Usage of primitiveFail is on purpose here because this is the source code
of the (misc) primitive.
So, it's an imperative style to make the primitive fail.

This is confusing if we run the primitive code as a fallback code
(we will run exact same code as primitive which is duplicating the work, if
the primitive really exist, and will fail for same reasons).

I thought we got rid of those MiscprimitivePlugin.
We really should.

Le mar. 28 mai 2019 à 11:09, <commits at source.squeak.org> a écrit :

> A new version of Graphics was added to project The Inbox:
> http://source.squeak.org/inbox/Graphics-cmfcmf.407.mcz
>
> ==================== Summary ====================
>
> Name: Graphics-cmfcmf.407
> Author: cmfcmf
> Time: 28 May 2019, 11:08:38.38585 am
> UUID: 02f1c0df-d0cd-4c46-a8bc-c2cd77ab3ed3
> Ancestors: Graphics-mt.406
>
> Send correct message when primitive fails (>>primitiveFailed instead of
> >>primitiveFail)
>
> I found no other occurrences of >>primitiveFail in the image.
>
> =============== Diff against Graphics-mt.406 ===============
>
> Item was changed:
>   ----- Method: Bitmap>>decompress:fromByteArray:at: (in category
> 'filing') -----
>   decompress: bm fromByteArray: ba at: index
>         "Decompress the body of a byteArray encoded by compressToByteArray
> (qv)...
>         The format is simply a sequence of run-coded pairs, {N D}*.
>                 N is a run-length * 4 + data code.
>                 D, the data, depends on the data code...
>                         0       skip N words, D is absent
>                                 (could be used to skip from one raster
> line to the next)
>                         1       N words with all 4 bytes = D (1 byte)
>                         2       N words all = D (4 bytes)
>                         3       N words follow in D (4N bytes)
>                 S and N are encoded as follows (see decodeIntFrom:)...
>                         0-223   0-223
>                         224-254 (0-30)*256 + next byte (0-7935)
>                         255             next 4 bytes"
>         "NOTE:  If fed with garbage, this routine could read past the end
> of ba, but it should fail before writing past the ned of bm."
>         | i code n anInt data end k pastEnd |
>         <primitive: 'primitiveDecompressFromByteArray' module:
> 'MiscPrimitivePlugin'>
>         <var: #bm type: 'int *'>
>         <var: #ba type: 'unsigned char *'>
>         <var: #anInt type: 'unsigned int'> "Force the type, otherwise it
> is inferred as unsigned char because assigned from ba"
>         <var: #data type: 'unsigned int'>
>         i := index.  "byteArray read index"
>         end := ba size.
>         k := 1.  "bitmap write index"
>         pastEnd := bm size + 1.
>         [i <= end] whileTrue:
>                 ["Decode next run start N"
>                 anInt := ba at: i.  i := i+1.
>                 anInt <= 223 ifFalse:
>                         [anInt <= 254
>                                 ifTrue: [anInt := (anInt-224)*256 + (ba
> at: i).  i := i+1]
>                                 ifFalse: [anInt := 0.
>                                                 1 to: 4 do: [:j | anInt :=
> (anInt bitShift: 8) + (ba at: i).  i := i+1]]].
>                 n := anInt >> 2.
> +               (k + n) > pastEnd ifTrue: [^ self primitiveFailed].
> -               (k + n) > pastEnd ifTrue: [^ self primitiveFail].
>                 code := anInt bitAnd: 3.
>                 code = 0 ifTrue: ["skip"].
>                 code = 1 ifTrue: ["n consecutive words of 4 bytes = the
> following byte"
>                                                 data := ba at: i.  i :=
> i+1.
>                                                 data := data bitOr: (data
> bitShift: 8).
>                                                 data := data bitOr: (data
> bitShift: 16).
>                                                 1 to: n do: [:j | bm at: k
> put: data.  k := k+1]].
>                 code = 2 ifTrue: ["n consecutive words = 4 following bytes"
>                                                 data := 0.
>                                                 1 to: 4 do: [:j | data :=
> (data bitShift: 8) bitOr: (ba at: i).  i := i+1].
>                                                 1 to: n do: [:j | bm at: k
> put: data.  k := k+1]].
>                 code = 3 ifTrue: ["n consecutive words from the data..."
>                                                 1 to: n do:
>                                                         [:m | data := 0.
>                                                         1 to: 4 do: [:j |
> data := (data bitShift: 8) bitOr: (ba at: i).  i := i+1].
>                                                         bm at: k put:
> data.  k := k+1]]]!
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20190528/efdd587c/attachment.html>