Function InterceptTransferData

example/plugins/c-api/intercept/intercept.cc:236–271

This function is called in response to a READ_READY event. We should transfer any data we find from one side of the transfer to the other.

// should transfer any data we find from one side of the transfer
// to the other.
static int64_t
InterceptTransferData(InterceptIO *from, InterceptIO *to)
{
  TSIOBufferBlock block;
  int64_t         consumed = 0;

  // Walk the list of buffer blocks in from the read VIO.
  for (block = TSIOBufferReaderStart(from->readio.reader); block; block = TSIOBufferBlockNext(block)) {
    int64_t     remain = 0;
    const char *ptr;

    VDEBUG("attempting to transfer %" PRId64 " available bytes", TSIOBufferBlockReadAvail(block, from->readio.reader));

    // Take the data from each buffer block, and write it into
    // the buffer of the write VIO.
    ptr = TSIOBufferBlockReadStart(block, from->readio.reader, &remain);
    while (ptr && remain) {
      int64_t nbytes;

      nbytes    = TSIOBufferWrite(to->writeio.iobuf, ptr, remain);
      remain   -= nbytes;
      ptr      += nbytes;
      consumed += nbytes;
    }
  }

  VDEBUG("consumed %" PRId64 " bytes reading from vc=%p, writing to vc=%p", consumed, from->vc, to->vc);
  if (consumed) {
    TSIOBufferReaderConsume(from->readio.reader, consumed);
    // Note that we don't have to call TSIOBufferProduce here.
    // This is because data passed into TSIOBufferWrite is
    // automatically "produced".
  }

  return consumed;
}

// Handle events from TSHttpTxnServerIntercept. The intercept
// starts with TS_EVENT_NET_ACCEPT, and then continues with