util

Documentation

Index

• Variables
• func CheckPathWritable(path string) error
• func DarkenColor(hex string, percent int) string
• func ExtractLastError(stderr string) string
• func FilenameTime(filename string) (time.Time, bool)
• func FormatDuration(ms int64) string
• func FormatHumanTime(rfc3339 string) string
• func GenerateBrandCSS(colorLight, colorDark string) string
• func GracefulSignal(p *os.Process) error
• func HumanTime() string
• func OldestToKeep(days int, now time.Time) time.Time
• func ResolveFFmpegPath(customPath string) string
• func ShutdownSignals() []os.Signal
• func TimeUntilNextHour(t time.Time) time.Duration
• func ValidatePath(field, path string) error
• func WrapError(operation string, err error) error
• type Backoff
  • func NewBackoff(initial, maxDelay time.Duration) *Backoff
  • func (b *Backoff) Current() time.Duration
  • func (b *Backoff) Next() time.Duration
  • func (b *Backoff) Reset()

Variables

var (
	// StationNamePattern matches printable characters excluding control characters.
	StationNamePattern = regexp.MustCompile(`^[^\x00-\x1F\x7F]+$`)

	// StationColorPattern matches hex color format (#RRGGBB).
	StationColorPattern = regexp.MustCompile(`^#[0-9A-Fa-f]{6}$`)

	// EmailPattern validates email address format.
	EmailPattern = regexp.MustCompile(`^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$`)
)

Shared validation patterns used across config and API validation.

Functions

func CheckPathWritable

func CheckPathWritable(path string) error

CheckPathWritable verifies that a directory path exists and is writable.

func DarkenColor

func DarkenColor(hex string, percent int) string

DarkenColor darkens a hex color by a percentage (0-100).

func ExtractLastError

func ExtractLastError(stderr string) string

ExtractLastError extracts the last meaningful line from stderr output.

func FilenameTime

func FilenameTime(filename string) (time.Time, bool)

FilenameTime extracts a timestamp from a filename. Supports: YYYY-MM-DD_HH-MM-SS, YYYY-MM-DD-HH-MM, YYYY-MM-DD.

func FormatDuration

func FormatDuration(ms int64) string

FormatDuration formats milliseconds as a human-readable duration string. Shows only the two most relevant units:

• < 1 minute: "45s"
• < 1 hour: "12m 34s"
• < 24 hours: "2h 24m"
• >= 24 hours: "1d 3h"

func FormatHumanTime

func FormatHumanTime(rfc3339 string) string

FormatHumanTime converts an RFC3339 timestamp to human-readable local time format.

func GenerateBrandCSS

func GenerateBrandCSS(colorLight, colorDark string) string

GenerateBrandCSS generates CSS custom properties for branding.

func GracefulSignal

func GracefulSignal(p *os.Process) error

GracefulSignal attempts graceful process termination.

func HumanTime

func HumanTime() string

HumanTime returns the current local time in a human-readable format.

func OldestToKeep

func OldestToKeep(days int, now time.Time) time.Time

OldestToKeep returns the oldest timestamp to retain during cleanup. Files older than this should be deleted.

Uses rolling retention: now - (days * 24 hours).

func ResolveFFmpegPath

func ResolveFFmpegPath(customPath string) string

ResolveFFmpegPath returns the path to the FFmpeg binary, or empty string if not found.

func ShutdownSignals

func ShutdownSignals() []os.Signal

ShutdownSignals returns the signals to listen for graceful shutdown.

func TimeUntilNextHour

func TimeUntilNextHour(t time.Time) time.Duration

TimeUntilNextHour returns the duration until the next hour boundary.

func ValidatePath

func ValidatePath(field, path string) error

ValidatePath validates a file path for security.

func WrapError

func WrapError(operation string, err error) error

WrapError wraps an error with a descriptive operation context.

Types

type Backoff

type Backoff struct {
	// contains filtered or unexported fields
}

Backoff provides retry delay calculation with exponential growth.

func NewBackoff

func NewBackoff(initial, maxDelay time.Duration) *Backoff

NewBackoff returns a new Backoff with the given initial and maximum delays.

func (*Backoff) Current

func (b *Backoff) Current() time.Duration

Current returns the current delay.

func (*Backoff) Next

func (b *Backoff) Next() time.Duration

Next returns the current delay and advances to the next value.

func (*Backoff) Reset

func (b *Backoff) Reset()

Reset restores the delay to its initial value.