/**
* Given the given fragmentation threshold, determine whether the given bundle should be split
* into several smaller bundles. If so, this returns true and generates a bunch of bundle received
* events for the individual fragments.
*
* @param bundle Bundle to split into fragments
* @param link Bundle to send on the given link
* @param max_length Maximum length of the fragment
* @return FragmentState that has the list of created fragments for the given bundle.
*/
public FragmentState proactively_fragment(Bundle bundle, final Link link, int max_length) {
int payload_len = bundle.payload().length();
Bundle fragment;
FragmentState state = new FragmentState(bundle);
int todo = payload_len;
int offset = 0;
int count = 0;
BlockInfoVec first_frag_blocks = new BlockInfoVec();
BlockInfoVec all_frag_blocks = new BlockInfoVec();
BlockInfoVec this_frag_blocks = first_frag_blocks;
ListIterator<BlockInfo> entry = bundle.xmit_link_block_set().find_blocks(link).listIterator();
while (entry.hasNext()) {
BlockInfo block_info = entry.next();
if ((block_info.type() == bundle_block_type_t.PRIMARY_BLOCK)
|| (block_info.type() == bundle_block_type_t.PAYLOAD_BLOCK)) {
all_frag_blocks.add(block_info);
first_frag_blocks.add(block_info);
} else if ((block_info.flags() & block_flag_t.BLOCK_FLAG_REPLICATE.getCode()) > 0) {
all_frag_blocks.add(block_info);
} else {
first_frag_blocks.add(block_info);
}
}
do {
fragment = create_fragment(bundle, link, this_frag_blocks, offset, max_length);
assert (fragment != null) : TAG + ": proactively_fragment() fragment not valid";
state.add_fragment(fragment);
offset += fragment.payload().length();
todo -= fragment.payload().length();
this_frag_blocks = all_frag_blocks;
++count;
} while (todo > 0);
Logger.getInstance()
.debug(
TAG,
String.format(
"proactively fragmenting " + "%s byte payload into %s %s byte fragments",
payload_len, count, max_length));
String[] hash_key = new String[1];
get_hash_key(fragment, hash_key);
fragment_table_.put(hash_key[0], state);
return state;
}
/**
* 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;
}
