls = true;
var port = 443;
var bAutoReconnect = true;
success = rest.Connect("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.
var authAws = new chilkat.AuthAws();
authAws.AccessKey = "AWS_ACCESS_KEY";
authAws.SecretKey = "AWS_SECRET_KEY";
authAws.ServiceName = "s3";
success = rest.SetAuthAws(authAws);
// Set the bucket name via the HOST header.
// In this case, the bucket name is "chilkat100".
rest.Host = "chilkat100.s3.amazonaws.com";
// --------------------------------------
var partNumber = 1;
var sbPartNumber = new chilkat.StringBuilder();
while ((partNumber <= numParts)) {
console.log("---- " + 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..
sbPartNumber.Clear();
sbPartNumber.AppendInt(partNumber);
var bPartAlreadyUploaded = false;
// If there are no children, then the XML is empty and no parts have yet been uploaded.
var numUploadedParts = partsListXml.NumChildren;
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: Xml
var xRec0 = partsListXml.GetChild(0);
// foundRec: Xml
var foundRec = xRec0.FindNextRecord("PartNumber",sbPartNumber.GetAsString());
if (xRec0.LastMethodSuccess == true) {
bPartAlreadyUploaded = true;
console.log("Part " + partNumber + " was previously uploaded.");
console.log(foundRec.GetXml());
}
}
// 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) {
console.log("Uploading part " + partNumber + " ...");
// Setup the stream source for the large file to be uploaded..
var fileStream = new chilkat.Stream();
fileStream.SourceFile = 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.
fileStream.SourceFilePartSize = 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.
rest.ClearAllQueryParams();
rest.AddQueryParam("partNumber",sbPartNumber.GetAsString());
rest.AddQueryParam("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.
fileStream.SourceFilePart = partNumber - 1;
// Because the SourceFilePart and SourceFilePartSize properties are set, the stream will
// will provide just that part of the file.
var responseStr = rest.FullRequestStream("PUT","/somethingBig.zip",fileStream);
if (rest.LastMethodSuccess !== true) {
console.log(rest.LastErrorText);
return;
}
if (rest.ResponseStatusCode !== 200) {
// Examine the request/response to see what happened.
console.log("response status code = " + rest.ResponseStatusCode);
console.log("response status text = " + rest.ResponseStatusText);
console.log("response header: " + rest.ResponseHeader);
console.log("response body: " + responseStr);
console.log("---");
console.log("LastRequestStartLine: " + rest.LastRequestStartLine);
console.log("LastRequestHeader: " + rest.LastRequestHeader);
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.
var etag = rest.ResponseHdrByName("ETag");
// It should be present, but just in case there was no ETag header...
if (rest.LastMethodSuccess !== true) {
console.log("No ETag response header found!");
console.log("response header: " + rest.ResponseHeader);
return;
}
// We need to add record to the partsListXml.
// The record will look like this:
// <Part>
// <PartNumber>PartNumber</PartNumber>
// <ETag>ETag</ETag>
// </Part>
// xPart: Xml
var xPart = partsListXml.NewChild("Part","");
xPart.NewChildInt2("PartNumber",partNumber);
xPart.NewChild2("ETag",etag);
success = partsListXml.SaveXml(partsListFile);
if (success !== true) {
console.log(partsListXml.LastErrorText);
return;
}
console.log("-- Part " + partNumber + " uploaded. ---------------------");
}
partNumber = partNumber+1;
}
console.log("Finished. All parts uploaded.");
}
chilkatExample();