Module: FastCuid2

Defined in:
lib/gem/fast_cuid2.rb,
lib/gem/fast_cuid2/version.rb,
ext/fast_cuid2/fast_cuid2.c

Defined Under Namespace

Classes: Error

Constant Summary collapse

VERSION = 
'1.0.0'

Class Method Summary collapse

Class Method Details

.generate ⇒ String

Generates a CUID2 (Collision-resistant Unique IDentifier). Format: <6 chars timestamp><18 chars random>

Returns:

  • (String) —

    A 24-character CUID2

Raises:

  • (RuntimeError) —

    If generation fails



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# File 'ext/fast_cuid2/fast_cuid2.c', line 63

static VALUE rb_generate_cuid2(VALUE self) {
    char cuid[CUID2_BUFFER_SIZE] = {0};
    struct timespec ts;
    unsigned char random_bytes[RANDOM_BYTES_LENGTH];

    // Get current timestamp in milliseconds
    if (clock_gettime(CLOCK_REALTIME, &ts) != 0) {
        rb_raise(rb_eRuntimeError, "Failed to get system time");
    }
    uint64_t timestamp = (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;

    // Generate random bytes
    generate_random_bytes(random_bytes, RANDOM_BYTES_LENGTH);

    // Encode timestamp (first 6 chars)
    encode_base32(timestamp, cuid, TIMESTAMP_LENGTH);

    // Fill remaining 18 chars with random data
    // Process 2 bytes at a time to generate 3 base32 chars
    for (int i = 0; i < RANDOM_BYTES_LENGTH; i += RANDOM_CHUNK_SIZE) {
        uint32_t rand_chunk =
            ((uint32_t)random_bytes[i] << 8) |
            ((uint32_t)random_bytes[i + 1]);
        encode_base32(rand_chunk, cuid + TIMESTAMP_LENGTH + (i / RANDOM_CHUNK_SIZE) * BASE32_CHARS_PER_CHUNK, BASE32_CHARS_PER_CHUNK);
    }

    ensure_first_char_is_letter(cuid);

    return rb_str_new2(cuid);
}

.valid?(str) ⇒ Boolean

Validates a CUID2 string.

Parameters:

  • str (String) —

    The string to validate

Returns:

  • (Boolean) —

    true if valid CUID2, false otherwise



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# File 'ext/fast_cuid2/fast_cuid2.c', line 99

static VALUE rb_validate_cuid2(VALUE self, VALUE str) {
    Check_Type(str, T_STRING);

    if (RSTRING_LEN(str) != CUID2_LENGTH) return Qfalse;

    const char *cuid = StringValuePtr(str);
    for (int i = 0; i < CUID2_LENGTH; i++) {
        if (!strchr(BASE32_CHARS, cuid[i])) return Qfalse;
    }

    // First character must be a letter
    if (strchr("0123456789", cuid[0])) return Qfalse;

    return Qtrue;
}