/**
* "Generate contents for the given BlockInfoVec on the given Link." [DTN2]
*
* @return "the total length of the formatted blocks for this bundle." [DTN2]
*/
public static int generate_blocks(Bundle bundle, BlockInfoVec blocks, final Link link) {
// "now assert there's at least 2 blocks (primary + payload) and
// that the primary is first" [DTN2]
assert (blocks.size() >= 2);
assert (blocks.front().type() == bundle_block_type_t.PRIMARY_BLOCK);
// "now we make a pass through the list and call generate on
// each block processor" [DTN2]
for (int i = 0; i < blocks.size(); i++) {
boolean last = i == blocks.size() - 1;
BlockInfo iter = blocks.get(i);
iter.owner().generate(bundle, blocks, iter, link, last);
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"generated block (owner %s type %s) "
+ "data_offset %d data_length %d , contents_length %d",
iter.owner().block_type(),
iter.type(),
iter.data_offset(),
iter.data_length(),
iter.contents().position()));
if (last) {
assert ((iter.flags() & BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode()) != 0);
} else {
assert ((iter.flags() & BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode()) == 0);
}
}
// "Now that all the EID references are added to the dictionary,
// generate the primary block." [DTN2]
PrimaryBlockProcessor pbp =
(PrimaryBlockProcessor) find_processor(BundleProtocol.bundle_block_type_t.PRIMARY_BLOCK);
assert (blocks.front().owner() == pbp);
pbp.generate_primary(bundle, blocks, blocks.front());
// "make a final pass through, calling finalize() and extracting
// the block length" [DTN2]
int total_len = 0;
for (int i = blocks.size() - 1; i >= 0; i--) {
BlockInfo iter = blocks.get(i);
iter.owner().finalize(bundle, blocks, iter, link);
total_len += iter.full_length();
}
return total_len;
}
/**
* "Parse the supplied chunk of arriving data and append it to the rcvd_blocks_ list in the given
* bundle, finding the appropriate BlockProcessor element and calling its receive() handler.
*
* <p>When called repeatedly for arriving chunks of data, this properly fills in the entire
* bundle, including the in_blocks_ record of the arriving blocks and the payload (which is stored
* externally)." [DTN2]
*
* @return "the length of data consumed or -1 on protocol error, plus sets last to true if the
* bundle is complete." [DTN2]
*/
public static int consume(Bundle bundle, IByteBuffer data, int len, boolean[] last) {
int old_position = data.position();
int origlen = len;
last[0] = false;
BlockInfoVec recv_blocks = bundle.recv_blocks();
// "special case for first time we get called, since we need to
// create a BlockInfo struct for the primary block without knowing
// the typecode or the length" [DTN2]
if (recv_blocks.isEmpty()) {
BPF.getInstance()
.getBPFLogger()
.debug(TAG, "consume: got first block... " + "creating primary block info");
recv_blocks.append_block(find_processor(bundle_block_type_t.PRIMARY_BLOCK), null);
}
// "loop as long as there is data left to process" [DTN2]
while (len != 0) {
BPF.getInstance()
.getBPFLogger()
.debug(TAG, String.format("consume: %d bytes left to process", len));
BlockInfo info = recv_blocks.back();
// "if the last received block is complete, create a new one
// and push it onto the vector. at this stage we consume all
// blocks, even if there's no BlockProcessor that understands
// how to parse it" [DTN2]
if (info.complete()) {
data.mark();
byte bundle_block_type_byte = data.get();
bundle_block_type_t type = bundle_block_type_t.get(bundle_block_type_byte);
data.reset();
info = recv_blocks.append_block(find_processor(type), null);
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"consume: previous block complete, " + "created new BlockInfo type %s",
info.owner().block_type()));
}
// "now we know that the block isn't complete, so we tell it to
// consume a chunk of data" [DTN2]
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"consume: block processor %s type %s incomplete, "
+ "calling consume (%d bytes already buffered)",
info.owner().block_type(), info.type(), info.contents().position()));
int cc = info.owner().consume(bundle, info, data, len);
if (cc < 0) {
BPF.getInstance()
.getBPFLogger()
.error(TAG, String.format("consume: protocol error handling block %s", info.type()));
return -1;
}
// "decrement the amount that was just handled from the overall
// total. verify that the block was either completed or
// consumed all the data that was passed in." [DTN2]
len -= cc;
data.position(data.position() + cc);
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"consume: consumed %d bytes of block type %s (%s)",
cc, info.type(), info.complete() ? "complete" : "not complete"));
if (info.complete()) {
// check if we're done with the bundle
if ((info.flags() & block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode()) > 0) {
last[0] = true;
break;
}
} else {
assert (len == 0);
}
}
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"bundle id %d consume completed, %d/%d bytes consumed %s",
bundle.bundleid(), origlen - len, origlen, last[0] ? "(completed bundle)" : ""));
data.position(old_position);
return origlen - len;
}