/**
* Create a bundle fragment from another bundle.
*
* @param bundle the source bundle from which we create the fragment. Note: the bundle may itself
* be a fragment
* @param offset the offset relative to this bundle (not the original) for the for the new
* fragment. note that if this bundle is already a fragment, the offset into the original
* bundle will be this bundle's frag_offset + offset
* @param length the length of the fragment we want
* @return Newly created bundle
*/
public Bundle create_fragment(Bundle bundle, BlockInfoVec blocks, int offset, int length) {
Bundle fragment = new Bundle(location_t.MEMORY);
bundle.copy_metadata(fragment);
fragment.set_is_fragment(true);
fragment.set_do_not_fragment(false);
// initialize the fragment's orig_length and figure out the offset
// into the payload
if (!bundle.is_fragment()) {
fragment.set_orig_length(bundle.payload().length());
fragment.set_frag_offset(offset);
} else {
fragment.set_orig_length(bundle.orig_length());
fragment.set_frag_offset(bundle.frag_offset() + offset);
}
// check for overallocated length
if ((offset + length) > fragment.orig_length()) {
Logger.getInstance()
.error(
TAG,
String.format(
"fragment length overrun: "
+ "orig_length %d frag_offset %d requested offset %d length %d",
fragment.orig_length(), fragment.frag_offset(), offset, length));
// Panic;
return null;
}
// initialize payload
fragment.payload().write_data(bundle.payload(), offset, length, 0);
// copy all blocks that follow the payload, and all those before
// the payload that are marked with the "must be replicated in every
// fragment" bit
ListIterator<BlockInfo> iter = blocks.listIterator();
// BlockInfoVec vec;
boolean found_payload = false;
while (iter.hasNext()) {
BlockInfo entry = iter.next();
int type = entry.type().getCode();
if ((type == bundle_block_type_t.PRIMARY_BLOCK.getCode())
|| (bundle_block_type_t.PAYLOAD_BLOCK.getCode() > 0)
|| found_payload
|| ((entry.flags() & block_flag_t.BLOCK_FLAG_REPLICATE.getCode()) > 0)) {
// we need to include this block; copy the BlockInfo into the
// fragment
fragment.recv_blocks().add(entry);
if (type == bundle_block_type_t.PAYLOAD_BLOCK.getCode()) {
found_payload = true;
}
}
}
return fragment;
}
/**
* Create a fragment to be sent out on a particular link.
*
* @param bundle Source Bundle from which we create a fragment.
* @param link Link on which we will send the fragment
* @param blocks_to_copy Blocks to copy on this fragment.
* @param offset The offset relative to this bundle for the for the new fragment
* @param max_length Maximum length of the newly created fragment
* @return Newly created fragment.
*/
public Bundle create_fragment(
Bundle bundle,
final Link link,
final BlockInfoVec blocks_to_copy,
int offset,
int max_length) {
int block_length = 0;
ListIterator<BlockInfo> entry = blocks_to_copy.listIterator();
BlockInfo block_i;
while (entry.hasNext()) {
block_i = entry.next();
if (block_i.type() == bundle_block_type_t.PRIMARY_BLOCK) {
block_length += block_i.data_length();
} else {
block_length += block_i.data_offset(); // data offset is the
// starting point of
}
}
if (block_length > max_length) {
Logger.getInstance()
.error(
TAG,
String.format(
"unable to create a fragment of length %s; minimum length " + "required is %s",
max_length, block_length));
return null;
}
Bundle fragment = new Bundle(location_t.DISK);
// copy the metadata into the new fragment (which can be further
// fragmented)
bundle.copy_metadata(fragment);
fragment.set_is_fragment(true);
fragment.set_do_not_fragment(false);
// initialize the fragment's orig_length and figure out the offset
// into the payload
if (!bundle.is_fragment()) {
fragment.set_orig_length(bundle.payload().length());
fragment.set_frag_offset(offset);
} else {
fragment.set_orig_length(bundle.orig_length());
fragment.set_frag_offset(bundle.frag_offset() + offset);
}
// initialize payload
int to_copy = Math.min(max_length - block_length, bundle.payload().length() - offset);
fragment.payload().set_length(to_copy);
fragment.payload().write_data(bundle.payload(), offset, to_copy, 0);
BlockInfoVec xmit_blocks = fragment.xmit_link_block_set().create_blocks(link);
entry = blocks_to_copy.listIterator(); // reset Iterator
while (entry.hasNext()) {
block_i = entry.next();
xmit_blocks.add(block_i);
}
Logger.getInstance()
.debug(
TAG,
String.format(
"created %s byte fragment bundle with %s bytes of payload",
to_copy + block_length, to_copy));
return fragment;
}
/**
* Given a newly arrived bundle fragment, append it to the table of fragments and see if it allows
* us to reassemble the bundle. If it does, a ReassemblyCompletedEvent will be posted.
*
* @param fragment Newly received fragment
*/
public void process_for_reassembly(Bundle fragment) {
FragmentState state;
assert (fragment.is_fragment()) : TAG + ": process_for_reassembly() not a fragment";
String[] hash_key = new String[1];
get_hash_key(fragment, hash_key);
FragmentState iter = fragment_table_.get(hash_key);
Logger.getInstance()
.debug(
TAG,
String.format(
"processing bundle fragment id=%s hash=%s %s",
fragment.bundleid(), hash_key, fragment.is_fragment()));
if (iter == null) {
state = new FragmentState();
fragment.copy_metadata(state.bundle());
state.bundle().set_is_fragment(false);
state.bundle().payload().set_length(fragment.orig_length());
fragment_table_.put(hash_key[0], state);
} else {
state = iter;
Logger.getInstance()
.debug(
TAG,
String.format(
"found reassembly state for key %s (%s fragments)",
hash_key, state.fragment_list().size()));
}
// stick the fragment on the reassembly list
state.add_fragment(fragment);
// store the fragment data in the partially reassembled bundle file
int fraglen = fragment.payload().length();
Logger.getInstance()
.debug(
TAG,
String.format(
"write_data: length_=%s src_offset=%s dst_offset=%s len %s",
state.bundle().payload().length(), 0, fragment.frag_offset(), fraglen));
state.bundle().payload().write_data(fragment.payload(), 0, fraglen, fragment.frag_offset());
// reassembled bundle, but eventually reassembly will have to do much
// more
if (fragment.frag_offset() == 0 && state.bundle().recv_blocks().size() > 0) {
BlockInfo block_i;
ListIterator<BlockInfo> entry = fragment.recv_blocks().listIterator();
while (entry.hasNext()) {
block_i = entry.next();
state.bundle().recv_blocks().add(block_i);
}
}
// check see if we're done
if (state.check_completed()) {
return;
}
BundleDaemon.getInstance()
.post_at_head(new ReassemblyCompletedEvent(state.bundle(), state.fragment_list()));
assert (state.fragment_list().size() == 0)
: TAG + ": process_for_reassembly size not 0"; // moved into the event
fragment_table_.remove(hash_key);
}
/** "Constructor-like function to create a new custody signal bundle." [DTN2] */
public static Bundle create_custody_signal(
final Bundle orig_bundle,
final EndpointID source_eid,
boolean succeeded,
BundleProtocol.custody_signal_reason_t reason) {
Bundle bundle = new Bundle(location_t.MEMORY);
bundle.source().assign(source_eid);
if (orig_bundle.custodian().equals(EndpointID.NULL_EID())) {
Logger.getInstance()
.error(
TAG,
String.format(
"create_custody_signal(for bundle id %d): "
+ "custody signal cannot be generated due to custodian is null eid",
orig_bundle.bundleid()));
}
bundle.dest().assign(orig_bundle.custodian());
bundle.replyto().assign(EndpointID.NULL_EID());
bundle.custodian().assign(EndpointID.NULL_EID());
bundle.set_is_admin(true);
bundle.set_expiration(orig_bundle.expiration());
int sdnv_encoding_len = 0;
int signal_len = 0;
// "format of custody signals:
//
// 1 byte admin payload type and flags
// 1 byte status code
// SDNV [Fragment Offset (if present)]
// SDNV [Fragment Length (if present)]
// SDNVx2 Time of custody signal
// SDNVx2 Copy of bundle X's Creation Timestamp
// SDNV Length of X's source endpoint ID
// vari Source endpoint ID of bundle X
//
// first calculate the length
//
// the non-optional, fixed-length fields above:" [DTN2]
signal_len = 1 + 1;
// "the 2 SDNV fragment fields:" [DTN2]
if (orig_bundle.is_fragment()) {
signal_len += SDNV.encoding_len(orig_bundle.frag_offset());
signal_len += SDNV.encoding_len(orig_bundle.orig_length());
}
// "Time field, set to the current time:" [DTN2]
DTNTime now = new DTNTime();
signal_len += DTNTime.SDNV_encoding_len(now);
// "The bundle's creation timestamp:" [DTN2]
signal_len += BundleTimestamp.SDNV_encoding_len(orig_bundle.creation_ts());
// the Source Endpoint ID length and value
signal_len += SDNV.encoding_len(orig_bundle.source().length()) + orig_bundle.source().length();
//
// "We got all the data ready, now format the buffer" [DTN2]
//
IByteBuffer bp = new SerializableByteBuffer(signal_len);
int len = signal_len;
bp.rewind();
// "Admin Payload Type and flags" [DTN2]
byte type_and_flags_byte =
(byte) (BundleProtocol.admin_record_type_t.ADMIN_CUSTODY_SIGNAL.getCode() << 4);
if (orig_bundle.is_fragment()) {
type_and_flags_byte |= BundleProtocol.admin_record_flags_t.ADMIN_IS_FRAGMENT.getCode();
}
bp.put(type_and_flags_byte);
len--;
// Status_Flag_Byte consists of Success flag and reason code
byte status_flag_byte = (byte) ((succeeded ? 1 : 0) << 7 | (reason.getCode() & 0x7f));
bp.put(status_flag_byte);
len--;
// "The 2 Fragment Fields" [DTN2]
if (orig_bundle.is_fragment()) {
sdnv_encoding_len = SDNV.encode(orig_bundle.frag_offset(), bp, len);
assert (sdnv_encoding_len > 0);
len -= sdnv_encoding_len;
sdnv_encoding_len = SDNV.encode(orig_bundle.orig_length(), bp, len);
assert (sdnv_encoding_len > 0);
len -= sdnv_encoding_len;
}
// DTNTime which is a time of signal field
sdnv_encoding_len = DTNTime.SDNV_encoding_len(now);
assert (sdnv_encoding_len > 0);
DTNTime.encodeSDNV(now, bp);
len -= sdnv_encoding_len;
// "Copy of bundle X's Creation Timestamp" [DTN2]
sdnv_encoding_len = BundleTimestamp.SDNV_encoding_len(orig_bundle.creation_ts());
assert (sdnv_encoding_len > 0);
BundleTimestamp.encodeSDNV(orig_bundle.creation_ts(), bp);
len -= sdnv_encoding_len;
// "The Endpoint ID length and data" [DTN2]
sdnv_encoding_len = SDNV.encode(orig_bundle.source().length(), bp, len);
assert (sdnv_encoding_len > 0);
len -= sdnv_encoding_len;
assert (len == orig_bundle.source().length());
bp.put(orig_bundle.source().byte_array());
//
// "Finished generating the payload" [DTN2]
//
bp.rewind();
bundle.payload().set_data(bp, signal_len);
return bundle;
}