README
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util
Utility functions used throughout Fornaxian projects. Needs to be centrally accessible in order to keep everything consistent.
Documentation
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Index ¶
- Variables
- func AddressIsLocal(ip string) bool
- func ConvertToInt(i any) (int, error)
- func ConvertToString(i any) (string, error)
- func DetectPauses()
- func DiskSpace(dir string) (uint64, error)
- func FormatData[T Number](size T) string
- func FreeSpace(dir string) (uint64, error)
- func IPMask(addr net.IP, v4mask, v6mask int) net.IP
- func IsNetError(err error) bool
- func NewBackgroundTask(task func(), taskName string, wg *sync.WaitGroup, stopChannel chan bool, ...)
- func PBKDF2Check(password, legacyHash string) (valid bool, err error)
- func RandString(n int) string
- func RemoteAddress(r *http.Request) (addr string)
- func SystemdFileByName(name string) (*os.File, error)
- func SystemdListenerByName(name string) (net.Listener, error)
- type ChangeWatcher
- type ChangeWatcherFunc
- type CountingSemaphore
- type LoadAvg
- type MemInfo
- type NetInfo
- type Number
- type Pool
Constants ¶
This section is empty.
Variables ¶
var ErrSocketNotFound = errors.New("socket not found")
Functions ¶
func AddressIsLocal ¶
AddressIsLocal checks if an IP address falls on a private subnet
func ConvertToInt ¶
ConvertToInt converts any type of number interface to a regular old integer. Runes will be treated as int32 and bytes as uint8. Strings will be converted using strings.Atoi. An error will be returned if the passed parameter cannot be converted to an int
func ConvertToString ¶
func DetectPauses ¶
func DetectPauses()
DetectPauses runs a continuous loop which detects stalls in the runtime and garbage collection cycles
func FormatData ¶
FormatData prints an amount of bytes in a readable rounded amount. The total number of digits before and after the decimal point will always be 3.
func IPMask ¶
IPMaskPrefix applies a netmask to an IPv4 or IPv6 address. Only the bits inside the mask are retained, the remaining bits are set to 0
func IsNetError ¶
func NewBackgroundTask ¶
func NewBackgroundTask( task func(), taskName string, wg *sync.WaitGroup, stopChannel chan bool, interval time.Duration, randomness time.Duration, )
NewBackgroundTask runs a function at an interval with some randomness. If the interval is 30 seconds and the randomness is 10 seconds the function will run every 25 to 35 seconds. The function will register itself to the waitgroup when starting and mark itself as done when the stopChannel is closed. When the stopChannel is closed the task will run one last time regardless of how long ago it ran.
func PBKDF2Check ¶
PBKDF2Check checks the passwords of legacy pixeldrain-spring users.
func RandString ¶
RandString generates a random base64 string of n characters long
func RemoteAddress ¶
RemoteAddress resolves the address of a HTTP request to the real remote address. It takes in account proxies if the request is originated from a private IP range
func SystemdFileByName ¶
SystemdFileByName returns a *os.File if there is a systemd socket with that name available
Types ¶
type ChangeWatcher ¶
type ChangeWatcher[T any] struct { // contains filtered or unexported fields }
ChangeWatcher watches a database row for changes and relays the events to a list of listeners
func NewChangeWatcher ¶
func NewChangeWatcher[T any]( changeFunc ChangeWatcherFunc[T], intervalStep time.Duration, maxInterval time.Duration, ) *ChangeWatcher[T]
NewChangeWatcher creates a new change watcher. The changeFunc is used to check whether a change occurred
func (*ChangeWatcher[T]) Close ¶
func (s *ChangeWatcher[T]) Close(id string, c chan T)
Close closes a channel and removes it from the list of change listeners. If this is the last listener for that feed the feed will be removed
func (*ChangeWatcher[T]) Open ¶
func (s *ChangeWatcher[T]) Open(id string) chan T
Open creates a new change listener for an item. Do not close the channel yourself because then the watcher thread will crash. Call Close() instead
func (*ChangeWatcher[T]) OpenWithChan ¶
func (s *ChangeWatcher[T]) OpenWithChan(id string, c chan T)
func (*ChangeWatcher[T]) Stats ¶
func (s *ChangeWatcher[T]) Stats() (watchers int, listeners int)
Stats returns some statistics about the change watcher. Currently the only available stat is the number of watcher threads active
type ChangeWatcherFunc ¶
ChangeWatcherFunc is the function which periodically checks if a value has changed. The ID is the ID of the thing to monitor. previousThing is the last value of the thing which was returned, use this to compare if the thing has changed. previousThing will be nil in the first run.
If the thing has changed you should return true and the new thing. Else return false and the thing which was checked
And an error occurs you should return changed=false and thing=nil
type CountingSemaphore ¶
type CountingSemaphore struct {
// contains filtered or unexported fields
}
CountingSemaphore is a utility which limits the concurrent execution of a function. When it is initialized it creates a channel with x capacity and fills it with x slots. Every time the Acquire() function is called a slot is removed from the channel. When the channel is empty the function will block until the Unlock function is called, which puts a new slot into the channel.
func NewCountingSemaphore ¶
func NewCountingSemaphore(slots int) (cs *CountingSemaphore)
NewCountingSemaphore creates a new semaphore. The slots parameter is how many threads can concurrently execute the function
func (*CountingSemaphore) Exec ¶
func (cs *CountingSemaphore) Exec(f func())
Exec obtains an execution slot, runs the provided function concurrently and then returns the slot
func (*CountingSemaphore) Wait ¶
func (cs *CountingSemaphore) Wait()
Wait takes all execution slots and releases them again. This ensures that no other threads are using the semaphore anymore. This essentially functions as the Wait function of a WaitGroup.
type LoadAvg ¶
type LoadAvg struct {
Load1Min float64
Load5Min float64
Load15Min float64
CurrentlyScheduling int
TotalScheduling int
LastPID int
}
LoadAvg contains information about the system load
func GetLoadAvg ¶
GetLoadAvg reads and parses Linux's /proc/loadavg file
type MemInfo ¶
type MemInfo struct {
MemTotal int64
MemFree int64
MemAvailable int64
Buffers int64
Cached int64
SwapCached int64
Active int64
Inactive int64
ActiveAnon int64
InactiveAnon int64
ActiveFile int64
InactiveFile int64
Unevictable int64
Mlocked int64
SwapTotal int64
SwapFree int64
Dirty int64
Writeback int64
AnonPages int64
Mapped int64
Shmem int64
KReclaimable int64
Slab int64
SReclaimable int64
SUnreclaim int64
KernelStack int64
PageTables int64
NFSUnstable int64
Bounce int64
WritebackTmp int64
CommitLimit int64
CommittedAs int64
VmallocTotal int64
VmallocUsed int64
VmallocChunk int64
Percpu int64
HardwareCorrupted int64
AnonHugePages int64
ShmemHugePages int64
ShmemPmdMapped int64
FileHugePages int64
FilePmdMapped int64
HugePagesTotal int64
HugePagesFree int64
HugePagesRsvd int64
HugePagesSurp int64
Hugepagesize int64
Hugetlb int64
DirectMap4k int64
DirectMap2M int64
DirectMap1G int64
}
MemInfo contains information about the system's random access memory
func GetMemInfo ¶
GetMemInfo reads and parses Linux's /proc/meminfo file
type NetInfo ¶
type NetInfo struct {
Interface string
RXBytes int64
RXPackets int64
RXErrors int64
RXDropped int64
RXFIFO int64
RXFrame int64
RXCompressed int64
RXMulticast int64
TXBytes int64
TXPackets int64
TXErrors int64
TXDropped int64
TXFIFO int64
TXCollisions int64
TXCarrier int64
TXCompressed int64
}
NetInfo contains information about the system's networking interfaces
func GetNetInfo ¶
GetNetInfo reads and parses Linux's /proc/net/dev file
type Pool ¶
type Pool[T any] struct { // contains filtered or unexported fields }
A Pool is a generic wrapper around a sync.Pool.
func NewPool ¶
New creates a new Pool with the provided new function.
The equivalent sync.Pool construct is "sync.Pool{New: fn}"
Source Files