Read the REST Response Body in Chunks

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Demonstrates Rest.ReadRespChunkBd, which reads the response body one chunk at a time, appending each chunk to a BinData. A return value of 0 signals the body is complete, while -1 indicates a read failure.

var success = false;

var rest = new CkRest();
var bTls = true;
var bAutoReconnect = true;
success = rest.Connect("example.com",443,bTls,bAutoReconnect);
if (success == false) {
    console.log(rest.LastErrorText);
    return;
}

success = rest.SendReqNoBody("GET","/api/largefile");
if (success == false) {
    console.log(rest.LastErrorText);
    return;
}

var statusCode = rest.ReadResponseHeader();
if (statusCode < 0) {
    console.log(rest.LastErrorText);
    return;
}

//  Check for the expected success status code.  If the response is not 200, the body is likely
//  error text formatted as JSON, XML, or HTML rather than the expected content.  In that case read
//  the body as text, report it, and return.
if (statusCode !== 200) {
    var sbError = new CkStringBuilder();
    success = rest.ReadRespSb(sbError);
    if (success == false) {
        console.log(rest.LastErrorText);
        return;
    }

    console.log("Request failed with status code " + statusCode);
    console.log(sbError.GetAsString());
    return;
}

//  The status code is 200.  Read the response body in chunks, appending each chunk to the BinData.
//  Each call waits until at least the requested number of bytes is available, unless the response
//  ends first.  A return value of 0 means the final bytes were returned and the body is complete;
//  -1 indicates a read failure.
var bdBody = new CkBinData();
var chunkResult = rest.ReadRespChunkBd(8192,bdBody);
while (chunkResult > 0) {
    chunkResult = rest.ReadRespChunkBd(8192,bdBody);
}

if (chunkResult < 0) {
    console.log(rest.LastErrorText);
    return;
}

console.log("Received " + bdBody.NumBytes + " bytes.");