Add jextract module: SQLite bindings generated with jextract, FFM arenas, C strings, out-parameters, errors, upcalls, and a JMH comparison with JNI

jextract-25 early-access build (25-jextract+2-4) on JDK 25.0.5+8 against SQLite 3.45.1: 25 functions and 13 constants generated into 4 committed files (the whole header would be 83 files), a small Db wrapper, the four arena kinds used wrongly on purpose, ADDRESS vs C_POINTER zero-length vs unbounded segments and the SIGSEGV from getString on a NULL pointer, sqlite3_open out-parameter, return codes to exceptions, a sqlite3_exec upcall and the VM exit when it throws, the JDK 25 native-access warning and --illegal-native-access=deny, library loading failures, and a JMH benchmark of FFM vs hand-written JNI vs plain Java (indicative only: shared 2-CPU machine). Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_017ic4b6Kg9RWSTJzyz6KP9X
2026-10-30 16:36:09 +00:00
parent 41101bea40
commit ecceaa8b32
37 changed files with 2867 additions and 0 deletions
@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+# Compile the JNI twin: javac -h generates the header, gcc builds libsqlitejni.so. Output goes to $BUILD (default ./build).
+set -euo pipefail
+unset JAVA_TOOL_OPTIONS
+HERE="$(cd "$(dirname "$0")/.." && pwd)"
+JAVA_HOME="${JAVA_HOME:?set JAVA_HOME to a JDK 25}"
+BUILD="${BUILD:-$HERE/build}"; mkdir -p "$BUILD/jni-classes" "$BUILD/jni-h" "$BUILD/lib"
+"$JAVA_HOME/bin/javac" -h "$BUILD/jni-h" -d "$BUILD/jni-classes" "$HERE/jni/SqliteJni.java"
+gcc -O2 -fPIC -shared -Wall -I"$JAVA_HOME/include" -I"$JAVA_HOME/include/linux" -I"$BUILD/jni-h" \
+    "$HERE/jni/sqlite_jni.c" -o "$BUILD/lib/libsqlitejni.so" -lsqlite3
+echo "built $BUILD/lib/libsqlitejni.so with $(gcc --version | head -1)"