(SQL Server) 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

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    DECLARE @iTmp1 int
    DECLARE @iTmp2 int
    DECLARE @iTmp3 int
    DECLARE @iTmp4 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- 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.

    DECLARE @socket int
    -- Use "Chilkat_9_5_0.Socket" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Socket', @socket OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @maxWaitMs int
    SELECT @maxWaitMs = 5000
    DECLARE @success int
    EXEC sp_OAMethod @socket, 'Connect', @success OUT, 'content.dropboxapi.com', 443, 1, @maxWaitMs
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @socket, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0

        EXEC sp_OAGetProperty @socket, 'ConnectFailReason', @iTmp0 OUT
        PRINT 'Connect Fail Reason: ' + @iTmp0
        EXEC @hr = sp_OADestroy @socket
        RETURN
      END

    -- Set the download bandwidth throttle rate to 50000 bytes per second.
    EXEC sp_OASetProperty @socket, 'BandwidthThrottleDown', 50000

    DECLARE @rest int
    -- Use "Chilkat_9_5_0.Rest" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Rest', @rest OUT

    -- Tell the REST object to use the connected socket.
    EXEC sp_OAMethod @rest, 'UseConnection', @success OUT, @socket, 1

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

    -- Add request headers.
    EXEC sp_OAMethod @rest, 'AddHeader', @success OUT, '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",
    -- }

    DECLARE @json int
    -- Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @json OUT

    EXEC sp_OAMethod @json, 'AppendString', @success OUT, 'path', '/Homework/lit/hamlet.xml'
    EXEC sp_OAMethod @json, 'Emit', @sTmp0 OUT
    EXEC sp_OAMethod @rest, 'AddHeader', @success OUT, 'Dropbox-API-Arg', @sTmp0

    -- Setup a file stream for the download
    DECLARE @fileStream int
    -- Use "Chilkat_9_5_0.Stream" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Stream', @fileStream OUT

    EXEC sp_OASetProperty @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.
    DECLARE @expectedStatus int
    SELECT @expectedStatus = 200
    EXEC sp_OAMethod @rest, 'SetResponseBodyStream', @success OUT, @expectedStatus, 1, @fileStream

    DECLARE @responseStr nvarchar(4000)
    EXEC sp_OAMethod @rest, 'FullRequestNoBody', @responseStr OUT, 'POST', '/2/files/download'
    EXEC sp_OAGetProperty @rest, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @socket
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @fileStream
        RETURN
      END

    -- When successful, Dropbox responds with a 200 response code.
    EXEC sp_OAGetProperty @rest, 'ResponseStatusCode', @iTmp0 OUT
    IF @iTmp0 <> 200
      BEGIN
        -- Examine the request/response to see what happened.

        EXEC sp_OAGetProperty @rest, 'ResponseStatusCode', @iTmp0 OUT
        PRINT 'response status code = ' + @iTmp0

        EXEC sp_OAGetProperty @rest, 'ResponseStatusText', @sTmp0 OUT
        PRINT 'response status text = ' + @sTmp0

        EXEC sp_OAGetProperty @rest, 'ResponseHeader', @sTmp0 OUT
        PRINT 'response header: ' + @sTmp0

        PRINT 'response body (if any): ' + @responseStr

        PRINT '---'

        EXEC sp_OAGetProperty @rest, 'LastRequestStartLine', @sTmp0 OUT
        PRINT 'LastRequestStartLine: ' + @sTmp0

        EXEC sp_OAGetProperty @rest, 'LastRequestHeader', @sTmp0 OUT
        PRINT 'LastRequestHeader: ' + @sTmp0
        EXEC @hr = sp_OADestroy @socket
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @fileStream
        RETURN
      END

    -- 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:
    DECLARE @apiResult nvarchar(4000)
    EXEC sp_OAMethod @rest, 'ResponseHdrByName', @apiResult OUT, 'dropbox-api-result'

    PRINT @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...
    DECLARE @jsonResult int
    -- Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @jsonResult OUT

    EXEC sp_OASetProperty @jsonResult, 'EmitCompact', 0
    EXEC sp_OAMethod @jsonResult, 'Load', @success OUT, @apiResult
    -- Show the JSON pretty-printed...
    EXEC sp_OAMethod @jsonResult, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    -- Sample code to get data from the JSON response:
    DECLARE @size int
    EXEC sp_OAMethod @jsonResult, 'IntOf', @size OUT, 'size'

    PRINT 'size = ' + @size

    DECLARE @rev nvarchar(4000)
    EXEC sp_OAMethod @jsonResult, 'StringOf', @rev OUT, 'rev'

    PRINT 'rev = ' + @rev

    DECLARE @clientModified nvarchar(4000)
    EXEC sp_OAMethod @jsonResult, 'StringOf', @clientModified OUT, 'client_modified'
    DECLARE @ckdt int
    -- Use "Chilkat_9_5_0.CkDateTime" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.CkDateTime', @ckdt OUT

    EXEC sp_OAMethod @ckdt, 'SetFromTimestamp', @success OUT, @clientModified
    DECLARE @bLocalTime int
    SELECT @bLocalTime = 1
    DECLARE @dt int
    EXEC sp_OAMethod @ckdt, 'GetDtObj', @dt OUT, @bLocalTime
    EXEC sp_OAGetProperty @dt, 'Day', @iTmp0 OUT

    EXEC sp_OAGetProperty @dt, 'Month', @iTmp1 OUT

    EXEC sp_OAGetProperty @dt, 'Year', @iTmp2 OUT

    EXEC sp_OAGetProperty @dt, 'Hour', @iTmp3 OUT

    EXEC sp_OAGetProperty @dt, 'Minute', @iTmp4 OUT
    PRINT @iTmp0 + '/' + @iTmp1 + '/' + @iTmp2 + ' ' + @iTmp3 + ':' + @iTmp4
    EXEC @hr = sp_OADestroy @dt


    EXEC @hr = sp_OADestroy @socket
    EXEC @hr = sp_OADestroy @rest
    EXEC @hr = sp_OADestroy @json
    EXEC @hr = sp_OADestroy @fileStream
    EXEC @hr = sp_OADestroy @jsonResult
    EXEC @hr = sp_OADestroy @ckdt


END
GO