// threadedProbeHost tries to fetch the settings of a host. If successful, the
// host is put in the set of active hosts. If unsuccessful, the host id deleted
// from the set of active hosts.
func (hdb *HostDB) threadedProbeHosts() {
for hostEntry := range hdb.scanPool {
// Request settings from the queued host entry.
var settings modules.HostSettings
err := func() error {
conn, err := net.DialTimeout("tcp", string(hostEntry.IPAddress), hostRequestTimeout)
if err != nil {
return err
}
defer conn.Close()
err = encoding.WriteObject(conn, [8]byte{'S', 'e', 't', 't', 'i', 'n', 'g', 's'})
if err != nil {
return err
}
return encoding.ReadObject(conn, &settings, maxSettingsLen)
}()
// Now that network communication is done, lock the hostdb to modify the
// host entry.
id := hdb.mu.Lock()
{
if err != nil {
hdb.decrementReliability(hostEntry.IPAddress, UnreachablePenalty)
hdb.mu.Unlock(id)
continue
}
// Update the host settings, reliability, and weight. The old IPAddress
// must be preserved.
settings.IPAddress = hostEntry.HostSettings.IPAddress
hostEntry.HostSettings = settings
hostEntry.reliability = MaxReliability
hostEntry.weight = hdb.hostWeight(*hostEntry)
// If the host is not already in the database and 'MaxActiveHosts' has not
// been reached, add the host to the database.
_, exists1 := hdb.activeHosts[hostEntry.IPAddress]
_, exists2 := hdb.allHosts[hostEntry.IPAddress]
if !exists1 && exists2 && len(hdb.activeHosts) < MaxActiveHosts {
hdb.insertNode(hostEntry)
hdb.notifySubscribers()
}
}
hdb.mu.Unlock(id)
}
}
// threadedProbeHost tries to fetch the settings of a host. If successful, the
// host is put in the set of active hosts. If unsuccessful, the host id deleted
// from the set of active hosts.
func (hdb *HostDB) threadedProbeHosts() {
for hostEntry := range hdb.scanPool {
// Request settings from the queued host entry.
var settings modules.HostSettings
err := func() error {
conn, err := hdb.dialer.DialTimeout(hostEntry.NetAddress, hostRequestTimeout)
if err != nil {
return err
}
defer conn.Close()
err = encoding.WriteObject(conn, modules.RPCSettings)
if err != nil {
return err
}
// COMPATv0.4.8 - If first decoding attempt fails, try decoding
// into the old HostSettings type. Because we decode twice, we
// must read the data into memory first.
settingsBytes, err := encoding.ReadPrefix(conn, maxSettingsLen)
if err != nil {
return err
}
err = encoding.Unmarshal(settingsBytes, &settings)
if err != nil {
var oldSettings oldHostSettings
err = encoding.Unmarshal(settingsBytes, &oldSettings)
if err != nil {
return err
}
// Convert the old type.
settings = modules.HostSettings{
NetAddress: oldSettings.NetAddress,
TotalStorage: oldSettings.TotalStorage,
MinDuration: oldSettings.MinDuration,
MaxDuration: oldSettings.MaxDuration,
WindowSize: oldSettings.WindowSize,
Price: oldSettings.Price,
Collateral: oldSettings.Collateral,
UnlockHash: oldSettings.UnlockHash,
}
}
return nil
}()
// Now that network communication is done, lock the hostdb to modify the
// host entry.
func() {
hdb.mu.Lock()
defer hdb.mu.Unlock()
// Regardless of whether the host responded, add it to allHosts.
if _, exists := hdb.allHosts[hostEntry.NetAddress]; !exists {
hdb.allHosts[hostEntry.NetAddress] = hostEntry
}
// If the scan was unsuccessful, decrement the host's reliability.
if err != nil {
hdb.decrementReliability(hostEntry.NetAddress, UnreachablePenalty)
return
}
// Update the host settings, reliability, and weight. The old NetAddress
// must be preserved.
settings.NetAddress = hostEntry.HostSettings.NetAddress
hostEntry.HostSettings = settings
hostEntry.reliability = MaxReliability
hostEntry.weight = calculateHostWeight(*hostEntry)
hostEntry.online = true
// If 'MaxActiveHosts' has not been reached, add the host to the
// activeHosts tree.
if _, exists := hdb.activeHosts[hostEntry.NetAddress]; !exists && len(hdb.activeHosts) < MaxActiveHosts {
hdb.insertNode(hostEntry)
}
}()
}
}