Thank you Chris. It's very helpful. The approach you took for dtype-next is very interesting. This library is closer to my work (numerical computation). Also, the efficient use of Java heap is very interesting although I admit I don't know enough about it. This reminds me of Rich Hickey's emphasis of understanding data structures.
On Friday, December 4, 2020 at 4:52:25 PM UTC+1 ch...@techascent.com wrote: > Ngwua, > > Looking through the caesium bindings just mentioned, it appears the author > dynamically creates an interface and then you can simply ask the native > library to instantiate a concrete implementation of that interface > <https://github.com/lvh/caesium/blob/master/src/caesium/binding.clj#L701>. > So you do not always have to create a class with 'native' methods. > > Integrating with C libraries is part of the reason I wrote dtype-next > <https://github.com/cnuernber/dtype-next> which has the ability to > efficiently write/read from either java heap or native heap storage. > dtype-next has no dependency on either JNA or JNR. > > Hope this helps, > > Chris > > On Fri, Dec 4, 2020 at 7:53 AM John Doe <buffer...@gmail.com> wrote: > >> Hello Everyone, >> >> *Motivation:* I want to invoke C-code functions from Clojure: writing >> Java functions in Clojure. >> >> *Plan of Attack:* Rather than go with the JNI approach I want to >> interface with C-Library via JNR-FFI (https://github.com/jnr/jnr-ffi) >> >> Based on some example of using JNR-FFI >> >> https://github.com/jnr/jnr-ffi-examples/blob/master/getpid/src/main/java/getpid/Getpid.java >> >> https://www.programcreek.com/java-api-examples/?api=jnr.ffi.LibraryLoader >> >> The wrapper in Java might look like >> ``` >> package blahblah; >> >> public class BlahNative { >> private static int[] intDummy; >> private static double[] doubleDummy; >> >> public BlahNative() { >> } >> >> public static native void native_a(char var0, char var1, int var2, int >> var3, int var4, double[] var7, int var8, int var9); >> >> static { >> lib = LibraryLoader >> .create(LibSodium.class) >> .search("/usr/local/lib") >> .search("/opt/local/lib") >> .search("/usr/lib") >> .search("/lib") >> .load(LIBRARY_NAME); >> initializeLibrary(lib); >> } >> } >> ``` >> >> Question: For my package >> ``` >> (defproject mypkg >> :dependencies [[org.clojure/clojure "1.10.1"] >> [com.github.jnr/jnr-ffi "2.2.0"]]) >> ``` >> How do I write the wrapper for the native functions in >> ``` >> (ns mypkg.native >> (:import [jnr.ffi LibraryLoader]) >> (:import [jnr.ffi.annotations IgnoreError]) >> (:import [jnr.ffi.provider FFIProvider])) >> ``` >> For the Java interop I am assuming the above namespace should be based on >> gen-class (http://clojure-doc.org/articles/language/interop.html). >> >> What is not clear to me is: >> *1. How does one create the `native` method* (since most (defn foo) are >> static methods)? >> *2. How do I access the native functions after loading* the Native >> Library (LibraryLoader.load(LIBRARY_NAME))? >> >> I am neither a C nor a Java expert so any guidance will be much >> appreciated. >> >> Thanks, >> Ngwua >> >> -- >> > You received this message because you are subscribed to the Google >> Groups "Clojure" group. >> To post to this group, send email to clo...@googlegroups.com >> Note that posts from new members are moderated - please be patient with >> your first post. >> To unsubscribe from this group, send email to >> clojure+u...@googlegroups.com >> For more options, visit this group at >> http://groups.google.com/group/clojure?hl=en >> --- >> You received this message because you are subscribed to the Google Groups >> "Clojure" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to clojure+u...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/clojure/3bd05d7a-297e-49cf-86d4-aec4a88c83cbn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/clojure/3bd05d7a-297e-49cf-86d4-aec4a88c83cbn%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/clojure/acd1be6c-5156-4316-98e2-e4df9d55566bn%40googlegroups.com.
