(PowerBuilder) REST Download Bandwidth Throttle

Demonstrates how to use download bandwidth throttling with the REST API. This example will download a file from Drobox using a file stream, with a limit on the bandwidth that can be used for the transfer.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_Socket
integer li_MaxWaitMs
integer li_Success
oleobject loo_Rest
oleobject loo_Json
oleobject loo_FileStream
integer li_ExpectedStatus
string ls_ResponseStr
string ls_ApiResult
oleobject loo_JsonResult
integer li_Size
string ls_Rev
string ls_ClientModified
oleobject loo_Ckdt
integer li_BLocalTime
oleobject loo_Dt

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// A Dropbox access token should have been previously obtained.
// Dropbox access tokens do not expire.
// See Dropbox Access Token.

// To use bandwidth throttling, the connection should be made using the socket API.
// This provides numerous properties to customize the connection, such as
// BandwidthThrottleDown, BandwidthThrottleUp, ClientIpAddress, ClintPort, Http Proxy,
// KeepAlive, PreferIpv6, RequireSslCertVerify, SoRcvBuf, SoSndBuf, SoReuseAddr,
// SOCKS proxy, TcpNoSDelay, TlsPinSet, TlsCipherSuite, SslAllowedCiphers, etc.

loo_Socket = create oleobject
// Use "Chilkat_9_5_0.Socket" for versions of Chilkat < 10.0.0
li_rc = loo_Socket.ConnectToNewObject("Chilkat.Socket")
if li_rc < 0 then
    destroy loo_Socket
    MessageBox("Error","Connecting to COM object failed")
    return
end if
li_MaxWaitMs = 5000
li_Success = loo_Socket.Connect("content.dropboxapi.com",443,1,li_MaxWaitMs)
if li_Success <> 1 then
    Write-Debug loo_Socket.LastErrorText
    Write-Debug "Connect Fail Reason: " + string(loo_Socket.ConnectFailReason)
    destroy loo_Socket
    return
end if

// Set the download bandwidth throttle rate to 50000 bytes per second.
loo_Socket.BandwidthThrottleDown = 50000

loo_Rest = create oleobject
// Use "Chilkat_9_5_0.Rest" for versions of Chilkat < 10.0.0
li_rc = loo_Rest.ConnectToNewObject("Chilkat.Rest")

// Tell the REST object to use the connected socket.
loo_Rest.UseConnection(loo_Socket,1)

// The remainder of this example is identical to the example at:
// Dropbox Download File.

// Add request headers.
loo_Rest.AddHeader("Authorization","Bearer DROPBOX_ACCESS_TOKEN")

// The download "parameters" are contained in JSON passed in an HTTP request header.
// This is the JSON indicating the file to be downloaded:
// { 
//    "path": "/Homework/lit/hamlet.xml",
// }

loo_Json = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")

loo_Json.AppendString("path","/Homework/lit/hamlet.xml")
loo_Rest.AddHeader("Dropbox-API-Arg",loo_Json.Emit())

// Setup a file stream for the download
loo_FileStream = create oleobject
// Use "Chilkat_9_5_0.Stream" for versions of Chilkat < 10.0.0
li_rc = loo_FileStream.ConnectToNewObject("Chilkat.Stream")

loo_FileStream.SinkFile = "qa_output/hamletFromDropbox.xml"

// Indicate that the call to FullRequestNoBody should send the response body
// to fileStream if the response status code is 200.
// If a non-success response status code is received, then nothing
// is streamed to the output file and the error response is returned by FullRequestNoBody.
li_ExpectedStatus = 200
loo_Rest.SetResponseBodyStream(li_ExpectedStatus,1,loo_FileStream)

ls_ResponseStr = loo_Rest.FullRequestNoBody("POST","/2/files/download")
if loo_Rest.LastMethodSuccess <> 1 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Socket
    destroy loo_Rest
    destroy loo_Json
    destroy loo_FileStream
    return
end if

// When successful, Dropbox responds with a 200 response code.
if loo_Rest.ResponseStatusCode <> 200 then
    // Examine the request/response to see what happened.
    Write-Debug "response status code = " + string(loo_Rest.ResponseStatusCode)
    Write-Debug "response status text = " + loo_Rest.ResponseStatusText
    Write-Debug "response header: " + loo_Rest.ResponseHeader
    Write-Debug "response body (if any): " + ls_ResponseStr
    Write-Debug "---"
    Write-Debug "LastRequestStartLine: " + loo_Rest.LastRequestStartLine
    Write-Debug "LastRequestHeader: " + loo_Rest.LastRequestHeader
    destroy loo_Socket
    destroy loo_Rest
    destroy loo_Json
    destroy loo_FileStream
    return
end if

// Information about the downloaded file is also available as JSON in a response header.
// The "dropbox-api-result" response header contains the information.  For example:
ls_ApiResult = loo_Rest.ResponseHdrByName("dropbox-api-result")
Write-Debug ls_ApiResult

// In this case, the pretty-formatted dropbox-api-result JSON looks like this:
// { 
//   "name": "hamlet.xml",
//   "path_lower": "/homework/lit/hamlet.xml",
//   "path_display": "/Homework/lit/hamlet.xml",
//   "id": "id:74FkdeNuyKAAAAAAAAAAAQ",
//   "client_modified": "2016-06-02T23:19:00Z",
//   "server_modified": "2016-06-02T23:19:00Z",
//   "rev": "9482db15f",
//   "size": 279658
// }

// Load the JSON, pretty-print it, and demonstrate how to get some values...
loo_JsonResult = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_JsonResult.ConnectToNewObject("Chilkat.JsonObject")

loo_JsonResult.EmitCompact = 0
loo_JsonResult.Load(ls_ApiResult)
// Show the JSON pretty-printed...
Write-Debug loo_JsonResult.Emit()

// Sample code to get data from the JSON response:
li_Size = loo_JsonResult.IntOf("size")
Write-Debug "size = " + string(li_Size)

ls_Rev = loo_JsonResult.StringOf("rev")
Write-Debug "rev = " + ls_Rev

ls_ClientModified = loo_JsonResult.StringOf("client_modified")
loo_Ckdt = create oleobject
// Use "Chilkat_9_5_0.CkDateTime" for versions of Chilkat < 10.0.0
li_rc = loo_Ckdt.ConnectToNewObject("Chilkat.CkDateTime")

loo_Ckdt.SetFromTimestamp(ls_ClientModified)
li_BLocalTime = 1
loo_Dt = loo_Ckdt.GetDtObj(li_BLocalTime)
Write-Debug string(loo_Dt.Day) + "/" + string(loo_Dt.Month) + "/" + string(loo_Dt.Year) + " " + string(loo_Dt.Hour) + ":" + string(loo_Dt.Minute)
destroy loo_Dt


destroy loo_Socket
destroy loo_Rest
destroy loo_Json
destroy loo_FileStream
destroy loo_JsonResult
destroy loo_Ckdt