Devoxx UK 2015 Presentation: Miniboxing - Fast Generics for Primitive Types

Miniboxing presentation at Devoxx UK 2015. Website: http://www.devoxx.co.uk/

The recording is available on parleys: https://www.parleys.com/tutorial/miniboxing-fast-generics-primitive-types

The two demos:
- Streams: not yet online
- Image processing: http://scala-miniboxing.org/example_pureimage.html

Project website: http://scala-miniboxing.org

Transcript

1. scala-miniboxing.org @miniboxing
   18th of June 2015
   Devoxx United Kingdom
   London, UK
   scala-miniboxing.org
   

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2. scala-miniboxing.org @miniboxing
   Vlad URECHE
   PhD student in the Scala Team @ EPFL
   Working on program transformations
   in the Scala programming language,
   focusing on data representation.
   Contributions to specialization,
   backend and Scaladoc.
   @
   @VladUreche
   @VladUreche
   vlad.ureche@epfl.ch
   

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3. scala-miniboxing.org @miniboxing
   scala-miniboxing.org
   

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4. scala-miniboxing.org @miniboxing
   STOP
   Please ask if things
   are not clear!
   

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5. scala-miniboxing.org @miniboxing
   STOP
   Please ask if things
   are not clear!
   Really! I mean it!
   

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6. scala-miniboxing.org @miniboxing
   What is miniboxing?
   Why use it?
   How does it... ?
   Conclusion
   Generics
   

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7. scala-miniboxing.org @miniboxing
   Compilers
   Compilers
   

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8. scala-miniboxing.org @miniboxing
   Compilers
   Compilers
   Source code
   (language 1)
   compiler
   C, C++, Java, Scala, C#,
   Haskell, Clojure, ...
   

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9. scala-miniboxing.org @miniboxing
   Compilers
   Compilers
   Source code
   (language 1)
   Source code
   (language 2)
   compiler
   C, C++, Java, Scala, C#,
   Haskell, Clojure, ...
   x86/ARM assembly
   LLVM bitcode
   Cuda code
   JVM bytecode
   .NET bytecode
   ...
   

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10. scala-miniboxing.org @miniboxing
    Compilers
    Compilers
    Source code
    (language 1)
    Source code
    (language 2)
    compiler
    C, C++, Java, Scala, C#,
    Haskell, Clojure, ...
    x86/ARM assembly
    LLVM bitcode
    Cuda code
    JVM bytecode
    .NET bytecode
    ...
    Why so much fuss ?
    

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11. scala-miniboxing.org @miniboxing
    Compilers
    Compilers
    Abstraction
    Imple-
    mentation
    compiler
    

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12. scala-miniboxing.org @miniboxing
    Compilers
    Compilers
    Abstraction
    Imple-
    mentation
    compiler
    Variable
    

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13. scala-miniboxing.org @miniboxing
    Compilers
    Compilers
    Abstraction
    Imple-
    mentation
    compiler
    Variable Stack slot or
    Processor register or
    Heap location
    

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14. scala-miniboxing.org @miniboxing
    Compilers
    Compilers
    Abstraction
    Imple-
    mentation
    compiler
    Variable Stack slot or
    Processor register or
    Heap location
    … Implementation details
    

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15. scala-miniboxing.org @miniboxing
    Generics Don't Exist
    Generics Don't Exist in the JVM
    in the JVM
    

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16. scala-miniboxing.org @miniboxing
    Generics Don't Exist
    Generics Don't Exist in the JVM
    in the JVM
    Java/
    Scala
    

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17. scala-miniboxing.org @miniboxing
    Generics Don't Exist
    Generics Don't Exist in the JVM
    in the JVM
    Java/
    Scala
    

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18. scala-miniboxing.org @miniboxing
    Generics Don't Exist
    Generics Don't Exist in the JVM
    in the JVM
    Javac
    Scalac
    Java/
    Scala
    

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19. scala-miniboxing.org @miniboxing
    Generics Don't Exist
    Generics Don't Exist in the JVM
    in the JVM
    Javac
    Scalac
    Generics
    Java/
    Scala
    

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20. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    def identity[T](t: T): T = t
    

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21. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    def identity[T](t: T): T = t
    scalac / javac
    

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22. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    def identity[T](t: T): T = t
    def identity(t: Object): Object = t
    scalac / javac
    

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23. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    identity(5)
    

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24. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    identity(5)
    scalac / javac
    

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25. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    identity(5)
    identity(java.lang.Integer.valueOf(5))
    scalac / javac
    

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26. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    identity(5)
    identity(java.lang.Integer.valueOf(5))
    scalac / javac
    Object representation
    

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27. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    java.lang.Integer.valueOf(5)
    boxing is not great ...
    boxing is not great ...
    inflates heap requirements
    

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28. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    java.lang.Integer.valueOf(5)
    boxing is not great ...
    boxing is not great ...
    inflates heap requirements
    produces garbage
    

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29. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    java.lang.Integer.valueOf(5)
    boxing is not great ...
    boxing is not great ...
    inflates heap requirements
    produces garbage
    value is accessed indirectly (slow)
    

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30. scala-miniboxing.org @miniboxing
    Erased Generics
    Erased Generics
    java.lang.Integer.valueOf(5)
    boxing is not great ...
    boxing is not great ...
    inflates heap requirements
    produces garbage
    value is accessed indirectly (slow)
    breaks locality guarantees
    

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31. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    Iulian Dragoș (@jaguarul)
    (circa 2009)
    

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32. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def identity[T](t: T): T = t
    

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33. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def identity[T](t: T): T = t
    specialization
    

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34. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def identity[T](t: T): T = t
    def identity(t: Object): Object = t
    specialization
    

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35. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def identity[T](t: T): T = t
    def identity(t: Object): Object = t
    specialization
    def identity_Z(t: bool): bool = t
    

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36. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def identity[T](t: T): T = t
    def identity(t: Object): Object = t
    specialization
    def identity_Z(t: bool): bool = t
    def identity_C(t: char): char = t
    

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37. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def identity[T](t: T): T = t
    def identity(t: Object): Object = t
    specialization
    def identity_Z(t: bool): bool = t
    def identity_C(t: char): char = t
    … (7 other variants)
    

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38. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    identity(5)
    

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39. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    identity(5)
    specialization
    

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40. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    identity(5)
    identity_I(5)
    specialization
    

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41. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    identity(5)
    identity_I(5)
    specialization
    No boxing, it automatically
    calls the specialized
    variant for integers
    

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42. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def tupled[T1, T2](t1: T1, t2: T2) ...
    

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43. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def tupled[T1, T2](t1: T1, t2: T2) ...
    specialization
    

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44. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def tupled[T1, T2](t1: T1, t2: T2) ...
    // 100 methods (102)
    specialization
    

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45. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def tupled[T1, T2](t1: T1, t2: T2) ...
    // 100 methods (102)
    specialization
    

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46. scala-miniboxing.org @miniboxing
    Specialization
    Specialization
    def tupled[T1, T2](t1: T1, t2: T2) ...
    // 100 methods (102)
    specialization
    Can we do
    better?
    

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47. scala-miniboxing.org @miniboxing
    What is miniboxing?
    Why use it?
    How does it... ?
    Conclusion
    Generics
    

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48. scala-miniboxing.org @miniboxing
    The idea behind
    The idea behind
    LONG
    miniboxing
    miniboxing
    

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49. scala-miniboxing.org @miniboxing
    The idea behind
    The idea behind
    LONG
    DOUBLE
    miniboxing
    miniboxing
    

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50. scala-miniboxing.org @miniboxing
    The idea behind
    The idea behind
    LONG
    DOUBLE
    INT
    miniboxing
    miniboxing
    

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51. scala-miniboxing.org @miniboxing
    The idea behind
    The idea behind
    ...
    LONG
    DOUBLE
    INT
    FLOAT
    SHORT
    miniboxing
    miniboxing
    

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52. scala-miniboxing.org @miniboxing
    The idea behind
    The idea behind
    ...
    LONG
    DOUBLE
    INT
    FLOAT
    SHORT
    ...
    LONG
    DOUBLE
    INT
    FLOAT
    SHORT
    a long integer
    miniboxing
    miniboxing
    

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53. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    def identity[T](t: T): T = t
    

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54. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    def identity[T](t: T): T = t
    miniboxing
    

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55. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    def identity[T](t: T): T = t
    def identity(t: Object): Object = t
    miniboxing
    

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56. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    def identity[T](t: T): T = t
    def identity(t: Object): Object = t
    miniboxing
    def identity_M(..., t: long): long = t
    

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57. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    def identity[T](t: T): T = t
    def identity(t: Object): Object = t
    miniboxing
    def identity_M(..., t: long): long = t
    long encodes all
    primitive types
    

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58. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    def identity[T](t: T): T = t
    def identity(t: Object): Object = t
    miniboxing
    def identity_M(..., t: long): long = t
    Only 2n variants
    long encodes all
    primitive types
    

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59. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    identity(3)
    

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60. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    identity(3)
    miniboxing
    

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61. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    identity(3)
    identity_M(..., int2minibox(3))
    miniboxing
    

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62. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    identity(3)
    identity_M(..., int2minibox(3))
    miniboxing
    The miniboxed
    variant of identity
    

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63. scala-miniboxing.org @miniboxing
    Miniboxing
    Miniboxing
    identity(3)
    identity_M(..., int2minibox(3))
    miniboxing
    The miniboxed
    variant of identity
    Unlike boxing,
    these conversions
    do not affect
    performance
    

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64. scala-miniboxing.org @miniboxing
    

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65. scala-miniboxing.org @miniboxing
    What is miniboxing?
    Why use it?
    How does it... ?
    Conclusion
    Generics
    

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66. scala-miniboxing.org @miniboxing
    

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67. scala-miniboxing.org @miniboxing
    Speedups
    

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68. scala-miniboxing.org @miniboxing
    Speedups
    Performance
    advisories
    

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69. scala-miniboxing.org @miniboxing
    DEMO
    

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70. scala-miniboxing.org @miniboxing
    Clash of the Lambdas
    Clash of the Lambdas
    

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71. scala-miniboxing.org @miniboxing
    

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72. scala-miniboxing.org @miniboxing
    

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73. scala-miniboxing.org @miniboxing
    Clash of the Lambdas
    Clash of the Lambdas
    ●
    Paper from 2014
    ●
    By Aggelos Biboudis, Uni of Athens
    

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74. scala-miniboxing.org @miniboxing
    Clash of the Lambdas
    Clash of the Lambdas
    ●
    Paper from 2014
    ●
    By Aggelos Biboudis, Uni of Athens
    ●
    Comparing Steaming support in
    – in Java 8
    – in Scala
    – in .NET
    

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75. scala-miniboxing.org @miniboxing
    Clash of the Lambdas
    Clash of the Lambdas
    ●
    Paper from 2014
    ●
    By Aggelos Biboudis, Uni of Athens
    ●
    Comparing Steaming support in
    – in Java 8
    – in Scala
    – in .NET
    ●
    … but Scala did not have streaming support
    

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76. scala-miniboxing.org @miniboxing
    Clash of the Lambdas
    Clash of the Lambdas
    ●
    Paper from 2014
    ●
    By Aggelos Biboudis, Uni of Athens
    ●
    Comparing Steaming support in
    – in Java 8
    – in Scala
    – in .NET
    ●
    But Scala lacks an equivalent streaming support
    – Thus the numbers :)
    

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77. scala-miniboxing.org @miniboxing
    In the meantime...
    he implemented it
    

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78. scala-miniboxing.org @miniboxing
    

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79. scala-miniboxing.org @miniboxing
    DEMO
    

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80. scala-miniboxing.org @miniboxing
    

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81. scala-miniboxing.org @miniboxing
    What is miniboxing?
    Why use it?
    How does it... ?
    Conclusion
    Generics
    

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82. scala-miniboxing.org @miniboxing
    Warnings
    Warnings
    scala> def baz[T](t: T): T = t
    baz: [T](t: T)T
    scala> baz(4)
    

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83. scala-miniboxing.org @miniboxing
    Warnings
    Warnings
    scala> def baz[T](t: T): T = t
    baz: [T](t: T)T
    scala> baz[Int](4)
    

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84. scala-miniboxing.org @miniboxing
    Warnings
    Warnings
    scala> def baz[T](t: T): T = t
    baz: [T](t: T)T
    scala> baz[Int](4)
    :9: warning: The method baz
    would benefit from miniboxing type
    parameter T, since it is instantiated by a
    primitive type.
    ...
    

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85. scala-miniboxing.org @miniboxing
    Call Graph
    Call Graph
    def foo[T](t: T): T = bar(t)
    

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86. scala-miniboxing.org @miniboxing
    Call Graph
    Call Graph
    def foo[T](t: T): T = bar(t)
    def bar[T](t: T): T = baz(t)
    

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87. scala-miniboxing.org @miniboxing
    Call Graph
    Call Graph
    def foo[T](t: T): T = bar(t)
    def bar[T](t: T): T = baz(t)
    def baz[T](t: T): T = t
    

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88. scala-miniboxing.org @miniboxing
    Call Graph
    Call Graph
    def foo[T](t: T): T = bar(t)
    def bar[T](t: T): T = baz(t)
    def baz[T](t: T): T = t
    call graph
    

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89. scala-miniboxing.org @miniboxing
    Call Graph
    Call Graph
    foo
    

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90. scala-miniboxing.org @miniboxing
    Call Graph
    Call Graph
    foo
    bar
    

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91. scala-miniboxing.org @miniboxing
    Call Graph
    Call Graph
    foo
    bar
    baz
    

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92. scala-miniboxing.org @miniboxing
    Miniboxed Call Graph
    Miniboxed Call Graph
    def foo[@miniboxed T](t: T): T = bar(t)
    def bar[@miniboxed T](t: T): T = baz(t)
    def baz[@miniboxed T](t: T): T = t
    

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93. scala-miniboxing.org @miniboxing
    Miniboxed Call Graph
    Miniboxed Call Graph
    def foo[@miniboxed T](t: T): T = bar(t)
    def bar[@miniboxed T](t: T): T = baz(t)
    def baz[@miniboxed T](t: T): T = t
    miniboxing
    

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94. scala-miniboxing.org @miniboxing
    Miniboxed Call Graph
    Miniboxed Call Graph
    def foo(...): ... = bar(t)
    def foo_M(...): ... = bar_M(t)
    def bar(...): ... = baz(t)
    def bar_M(...): ... = baz_M(t)
    def baz(...): ... = t
    def baz_M(...): ... = t
    

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95. scala-miniboxing.org @miniboxing
    Miniboxed Call Graph
    Miniboxed Call Graph
    foo foo_M
    bar bar_M
    baz baz_M
    

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96. scala-miniboxing.org @miniboxing
    Miniboxed Call Graph
    Miniboxed Call Graph
    foo foo_M
    bar bar_M
    baz baz_M
    Data is pased in the
    miniboxed encoding
    no boxing necessary!
    

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97. scala-miniboxing.org @miniboxing
    Suboptimal Call Graph
    Suboptimal Call Graph
    def foo[@miniboxed T](t: T): T = bar(t)
    def bar[@miniboxed T](t: T): T = baz(t)
    def baz[@miniboxed T](t: T): T = t
    

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98. scala-miniboxing.org @miniboxing
    Suboptimal Call Graph
    Suboptimal Call Graph
    def foo[@miniboxed T](t: T): T = bar(t)
    def bar[@miniboxed T](t: T): T = baz(t)
    def baz[@miniboxed T](t: T): T = t
    

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99. scala-miniboxing.org @miniboxing
    Suboptimal Call Graph
    Suboptimal Call Graph
    def foo[@miniboxed T](t: T): T = bar(t)
    def bar[@miniboxed T](t: T): T = baz(t)
    def baz[@miniboxed T](t: T): T = t
    miniboxing
    

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100. scala-miniboxing.org @miniboxing
     Suboptimal Call Graph
     Suboptimal Call Graph
     foo foo_M
     bar
     baz baz_M
     

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101. scala-miniboxing.org @miniboxing
     Suboptimal Call Graph
     Suboptimal Call Graph
     foo foo_M
     bar
     baz baz_M
     

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102. scala-miniboxing.org @miniboxing
     Suboptimal Call Graph
     Suboptimal Call Graph
     foo foo_M
     bar
     baz baz_M
     boxing arguments → warn
     

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103. scala-miniboxing.org @miniboxing
     Suboptimal Call Graph
     Suboptimal Call Graph
     foo foo_M
     bar
     baz baz_M
     boxing arguments → warn
     

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104. scala-miniboxing.org @miniboxing
     Suboptimal Call Graph
     Suboptimal Call Graph
     foo foo_M
     bar
     baz baz_M
     boxing arguments → warn
     

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105. scala-miniboxing.org @miniboxing
     Suboptimal Call Graph
     Suboptimal Call Graph
     foo foo_M
     bar
     baz baz_M
     boxing arguments → warn
     there is a better version
     but I can't call it → warn
     

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106. scala-miniboxing.org @miniboxing
     Suboptimal Call Graph
     Suboptimal Call Graph
     scala> object Test {
     | def foo[@miniboxed T](t: T): T = bar(t)
     | def bar[ T](t: T): T = baz(t)
     | def baz[@miniboxed T](t: T): T = t
     | }
     :10: warning: The method Test.bar would benefit
     from miniboxing type parameter T, since it is instantiated
     by miniboxed type parameter T of method foo:
     def foo[@miniboxed T](t: T): T = bar(t)
     ^
     :11: warning: The following code could benefit
     from miniboxing specialization if the type parameter T
     of method bar would be marked as "@miniboxed T":
     def bar[T](t: T): T = baz(t)
     ^
     defined object Test
     

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107. scala-miniboxing.org @miniboxing
     Warnings
     Warnings
     ●
     Miniboxing tries to avoid boxing
     ●
     When it can't avoid it, it warns you
     – And you can act on it
     ●
     Many other warnings
     – To keep you from shooting yourself in the foot
     

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108. scala-miniboxing.org @miniboxing
     

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109. scala-miniboxing.org @miniboxing
     Who's that JVM
     performance
     expert over there?
     

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110. scala-miniboxing.org @miniboxing
     Miniboxing
     Miniboxing
     ●
     Replaces the library constructs
     – Functions
     – Arrays
     – Numeric type classes
     ... library
     ... library
     

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111. scala-miniboxing.org @miniboxing
     Miniboxing
     Miniboxing
     ●
     Replaces the library constructs
     – Functions
     – Arrays
     – Numeric type classes
     ●
     Adds
     – Interfaces to other constructs
     – Miniboxed state reflection
     ... library
     ... library
     

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112. scala-miniboxing.org @miniboxing
     Miniboxing
     Miniboxing
     ●
     Replaces the library constructs
     – Functions
     – Arrays
     – Numeric type classes
     ●
     Adds
     – Interfaces to other constructs
     – Miniboxed state reflection
     ... library
     ... library
     Am I inside a
     miniboxed class?
     If so, what is T?
     

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113. scala-miniboxing.org @miniboxing
     What is miniboxing?
     Why use it?
     How does it... ?
     Conclusion
     Generics
     

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114. scala-miniboxing.org @miniboxing
     

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115. scala-miniboxing.org @miniboxing
     

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116. scala-miniboxing.org @miniboxing
     

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117. scala-miniboxing.org @miniboxing
     

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118. scala-miniboxing.org @miniboxing
     

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119. scala-miniboxing.org @miniboxing
     

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120. scala-miniboxing.org @miniboxing
     

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121. scala-miniboxing.org @miniboxing
     scala-miniboxing.org
     

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122. scala-miniboxing.org @miniboxing
     scala-miniboxing.org
     

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123. scala-miniboxing.org @miniboxing
     scala-miniboxing.org
     tutorials
     

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124. scala-miniboxing.org @miniboxing
     scala-miniboxing.org
     tutorials
     sbt config
     

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125. scala-miniboxing.org @miniboxing
     scala-miniboxing.org
     tutorials
     sbt config
     examples
     

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126. scala-miniboxing.org @miniboxing
     scala-miniboxing.org
     tutorials
     sbt config
     examples
     support
     

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127. scala-miniboxing.org @miniboxing
     Credits and Thank you-s
     ●
     Martin Odersky - without Scala, there would be no miniboxing
     ●
     Cristian Talau - developed the initial prototype, as a semester project
     ●
     Milos Stojanovic - work on warnings, tuple accessors and others
     ●
     Romain Beguet - work on miniboxed arrays
     ●
     Eugene Burmako - the value class plugin based on the LDL transformation
     ●
     Aymeric Genet - developing collection-like benchmarks for the miniboxing plugin
     ●
     Martin Odersky, for his patient guidance
     ●
     Dmitry Petrashko, for the many cool discussions we had
     ●
     Ilya Klyuchnikov and Pablo Guerrero - fixes and commits
     ●
     Iulian Dragos, for his work on specialization and many explanations
     ●
     Miguel Garcia, for his original insights that spawned the miniboxing idea
     ●
     Michel Schinz, for his wonderful comments and enlightening ACC course
     ●
     Andrew Myers and Roland Ducournau for the discussions we had and the feedback provided
     ●
     Heather Miller for the eye-opening discussions we had
     ●
     Vojin Jovanovic, Sandro Stucki, Manohar Jonalagedda and the whole LAMP laboratory in EPFL
     ●
     Adriaan Moors, for the miniboxing name which stuck :))
     ●
     Thierry Coppey, Vera Salvisberg and George Nithin, for the feedback
     

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128. scala-miniboxing.org @miniboxing
     Credits and Thank you-s
     ●
     Grzegorz Kossakowski, for the many brainstorming sessions on specialization
     ●
     Erik Osheim, Tom Switzer and Rex Kerr for their guidance on the Scala community side
     ●
     Sandro, Vojin, Nada, Heather, Manohar - reviews and discussions on the LDL paper
     ●
     Hubert Plociniczak for the type notation in the LDL paper
     ●
     Denys Shabalin (@densh), Dmitry Petrashko (@darkdimius) for their patient reviews of the LDL paper
     ●
     Alexandru Nedelcu (@alex_ndc) - for the functions direction
     ●
     Stu Hood (@stuhood) - for the initial support, ideas
     ●
     Julien Truffault (@JulienTruffaut) - for motivating the development of tuple accessors, sticky plugin warnings
     ●
     Aggelos Biboudis (@biboudis) - for pushing the functions project forward and the stream benchmarks
     ●
     Tom Switzer (@tixxit) - for pushing the array project forward and the vector benchmarks
     ●
     Philip Stutz (@PhilipStutz) - for the ideas on warnings
     ●
     Rex Kerr (@ichoran) - for ideas on reflection
     ●
     Vlad Patryshev (@vpatryshev) - for organizing the Scala Bay Meetup, wehre I presented once
     ●
     The Scala Community
     ●
     The Valhalla Project Architects
     ●
     The Devoxx, PNWScala and ScalaDays organizers!
     

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129. scala-miniboxing.org @miniboxing
     scala-miniboxing.org
     Thank you!
     

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130. scala-miniboxing.org @miniboxing
     

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131. scala-miniboxing.org @miniboxing
     

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132. scala-miniboxing.org @miniboxing
     scala-miniboxing.org
     

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133. scala-miniboxing.org @miniboxing
     http://stephenjudkins.github.io/pureimage-presentation/#/
     

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134. scala-miniboxing.org @miniboxing
     http://stephenjudkins.github.io/pureimage-presentation/#/32
     

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135. scala-miniboxing.org @miniboxing
     PureImage
     PureImage
     ●
     has very nice abstractions
     – generalizes over input, output format
     – generalizes over pixel format
     – provides collection-like mapping over images
     ●
     liked it a lot
     

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136. scala-miniboxing.org @miniboxing
     PureImage
     PureImage
     ●
     took the usual path to using miniboxing
     – code up a mock-up
     – become familiar with the problem
     – try out miniboxing on a small scale
     

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137. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     

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138. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     abstract class Image[Repr: Pixel] {
     def width: Int
     def height: Int
     def apply(x: Int, y: Int): Repr
     def map[Repr2: Pixel](f: Image[Repr] =>
     Generator[Repr2]): Image[Repr2]
     }
     

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139. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     abstract class Image[Repr: Pixel] {
     def width: Int
     def height: Int
     def apply(x: Int, y: Int): Repr
     def map[Repr2: Pixel](f: Image[Repr] =>
     Generator[Repr2]): Image[Repr2]
     }
     What's a generator?
     

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140. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     abstract class Generator[Repr: Pixel] {
     def width: Int
     def height: Int
     def generate(x: Int, y: Int): Repr
     }
     

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141. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     abstract class Generator[Repr: Pixel] {
     def width: Int
     def height: Int
     def generate(x: Int, y: Int): Repr
     }
     Why generic? What is pixel?
     

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142. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     Image on
     disk
     Indexed
     colors
     

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143. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     Image on
     disk
     Indexed
     colors
     Loaded
     image
     8-bit RGBA
     channels
     

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144. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     Image on
     disk
     Indexed
     colors
     Loaded
     image
     8-bit RGBA
     channels
     Transformed
     image
     8-bit RGBA
     channels
     

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145. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     Image on
     disk
     Indexed
     colors
     Loaded
     image
     8-bit RGBA
     channels
     Transformed
     image
     8-bit RGBA
     channels
     Transformed
     image
     8-bit RGBA
     channels
     ...
     

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146. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     Image on
     disk
     Indexed
     colors
     Loaded
     image
     8-bit RGBA
     channels
     Transformed
     image
     8-bit RGBA
     channels
     Image on
     disk
     Indexed
     colors
     Transformed
     image
     8-bit RGBA
     channels
     ...
     

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147. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     Image on
     disk
     Indexed
     colors
     Loaded
     image
     8-bit RGBA
     channels
     Transformed
     image
     8-bit RGBA
     channels
     Image on
     disk
     Indexed
     colors
     Transformed
     image
     8-bit RGBA
     channels
     ...
     discretization after
     each filter => artifacts
     

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148. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     Image on
     disk
     Indexed
     colors
     Loaded
     image
     8-bit RGBA
     channels
     Transformed
     image
     8-bit RGBA
     channels
     Image on
     disk
     Indexed
     colors
     Transformed
     image
     8-bit RGBA
     channels
     ...
     discretization after
     each filter => artifacts
     double
     precision
     RGBA
     double
     precision
     RGBA
     

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149. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     Image on
     disk
     Indexed
     colors
     Loaded
     image
     8-bit RGBA
     channels
     Transformed
     image
     8-bit RGBA
     channels
     Image on
     disk
     Indexed
     colors
     Transformed
     image
     8-bit RGBA
     channels
     ...
     discretization after
     each filter => artifacts
     double
     precision
     RGBA
     double
     precision
     RGBA
     discretization only when saving
     the file => better quality
     

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150. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     Image on
     disk
     Indexed
     colors
     Loaded
     image
     8-bit RGBA
     channels
     Transformed
     image
     8-bit RGBA
     channels
     Image on
     disk
     Indexed
     colors
     Transformed
     image
     8-bit RGBA
     channels
     ...
     discretization after
     each filter => artifacts
     double
     precision
     RGBA
     double
     precision
     RGBA
     discretization only when saving
     the file => better quality
     Pixel representation
     

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151. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     abstract class Pixel[Repr: Manifest] {
     def r(t: Repr): Double // red
     def g(t: Repr): Double // green
     def b(t: Repr): Double // blue
     def a(t: Repr): Double // alpha
     def pack(r: Double,
     g: Double,
     b: Double,
     a: Double): Repr
     ...
     }
     

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152. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     abstract class Pixel[Repr: Manifest] {
     def r(t: Repr): Double // red
     def g(t: Repr): Double // green
     def b(t: Repr): Double // blue
     def a(t: Repr): Double // alpha
     def pack(r: Double,
     g: Double,
     b: Double,
     a: Double): Repr
     ...
     }
     All transformations
     occur on doubles
     

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153. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     abstract class Pixel[Repr: Manifest] {
     def r(t: Repr): Double // red
     def g(t: Repr): Double // green
     def b(t: Repr): Double // blue
     def a(t: Repr): Double // alpha
     def pack(r: Double,
     g: Double,
     b: Double,
     a: Double): Repr
     ...
     }
     All transformations
     occur on doubles
     But the data can be
     encoded differently
     

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154. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     object RGBA extends Pixel[Int] { ... }
     object RGBAExtended extends Pixel[Long] { ... }
     

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155. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     object RGBA extends Pixel[Int] { ... }
     object RGBAExtended extends Pixel[Long] { ... }
     Encoding all channels
     

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156. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     object RGBA extends Pixel[Int] { ... }
     object RGBAExtended extends Pixel[Long] { ... }
     case class DiscreteChannels[T](r: T, g: T, b: T, a: T)
     object FullPixel extends FourChannelPixel[Double]
     object HalfPixel extends FourChannelPixel[Float]
     Encoding all channels
     

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157. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     object RGBA extends Pixel[Int] { ... }
     object RGBAExtended extends Pixel[Long] { ... }
     case class DiscreteChannels[T](r: T, g: T, b: T, a: T)
     object FullPixel extends FourChannelPixel[Double]
     object HalfPixel extends FourChannelPixel[Float]
     Storing channels individually
     Encoding all channels
     

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158. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     

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159. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     "More London Office Development at Dusk, London, UK - Diliff" by Diliff - Own work.
     Licensed under CC BY-SA 3.0 via Wikimedia Commons -
     https://commons.wikimedia.org/wiki/File:More_London_Office_Development_at_Dusk,_London,_UK_-_Diliff.jpg
     

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160. scala-miniboxing.org @miniboxing
     PureImage Mock-up
     PureImage Mock-up
     "More London Office Development at Dusk, London, UK - Diliff" by Diliff - Own work.
     Licensed under CC BY-SA 3.0 via Wikimedia Commons -
     https://commons.wikimedia.org/wiki/File:More_London_Office_Development_at_Dusk,_London,_UK_-_Diliff.jpg
     

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161. scala-miniboxing.org @miniboxing
     scala-miniboxing.org
     Last example is at
     http://scala-miniboxing.org/example_pureimage.html
     

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