Uuid class

A powerful, secure implementation of Universally Unique Identifiers (UUIDs) following RFC 4122 specifications.

The Uuid class provides comprehensive support for UUID generation, parsing, validation, and manipulation with cryptographically secure random number generation and multiple UUID versions.

Supported UUID Versions

• Version 1: Time-based UUIDs with MAC address
• Version 3: Name-based UUIDs using MD5 hashing
• Version 4: Random or pseudo-random UUIDs (most common)
• Version 5: Name-based UUIDs using SHA-1 hashing

Security Features

• Cryptographically secure random number generation
• Proper entropy collection for version 4 UUIDs
• Secure hashing for name-based UUIDs
• Protection against timing attacks
• Validation of UUID format and version compliance

Performance Characteristics

• Generation: O(1) for version 4, O(log n) for name-based versions
• Parsing: O(1) with input validation
• Comparison: O(1) lexicographic comparison
• Memory: 16 bytes storage + minimal overhead

Example Usage

// Generate random UUID (version 4)
final uuid1 = Uuid.randomUuid();
print(uuid1); // e.g., "550e8400-e29b-41d4-a716-446655440000"

// Parse from string
final uuid2 = Uuid.fromString('550e8400-e29b-41d4-a716-446655440000');

// Generate name-based UUID (version 5)
final namespace = Uuid.NAMESPACE_DNS;
final uuid3 = Uuid.nameUuidFromBytes(namespace, utf8.encode('example.com'));

// Generate time-based UUID (version 1)
final uuid4 = Uuid.timeBasedUuid();

// Comparison and validation
print(uuid1 == uuid2); // false
print(uuid1.compareTo(uuid2)); // -1, 0, or 1
print(Uuid.isValidUuid('invalid')); // false

// Access UUID components
print(uuid1.version); // 4
print(uuid1.variant); // 2 (RFC 4122)
print(uuid1.mostSignificantBits);
print(uuid1.leastSignificantBits);

Thread Safety

All UUID operations are thread-safe. The internal random number generator uses secure system entropy and can be safely called from multiple threads concurrently.

Format Compliance

Generated UUIDs strictly follow RFC 4122 format:

• 8-4-4-4-12 hexadecimal digit groups separated by hyphens
• Proper version and variant bits set according to specification
• Case-insensitive parsing with canonical lowercase output