##########################################	The implemention of DFSUtil.#	It implements functions and comparators.##	@author Kai Yao(yaokai)######################################### implement DFSUtil; include "dfsutil.m";include "sys.m";include "lists.m";lists : Lists;sys : Sys; # load the Sys and Lists module, must be called before using toString and removeChunk, removeNodeinit(){	sys = load Sys Sys->PATH;	lists = load Lists Lists->PATH;} # implement functions of DFSNodeDFSNode.eq(a, b : ref DFSNode) : int{	return (a.addr == b.addr) && (a.port == b.port);} DFSNode.toString(dn : self ref DFSNode) : string{	ret := sys->sprint("addr: %s, port: %d, chunkNumber: %d\n", dn.addr, dn.port, dn.chunkNumber);	return ret;} # implement DFSNodeCmp, a comparator of DFSNodeDFSNodeCmp.gt(dnc : self ref DFSNodeCmp, x, y : ref DFSNode) : int{	if (x.chunkNumber > y.chunkNumber)		return 1;	else		return 0;} # implement functions of DFSChunkDFSChunk.getNodes(dc : self ref DFSChunk) : array of ref DFSNode {	length := len dc.nodes;	ret := array [length] of ref DFSNode;	i := 0;	for (p := dc.nodes; p != nil; p = tl p) {		ret[i] = hd p; 		i++;	}	return ret;} DFSChunk.addNode(dc : self ref DFSChunk, node : ref DFSNode){	dc.nodes = node :: dc.nodes;} DFSChunk.removeNode(dc : self ref DFSChunk, node : ref DFSNode){	dc.nodes = lists->delete(node, dc.nodes);} DFSChunk.eq(a, b : ref DFSChunk) : int{	return (a.id == b.id) && (a.fileId == b.fileId);} DFSChunk.toString(dc : self ref DFSChunk) : string{	ret := sys->sprint("id: %d, fileId: %d, offset: %d, size: %d\n", dc.id, dc.fileId, int dc.offset, dc.size);	return ret;} # implement DFSChunkCmp, a comparator of DFSChunkDFSChunkCmp.gt(dcc : self ref DFSChunkCmp, x, y : ref DFSChunk) : int {	if (x.offset > y.offset)		return 1;	else		return 0;} # implement functions of DFSFileDFSFile.getChunks(df : self ref DFSFile) : array of ref DFSChunk{	length := len df.chunks;	ret := array [length] of ref DFSChunk;	i := 0;	for (p := df.chunks; p != nil; p = tl p) {		ret[i] = hd p;		i++;	}	return ret;} DFSFile.addChunk(df : self ref DFSFile, chunk : ref DFSChunk){	df.chunks = chunk :: df.chunks;} DFSFile.removeChunk(df : self ref DFSFile, chunk : ref DFSChunk){	df.chunks = lists->delete(chunk, df.chunks);}			DFSFile.toString(df : self ref DFSFile) : string{	ret := sys->sprint("id: %d, name: %s, replicas: %d\n", df.id, df.name, df.replicas);	return ret;}	DFSFile.eq(a, b : ref DFSFile) : int{	return a.id == b.id;}