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Re: [Pharo-users] [UFFI] Getting an array of opaque structures filled

by Julien Delplanque

No problem, give me as much version(s) to test as you want. :p Julien On 01/07/16 14:00, Esteban Lorenzano wrote: > yes, I made a mistakeâ¦ the problem of not being capable of test here :( > > 1 minute. > > Esteban > >> On 01 Jul 2016, at 13:56, Julien Delplanque <julien(a)tamere.eu> wrote: >> >> Ok, now I get a different exception! :-) >> >> "MessageNotUnderstood: LUDevice class>>fromHandle:" >> >> when executing: "array first." >> >> Where LUDevice is defined like this: >> >> FFIOpaqueObject subclass: #LUDevice >> instanceVariableNames: '' >> classVariableNames: '' >> package: 'LibUsb-Kernel' >> >> Julien >> >> >> On 01/07/16 13:51, Esteban Lorenzano wrote: >>> I need you to test :) >>> >>> can you execute this: >>> >>> (ConfigurationOfUnifiedFFI project version: #development) load. >>> >>> and then retry your example? >>> >>> thanks, >>> Esteban >>> >>> ps: this became pharo-dev, but wellâ¦ still here :) >>> >>>> On 01 Jul 2016, at 13:48, Julien Delplanque <julien(a)tamere.eu> wrote: >>>> >>>> Oh, ok :p >>>> >>>> Can you notify me know when the bug will be resolved? >>>> >>>> Thanks, >>>> >>>> Julien >>>> >>>> >>>> On 01/07/16 13:36, Esteban Lorenzano wrote: >>>>> â¦ and now you hit a bug. >>>>> bah, an ânon implemented featureâ :P >>>>> >>>>> I never tested arrays with complex types. >>>>> it should not be hardâ¦ I will provide a fix. >>>>> >>>>> Esteban >>>>> >>>>> >>>>>> On 01 Jul 2016, at 13:30, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>> >>>>>> Ok, the ffi call is done without problem with your method thanks. :) >>>>>> >>>>>> But now that I have the array, when I try to access the first element using: >>>>>> >>>>>> array first. >>>>>> >>>>>> I get a exception saying I need to override a method: >>>>>> >>>>>> "SubclassResponsibility: FFIOpaqueObjectType had the subclass responsibility to implement #basicHandle:at:" >>>>>> >>>>>> I looked at others implementors but I am not sure of how I should override it, nor if I should. >>>>>> >>>>>> Thanks for the time your taking to answer me. :-) >>>>>> >>>>>> Julien >>>>>> >>>>>> On 01/07/16 12:29, Esteban Lorenzano wrote: >>>>>>>> On 01 Jul 2016, at 12:27, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: >>>>>>>> >>>>>>>> hi, >>>>>>>> >>>>>>>> this is because you want to get an array with opaque objects. Do not let the *** confuses youâ¦ cwhat you actually want, conceptually is something like this: >>>>>>>> >>>>>>>> *((FFIOpaqueObject*)[]) >>>>>>>> >>>>>>>> means: you pass the address of an array of opaque types (who are always pointers). >>>>>>>> >>>>>>>> So, what you need to pass is the address of an arrayâ¦ you will need to work a bit here, since translation is not automatic. >>>>>>>> >>>>>>>> 1) you need to declare your type. Letâ say it will be: >>>>>>>> >>>>>>>> FFIOpaqueObject subclass: USBDevice. >>>>>>>> >>>>>>>> 2) then you need to get the pointer to this array. You need to rewrite you code as this: >>>>>>>> >>>>>>>> arrayPtr := ExternalAddress new. >>>>>>>> size := self getDevice: ctx list: arrayPtr. >>>>>>>> >>>>>>>> getDevice: ctx list: list >>>>>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, void **list)) >>>>>>>> >>>>>>>> NOTE that we change the type to "void **â. This is because this is what you actually want: the array of devices >>>>>>>> >>>>>>>> 3) now you will have size and arrayPtr. Then you declare the array: >>>>>>>> >>>>>>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice >>>>>>> sorry, this expression (while possible) does not stops in âsizeââ¦ it has to be like this, instead: >>>>>>> >>>>>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice size: size. âyou already has the size for the result" >>>>>>> >>>>>>>> â¦ and you should be able to iterate this array normally :) >>>>>>>> >>>>>>>> let me know if this works for youâ¦ Iâm âcoding in mail clientâ, so it can fail :P >>>>>>>> >>>>>>>> cheers, >>>>>>>> Esteban >>>>>>>> >>>>>>>> >>>>>>>>> On 01 Jul 2016, at 12:02, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>>>>> >>>>>>>>> Thanks, it works I get an instance of FFIOpaqueObject. >>>>>>>>> >>>>>>>>> But how do I get a specific libusb_device object from the list? >>>>>>>>> >>>>>>>>> Thanks again for you quick answer :-). >>>>>>>>> >>>>>>>>> Julien >>>>>>>>> >>>>>>>>> On 01/07/16 11:44, Esteban Lorenzano wrote: >>>>>>>>>> Hi, >>>>>>>>>> >>>>>>>>>> an opaque structure is not an FFIExternalObject but an FFIOpaqueObject. >>>>>>>>>> in that case, something like (simplified): >>>>>>>>>> >>>>>>>>>> ctx := (your context). >>>>>>>>>> list := FFIOpaqueObject new. >>>>>>>>>> size := self getDevice: ctx list: list. >>>>>>>>>> >>>>>>>>>> getDevice: ctx list: list >>>>>>>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, FFIOpaqueObject ***list)) >>>>>>>>>> >>>>>>>>>> should work (note that of course you can make libusb_device an alias for your typeâ¦ that does not matters much, this is just a simplification). >>>>>>>>>> >>>>>>>>>> if this does not works, if you can provide me code to reproduce it, I can give it a shot and see what happens :) >>>>>>>>>> >>>>>>>>>> Esteban >>>>>>>>>> >>>>>>>>>>> On 01 Jul 2016, at 11:19, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>>>>>>> >>>>>>>>>>> Hello everyone, >>>>>>>>>>> >>>>>>>>>>> I have a question about the UFFI API. I have the following function: >>>>>>>>>>> >>>>>>>>>>> ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list) >>>>>>>>>>> >>>>>>>>>>> where libusb_device is an opaque structure. >>>>>>>>>>> >>>>>>>>>>> I made a type mapping "ssize_t" -> "int" and an object inheriting >>>>>>>>>>> from FFIExternalObject for the "libusb_context" (others methods >>>>>>>>>>> using it are working). >>>>>>>>>>> >>>>>>>>>>> I can not find how to get an array filled with libusb_device using UFFI from Pharo. :-( >>>>>>>>>>> >>>>>>>>>>> Thanks in advance, >>>>>>>>>>> >>>>>>>>>>> Julien >>>>>>>>>>> >> >

July 1, 2016

Re: [Pharo-users] [UFFI] Getting an array of opaque structures filled

by Esteban Lorenzano

ok, can you reload development version and try again? ps: this is easier on slack ;) > On 01 Jul 2016, at 14:00, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: > > yes, I made a mistakeâ¦ the problem of not being capable of test here :( > > 1 minute. > > Esteban > >> On 01 Jul 2016, at 13:56, Julien Delplanque <julien(a)tamere.eu> wrote: >> >> Ok, now I get a different exception! :-) >> >> "MessageNotUnderstood: LUDevice class>>fromHandle:" >> >> when executing: "array first." >> >> Where LUDevice is defined like this: >> >> FFIOpaqueObject subclass: #LUDevice >> instanceVariableNames: '' >> classVariableNames: '' >> package: 'LibUsb-Kernel' >> >> Julien >> >> >> On 01/07/16 13:51, Esteban Lorenzano wrote: >>> I need you to test :) >>> >>> can you execute this: >>> >>> (ConfigurationOfUnifiedFFI project version: #development) load. >>> >>> and then retry your example? >>> >>> thanks, >>> Esteban >>> >>> ps: this became pharo-dev, but wellâ¦ still here :) >>> >>>> On 01 Jul 2016, at 13:48, Julien Delplanque <julien(a)tamere.eu> wrote: >>>> >>>> Oh, ok :p >>>> >>>> Can you notify me know when the bug will be resolved? >>>> >>>> Thanks, >>>> >>>> Julien >>>> >>>> >>>> On 01/07/16 13:36, Esteban Lorenzano wrote: >>>>> â¦ and now you hit a bug. >>>>> bah, an ânon implemented featureâ :P >>>>> >>>>> I never tested arrays with complex types. >>>>> it should not be hardâ¦ I will provide a fix. >>>>> >>>>> Esteban >>>>> >>>>> >>>>>> On 01 Jul 2016, at 13:30, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>> >>>>>> Ok, the ffi call is done without problem with your method thanks. :) >>>>>> >>>>>> But now that I have the array, when I try to access the first element using: >>>>>> >>>>>> array first. >>>>>> >>>>>> I get a exception saying I need to override a method: >>>>>> >>>>>> "SubclassResponsibility: FFIOpaqueObjectType had the subclass responsibility to implement #basicHandle:at:" >>>>>> >>>>>> I looked at others implementors but I am not sure of how I should override it, nor if I should. >>>>>> >>>>>> Thanks for the time your taking to answer me. :-) >>>>>> >>>>>> Julien >>>>>> >>>>>> On 01/07/16 12:29, Esteban Lorenzano wrote: >>>>>>>> On 01 Jul 2016, at 12:27, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: >>>>>>>> >>>>>>>> hi, >>>>>>>> >>>>>>>> this is because you want to get an array with opaque objects. Do not let the *** confuses youâ¦ cwhat you actually want, conceptually is something like this: >>>>>>>> >>>>>>>> *((FFIOpaqueObject*)[]) >>>>>>>> >>>>>>>> means: you pass the address of an array of opaque types (who are always pointers). >>>>>>>> >>>>>>>> So, what you need to pass is the address of an arrayâ¦ you will need to work a bit here, since translation is not automatic. >>>>>>>> >>>>>>>> 1) you need to declare your type. Letâ say it will be: >>>>>>>> >>>>>>>> FFIOpaqueObject subclass: USBDevice. >>>>>>>> >>>>>>>> 2) then you need to get the pointer to this array. You need to rewrite you code as this: >>>>>>>> >>>>>>>> arrayPtr := ExternalAddress new. >>>>>>>> size := self getDevice: ctx list: arrayPtr. >>>>>>>> >>>>>>>> getDevice: ctx list: list >>>>>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, void **list)) >>>>>>>> >>>>>>>> NOTE that we change the type to "void **â. This is because this is what you actually want: the array of devices >>>>>>>> >>>>>>>> 3) now you will have size and arrayPtr. Then you declare the array: >>>>>>>> >>>>>>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice >>>>>>> sorry, this expression (while possible) does not stops in âsizeââ¦ it has to be like this, instead: >>>>>>> >>>>>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice size: size. âyou already has the size for the result" >>>>>>> >>>>>>>> â¦ and you should be able to iterate this array normally :) >>>>>>>> >>>>>>>> let me know if this works for youâ¦ Iâm âcoding in mail clientâ, so it can fail :P >>>>>>>> >>>>>>>> cheers, >>>>>>>> Esteban >>>>>>>> >>>>>>>> >>>>>>>>> On 01 Jul 2016, at 12:02, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>>>>> >>>>>>>>> Thanks, it works I get an instance of FFIOpaqueObject. >>>>>>>>> >>>>>>>>> But how do I get a specific libusb_device object from the list? >>>>>>>>> >>>>>>>>> Thanks again for you quick answer :-). >>>>>>>>> >>>>>>>>> Julien >>>>>>>>> >>>>>>>>> On 01/07/16 11:44, Esteban Lorenzano wrote: >>>>>>>>>> Hi, >>>>>>>>>> >>>>>>>>>> an opaque structure is not an FFIExternalObject but an FFIOpaqueObject. >>>>>>>>>> in that case, something like (simplified): >>>>>>>>>> >>>>>>>>>> ctx := (your context). >>>>>>>>>> list := FFIOpaqueObject new. >>>>>>>>>> size := self getDevice: ctx list: list. >>>>>>>>>> >>>>>>>>>> getDevice: ctx list: list >>>>>>>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, FFIOpaqueObject ***list)) >>>>>>>>>> >>>>>>>>>> should work (note that of course you can make libusb_device an alias for your typeâ¦ that does not matters much, this is just a simplification). >>>>>>>>>> >>>>>>>>>> if this does not works, if you can provide me code to reproduce it, I can give it a shot and see what happens :) >>>>>>>>>> >>>>>>>>>> Esteban >>>>>>>>>> >>>>>>>>>>> On 01 Jul 2016, at 11:19, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>>>>>>> >>>>>>>>>>> Hello everyone, >>>>>>>>>>> >>>>>>>>>>> I have a question about the UFFI API. I have the following function: >>>>>>>>>>> >>>>>>>>>>> ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list) >>>>>>>>>>> >>>>>>>>>>> where libusb_device is an opaque structure. >>>>>>>>>>> >>>>>>>>>>> I made a type mapping "ssize_t" -> "int" and an object inheriting >>>>>>>>>>> from FFIExternalObject for the "libusb_context" (others methods >>>>>>>>>>> using it are working). >>>>>>>>>>> >>>>>>>>>>> I can not find how to get an array filled with libusb_device using UFFI from Pharo. :-( >>>>>>>>>>> >>>>>>>>>>> Thanks in advance, >>>>>>>>>>> >>>>>>>>>>> Julien >>>>>>>>>>> >>>> >>> >> >> >

July 1, 2016

Re: [Pharo-users] [UFFI] Getting an array of opaque structures filled

by Esteban Lorenzano

yes, I made a mistakeâ¦ the problem of not being capable of test here :( 1 minute. Esteban > On 01 Jul 2016, at 13:56, Julien Delplanque <julien(a)tamere.eu> wrote: > > Ok, now I get a different exception! :-) > > "MessageNotUnderstood: LUDevice class>>fromHandle:" > > when executing: "array first." > > Where LUDevice is defined like this: > > FFIOpaqueObject subclass: #LUDevice > instanceVariableNames: '' > classVariableNames: '' > package: 'LibUsb-Kernel' > > Julien > > > On 01/07/16 13:51, Esteban Lorenzano wrote: >> I need you to test :) >> >> can you execute this: >> >> (ConfigurationOfUnifiedFFI project version: #development) load. >> >> and then retry your example? >> >> thanks, >> Esteban >> >> ps: this became pharo-dev, but wellâ¦ still here :) >> >>> On 01 Jul 2016, at 13:48, Julien Delplanque <julien(a)tamere.eu> wrote: >>> >>> Oh, ok :p >>> >>> Can you notify me know when the bug will be resolved? >>> >>> Thanks, >>> >>> Julien >>> >>> >>> On 01/07/16 13:36, Esteban Lorenzano wrote: >>>> â¦ and now you hit a bug. >>>> bah, an ânon implemented featureâ :P >>>> >>>> I never tested arrays with complex types. >>>> it should not be hardâ¦ I will provide a fix. >>>> >>>> Esteban >>>> >>>> >>>>> On 01 Jul 2016, at 13:30, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>> >>>>> Ok, the ffi call is done without problem with your method thanks. :) >>>>> >>>>> But now that I have the array, when I try to access the first element using: >>>>> >>>>> array first. >>>>> >>>>> I get a exception saying I need to override a method: >>>>> >>>>> "SubclassResponsibility: FFIOpaqueObjectType had the subclass responsibility to implement #basicHandle:at:" >>>>> >>>>> I looked at others implementors but I am not sure of how I should override it, nor if I should. >>>>> >>>>> Thanks for the time your taking to answer me. :-) >>>>> >>>>> Julien >>>>> >>>>> On 01/07/16 12:29, Esteban Lorenzano wrote: >>>>>>> On 01 Jul 2016, at 12:27, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: >>>>>>> >>>>>>> hi, >>>>>>> >>>>>>> this is because you want to get an array with opaque objects. Do not let the *** confuses youâ¦ cwhat you actually want, conceptually is something like this: >>>>>>> >>>>>>> *((FFIOpaqueObject*)[]) >>>>>>> >>>>>>> means: you pass the address of an array of opaque types (who are always pointers). >>>>>>> >>>>>>> So, what you need to pass is the address of an arrayâ¦ you will need to work a bit here, since translation is not automatic. >>>>>>> >>>>>>> 1) you need to declare your type. Letâ say it will be: >>>>>>> >>>>>>> FFIOpaqueObject subclass: USBDevice. >>>>>>> >>>>>>> 2) then you need to get the pointer to this array. You need to rewrite you code as this: >>>>>>> >>>>>>> arrayPtr := ExternalAddress new. >>>>>>> size := self getDevice: ctx list: arrayPtr. >>>>>>> >>>>>>> getDevice: ctx list: list >>>>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, void **list)) >>>>>>> >>>>>>> NOTE that we change the type to "void **â. This is because this is what you actually want: the array of devices >>>>>>> >>>>>>> 3) now you will have size and arrayPtr. Then you declare the array: >>>>>>> >>>>>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice >>>>>> sorry, this expression (while possible) does not stops in âsizeââ¦ it has to be like this, instead: >>>>>> >>>>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice size: size. âyou already has the size for the result" >>>>>> >>>>>>> â¦ and you should be able to iterate this array normally :) >>>>>>> >>>>>>> let me know if this works for youâ¦ Iâm âcoding in mail clientâ, so it can fail :P >>>>>>> >>>>>>> cheers, >>>>>>> Esteban >>>>>>> >>>>>>> >>>>>>>> On 01 Jul 2016, at 12:02, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>>>> >>>>>>>> Thanks, it works I get an instance of FFIOpaqueObject. >>>>>>>> >>>>>>>> But how do I get a specific libusb_device object from the list? >>>>>>>> >>>>>>>> Thanks again for you quick answer :-). >>>>>>>> >>>>>>>> Julien >>>>>>>> >>>>>>>> On 01/07/16 11:44, Esteban Lorenzano wrote: >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> an opaque structure is not an FFIExternalObject but an FFIOpaqueObject. >>>>>>>>> in that case, something like (simplified): >>>>>>>>> >>>>>>>>> ctx := (your context). >>>>>>>>> list := FFIOpaqueObject new. >>>>>>>>> size := self getDevice: ctx list: list. >>>>>>>>> >>>>>>>>> getDevice: ctx list: list >>>>>>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, FFIOpaqueObject ***list)) >>>>>>>>> >>>>>>>>> should work (note that of course you can make libusb_device an alias for your typeâ¦ that does not matters much, this is just a simplification). >>>>>>>>> >>>>>>>>> if this does not works, if you can provide me code to reproduce it, I can give it a shot and see what happens :) >>>>>>>>> >>>>>>>>> Esteban >>>>>>>>> >>>>>>>>>> On 01 Jul 2016, at 11:19, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>>>>>> >>>>>>>>>> Hello everyone, >>>>>>>>>> >>>>>>>>>> I have a question about the UFFI API. I have the following function: >>>>>>>>>> >>>>>>>>>> ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list) >>>>>>>>>> >>>>>>>>>> where libusb_device is an opaque structure. >>>>>>>>>> >>>>>>>>>> I made a type mapping "ssize_t" -> "int" and an object inheriting >>>>>>>>>> from FFIExternalObject for the "libusb_context" (others methods >>>>>>>>>> using it are working). >>>>>>>>>> >>>>>>>>>> I can not find how to get an array filled with libusb_device using UFFI from Pharo. :-( >>>>>>>>>> >>>>>>>>>> Thanks in advance, >>>>>>>>>> >>>>>>>>>> Julien >>>>>>>>>> >>> >> > >

July 1, 2016

Re: [Pharo-users] [UFFI] Getting an array of opaque structures filled

by Julien Delplanque

Ok, now I get a different exception! :-) "MessageNotUnderstood: LUDevice class>>fromHandle:" when executing: "array first." Where LUDevice is defined like this: FFIOpaqueObject subclass: #LUDevice instanceVariableNames: '' classVariableNames: '' package: 'LibUsb-Kernel' Julien On 01/07/16 13:51, Esteban Lorenzano wrote: > I need you to test :) > > can you execute this: > > (ConfigurationOfUnifiedFFI project version: #development) load. > > and then retry your example? > > thanks, > Esteban > > ps: this became pharo-dev, but wellâ¦ still here :) > >> On 01 Jul 2016, at 13:48, Julien Delplanque <julien(a)tamere.eu> wrote: >> >> Oh, ok :p >> >> Can you notify me know when the bug will be resolved? >> >> Thanks, >> >> Julien >> >> >> On 01/07/16 13:36, Esteban Lorenzano wrote: >>> â¦ and now you hit a bug. >>> bah, an ânon implemented featureâ :P >>> >>> I never tested arrays with complex types. >>> it should not be hardâ¦ I will provide a fix. >>> >>> Esteban >>> >>> >>>> On 01 Jul 2016, at 13:30, Julien Delplanque <julien(a)tamere.eu> wrote: >>>> >>>> Ok, the ffi call is done without problem with your method thanks. :) >>>> >>>> But now that I have the array, when I try to access the first element using: >>>> >>>> array first. >>>> >>>> I get a exception saying I need to override a method: >>>> >>>> "SubclassResponsibility: FFIOpaqueObjectType had the subclass responsibility to implement #basicHandle:at:" >>>> >>>> I looked at others implementors but I am not sure of how I should override it, nor if I should. >>>> >>>> Thanks for the time your taking to answer me. :-) >>>> >>>> Julien >>>> >>>> On 01/07/16 12:29, Esteban Lorenzano wrote: >>>>>> On 01 Jul 2016, at 12:27, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: >>>>>> >>>>>> hi, >>>>>> >>>>>> this is because you want to get an array with opaque objects. Do not let the *** confuses youâ¦ cwhat you actually want, conceptually is something like this: >>>>>> >>>>>> *((FFIOpaqueObject*)[]) >>>>>> >>>>>> means: you pass the address of an array of opaque types (who are always pointers). >>>>>> >>>>>> So, what you need to pass is the address of an arrayâ¦ you will need to work a bit here, since translation is not automatic. >>>>>> >>>>>> 1) you need to declare your type. Letâ say it will be: >>>>>> >>>>>> FFIOpaqueObject subclass: USBDevice. >>>>>> >>>>>> 2) then you need to get the pointer to this array. You need to rewrite you code as this: >>>>>> >>>>>> arrayPtr := ExternalAddress new. >>>>>> size := self getDevice: ctx list: arrayPtr. >>>>>> >>>>>> getDevice: ctx list: list >>>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, void **list)) >>>>>> >>>>>> NOTE that we change the type to "void **â. This is because this is what you actually want: the array of devices >>>>>> >>>>>> 3) now you will have size and arrayPtr. Then you declare the array: >>>>>> >>>>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice >>>>> sorry, this expression (while possible) does not stops in âsizeââ¦ it has to be like this, instead: >>>>> >>>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice size: size. âyou already has the size for the result" >>>>> >>>>>> â¦ and you should be able to iterate this array normally :) >>>>>> >>>>>> let me know if this works for youâ¦ Iâm âcoding in mail clientâ, so it can fail :P >>>>>> >>>>>> cheers, >>>>>> Esteban >>>>>> >>>>>> >>>>>>> On 01 Jul 2016, at 12:02, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>>> >>>>>>> Thanks, it works I get an instance of FFIOpaqueObject. >>>>>>> >>>>>>> But how do I get a specific libusb_device object from the list? >>>>>>> >>>>>>> Thanks again for you quick answer :-). >>>>>>> >>>>>>> Julien >>>>>>> >>>>>>> On 01/07/16 11:44, Esteban Lorenzano wrote: >>>>>>>> Hi, >>>>>>>> >>>>>>>> an opaque structure is not an FFIExternalObject but an FFIOpaqueObject. >>>>>>>> in that case, something like (simplified): >>>>>>>> >>>>>>>> ctx := (your context). >>>>>>>> list := FFIOpaqueObject new. >>>>>>>> size := self getDevice: ctx list: list. >>>>>>>> >>>>>>>> getDevice: ctx list: list >>>>>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, FFIOpaqueObject ***list)) >>>>>>>> >>>>>>>> should work (note that of course you can make libusb_device an alias for your typeâ¦ that does not matters much, this is just a simplification). >>>>>>>> >>>>>>>> if this does not works, if you can provide me code to reproduce it, I can give it a shot and see what happens :) >>>>>>>> >>>>>>>> Esteban >>>>>>>> >>>>>>>>> On 01 Jul 2016, at 11:19, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>>>>> >>>>>>>>> Hello everyone, >>>>>>>>> >>>>>>>>> I have a question about the UFFI API. I have the following function: >>>>>>>>> >>>>>>>>> ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list) >>>>>>>>> >>>>>>>>> where libusb_device is an opaque structure. >>>>>>>>> >>>>>>>>> I made a type mapping "ssize_t" -> "int" and an object inheriting >>>>>>>>> from FFIExternalObject for the "libusb_context" (others methods >>>>>>>>> using it are working). >>>>>>>>> >>>>>>>>> I can not find how to get an array filled with libusb_device using UFFI from Pharo. :-( >>>>>>>>> >>>>>>>>> Thanks in advance, >>>>>>>>> >>>>>>>>> Julien >>>>>>>>> >> >

July 1, 2016

Re: [Pharo-users] [UFFI] Getting an array of opaque structures filled

by Esteban Lorenzano

I need you to test :) can you execute this: (ConfigurationOfUnifiedFFI project version: #development) load. and then retry your example? thanks, Esteban ps: this became pharo-dev, but wellâ¦ still here :) > On 01 Jul 2016, at 13:48, Julien Delplanque <julien(a)tamere.eu> wrote: > > Oh, ok :p > > Can you notify me know when the bug will be resolved? > > Thanks, > > Julien > > > On 01/07/16 13:36, Esteban Lorenzano wrote: >> â¦ and now you hit a bug. >> bah, an ânon implemented featureâ :P >> >> I never tested arrays with complex types. >> it should not be hardâ¦ I will provide a fix. >> >> Esteban >> >> >>> On 01 Jul 2016, at 13:30, Julien Delplanque <julien(a)tamere.eu> wrote: >>> >>> Ok, the ffi call is done without problem with your method thanks. :) >>> >>> But now that I have the array, when I try to access the first element using: >>> >>> array first. >>> >>> I get a exception saying I need to override a method: >>> >>> "SubclassResponsibility: FFIOpaqueObjectType had the subclass responsibility to implement #basicHandle:at:" >>> >>> I looked at others implementors but I am not sure of how I should override it, nor if I should. >>> >>> Thanks for the time your taking to answer me. :-) >>> >>> Julien >>> >>> On 01/07/16 12:29, Esteban Lorenzano wrote: >>>>> On 01 Jul 2016, at 12:27, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: >>>>> >>>>> hi, >>>>> >>>>> this is because you want to get an array with opaque objects. Do not let the *** confuses youâ¦ cwhat you actually want, conceptually is something like this: >>>>> >>>>> *((FFIOpaqueObject*)[]) >>>>> >>>>> means: you pass the address of an array of opaque types (who are always pointers). >>>>> >>>>> So, what you need to pass is the address of an arrayâ¦ you will need to work a bit here, since translation is not automatic. >>>>> >>>>> 1) you need to declare your type. Letâ say it will be: >>>>> >>>>> FFIOpaqueObject subclass: USBDevice. >>>>> >>>>> 2) then you need to get the pointer to this array. You need to rewrite you code as this: >>>>> >>>>> arrayPtr := ExternalAddress new. >>>>> size := self getDevice: ctx list: arrayPtr. >>>>> >>>>> getDevice: ctx list: list >>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, void **list)) >>>>> >>>>> NOTE that we change the type to "void **â. This is because this is what you actually want: the array of devices >>>>> >>>>> 3) now you will have size and arrayPtr. Then you declare the array: >>>>> >>>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice >>>> sorry, this expression (while possible) does not stops in âsizeââ¦ it has to be like this, instead: >>>> >>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice size: size. âyou already has the size for the result" >>>> >>>>> â¦ and you should be able to iterate this array normally :) >>>>> >>>>> let me know if this works for youâ¦ Iâm âcoding in mail clientâ, so it can fail :P >>>>> >>>>> cheers, >>>>> Esteban >>>>> >>>>> >>>>>> On 01 Jul 2016, at 12:02, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>> >>>>>> Thanks, it works I get an instance of FFIOpaqueObject. >>>>>> >>>>>> But how do I get a specific libusb_device object from the list? >>>>>> >>>>>> Thanks again for you quick answer :-). >>>>>> >>>>>> Julien >>>>>> >>>>>> On 01/07/16 11:44, Esteban Lorenzano wrote: >>>>>>> Hi, >>>>>>> >>>>>>> an opaque structure is not an FFIExternalObject but an FFIOpaqueObject. >>>>>>> in that case, something like (simplified): >>>>>>> >>>>>>> ctx := (your context). >>>>>>> list := FFIOpaqueObject new. >>>>>>> size := self getDevice: ctx list: list. >>>>>>> >>>>>>> getDevice: ctx list: list >>>>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, FFIOpaqueObject ***list)) >>>>>>> >>>>>>> should work (note that of course you can make libusb_device an alias for your typeâ¦ that does not matters much, this is just a simplification). >>>>>>> >>>>>>> if this does not works, if you can provide me code to reproduce it, I can give it a shot and see what happens :) >>>>>>> >>>>>>> Esteban >>>>>>> >>>>>>>> On 01 Jul 2016, at 11:19, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>>>> >>>>>>>> Hello everyone, >>>>>>>> >>>>>>>> I have a question about the UFFI API. I have the following function: >>>>>>>> >>>>>>>> ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list) >>>>>>>> >>>>>>>> where libusb_device is an opaque structure. >>>>>>>> >>>>>>>> I made a type mapping "ssize_t" -> "int" and an object inheriting >>>>>>>> from FFIExternalObject for the "libusb_context" (others methods >>>>>>>> using it are working). >>>>>>>> >>>>>>>> I can not find how to get an array filled with libusb_device using UFFI from Pharo. :-( >>>>>>>> >>>>>>>> Thanks in advance, >>>>>>>> >>>>>>>> Julien >>>>>>>> >>> >> > >

July 1, 2016

Re: [Pharo-users] [UFFI] Getting an array of opaque structures filled

by Julien Delplanque

Oh, ok :p Can you notify me know when the bug will be resolved? Thanks, Julien On 01/07/16 13:36, Esteban Lorenzano wrote: > â¦ and now you hit a bug. > bah, an ânon implemented featureâ :P > > I never tested arrays with complex types. > it should not be hardâ¦ I will provide a fix. > > Esteban > > >> On 01 Jul 2016, at 13:30, Julien Delplanque <julien(a)tamere.eu> wrote: >> >> Ok, the ffi call is done without problem with your method thanks. :) >> >> But now that I have the array, when I try to access the first element using: >> >> array first. >> >> I get a exception saying I need to override a method: >> >> "SubclassResponsibility: FFIOpaqueObjectType had the subclass responsibility to implement #basicHandle:at:" >> >> I looked at others implementors but I am not sure of how I should override it, nor if I should. >> >> Thanks for the time your taking to answer me. :-) >> >> Julien >> >> On 01/07/16 12:29, Esteban Lorenzano wrote: >>>> On 01 Jul 2016, at 12:27, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: >>>> >>>> hi, >>>> >>>> this is because you want to get an array with opaque objects. Do not let the *** confuses youâ¦ cwhat you actually want, conceptually is something like this: >>>> >>>> *((FFIOpaqueObject*)[]) >>>> >>>> means: you pass the address of an array of opaque types (who are always pointers). >>>> >>>> So, what you need to pass is the address of an arrayâ¦ you will need to work a bit here, since translation is not automatic. >>>> >>>> 1) you need to declare your type. Letâ say it will be: >>>> >>>> FFIOpaqueObject subclass: USBDevice. >>>> >>>> 2) then you need to get the pointer to this array. You need to rewrite you code as this: >>>> >>>> arrayPtr := ExternalAddress new. >>>> size := self getDevice: ctx list: arrayPtr. >>>> >>>> getDevice: ctx list: list >>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, void **list)) >>>> >>>> NOTE that we change the type to "void **â. This is because this is what you actually want: the array of devices >>>> >>>> 3) now you will have size and arrayPtr. Then you declare the array: >>>> >>>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice >>> sorry, this expression (while possible) does not stops in âsizeââ¦ it has to be like this, instead: >>> >>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice size: size. âyou already has the size for the result" >>> >>>> â¦ and you should be able to iterate this array normally :) >>>> >>>> let me know if this works for youâ¦ Iâm âcoding in mail clientâ, so it can fail :P >>>> >>>> cheers, >>>> Esteban >>>> >>>> >>>>> On 01 Jul 2016, at 12:02, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>> >>>>> Thanks, it works I get an instance of FFIOpaqueObject. >>>>> >>>>> But how do I get a specific libusb_device object from the list? >>>>> >>>>> Thanks again for you quick answer :-). >>>>> >>>>> Julien >>>>> >>>>> On 01/07/16 11:44, Esteban Lorenzano wrote: >>>>>> Hi, >>>>>> >>>>>> an opaque structure is not an FFIExternalObject but an FFIOpaqueObject. >>>>>> in that case, something like (simplified): >>>>>> >>>>>> ctx := (your context). >>>>>> list := FFIOpaqueObject new. >>>>>> size := self getDevice: ctx list: list. >>>>>> >>>>>> getDevice: ctx list: list >>>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, FFIOpaqueObject ***list)) >>>>>> >>>>>> should work (note that of course you can make libusb_device an alias for your typeâ¦ that does not matters much, this is just a simplification). >>>>>> >>>>>> if this does not works, if you can provide me code to reproduce it, I can give it a shot and see what happens :) >>>>>> >>>>>> Esteban >>>>>> >>>>>>> On 01 Jul 2016, at 11:19, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>>> >>>>>>> Hello everyone, >>>>>>> >>>>>>> I have a question about the UFFI API. I have the following function: >>>>>>> >>>>>>> ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list) >>>>>>> >>>>>>> where libusb_device is an opaque structure. >>>>>>> >>>>>>> I made a type mapping "ssize_t" -> "int" and an object inheriting >>>>>>> from FFIExternalObject for the "libusb_context" (others methods >>>>>>> using it are working). >>>>>>> >>>>>>> I can not find how to get an array filled with libusb_device using UFFI from Pharo. :-( >>>>>>> >>>>>>> Thanks in advance, >>>>>>> >>>>>>> Julien >>>>>>> >> >

July 1, 2016

Re: [Pharo-users] [UFFI] Getting an array of opaque structures filled

by Esteban Lorenzano

â¦ and now you hit a bug. bah, an ânon implemented featureâ :P I never tested arrays with complex types. it should not be hardâ¦ I will provide a fix. Esteban > On 01 Jul 2016, at 13:30, Julien Delplanque <julien(a)tamere.eu> wrote: > > Ok, the ffi call is done without problem with your method thanks. :) > > But now that I have the array, when I try to access the first element using: > > array first. > > I get a exception saying I need to override a method: > > "SubclassResponsibility: FFIOpaqueObjectType had the subclass responsibility to implement #basicHandle:at:" > > I looked at others implementors but I am not sure of how I should override it, nor if I should. > > Thanks for the time your taking to answer me. :-) > > Julien > > On 01/07/16 12:29, Esteban Lorenzano wrote: >>> On 01 Jul 2016, at 12:27, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: >>> >>> hi, >>> >>> this is because you want to get an array with opaque objects. Do not let the *** confuses youâ¦ cwhat you actually want, conceptually is something like this: >>> >>> *((FFIOpaqueObject*)[]) >>> >>> means: you pass the address of an array of opaque types (who are always pointers). >>> >>> So, what you need to pass is the address of an arrayâ¦ you will need to work a bit here, since translation is not automatic. >>> >>> 1) you need to declare your type. Letâ say it will be: >>> >>> FFIOpaqueObject subclass: USBDevice. >>> >>> 2) then you need to get the pointer to this array. You need to rewrite you code as this: >>> >>> arrayPtr := ExternalAddress new. >>> size := self getDevice: ctx list: arrayPtr. >>> >>> getDevice: ctx list: list >>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, void **list)) >>> >>> NOTE that we change the type to "void **â. This is because this is what you actually want: the array of devices >>> >>> 3) now you will have size and arrayPtr. Then you declare the array: >>> >>> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice >> sorry, this expression (while possible) does not stops in âsizeââ¦ it has to be like this, instead: >> >> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice size: size. âyou already has the size for the result" >> >>> â¦ and you should be able to iterate this array normally :) >>> >>> let me know if this works for youâ¦ Iâm âcoding in mail clientâ, so it can fail :P >>> >>> cheers, >>> Esteban >>> >>> >>>> On 01 Jul 2016, at 12:02, Julien Delplanque <julien(a)tamere.eu> wrote: >>>> >>>> Thanks, it works I get an instance of FFIOpaqueObject. >>>> >>>> But how do I get a specific libusb_device object from the list? >>>> >>>> Thanks again for you quick answer :-). >>>> >>>> Julien >>>> >>>> On 01/07/16 11:44, Esteban Lorenzano wrote: >>>>> Hi, >>>>> >>>>> an opaque structure is not an FFIExternalObject but an FFIOpaqueObject. >>>>> in that case, something like (simplified): >>>>> >>>>> ctx := (your context). >>>>> list := FFIOpaqueObject new. >>>>> size := self getDevice: ctx list: list. >>>>> >>>>> getDevice: ctx list: list >>>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, FFIOpaqueObject ***list)) >>>>> >>>>> should work (note that of course you can make libusb_device an alias for your typeâ¦ that does not matters much, this is just a simplification). >>>>> >>>>> if this does not works, if you can provide me code to reproduce it, I can give it a shot and see what happens :) >>>>> >>>>> Esteban >>>>> >>>>>> On 01 Jul 2016, at 11:19, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>>> >>>>>> Hello everyone, >>>>>> >>>>>> I have a question about the UFFI API. I have the following function: >>>>>> >>>>>> ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list) >>>>>> >>>>>> where libusb_device is an opaque structure. >>>>>> >>>>>> I made a type mapping "ssize_t" -> "int" and an object inheriting >>>>>> from FFIExternalObject for the "libusb_context" (others methods >>>>>> using it are working). >>>>>> >>>>>> I can not find how to get an array filled with libusb_device using UFFI from Pharo. :-( >>>>>> >>>>>> Thanks in advance, >>>>>> >>>>>> Julien >>>>>> >>>> >> > >

July 1, 2016

Re: [Pharo-users] [UFFI] Getting an array of opaque structures filled

by Julien Delplanque

Ok, the ffi call is done without problem with your method thanks. :) But now that I have the array, when I try to access the first element using: array first. I get a exception saying I need to override a method: "SubclassResponsibility: FFIOpaqueObjectType had the subclass responsibility to implement #basicHandle:at:" I looked at others implementors but I am not sure of how I should override it, nor if I should. Thanks for the time your taking to answer me. :-) Julien On 01/07/16 12:29, Esteban Lorenzano wrote: >> On 01 Jul 2016, at 12:27, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: >> >> hi, >> >> this is because you want to get an array with opaque objects. Do not let the *** confuses youâ¦ cwhat you actually want, conceptually is something like this: >> >> *((FFIOpaqueObject*)[]) >> >> means: you pass the address of an array of opaque types (who are always pointers). >> >> So, what you need to pass is the address of an arrayâ¦ you will need to work a bit here, since translation is not automatic. >> >> 1) you need to declare your type. Letâ say it will be: >> >> FFIOpaqueObject subclass: USBDevice. >> >> 2) then you need to get the pointer to this array. You need to rewrite you code as this: >> >> arrayPtr := ExternalAddress new. >> size := self getDevice: ctx list: arrayPtr. >> >> getDevice: ctx list: list >> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, void **list)) >> >> NOTE that we change the type to "void **â. This is because this is what you actually want: the array of devices >> >> 3) now you will have size and arrayPtr. Then you declare the array: >> >> array := FFIExternalArray fromPointer: arrayPtr type: USBDevice > sorry, this expression (while possible) does not stops in âsizeââ¦ it has to be like this, instead: > > array := FFIExternalArray fromPointer: arrayPtr type: USBDevice size: size. âyou already has the size for the result" > >> â¦ and you should be able to iterate this array normally :) >> >> let me know if this works for youâ¦ Iâm âcoding in mail clientâ, so it can fail :P >> >> cheers, >> Esteban >> >> >>> On 01 Jul 2016, at 12:02, Julien Delplanque <julien(a)tamere.eu> wrote: >>> >>> Thanks, it works I get an instance of FFIOpaqueObject. >>> >>> But how do I get a specific libusb_device object from the list? >>> >>> Thanks again for you quick answer :-). >>> >>> Julien >>> >>> On 01/07/16 11:44, Esteban Lorenzano wrote: >>>> Hi, >>>> >>>> an opaque structure is not an FFIExternalObject but an FFIOpaqueObject. >>>> in that case, something like (simplified): >>>> >>>> ctx := (your context). >>>> list := FFIOpaqueObject new. >>>> size := self getDevice: ctx list: list. >>>> >>>> getDevice: ctx list: list >>>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, FFIOpaqueObject ***list)) >>>> >>>> should work (note that of course you can make libusb_device an alias for your typeâ¦ that does not matters much, this is just a simplification). >>>> >>>> if this does not works, if you can provide me code to reproduce it, I can give it a shot and see what happens :) >>>> >>>> Esteban >>>> >>>>> On 01 Jul 2016, at 11:19, Julien Delplanque <julien(a)tamere.eu> wrote: >>>>> >>>>> Hello everyone, >>>>> >>>>> I have a question about the UFFI API. I have the following function: >>>>> >>>>> ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list) >>>>> >>>>> where libusb_device is an opaque structure. >>>>> >>>>> I made a type mapping "ssize_t" -> "int" and an object inheriting >>>>> from FFIExternalObject for the "libusb_context" (others methods >>>>> using it are working). >>>>> >>>>> I can not find how to get an array filled with libusb_device using UFFI from Pharo. :-( >>>>> >>>>> Thanks in advance, >>>>> >>>>> Julien >>>>> >>> >

July 1, 2016

Re: [Pharo-users] [UFFI] Getting an array of opaque structures filled

by Esteban Lorenzano

> On 01 Jul 2016, at 12:27, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: > > hi, > > this is because you want to get an array with opaque objects. Do not let the *** confuses youâ¦ cwhat you actually want, conceptually is something like this: > > *((FFIOpaqueObject*)[]) > > means: you pass the address of an array of opaque types (who are always pointers). > > So, what you need to pass is the address of an arrayâ¦ you will need to work a bit here, since translation is not automatic. > > 1) you need to declare your type. Letâ say it will be: > > FFIOpaqueObject subclass: USBDevice. > > 2) then you need to get the pointer to this array. You need to rewrite you code as this: > > arrayPtr := ExternalAddress new. > size := self getDevice: ctx list: arrayPtr. > > getDevice: ctx list: list > ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, void **list)) > > NOTE that we change the type to "void **â. This is because this is what you actually want: the array of devices > > 3) now you will have size and arrayPtr. Then you declare the array: > > array := FFIExternalArray fromPointer: arrayPtr type: USBDevice sorry, this expression (while possible) does not stops in âsizeââ¦ it has to be like this, instead: array := FFIExternalArray fromPointer: arrayPtr type: USBDevice size: size. âyou already has the size for the result" > > â¦ and you should be able to iterate this array normally :) > > let me know if this works for youâ¦ Iâm âcoding in mail clientâ, so it can fail :P > > cheers, > Esteban > > >> On 01 Jul 2016, at 12:02, Julien Delplanque <julien(a)tamere.eu> wrote: >> >> Thanks, it works I get an instance of FFIOpaqueObject. >> >> But how do I get a specific libusb_device object from the list? >> >> Thanks again for you quick answer :-). >> >> Julien >> >> On 01/07/16 11:44, Esteban Lorenzano wrote: >>> Hi, >>> >>> an opaque structure is not an FFIExternalObject but an FFIOpaqueObject. >>> in that case, something like (simplified): >>> >>> ctx := (your context). >>> list := FFIOpaqueObject new. >>> size := self getDevice: ctx list: list. >>> >>> getDevice: ctx list: list >>> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, FFIOpaqueObject ***list)) >>> >>> should work (note that of course you can make libusb_device an alias for your typeâ¦ that does not matters much, this is just a simplification). >>> >>> if this does not works, if you can provide me code to reproduce it, I can give it a shot and see what happens :) >>> >>> Esteban >>> >>>> On 01 Jul 2016, at 11:19, Julien Delplanque <julien(a)tamere.eu> wrote: >>>> >>>> Hello everyone, >>>> >>>> I have a question about the UFFI API. I have the following function: >>>> >>>> ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list) >>>> >>>> where libusb_device is an opaque structure. >>>> >>>> I made a type mapping "ssize_t" -> "int" and an object inheriting >>>> from FFIExternalObject for the "libusb_context" (others methods >>>> using it are working). >>>> >>>> I can not find how to get an array filled with libusb_device using UFFI from Pharo. :-( >>>> >>>> Thanks in advance, >>>> >>>> Julien >>>> >>> >> >> >

July 1, 2016

Re: [Pharo-users] [UFFI] Getting an array of opaque structures filled

by Esteban Lorenzano

hi, this is because you want to get an array with opaque objects. Do not let the *** confuses youâ¦ cwhat you actually want, conceptually is something like this: *((FFIOpaqueObject*)[]) means: you pass the address of an array of opaque types (who are always pointers). So, what you need to pass is the address of an arrayâ¦ you will need to work a bit here, since translation is not automatic. 1) you need to declare your type. Letâ say it will be: FFIOpaqueObject subclass: USBDevice. 2) then you need to get the pointer to this array. You need to rewrite you code as this: arrayPtr := ExternalAddress new. size := self getDevice: ctx list: arrayPtr. getDevice: ctx list: list ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, void **list)) NOTE that we change the type to "void **â. This is because this is what you actually want: the array of devices 3) now you will have size and arrayPtr. Then you declare the array: array := FFIExternalArray fromPointer: arrayPtr type: USBDevice â¦ and you should be able to iterate this array normally :) let me know if this works for youâ¦ Iâm âcoding in mail clientâ, so it can fail :P cheers, Esteban > On 01 Jul 2016, at 12:02, Julien Delplanque <julien(a)tamere.eu> wrote: > > Thanks, it works I get an instance of FFIOpaqueObject. > > But how do I get a specific libusb_device object from the list? > > Thanks again for you quick answer :-). > > Julien > > On 01/07/16 11:44, Esteban Lorenzano wrote: >> Hi, >> >> an opaque structure is not an FFIExternalObject but an FFIOpaqueObject. >> in that case, something like (simplified): >> >> ctx := (your context). >> list := FFIOpaqueObject new. >> size := self getDevice: ctx list: list. >> >> getDevice: ctx list: list >> ^ self ffiCall: #(size_t libusb_get_device_list (libusb_context *ctx, FFIOpaqueObject ***list)) >> >> should work (note that of course you can make libusb_device an alias for your typeâ¦ that does not matters much, this is just a simplification). >> >> if this does not works, if you can provide me code to reproduce it, I can give it a shot and see what happens :) >> >> Esteban >> >>> On 01 Jul 2016, at 11:19, Julien Delplanque <julien(a)tamere.eu> wrote: >>> >>> Hello everyone, >>> >>> I have a question about the UFFI API. I have the following function: >>> >>> ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list) >>> >>> where libusb_device is an opaque structure. >>> >>> I made a type mapping "ssize_t" -> "int" and an object inheriting >>> from FFIExternalObject for the "libusb_context" (others methods >>> using it are working). >>> >>> I can not find how to get an array filled with libusb_device using UFFI from Pharo. :-( >>> >>> Thanks in advance, >>> >>> Julien >>> >> > >

July 1, 2016