Starts an IO buffer.
INKIOBufferBlock INKIOBufferStart (INKIOBuffer
bufp)
Gets the write start block for the IO buffer
bufpINKIOBufferStart always returns a block
with a non-zero amount of space available for writing. If necessary, a new
block is added to accomplish this.
The write start block for the IO buffer writer.
INK_ERROR_PTR if an error occurs.