Hi, I did a talk on this and conveniently my library caesium wraps the library you're referencing :)
https://www.youtube.com/watch?v=Lf-M1ZH6KME https://github.com/lvh/caesium/ I still think that approach is great particularly for libraries like libsodium where some care was taken to make them easy to FFI. That is typically less true for more complex, often C++, libraries. In that case I would consider JavaCPP, where you basically do more up front work to tell it how it works and it generates JNI for you (up front, not dynamically like jnr). Which one I'd recommend depends on what you're binding. Like I said, for libsodium I think jnr is probably easier to use. lvh On Fri, Dec 4, 2020 at 8:53 AM John Doe <bufferlogh...@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 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/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/CAE_Hg6Z3hefnM4YWmQsYamERnXoZi9L1hJOnPzQD1fjQYMgiBA%40mail.gmail.com.
