Identify All the Things With UUIDs! (Dutch PHP 2016)

Universally unique identifiers (UUIDs) are a fun and exciting way to identify things. We can issue UUIDs forever and never run out; they're practically unique! Join this whirlwind adventure in search of the perfect identifier to find out why UUIDs might be good for your projects. Along the way, you'll learn what is a UUID, the various types of UUIDs, pros and cons of using UUIDs, and how to use the ramsey/uuid library. Advanced and little-known features of ramsey/uuid will be covered.

Transcript

1. Identify All the
   Things With
   UUIDs
   Ben Ramsey
   
   Dutch PHP Conference
   
   24 June 2016
   

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3. universally unique identifier
   U U ID
   

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4. universally unique
   There are 1632 possible UUIDs
   
   “only after generating 1 billion UUIDs every
   second for the next 100 years, the probability
   of creating just one duplicate would be about
   50%”
   — Wikipedia, UUID
   

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5. 379dae82-5a2b-4c4b-8193-b8e7749a3495
   Unsigned 128-bit integer
   

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6. 73 926 269 841 798 498 179 266 328 839 241 479 317
   Unsigned 128-bit integer
   

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7. b"7Ø«éZ+LKüô©þtÜ4ò"
   Unsigned 128-bit integer
   

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9. HI, I’M BEN.
   I’m a web craftsman, author, and
   speaker. I build a platform for
   professional photographers at
   ShootProof. I enjoy APIs, open
   source software, organizing user
   groups, good beer, and
   spending time with my family.
   Nashville, TN is my home.
   ▸ Zend PHP Certification
   Study Guide
   ▸ Nashville PHP & Atlanta
   PHP user groups
   ▸ array_column()
   ▸ league/oauth2-client
   ▸ ramsey/uuid
   

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11. ramsey/uuid
    

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12. composer require ramsey/uuid
    

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13. use Ramsey\Uuid\Uuid;
    

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14. RFC 4122
    Defines a specific variant of UUID with five
    versions.
    

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15. Anatomy of
    a UUID
    

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16. 379dae82-5a2b-4c4b-8193-b8e7749a3495
    

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17. 379dae82-5a2b-4c4b-8193-b8e7749a3495
    time low
    

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18. 379dae82-5a2b-4c4b-8193-b8e7749a3495
    time mid
    

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19. 379dae82-5a2b-4c4b-8193-b8e7749a3495
    time high & version
    

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20. 379dae82-5a2b-4c4b-8193-b8e7749a3495
    time high & version
    UUID version
    

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21. 379dae82-5a2b-4c4b-8193-b8e7749a3495
    clock sequence high & reserved
    

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22. 379dae82-5a2b-4c4b-8193-b8e7749a3495
    clock sequence high & reserved
    UUID variant
    

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23. 379dae82-5a2b-4c4b-8193-b8e7749a3495
    clock sequence low
    

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24. 379dae82-5a2b-4c4b-8193-b8e7749a3495
    node
    

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25. Version 1:
    Time Based
    

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26. $uuid = Uuid::uuid1();
    echo $uuid->toString();
    

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27. for ($i = 0; $i < 5; $i++) {
    echo Uuid::uuid1()->toString();
    echo "\n";
    }
    

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28. 68845efc-1303-11e6-8d40-3c15c2cafa76
    68846d0c-1303-11e6-8088-3c15c2cafa76
    68847216-1303-11e6-830b-3c15c2cafa76
    68847590-1303-11e6-892a-3c15c2cafa76
    68847806-1303-11e6-913b-3c15c2cafa76
    

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29. Version 4:
    Random
    

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30. for ($i = 0; $i < 5; $i++) {
    echo Uuid::uuid4()->toString();
    echo "\n";
    }
    

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31. 28b7883f-3df0-4e8a-9994-57b28f01fab2
    dd78278c-03d7-4ca4-8411-06380c4cfd57
    ae8de9f1-6ffc-454e-8522-b2c260e4c66b
    a5e9ac6b-0680-4fb7-a019-f305c7d2d5da
    09fd4b15-2b2d-49be-af51-30899169ff99
    

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32. Name Based:
    Version 3 & 5
    

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33. $uuid = Uuid::uuid3(
    Uuid::NAMESPACE_DNS,
    'www.phpconference.nl/about-dpc'
    );
    

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34. 2f75e334-aa61-3af8-b570-49dd823d7248
    

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35. $uuid = Uuid::uuid5(
    Uuid::NAMESPACE_DNS,
    'www.phpconference.nl/about-dpc'
    );
    

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36. f2a7c7f9-358c-51b7-ab30-cc456c5b2256
    

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37. $dpcNS = Uuid::uuid5(
    Uuid::NAMESPACE_DNS,
    'www.phpconference.nl'
    );
    define(
    'NAMESPACE_DPC',
    $dpcNS->toString()
    );
    $pageId = Uuid::uuid5(
    NAMESPACE_DPC,
    '/about-dpc'
    );
    

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38. Version 2?
    

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39. Version 2:
    DCE Security
    

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40. Advanced

    Topics
    

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41. Database Considerations
    • Some databases have UUID as native type
    
    • MySQL does not
    
    • InnoDB uses PK in all secondary keys; if PK
    is big (CHAR(36)), then all keys will be huge
    
    • InnoDB stores data in PK order; if UUID is
    PK and not sequential, then inserts are
    scattered
    

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42. Database Solutions
    • Use binary instead of string UUID
    
    • CHAR(16)
    • $uuid->getBytes()
    • Pull request #118: Codec to store UUID in
    an optimized way for InnoDB
    
    • Read Percona blog post “Store UUID in an
    optimized way”
    

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43. COMB
    • Combined random UUID/timestamp
    
    • Replaces the least significant bytes of the
    node field with the current timestamp
    
    • Tries to compensate for the reduced
    clustering in database indexes
    

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44. $factory = new UuidFactory();
    $generator = new CombGenerator(
    $factory->getRandomGenerator(),
    $factory->getNumberConverter()
    );
    $factory->setRandomGenerator($generator);
    $combUuid = $factory->uuid4();
    

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45. Override Time Generator
    Want to use pecl-uuid as your time
    generator?
    
    We can do that.
    

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46. $factory = new UuidFactory();
    $factory->setTimeGenerator(
    new PeclUuidTimeGenerator()
    );
    $uuid = $factory->uuid1();
    

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47. Override Random Generator
    Want to use libsodium as your random
    generator?
    
    We can do that.
    

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48. $factory = new UuidFactory();
    $factory->setRandomGenerator(
    new SodiumRandomGenerator()
    );
    $uuid = $factory->uuid4();
    

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49. More Customization
    In fact, you’re able to customize ramsey/uuid
    in any way you need by using interfaces and
    injecting dependencies in the factory:
    - Generators
    
    - Codecs
    
    - Converters
    
    - Providers
    

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50. UUID all the
    things?
    

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51. Cons
    • Takes up much more DB space than integer
    
    • By default (and spec) not sequential
    
    • Decreases database performance
    
    • Can’t use ORDER BY
    
    • Ugly in URLs
    

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52. Pros
    • Unique everywhere
    
    • Easily able to merge recordsets from
    multiple sources
    
    • Easy distribution of databases across
    multiple servers
    
    • May be generated anywhere, independently
    

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53. THANK YOU.
    ANY QUESTIONS?
    If you want to talk more, feel
    free to contact me.
    benramsey.com
    @ramsey
    github.com/ramsey
    ben@benramsey.com
    Identify All the Things With UUIDs
    
    Copyright © 2016 Ben Ramsey
    
    This work is licensed under Creative Commons
    Attribution-ShareAlike 4.0 International. For uses not
    covered under this license, please contact the author.
    Ramsey, Ben. “Identify All the Things With UUIDs.” Dutch PHP
    Conference. RAI Amsterdam Convention Centre, Amsterdam. 24
    Jun. 2016. Conference presentation.
    This presentation was created using Keynote. The text
    is set in Chunk Five and Helvetica Neue. The source
    code is set in Menlo. The iconography is provided by
    Font Awesome.
    
    Unless otherwise noted, all photographs are used by
    permission under a Creative Commons license. Please
    refer to the Photo Credits slide for more information.
    Ŏ joind.in/talk/11781
    

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54. Photo Credits
    1. “38-365 Fingerprint” by Bram Cymet
    2. “Baby Feet” by Katelyn Kenderdine
    3. “Random” by Vladimer Shioshvili
    4. “Hello My Name Is.... 221/365” by Robert Occhialini
    5. “Curvy Road Ahead” by Kit Ng
    6. “Security door” by reynermedia
    7. “Hello! My Name Is JEDi.” by Tyrone J Moore
    8. “Mr Anatomini” by clement127
    9. “Everything” by Dan Dvorscak
    10. “thinker” by Fredrik Rubensson
    1 2
    3 4
    5 6
    7 8
    9 10
    

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