Pikaid (PHP)

Small · Sortable · Secure ID generator

This is the official PHP implementation. Fully compliant with v1.0.1.

Pikaid is a 26-character, lowercase Base36 identifier, composed of:

• 7-character timestamp (seconds since epoch)
• 19-character cryptographically secure randomness

It’s a modern, compact alternative to UUID and ULID:

• Lexicographically sortable
• Collision-resistant
• Compact binary form (BINARY(17))

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📚 Specifications & Benchmarks

See the full technical specs and benchmarks at pikaid/pikaid-specs

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⚙️ Requirements

• PHP 7.4+ (PHP 8 recommended)
• ext-gmp (recommended for best performance) or ext-bcmath (optional)
• If neither extension is installed, a pure-PHP fallback is used.

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📦 Installation

Install via Composer:

composer require pikaid/pikaid-php

Include Composer's autoloader in your project:

require 'vendor/autoload.php';

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🚀 Basic Usage

<?php

use Pikaid\Pikaid;

// Generate a new Pikaid string
$id = Pikaid::generate();
echo "ID: $id\n"; // e.g. 0swct4q01ch83h91onl6l47vb6

// Validate
if (Pikaid::isValid($id)) {
    echo "Valid ID!\n";
}

// Parse components
$data = Pikaid::parse($id);
echo "Timestamp: " . $data['timestamp']->format('Y-m-d H:i:s') . " UTC\n";
echo "Randomness (hex): {$data['randomness']}\n";

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🧩 API Reference

Pikaid::generate(): string

Generate a new 26-character string ID.

• Layout: [7 chars timestamp][19 chars randomness]
• Sortable by second.

$id = Pikaid::generate();

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Pikaid::generateBinary(): string

Generate the binary form directly (BINARY(17)).

• Layout: [5 bytes timestamp (uint40, big-endian)][12 bytes entropy].

$bin = Pikaid::generateBinary();

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Pikaid::toBinary(string $id): string

Convert a string ID to its binary (17 bytes) representation. Throws InvalidArgumentException if the input is not a valid 26-character Pikaid or if the timestamp is out of range.

$bin = Pikaid::toBinary($id);

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Pikaid::fromBinary(string $bin): string

Convert binary (17 bytes) back into a 26-char string. Throws InvalidArgumentException if the binary length isn’t exactly 17 bytes.

$id = Pikaid::fromBinary($bin);

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Pikaid::isValid(string $id): bool

Check if the given string is a valid Pikaid.

• Must be 26 chars long
• Must match regex: /^[0-9a-z]{26}$/

if (Pikaid::isValid($id)) {
    echo "Valid format!";
}

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Pikaid::parse(string $id): array

Parse a string ID into its components:

• timestamp → DateTimeImmutable (UTC)
• randomness → lowercase hex string (24 chars = 12 bytes)

Throws InvalidArgumentException on invalid input.

$info = Pikaid::parse($id);
/*
[
  'timestamp' => DateTimeImmutable(...),
  'randomness' => 'a1b2c3d4e5f6a7b8c9d0e1f2'
]
*/

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Pikaid::fromDateTime(DateTimeInterface $t): string

Generate a string ID for a specific timestamp (seconds precision).

$id = Pikaid::fromDateTime(new DateTimeImmutable('@1234567890'));

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🔄 Order Guarantee

• String and binary representations sort lexicographically by second:

$id1 = Pikaid::generate();
sleep(1);
$id2 = Pikaid::generate();
assert($id1 < $id2); // always true

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🛢 Storage Recommendations

Pikaid is designed to be compact and index-friendly, with a predictable layout:

Representation	Size	Sortable	Recommended for
BINARY(17)	17B	Yes	High-performance storage and indexing
CHAR(26)	26B	Yes	Readability in SQL, debugging, or logs

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🔹 Option 1: Store as BINARY(17) (Recommended)

Binary form stores exactly 17 bytes:

[5 bytes timestamp (uint40, big-endian)][12 bytes entropy]

Table Definition

CREATE TABLE pika_events (
  id BINARY(17) NOT NULL, -- Primary key
  payload JSON NULL,
  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  -- Optional: Extract timestamp for range queries and indexing
  ts_seconds BIGINT UNSIGNED
    AS ( ORD(SUBSTR(id, 1, 1)) * 4294967296
      + CONV(HEX(SUBSTR(id, 2, 4)), 16, 10) ) STORED,
  PRIMARY KEY (id),
  KEY idx_ts_seconds (ts_seconds),
  KEY idx_created_at (created_at)
) ENGINE=InnoDB;

Insert Example (PHP)

use Pikaid\Pikaid;

// Generate binary ID and store it
$binId = Pikaid::generateBinary();
$stmt = $pdo->prepare('INSERT INTO pika_events (id, payload) VALUES (?, ?)');
$stmt->execute([$binId, json_encode(['event' => 'signup'])]);

Select Example (PHP)

$stmt = $pdo->query('SELECT id, ts_seconds FROM pika_events ORDER BY id ASC');
foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row) {
    $stringId = Pikaid::fromBinary($row['id']); // Convert back to string
    echo $stringId . ' @ ' . gmdate('c', (int)$row['ts_seconds']) . PHP_EOL;
}

Benefits

• Small index size = better performance
• Binary comparison matches chronological order
• Perfect for PRIMARY KEY or clustered indexes

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🔹 Option 2: Store as CHAR(26) (String)

If you need IDs to remain human-readable directly in SQL queries, store the string form.

Table Definition

CREATE TABLE pika_events_str (
  id CHAR(26) CHARACTER SET ascii COLLATE ascii_bin NOT NULL, -- Primary key
  payload JSON NULL,
  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  -- Optional: Extract timestamp for range queries and indexing
  ts_seconds BIGINT UNSIGNED
    AS (CONV(SUBSTR(id, 1, 7), 36, 10)) STORED,
  PRIMARY KEY (id),
  KEY idx_ts_seconds (ts_seconds),
  KEY idx_created_at (created_at)
) ENGINE=InnoDB;

Insert Example (PHP)

use Pikaid\Pikaid;

$id = Pikaid::generate();
$stmt = $pdo->prepare('INSERT INTO pika_events_str (id, payload) VALUES (?, ?)');
$stmt->execute([$id, json_encode(['event' => 'login'])]);

Select Example (PHP)

$stmt = $pdo->query('SELECT id, ts_seconds FROM pika_events_str ORDER BY id ASC');
foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row) {
    echo $row['id'] . ' @ ' . gmdate('c', (int)$row['ts_seconds']) . PHP_EOL;
}

Notes

• Slightly larger storage and index compared to BINARY(17)
• Ideal for debugging or manual inspection of IDs

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🔄 Order Guarantee

Both BINARY(17) and CHAR(26) maintain natural chronological order:

$id1 = Pikaid::generate();
sleep(1);
$id2 = Pikaid::generate();

assert($id1 < $id2); // String order is chronological
assert(strcmp(Pikaid::toBinary($id1), Pikaid::toBinary($id2)) < 0); // Binary order too

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📜 License

Pikaid is released under the MIT License.

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