Uploading Files to S-Drive

// STEP 1 — Prepare the upload: creates the WIP record and returns signed credentials
Blob fileBody = /* your file's bytes */;

cg__CaseFile__c fileRecord = new cg__CaseFile__c(
    cg__File_Name__c = 'invoice.pdf',
    cg__File_Size_in_Bytes__c = fileBody.size(),
    cg__Case__c = caseId,
    cg__Parent_Folder_Id__c = null // null = uploading to the case's root, not a subfolder
);

List<UploadRequestInfo> uploadInfos = SDriveTools.initializeUpload(
    caseId,
    new List<SObject>{ fileRecord },
    (Map<String,String>) null
);
UploadRequestInfo info = uploadInfos[0];

// STEP 2 — Upload the actual bytes directly to storage.
// This example uses Apex's Http class to illustrate the mechanics; in practice, many
// implementations do this step from client-side JavaScript instead (a Visualforce/LWC
// page posting directly to storage), to avoid Apex callout size and time limits.
String boundary = '----SDriveBoundary' + String.valueOf(Crypto.getRandomInteger());
String endpoint = 'https://' + info.bucketName + '.' + info.s3Endpoint;

// Build the form fields — see the table above for what each one means and which are conditional.
// Field order matters, and 'file' must be last.
Map<String,String> formFields = new Map<String,String>{
    'key'                    => info.fileLocation,
    'Content-Type'           => info.fileType,
    'policy'                 => info.policy,
    'x-amz-credential'       => info.awsCredential,
    'x-amz-date'             => info.timeStamp,
    'x-amz-algorithm'        => 'AWS4-HMAC-SHA256', // GCS-backed orgs use different, x-goog-* fields — not covered here
    'x-amz-signature'        => info.signature,
    'success_action_status'  => '201' // optional — without it, S3 returns 204 No Content instead
};

// Only include 'acl' if the bucket doesn't control its own ACL
if (!info.bucketControlledAcl) {
    formFields.put('acl', 'private');
}

// Only include server-side encryption if this org is configured to use it
if (String.isNotBlank(info.s3EncryptionType)) {
    formFields.put('x-amz-server-side-encryption', info.s3EncryptionType);
}

// Content-Disposition is optional, and only usable if you added a matching condition
// to policyMap when you called initializeUpload — otherwise S3 rejects the request
// as violating the signed policy. Omitted here since this example didn't set one.

Blob requestBody = buildMultipartBody(formFields, boundary, 'file', fileRecord.cg__File_Name__c, fileBody); // your own helper — 'file' must be the LAST field

HttpRequest req = new HttpRequest();
req.setEndpoint(endpoint);
req.setMethod('POST');
req.setHeader('Content-Type', 'multipart/form-data; boundary=' + boundary);
req.setBodyAsBlob(requestBody);

HttpResponse res = new Http().send(req);
if (res.getStatusCode() != 201) {
    throw new SDriveException('Upload to storage failed: ' + res.getBody());
}

// STEP 3 — Tell Salesforce the upload is finished (required — don't skip this)
List<ResultObject> results = SDriveTools.completeUpload(new List<Id>{ info.wipFileId });
for (ResultObject r : results) {
    if (r.status == 'fail') {
        System.debug(LoggingLevel.ERROR, 'Failed to finalize upload: ' + r.errorMessage);
    }
}

// STEP 1 — Same as above: creates the WIP record and returns signed credentials
List<UploadRequestInfo> uploadInfos = SDriveTools.initializeUpload(
    caseId,
    new List<SObject>{ largeFileRecord },
    (Map<String,String>) null
);
UploadRequestInfo info = uploadInfos[0];

// STEP 2 — Start the multipart session
String uploadId = SDriveTools.initializeMultiPartUpload(info.fileLocation);

// STEP 3 — Upload each chunk, then register it as a part
List<String> partETags = new List<String>();
Integer partNumber = 1;

for (Blob chunk : splitIntoChunks(largeFileBody)) { // your own chunking logic — 5MB minimum per part except the last
    String tempKey = info.fileLocation + '.' + (partNumber - 1); // note the off-by-one

    putBytesDirectlyToStorage(tempKey, chunk); // your own direct PUT of this chunk's bytes to storage

    String eTag = SDriveTools.copyPartMultiPartUpload(info.fileLocation, uploadId, partNumber);
    partETags.add(eTag);
    partNumber++;
}

// STEP 4 — Assemble all parts into the final object
SDriveTools.completeMultiPartUpload(info.fileLocation, uploadId, partETags);

// STEP 5 — Same required final step as the simple path — don't skip this
List<ResultObject> results = SDriveTools.completeUpload(new List<Id>{ info.wipFileId });
for (ResultObject r : results) {
    if (r.status == 'fail') {
        System.debug(LoggingLevel.ERROR, 'Failed to finalize upload: ' + r.errorMessage);
    }
}