/** "Return the total length of the formatted bundle block data." [DTN2] */
public static int total_length(final BlockInfoVec blocks) {
int ret = 0;
Iterator<BlockInfo> itr = blocks.iterator();
while (itr.hasNext()) {
BlockInfo block = itr.next();
ret += block.full_length();
}
return ret;
}
/** "Give the processors a chance to chew on the bundle after reloading from disk." [DTN2] */
public static void reload_post_process(Bundle bundle) {
BlockInfoVec recv_blocks = bundle.recv_blocks();
Iterator<BlockInfo> iter = recv_blocks.iterator();
while (iter.hasNext()) {
// "allow BlockProcessors [and Ciphersuites] a chance to re-do
// things needed after a load-from-store" [DTN2]
BlockInfo block = iter.next();
block.owner().reload_post_process(bundle, recv_blocks, block);
}
}
/**
* "Generate a BlockInfoVec for the outgoing link and put it into xmit_blocks_." [DTN2]
*
* @return a list of new BLockInfo
*/
public static BlockInfoVec prepare_blocks(Bundle bundle, final Link link) {
// "create a new block list for the outgoing link by first calling
// prepare on all the BlockProcessor classes for the blocks that
// arrived on the link" [DTN2]
BlockInfoVec xmit_blocks = bundle.xmit_link_block_set().create_blocks(link);
BlockInfoVec recv_blocks = bundle.recv_blocks();
if (recv_blocks.size() > 0) {
// "if there is a received block, the first one better be the primary"
// [DTN2]
assert (recv_blocks.front().type() == bundle_block_type_t.PRIMARY_BLOCK);
Iterator<BlockInfo> iter = recv_blocks.iterator();
while (iter.hasNext()) {
BlockInfo block = iter.next();
if (bundle.fragmented_incoming()
&& xmit_blocks.find_block(BundleProtocol.bundle_block_type_t.PAYLOAD_BLOCK) != null) {
continue;
}
block
.owner()
.prepare(bundle, xmit_blocks, block, link, BlockInfo.list_owner_t.LIST_RECEIVED);
}
} else {
BPF.getInstance().getBPFLogger().debug(TAG, "adding primary and payload block");
BlockProcessor bp = find_processor(BundleProtocol.bundle_block_type_t.PRIMARY_BLOCK);
bp.prepare(bundle, xmit_blocks, null, link, BlockInfo.list_owner_t.LIST_NONE);
bp = find_processor(bundle_block_type_t.PAYLOAD_BLOCK);
bp.prepare(bundle, xmit_blocks, null, link, BlockInfo.list_owner_t.LIST_NONE);
}
// "now we also make sure to prepare() on any registered processors
// that don't already have a block in the output list. this
// handles the case where we have a locally generated block with
// nothing in the recv_blocks vector" [DTN2]
Iterator<BlockProcessor> itr = processors_.iterator();
while (itr.hasNext()) {
BlockProcessor bp = itr.next();
if (!xmit_blocks.has_block(bp.block_type())) {
bp.prepare(bundle, xmit_blocks, null, link, BlockInfo.list_owner_t.LIST_NONE);
}
}
// Now prepare security blocks
BPF.getInstance().getBPFLogger().debug(TAG, "Now preparing security blocks...");
Security.prepare_out_blocks(bundle, link, xmit_blocks);
return xmit_blocks;
}
/**
* "Temporary helper function to find the offset of the first byte of the payload in a
* BlockInfoVec." [DTN2]
*/
public static int payload_offset(final BlockInfoVec blocks) {
int ret = 0;
Iterator<BlockInfo> itr = blocks.iterator();
while (itr.hasNext()) {
BlockInfo block = itr.next();
if (block.type() == BundleProtocol.bundle_block_type_t.PAYLOAD_BLOCK) {
ret += block.data_offset();
return ret;
}
ret += block.full_length();
}
return ret;
}
/**
* "Copies out a chunk of formatted bundle data at a specified offset from the provided
* BlockInfoVec." [DTN2]
*
* @return "the length of the chunk produced (up to the supplied length) and sets last to true if
* the bundle is complete." [DTN2]
*/
public static int produce(
final Bundle bundle,
final BlockInfoVec blocks,
IByteBuffer data,
int offset,
int len,
boolean[] last) {
int old_position = data.position();
int origlen = len;
last[0] = false;
if (len == 0) return 0;
assert (!blocks.isEmpty());
Iterator<BlockInfo> iter = blocks.iterator();
BlockInfo current_block = iter.next();
// "advance past any blocks that are skipped by the given offset."[DTN2]
while (offset >= current_block.full_length()) {
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"BundleProtocol::produce skipping block type %s "
+ "since offset %d >= block length %d",
current_block.type().toString(), offset, current_block.full_length()));
offset -= current_block.full_length();
current_block = iter.next();
}
// "the offset value now should be within the current block" [DTN2]
while (true) {
// The first time remainder will be minus from leftover offset above
// but later on it will be the full content of the block
int remainder = current_block.full_length() - offset;
int tocopy = Math.min(len, remainder);
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"BundleProtocol::produce copying %d/%d bytes from "
+ "block type %s at offset %d",
tocopy, remainder, current_block.type().toString(), offset));
current_block.owner().produce(bundle, current_block, data, offset, tocopy);
len -= tocopy;
// move the position of IByteBuffer
data.position(data.position() + tocopy);
// "if we've copied out the full amount the user asked for,
// we're done. note that we need to check the corner case
// where we completed the block exactly to properly set the
// last bit" [DTN2]
if (len == 0) {
if ((tocopy == remainder)
&& ((current_block.flags()
& BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode())
> 0)) {
last[0] = true;
}
break;
}
// "we completed the current block, so we're done if this
// is the last block, even if there's space in the user buffer"
// [DTN2]
assert (tocopy == remainder);
if ((current_block.flags() & BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode())
> 0) {
last[0] = true;
break;
}
// advance to next block
current_block = iter.next();
offset = 0;
}
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"BundleProtocol::produce complete: "
+ "produced %d bytes, bundle id %d, status is %s",
origlen - len, bundle.bundleid(), last[0] ? "complete" : "not complete"));
data.position(old_position);
return origlen - len;
}