SQL Server

Socket Send/Receive 16-bit Integers

Demonstrates sending and receiving 16-bit integers over a socket connection using either big-endian or little-endian byte ordering. SQL Server

-- 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
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

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

    DECLARE @sock int
    EXEC @hr = sp_OACreate 'Chilkat.Socket', @sock OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- --------------------------------------------------------------------
    -- This example uses the public TCP echo service at https://tcpbin.com/
    -- --------------------------------------------------------------------

    DECLARE @useTls int
    SELECT @useTls = 0
    DECLARE @port int
    SELECT @port = 4242
    DECLARE @maxWaitMs int
    SELECT @maxWaitMs = 5000
    EXEC sp_OAMethod @sock, 'Connect', @success OUT, 'tcpbin.com', @port, @useTls, @maxWaitMs
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @sock, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sock
        RETURN
      END

    -- Wait a max of 2 seconds for a response..
    EXEC sp_OASetProperty @sock, 'MaxReadIdleMs', 2000

    -- Send a 16-bit integer using big-endian byte ordering (also called network byte order)
    -- 12022 decimal = 2EF6 hex
    DECLARE @value int
    SELECT @value = 12022
    DECLARE @bigEndian int
    SELECT @bigEndian = 1
    EXEC sp_OAMethod @sock, 'SendInt16', @success OUT, @value, @bigEndian
    -- Send it again, because we'll read it two different ways..
    EXEC sp_OAMethod @sock, 'SendInt16', @success OUT, @value, @bigEndian

    -- The tcpbin.com echo server only echoes after receiving an LF (linefeed char)
    EXEC sp_OAMethod @sock, 'SendByte', @success OUT, 10

    -- Let's see hex values of the 2 bytes sent in network byte order (big-endian)
    -- (The echo server sends back exactly the bytes received.)
    DECLARE @hexStr nvarchar(4000)
    EXEC sp_OAMethod @sock, 'ReceiveNBytesENC', @hexStr OUT, 2, 'hex'

    -- In the big-ending byte order, the byte order is most significant byte to least significant,
    -- therefore we should see the bytes in the order 0x2E 0xF6.

    PRINT 'Expecting big-endian 2EF6'

    PRINT @hexStr

    -- Let's read directly to an integer..
    EXEC sp_OAMethod @sock, 'ReceiveInt16', @success OUT, @bigEndian, 1

    PRINT 'Expecting 12022'

    EXEC sp_OAGetProperty @sock, 'ReceivedInt', @iTmp0 OUT
    PRINT 'Received: ' + @iTmp0

    -- Consume the LF that gets echoed back..
    EXEC sp_OAMethod @sock, 'ReceiveByte', @success OUT, 1

    -- --------------------------------------------------------------------
    -- Let's do the same thing, but with little-endian byte ordering.


    PRINT '----'

    -- 12022 decimal = 2EF6 hex, but little-endian byte ordering will send the bytes in the order 0xF6 0x2E
    SELECT @value = 12022
    SELECT @bigEndian = 0
    EXEC sp_OAMethod @sock, 'SendInt16', @success OUT, @value, @bigEndian
    EXEC sp_OAMethod @sock, 'SendInt16', @success OUT, @value, @bigEndian
    EXEC sp_OAMethod @sock, 'SendByte', @success OUT, 10

    EXEC sp_OAMethod @sock, 'ReceiveNBytesENC', @hexStr OUT, 2, 'hex'


    PRINT 'Expecting little-endian F62E'

    PRINT @hexStr

    EXEC sp_OAMethod @sock, 'ReceiveInt16', @success OUT, @bigEndian, 1

    PRINT 'Expecting 12022'

    EXEC sp_OAGetProperty @sock, 'ReceivedInt', @iTmp0 OUT
    PRINT 'Received: ' + @iTmp0

    -- Consume the LF that gets echoed back..
    EXEC sp_OAMethod @sock, 'ReceiveByte', @success OUT, 1

    EXEC sp_OAMethod @sock, 'Close', @success OUT, 1000

    -- Output:

    -- Expecting big-endian 2EF6
    -- 2EF6
    -- Expecting 12022
    -- Received: 12022
    -- ----
    -- Expecting little-endian F62E
    -- F62E
    -- Expecting 12022
    -- Received: 12022

    EXEC @hr = sp_OADestroy @sock


END
GO