// Adds a peer to the swarm.info file
// @param string addPath - the path of the file to be added
// @param string swarmPath - the path of the swarminfo file
// @return error - An error can be produced when issues arise from trying to access
// the swarm file or if the file to be added already exists in the swarm file - otherwise
// error will be nil.
func addToSwarminfo(addPeer lynxutil.Peer, swarmPath string) error {
swarmFile, err := os.OpenFile(swarmPath, os.O_APPEND|os.O_WRONLY, 0644) // Opens for appending
if err != nil {
return err
}
lynkName := getTLynkName(swarmPath)
lynk := lynxutil.GetLynk(tLynks, lynkName)
if lynk == nil {
tLynks = append(tLynks, lynxutil.Lynk{Name: lynkName})
lynk = lynxutil.GetLynk(tLynks, lynkName)
}
parseSwarminfo(swarmPath)
i := 0
for i < len(lynk.Peers) {
if lynk.Peers[i].IP == addPeer.IP && lynk.Peers[i].Port == addPeer.Port {
return errors.New("Can't Add Duplicates To Swarminfo")
}
i++
}
// Write to swarminfo file using ::: to IP and Port
swarmFile.WriteString(addPeer.IP + ":::" + addPeer.Port + "\n")
return swarmFile.Close()
}
// Gets a file from the peer(s)
// @param string fileName - The name of the file to find in the peers
// @param string metaPath - The meta.info path associated with the lynk we're interested in
// @return error - An error can be produced if there are connection issues,
// problems creating or writing to the file, or from not being able to get there
// desired file - otherwise error will be nil.
func getFile(fileName, metaPath string) error {
// Will parseMetainfo file and then ask tracker for list of peers
parseMetainfo(metaPath)
lynkName := GetLynkName(metaPath)
lynk := lynxutil.GetLynk(lynks, lynkName)
//fmt.Println("Asking For File From: " + metaPath)
askTrackerForPeers(lynkName)
//fmt.Println(lynk.Peers)
i := 0
gotFile := false
for i < len(lynk.Peers) && !gotFile {
conn, err := net.Dial("tcp", lynk.Peers[i].IP+":"+lynk.Peers[i].Port)
// We don't want to return on err because we might be able to connect to next peer.
if err == nil {
gotFile = askForFile(lynkName, fileName, conn)
}
//fmt.Println(i)
i++
}
if gotFile {
return nil
}
return errors.New("Did not receive file") // If we got here - we didn't have the file.
}
// Parses the information in swarm.info file and places each entry into a Peer
// struct and appends that struct to the array of peers
// @param string swarmPath - The path to the swarminfo file
// @return error - An error can be produced when issues arise from trying to access
// the swarm file or from an invalid swarm file type - otherwise error will be nil.
func parseSwarminfo(swarmPath string) error {
lynkName := getTLynkName(swarmPath)
lynk := lynxutil.GetLynk(tLynks, lynkName)
//fmt.Println(lynk)
lynk.Peers = nil // Resets peers array
swarmFile, err := os.Open(swarmPath)
if err != nil {
return err
} else if !strings.Contains(swarmPath, "swarm.info") {
return errors.New("Invalid File Type")
}
scanner := bufio.NewScanner(swarmFile)
tempPeer := lynxutil.Peer{}
// Scan each line
for scanner.Scan() {
line := strings.TrimSpace(scanner.Text()) // Trim helps with errors in \n
split := strings.Split(line, ":::")
tempPeer.IP = split[0]
tempPeer.Port = split[1]
lynk.Peers = append(lynk.Peers, tempPeer)
}
//fmt.Println(lynk.Peers)
return swarmFile.Close()
}
// Deletes the current swarm.info and replaces it with a new version that
// accurately reflects the array of Peers after they have been modified
// @return error - An error can be produced when issues arise from trying to create
// or remove the swarm file - otherwise error will be nil.
func updateSwarminfo(swarmPath string) error {
parseSwarminfo(swarmPath)
err := os.Remove(swarmPath)
if err != nil {
fmt.Println(err)
return err
}
newSwarmInfo, err := os.Create(swarmPath)
if err != nil {
fmt.Println(err)
return err
}
lynkName := getTLynkName(swarmPath)
lynk := lynxutil.GetLynk(tLynks, lynkName)
i := 0
for i < len(lynk.Peers) {
newSwarmInfo.WriteString(lynk.Peers[i].IP + ":::" + lynk.Peers[i].Port + "\n")
i++
}
return newSwarmInfo.Close()
}
// UpdateMetainfo - Deletes the current meta.info and replaces it with a new version that
// accurately reflects the array of Files after they have been modified.
// @return error - An error can be produced when issues arise from trying to create
// or remove the meta file - otherwise error will be nil.
func UpdateMetainfo(metaPath string) error {
parseMetainfo(metaPath)
lynkName := GetLynkName(metaPath)
lynk := lynxutil.GetLynk(lynks, lynkName)
err := os.Remove(metaPath)
if err != nil {
fmt.Println(err)
return err
}
newMetainfo, err := os.Create(metaPath)
if err != nil {
fmt.Println(err)
return err
}
newMetainfo.WriteString("announce:::" + lynk.Tracker + "\n") // Write tracker IP
newMetainfo.WriteString("lynkName:::" + lynk.Name + "\n")
newMetainfo.WriteString("owner:::" + lynk.Owner + "\n")
i := 0
for i < len(lynk.Files) {
newMetainfo.WriteString("length:::" + strconv.Itoa(lynk.Files[i].Length) + "\n") // str conv
newMetainfo.WriteString("path:::" + lynk.Files[i].Path + "\n")
newMetainfo.WriteString("name:::" + lynk.Files[i].Name + "\n")
newMetainfo.WriteString("chunkLength:::" + strconv.Itoa(lynk.Files[i].ChunkLength) + "\n")
newMetainfo.WriteString("chunks:::" + lynk.Files[i].Chunks + "\n")
newMetainfo.WriteString(endOfEntry + "\n")
i++
}
return newMetainfo.Close()
}
// HaveFile - Checks to see if we have the passed in file.
// @param string filePath - The name of the file to check for - This includes the lynk name.
// E.G. - 'Cool_Lynk/coolFile.txt'
// @return bool - A boolean indicating whether or not we have a file in our
// files array.
func HaveFile(filePath string) bool {
have := false
lynkInfo := strings.Split(filePath, "/")
if len(lynkInfo) != 2 {
fmt.Println(filePath + " is an invalid filepath")
return have
}
lynkName := lynkInfo[0]
fileName := lynkInfo[1]
metaPath := lynxutil.HomePath + lynkName + "/meta.info"
parseMetainfo(metaPath)
lynk := lynxutil.GetLynk(lynks, lynkName)
i := 0
for i < len(lynk.Files) && !have {
if lynk.Files[i].Name == fileName {
have = true
}
i++
}
return have
}
// Helper function that verifies there has been a change in the files for the system tests lynk.
// @returns True if there has been a change, False if there has not been a change
func checkChanges() bool {
changed := len(lynxutil.GetLynk(client.GetLynks(), "SysTests").Files)
result := false
if changed != original {
original = changed
result = true
}
return result
}
// Unit tests for addToMetainfo function
// @param *testing.T t - The wrapper for the test
func TestAddToMetainfo(t *testing.T) {
fmt.Println("\n----------------TestAddToMetainfo----------------")
parseMetainfo(mPath)
hasTest := false
tLynk := lynxutil.GetLynk(lynks, "Tests")
i := 0
for i < len(tLynk.Files) {
//fmt.Print(files[i].name)
if tLynk.Files[i].Name == "test.txt" {
//fmt.Print(files[i].name)
hasTest = true
}
i++
}
// add test.txt to the metainfo
result := AddToMetainfo("test.txt", mPath)
if result != nil && !hasTest {
t.Error("Test failed, expected no errors. Got ", result)
} else {
fmt.Println("Successfully Added To Metainfo")
successful++
}
parseMetainfo(mPath)
// check that test.txt is in the File struct list
i = 0
for i < len(tLynk.Files) {
if tLynk.Files[i].Name == "test.txt" {
hasTest = true
}
i++
}
if !hasTest {
t.Error("test.txt was not added to metainfo.")
} else {
fmt.Println("Successfully Added test.txt To Metainfo")
successful++
}
result = AddToMetainfo("test.txt", mPath)
if result == nil {
t.Error("Test failed, expected failure due to duplicates. Got ", result)
} else {
fmt.Println("Successfully Avoided Adding Duplicates")
successful++
}
}
// UpdateLynk - Function which will update the files of a Lynk with the current versions.
// @param lynkName string - the name of the Lynk we want to update
func UpdateLynk(lynkName string) error {
// We actually get the files we need over the network.
lynk := lynxutil.GetLynk(lynks, lynkName)
var err error // Creates nil error
for _, file := range lynk.Files {
err = getFile(file.Name, lynxutil.HomePath+lynkName+"/meta.info")
// If we fail to get the file the first time, we attempt again.
if err.Error() == "Did not receive file" {
for i := 0; i < lynxutil.ReconnAttempts; i++ {
err = getFile(file.Name, lynxutil.HomePath+lynkName+"/meta.info")
}
}
}
return err
}
// Unit tests for GetTrackerIP function
// @param *testing.T t - The wrapper for the test
func TestAskTrackerForPeers(t *testing.T) {
fmt.Println("\n----------------TestAskTracker----------------")
lynkName := GetLynkName(mPath)
lynk := lynxutil.GetLynk(lynks, lynkName)
askTrackerForPeers(lynkName)
if len(lynk.Peers) <= 0 {
t.Error("Did Not Get Correct List Of Peers")
} else {
fmt.Println("Successfully Got Peers")
successful++
}
fmt.Println("\nSuccess on ", successful, "/", total, " tests.")
}
// BroadcastNewIP - This function broadcasts a tracker's new IP address to all of its peers
// @param string swarmPath - The swarm.info path associated with the lynk we're interested in
func BroadcastNewIP(swarmPath string) {
// Can update Meta here if needed
lynkName := getTLynkName(swarmPath)
lynk := lynxutil.GetLynk(tLynks, lynkName)
i := 0
for i < len(lynk.Peers) {
fmt.Println(i)
conn, err := net.Dial("tcp", lynk.Peers[i].IP+":"+lynk.Peers[i].Port)
if err == nil {
sendFile(lynxutil.HomePath+lynk.Name+"/meta.info", conn)
}
fmt.Println(lynk.Peers[i].IP)
i++
}
}
// Asks the tracker for a list of peers and then places them into a lynk's peers array
// @param string lynkName - The name of the lynk we're interested in
func askTrackerForPeers(lynkName string) error {
lynk := lynxutil.GetLynk(lynks, lynkName)
// Connects to tracker
conn, err := net.Dial("tcp", lynk.Tracker)
if err != nil {
i := 0
for i < len(lynk.Peers) && err != nil {
pConn, _ := net.Dial("tcp", lynk.Peers[i].IP+":"+lynk.Peers[i].Port)
fmt.Fprintf(pConn, "Tracker_Request:"+lynkName+"/\n")
reply := ""
reply, err = bufio.NewReader(pConn).ReadString('\n') // Waits for a String ending in newline
reply = strings.TrimSpace(reply)
conn, err = net.Dial("tcp", reply)
i++
}
// We could not connect to the tracker
if err != nil {
return err
}
}
// Gives IP and ServerPort So It Can Be Added To swarm.info
fmt.Fprintf(conn, "Swarm_Request:"+lynxutil.GetIP()+":"+lynxutil.ServerPort+":"+lynkName+"\n")
reader := bufio.NewReader(conn)
tp := textproto.NewReader(reader)
reply, err := tp.ReadLine()
//fmt.Println(reply)
// Tracker will close connection when finished - which will break us out of this loop
for err == nil {
peerArray := strings.Split(reply, ":::")
tmpPeer := lynxutil.Peer{IP: peerArray[0], Port: peerArray[1]}
if !contains(lynk.Peers, tmpPeer) {
lynk.Peers = append(lynk.Peers, tmpPeer)
}
reply, err = tp.ReadLine()
}
return nil // Did not have an error if we reached this point
}
// Unit tests for deleteEntry function
// @param *testing.T t - The wrapper for the test
func TestDeleteFile(t *testing.T) {
fmt.Println("\n----------------TestDeleteFiley----------------")
failed := false
parseMetainfo(mPath)
lynkName := GetLynkName(mPath)
DeleteFile("test.txt", lynkName)
tLynk := lynxutil.GetLynk(lynks, lynkName)
i := 0
for i < len(tLynk.Files) {
if tLynk.Files[i].Name == "test.txt" {
t.Error("Error, test.txt is still in files")
failed = true
}
i++
}
if !failed {
fmt.Println("Successfully Removed The test.txt File")
successful++
} else {
failed = false
}
DeleteFile("test11.txt", lynkName)
i = 0
for i < len(tLynk.Files) {
if tLynk.Files[i].Name == "test11.txt" {
t.Error("Error, test11.txt is still in files")
failed = true
}
i++
}
if !failed {
fmt.Println("Successfully Removed The test11.txt File")
successful++
}
}
// DeleteFile - Function that deletes an entry from a lynk's files array.
// @param string nameToDelete - This is the name of the file we want to delete
// @param string lynkName - The lynk we want to delete it from
func DeleteFile(nameToDelete, lynkName string) error {
// Need to delete the local file too - so parseMeta properly picks it up
lynk := lynxutil.GetLynk(lynks, lynkName)
var err error
if lynk == nil {
err = errors.New("Could not delete file")
}
i := 0
for i < len(lynk.Files) {
if nameToDelete == lynk.Files[i].Name {
lynk.Files = append(lynk.Files[:i], lynk.Files[i+1:]...)
}
i++
}
fmt.Println(lynk.Files)
return err
}
// Parses the information in meta.info file and places each entry into a File
// struct and appends that struct to the array of structs
// @param string metaPath - The path to the metainfo file
// @return error - An error can be produced when issues arise from trying to access
// the meta file or from an invalid meta file type - otherwise error will be nil.
func parseMetainfo(metaPath string) error {
lynk := lynxutil.GetLynk(lynks, GetLynkName(metaPath))
if lynk == nil {
return errors.New("Lynk Not Found")
}
lynk.Files = nil // Resets files array
metaFile, err := os.Open(metaPath)
if err != nil {
return err
} else if !strings.Contains(metaPath, "meta.info") {
return errors.New("Invalid File Type")
}
scanner := bufio.NewScanner(metaFile)
tempFile := lynxutil.File{}
for scanner.Scan() { // Scan each line
split := strings.Split(strings.TrimSpace(scanner.Text()), ":::")
if split[0] == "announce" {
lynk.Tracker = split[metaValueIndex]
} else if split[0] == "owner" {
lynk.Owner = split[metaValueIndex]
} else if split[0] == "lynkName" {
lynk.Name = split[metaValueIndex]
} else if split[0] == "chunkLength" {
tempFile.ChunkLength, _ = strconv.Atoi(split[metaValueIndex])
} else if split[0] == "length" {
tempFile.Length, _ = strconv.Atoi(split[metaValueIndex])
} else if split[0] == "path" {
tempFile.Path = split[metaValueIndex]
} else if split[0] == "name" {
tempFile.Name = split[metaValueIndex]
} else if split[0] == "chunks" {
tempFile.Chunks = split[metaValueIndex]
} else if split[0] == endOfEntry {
lynk.Files = append(lynk.Files, tempFile) // Append the current file to the file array
tempFile = lynxutil.File{} // Empty the current file
}
}
return metaFile.Close()
}
// AddToMetainfo - Adds a file to the meta.info by parsing that file's information
// @param string addPath - the path of the file to be added
// @param string metaPath - the path of the metainfo file - must be full path from root.
// @return error - An error can be produced when issues arise from trying to access
// the meta file or if the file to be added already exists in the meta file - otherwise
// error will be nil.
func AddToMetainfo(addPath, metaPath string) error {
metaFile, err := os.OpenFile(metaPath, os.O_APPEND|os.O_WRONLY, 0644) // Opens for appending
if err != nil {
fmt.Println(err)
return err
}
addStat, err := os.Stat(addPath)
if err != nil {
fmt.Println(err)
return err
}
parseMetainfo(metaPath)
lynkName := GetLynkName(metaPath)
lynk := lynxutil.GetLynk(lynks, lynkName)
i := 0
for i < len(lynk.Files) {
if lynk.Files[i].Name == addStat.Name() {
return errors.New("Can't Add Duplicates To Metainfo")
}
i++
}
lengthStr := strconv.FormatInt(addStat.Size(), 10) // Convert int64 to string
metaFile.WriteString("length:::" + lengthStr + "\n")
tempPath, err := filepath.Abs(addPath) // Find the path of the current file
if err != nil {
return err
}
// Write to metainfo file using ::: to separate keys and values
metaFile.WriteString("path:::" + tempPath + "\n")
metaFile.WriteString("name:::" + addStat.Name() + "\n")
metaFile.WriteString("chunkLength:::32\n")
metaFile.WriteString("chunks:::256\n")
metaFile.WriteString(endOfEntry + "\n")
return metaFile.Close()
}
// Function that deletes an entry from a lynk's peers array and the swarm.info file.
// @param string peerToDelete - This is the peer struct we want to delete - uses the IP address
// @param string lynkName - The lynk we want to delete it from
func deletePeer(peerToDelete, lynkName string) {
lynk := lynxutil.GetLynk(tLynks, lynkName)
i := 0
for i < len(lynk.Peers) {
if peerToDelete == lynk.Peers[i].IP {
lynk.Peers = append(lynk.Peers[:i], lynk.Peers[i+1:]...)
}
i++
}
swarmPath := lynxutil.HomePath + lynkName + "/" + lynkName + "_Tracker/" + "swarm.info"
os.Remove(swarmPath)
newSwarmInfo, _ := os.Create(swarmPath)
i = 0
for i < len(lynk.Peers) {
newSwarmInfo.WriteString(lynk.Peers[i].IP + ":::" + lynk.Peers[i].Port + "\n")
i++
}
}
// StopDownload - Sets a boolean to stop the lynk from downloading
func StopDownload(lynkName string) {
lynk := lynxutil.GetLynk(lynks, lynkName)
lynk.DLing = false
}
// IsDownloading - Returns whether or not the client associated the specified lynk is downloading
// @param lynkName
// @returns - Returns whether or not the client associated the specified lynk is downloading
func IsDownloading(lynkName string) bool {
lynk := lynxutil.GetLynk(lynks, lynkName)
return lynk.DLing
}
// GetTracker - Simply returns the tracker associated with the passed in Lynk
// @param string metaPath - The meta.info path associated with the lynk we're interested in
// @return string - A string representing the tracker's IP address.
func GetTracker(metaPath string) string {
parseMetainfo(metaPath)
lynkName := GetLynkName(metaPath)
lynk := lynxutil.GetLynk(lynks, lynkName)
return lynk.Tracker
}