/** * 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; }