uid

func GenerateShortID ¶

func GenerateShortID() string

GenerateShortID creates a new 11-character lowercase short ID. It encodes the current microsecond timestamp in Crockford Base32. Thread-safe via mutex to prevent duplicate IDs under concurrency.

Business Logic:

• Uses time.Now().UnixMicro() as the uniqueness base.
• Maintains package-level lastTimestamp and counter across calls.
• Counter increments when the timestamp equals the previous call; resets to 0 when the timestamp changes.
• The counter is 4 bits (0-15), giving 16 unique IDs per timestamp tick.
• On Windows the system timer resolution is ~1 ms, so UnixMicro returns the same value for every call within the same millisecond.
• Once the counter exceeds 15 it would overflow and wrap back to 0, producing the exact same composite value and therefore a duplicate ID.
• Sleeping 1 ms guarantees the timestamp advances to the next tick.
• Packs timestamp and counter into a single int64: (ts << 4) | counter.
• The timestamp occupies the high bits; the counter occupies the low 4 bits.
• Encodes the composite value using Crockford Base32 alphabet.
• Converts the result to lowercase.
• Returns an 11-character string (e.g. "sa4rc789wxg").

func IsShortID ¶

func IsShortID(id string) bool

IsShortID checks whether the given string matches short ID lengths (11 or 21 chars).

func NormalizeID ¶

func NormalizeID(id string) string

NormalizeID normalizes an ID to lowercase for consistent lookups.