[squeak-dev] The Trunk: Network-topa.165.mcz

Eliot Miranda eliot.miranda at gmail.com
Mon Nov 2 16:04:26 UTC 2015


Bravo!

_,,,^..^,,,_ (phone)

> On Oct 24, 2015, at 7:29 AM, commits at source.squeak.org wrote:
> 
> Tobias Pape uploaded a new version of Network to project The Trunk:
> http://source.squeak.org/trunk/Network-topa.165.mcz
> 
> ==================== Summary ====================
> 
> Name: Network-topa.165
> Author: topa
> Time: 19 October 2015, 11:28:20.052 pm
> UUID: b4b1febc-df00-4213-b76f-c007b06bb2e2
> Ancestors: Network-ul.164
> 
> Simplify and speed up non-primitive UUID generation (hat-tip to Martin McClure <martin.mcclure at gemtalksystems.com>)
> 
> Instead of generating all parts of the UUID separately, we generate
> a single, 128-bit number and modify it slightly to match the UUID definition.
> This complies with RFC 4122, Sec. 4.4.
> 
> This approach is 2500 times faster than the old method and only about 3 times
> slower than the primitive. Hence, we disable the primitive and no longer need
> to rely on the UUIDPlugin to be present.
> 
> Informational: The Timings:
> 
> {
> 'Pure allocation' -> [UUID basicNew: 16] bench.
> 'Primitive + alloc' -> [(UUID basicNew: 16) primMakeUUID] bench.
> 'Old +  alloc' -> [|u| u := (UUID basicNew: 16). UUIDGeneratorOld new generateBytes: u forVersion: 4] bench.
> 'New + alloc' -> [|u| u := (UUID basicNew: 16). UUIDGeneratorNew new generateBytes: u forVersion: 4] bench.
> }. 
> "{
> 'Pure allocation'->'56,500,000 per second. 17.7 nanoseconds per run.' .
> 'Primitive + alloc'->'1,510,000 per second. 663 nanoseconds per run.' . 
> 'Old +  alloc'->'202 per second. 4.95 milliseconds per run.' . 
> 'New + alloc'->'519,000 per second. 1.93 microseconds per run.'
> }."
> 
> =============== Diff against Network-ul.164 ===============
> 
> Item was changed:
>  ----- Method: String>>asAlphaNumeric:extraChars:mergeUID: (in category '*network-uuid') -----
>  asAlphaNumeric: totalSize extraChars: additionallyAllowed mergeUID: minimalSizeOfRandomPart
>      "Generates a String with unique identifier ( UID ) qualities, the difference to a
>       UUID is that its beginning is derived from the receiver, so that it has a meaning
>       for a human reader.
> 
>       Answers a String of totalSize, which consists of 3 parts
>       1.part: the beginning of the receiver only consisting of
>          a-z, A-Z, 0-9 and extraChars in Collection additionallyAllowed ( which can be nil )
>       2.part: a single _
>       3.part: a ( random ) UID of size >= minimalSizeOfRandomPart consisting of
>          a-z, A-Z, 0-9
> 
>       Starting letters are capitalized. 
>       TotalSize must be at least 1.
>       Exactly 1 occurrence of $_ is guaranteed ( unless additionallyAllowed includes $_ ).
>       The random part has even for small sizes good UID qualitites for many practical purposes.
>       If only lower- or uppercase letters are demanded, simply convert the answer with
>       say #asLowercase. The probability of a duplicate will rise only moderately ( see below ).
> 
>       Example: 
>          size of random part = 10
>          in n generated UIDs the chance p of having non-unique UIDs is
>              n = 10000 ->  p < 1e-10        if answer is reduced to lowerCase: p < 1.4 e-8
>              n = 100000 -> p < 1e-8
>          at the bottom is a snippet for your own calculations  
>          Note: the calculated propabilites are theoretical,
>              for the actually used random generator they may be much worse"
> 
>      | stream out sizeOfFirstPart index ascii ch skip array random |
>      totalSize > minimalSizeOfRandomPart 
>          ifFalse: [ self errorOutOfBounds ].
>      stream := ReadStream on: self.
>      out := WriteStream on: ( String new: totalSize ).
>      index := 0.
>      skip := true.
>      sizeOfFirstPart := totalSize - minimalSizeOfRandomPart - 1.
>      [ stream atEnd or: [ index >= sizeOfFirstPart ]]
>      whileFalse: [
>          ((( ascii := ( ch := stream next ) asciiValue ) >= 65 and: [ ascii <= 90 ]) or: [
>              ( ascii >= 97 and: [ ascii <= 122 ]) or: [             
>              ch isDigit or: [
>              additionallyAllowed notNil and: [ additionallyAllowed includes: ch ]]]])
>          ifTrue: [
>              skip
>                  ifTrue: [ out nextPut: ch asUppercase ]
>                  ifFalse: [ out nextPut: ch ].
>              index := index + 1.
>              skip := false ]
>          ifFalse: [ skip := true ]].
>      out nextPut: $_.
>      array := Array new: 62.
>      1 to: 26 do: [ :i |
>          array at: i put: ( i + 64 ) asCharacter.
>          array at: i + 26 put: ( i + 96 ) asCharacter ].
>      53 to: 62 do: [ :i |
>          array at: i put: ( i - 5 ) asCharacter ].
> +    random := ThreadSafeRandom value. 
> -    random := UUIDGenerator default randomGenerator. 
>      totalSize - index - 1 timesRepeat: [
>          out nextPut: ( array atRandom: random )].
>      ^out contents
> 
>      "    calculation of probability p for failure of uniqueness in n UIDs
>          Note: if answer will be converted to upper or lower case replace 62 with 36
>      | n i p all |
>      all := 62 raisedTo: sizeOfRandomPart.
>      i := 1.
>      p := 0.0 .
>      n := 10000.
>      [ i <= n ]
>      whileTrue: [
>          p := p + (( i - 1 ) / all ).
>          i := i + 1 ].
>      p   
> 
>      approximation formula: n squared / ( 62.0 raisedTo: sizeOfRandomPart ) / 2 
>      " 
> 
>      "'Crop SketchMorphs and Grab Screen Rect to JPG' 
>              asAlphaNumeric: 31 extraChars: nil mergeUID: 10  
>                  'CropSketchMorphsAndG_iOw94jquN6'
>       'Monticello' 
>              asAlphaNumeric: 31 extraChars: nil mergeUID: 10    
>                  'Monticello_kp6aV2l0IZK9uBULGOeG' 
>       'version-', ( '1.1.2' replaceAll: $. with: $- )
>              asAlphaNumeric: 31 extraChars: #( $- ) mergeUID: 10    
>                  'Version-1-1-2_kuz2tMg2xX9iRLDVR'"
>          !
> 
> Item was changed:
>  ----- Method: UUID>>initialize (in category 'initalize-release') -----
>  initialize
> +    self makeUUID.!
> -    self primMakeUUID.!
> 
> Item was added:
> + ----- Method: UUID>>makeUUID (in category 'as yet unclassified') -----
> + makeUUID
> +    UUIDGenerator default generateBytes: self forVersion: 4.!
> 
> Item was changed:
>  ----- Method: UUID>>primMakeUUID (in category 'system primitives') -----
>  primMakeUUID
>      <primitive: 'primitiveMakeUUID' module: 'UUIDPlugin'>
> +    self makeUUID!
> -    UUIDGenerator default generateBytes: self forVersion: 4.!
> 
> Item was changed:
>  Object subclass: #UUIDGenerator
> +    instanceVariableNames: 'bits'
> +    classVariableNames: 'Default TheRandom TheSemaphore'
> -    instanceVariableNames: 'timeLow timeMid timeHiAndVersion clockSeqHiAndReserved clockSeqLow node randomCounter randomGenerator semaphoreForGenerator'
> -    classVariableNames: 'Default'
>      poolDictionaries: ''
>      category: 'Network-UUID'!
> 
> + !UUIDGenerator commentStamp: 'topa 10/19/2015 23:23:19' prior: 0!
> + I generate a pseudo-random UUID by asking Random for a 128 bit value.
> - !UUIDGenerator commentStamp: '<historical>' prior: 0!
> - This class generates a pseudo-random UUID
> - by John M McIntosh johnmci at smalltalkconsulting.com
> 
> + See https://tools.ietf.org/html/rfc4122.html#section-4.4 for reference.!
> - See http://www.webdav.org/specs/draft-leach-uuids-guids-01.txt!
> 
> Item was changed:
>  ----- Method: UUIDGenerator class>>initialize (in category 'class initialization') -----
>  initialize
> +    TheRandom := Random new.
> +    TheSemaphore := Semaphore forMutualExclusion.
>      Smalltalk addToStartUpList: self after: nil.!
> 
> Item was changed:
>  ----- Method: UUIDGenerator>>generateFieldsVersion4 (in category 'instance creation') -----
>  generateFieldsVersion4
> +  
> +    TheSemaphore critical: [
> +        bits := 16rffffffffffffffffffffffffffffffff atRandom: TheRandom. "128 bit"].!
> - 
> -    timeLow := self generateRandomBitsOfLength: 32.
> -    timeMid := self generateRandomBitsOfLength: 16.
> -    timeHiAndVersion := 16r4000 bitOr: (self generateRandomBitsOfLength: 12).
> -    clockSeqHiAndReserved := 16r80 bitOr: (self generateRandomBitsOfLength: 6).
> -    clockSeqLow := self generateRandomBitsOfLength: 8.
> -    node := self generateRandomBitsOfLength: 48.
> -    !
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>generateOneOrZero (in category 'generator') -----
> - generateOneOrZero
> -    ^self semaphoreForGenerator
> -        critical: [| value | 
> -            value := self randomGenerator next.
> -            self randomCounter: self randomCounter + 1.
> -            self randomCounter > 100000
> -                ifTrue: [self setupRandom].
> -            value < 0.5
> -                ifTrue: [0]
> -                ifFalse: [1]].!
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>generateRandomBitsOfLength: (in category 'generator') -----
> - generateRandomBitsOfLength: aNumberOfBits
> - | target |
> -    target := 0.
> -    aNumberOfBits isZero ifTrue: [^target].
> -    target := self generateOneOrZero.
> -    (aNumberOfBits - 1)  timesRepeat:
> -        [target := (target bitShift: 1)  bitOr: self generateOneOrZero].
> -    ^target!
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>initialize (in category 'instance creation') -----
> - initialize
> -    self setupRandom.
> -    semaphoreForGenerator := Semaphore forMutualExclusion.
> -    !
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>makeSeed (in category 'random seed') -----
> - makeSeed
> -    "Try various methods of getting good seeds"
> -    | seed |
> -    seed := self makeUnixSeed.
> -    seed ifNotNil: [^seed].
> - 
> -    "not sure if this is reliably random... commented out for now. -dew"
> -    "seed := self makeSeedFromSound.
> -    seed ifNotNil: [^seed]."
> -    
> -    "default"
> -    [seed := (Time millisecondClockValue bitAnd: 16r3FFFFFFF) bitXor: self hash.
> -    seed := seed bitXor: (Time totalSeconds bitAnd: 16r3FFFFFFF).
> -    seed = 0] whileTrue: ["Try again if ever get a seed = 0"].
> - 
> -    ^seed
> - !
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>makeSeedFromSound (in category 'random seed') -----
> - makeSeedFromSound
> -    ^[SoundService default randomBitsFromSoundInput: 32]
> -        ifError: [nil].!
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>makeUnixSeed (in category 'random seed') -----
> - makeUnixSeed
> -    
> -    ^[
> -        StandardFileStream readOnlyFileNamed: '/dev/urandom' do: [ :stream |
> -            stream binary.
> -            (Integer
> -                byte1: stream next
> -                byte2: stream next
> -                byte3: stream next
> -                byte4: stream next) ] ] 
> -        on: Error
> -        do: [ nil ]!
> 
> Item was changed:
>  ----- Method: UUIDGenerator>>placeFields: (in category 'instance creation') -----
>  placeFields: aByteArray
> 
> +    | version fixed |
> +    bits isLarge
> +        ifTrue: [    aByteArray replaceFrom: 1 to: bits size with: bits]
> +        ifFalse: [aByteArray unsignedLongAt: 1 put: bits bigEndian: false].
> + 
> +    version := ((aByteArray at: 7) bitAnd: 16r0F) bitOr: 16r40. "Version 4"
> +    fixed := ((aByteArray at: 9) bitAnd: 16r3F) bitOr: 16r80. "Fixed 8..b value"
> +    aByteArray
> +        at: 7 put: version;
> +        at: 9 put: fixed.!
> -    aByteArray at: 1 put: ((timeLow bitShift: -24) bitAnd: 16rFF).
> -    aByteArray at: 2 put: ((timeLow bitShift: -16) bitAnd: 16rFF).
> -    aByteArray at: 3 put: ((timeLow bitShift: -8) bitAnd: 16rFF).
> -    aByteArray at: 4 put: (timeLow bitAnd: 16rFF).
> -    aByteArray at: 5 put: ((timeMid bitShift: -8) bitAnd: 16rFF).
> -    aByteArray at: 6 put: (timeMid bitAnd: 16rFF).
> -    aByteArray at: 7 put: ((timeHiAndVersion bitShift: -8) bitAnd: 16rFF).
> -    aByteArray at: 8 put: (timeHiAndVersion bitAnd: 16rFF).
> -    aByteArray at: 9 put: clockSeqHiAndReserved.
> -    aByteArray at: 10 put: clockSeqLow.
> -    0 to: 5 do: [:i |
> -        aByteArray at: 11 + i put: ((node bitShift: (-8*i)) bitAnd: 16rFF)]
> - !
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>randomCounter (in category 'accessors and mutators') -----
> - randomCounter
> -    ^randomCounter!
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>randomCounter: (in category 'accessors and mutators') -----
> - randomCounter: aNumber
> -    randomCounter := aNumber
> - !
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>randomGenerator (in category 'accessors and mutators') -----
> - randomGenerator
> -    ^randomGenerator
> - !
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>randomGenerator: (in category 'accessors and mutators') -----
> - randomGenerator: aGenerator
> -    randomGenerator := aGenerator
> - !
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>semaphoreForGenerator (in category 'accessors and mutators') -----
> - semaphoreForGenerator
> -    ^semaphoreForGenerator!
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>semaphoreForGenerator: (in category 'accessors and mutators') -----
> - semaphoreForGenerator: aSema
> -    semaphoreForGenerator := aSema
> - !
> 
> Item was removed:
> - ----- Method: UUIDGenerator>>setupRandom (in category 'instance creation') -----
> - setupRandom
> -    randomCounter := 0.
> -    randomGenerator := Random seed: self makeSeed.!
> 
> 


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