refactor: ptr abstraction

glue/src/e2e.rs

@@ -69,8 +69,7 @@ fn message_ref_should_throw_when_used_after_close(State {runtime, env, client, s
 
   let err = env.exception_occurred().unwrap();
   env.exception_clear().unwrap();
-  assert!(env.is_instance_of(err,
-                             concat!(package!(dev.toad.RefHawk), "$IllegalStorageOfRefError"))
+  assert!(env.is_instance_of(err, concat!(package!(dev.toad.ffi.Ptr), "$ExpiredError"))
              .unwrap());
 }
 

src/main/java/dev.toad/RefHawk.java

@@ -1,89 +0,0 @@
-package dev.toad;
-
-import java.lang.ref.Cleaner;
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Optional;
-
-/**
- * Static class used to track pointers issued by rust code
- *
- * When an object instance containing a pointer tracked by RefHawk
- * is not automatically freed before `RefHawk.ensureReleased` invoked,
- * an error is thrown indicating incorrect usage of an object containing
- * a native pointer.
- */
-public class RefHawk {
-
-  private static final HashSet<Long> addrs = new HashSet<>();
-
-  private RefHawk() {}
-
-  public static class IllegalStorageOfRefError extends Error {
-
-    private static final String fmt =
-      "Instance of %s may not be stored by user code.\n" +
-      "Object was registered by:\n" +
-      ">>>>>>\n" +
-      "%s\n" +
-      "<<<<<<\n";
-
-    IllegalStorageOfRefError(Ptr ptr) {
-      super(String.format(fmt, ptr.clazz, ptr.trace));
-    }
-  }
-
-  public static class Ptr {
-
-    protected final long addr;
-    private final String clazz;
-    private final String trace;
-
-    Ptr(long addr, String clazz, String trace) {
-      this.clazz = clazz;
-      this.addr = addr;
-      this.trace = trace;
-    }
-
-    public long addr() {
-      RefHawk.ensureValid(this);
-      return this.addr;
-    }
-  }
-
-  /**
-   * Associate an object with a raw `long` pointer and a short text
-   * describing the scope in which the object is intended to be valid for
-   * (e.g. "lambda")
-   */
-  public static Ptr register(Class c, long addr) {
-    var trace = Thread.currentThread().getStackTrace();
-    var traceStr = Arrays
-      .asList(trace)
-      .stream()
-      .skip(2)
-      .map(StackTraceElement::toString)
-      .reduce("", (s, tr) -> s == "" ? tr : s + "\n\t" + tr);
-
-    RefHawk.addrs.add(addr);
-    return new Ptr(addr, c.toString(), traceStr);
-  }
-
-  /**
-   * Invokes the cleaning action on the object associated with an address
-   */
-  public static void release(Ptr ptr) {
-    RefHawk.addrs.remove(ptr.addr);
-  }
-
-  /**
-   * Throw `IllegalStorageOfRefError` if object has been leaked
-   * outside of its appropriate context.
-   */
-  public static void ensureValid(Ptr ptr) {
-    if (!RefHawk.addrs.contains(ptr.addr)) {
-      throw new IllegalStorageOfRefError(ptr);
-    }
-  }
-}

src/main/java/dev.toad/ffi/Ptr.java

@@ -0,0 +1,84 @@
+package dev.toad.ffi;
+
+import java.lang.ref.Cleaner;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * A native pointer into the memory region shared between toadlib and the jvm
+ *
+ * Most notably, this ties into all `_Ref` classes' `close()` implementations;
+ * when the toad runtime closes these objects, their pointers are `release()`d.
+ *
+ * Attempts to store and then use one of these Ref objects will throw a
+ * `Ptr.ExpiredError`, as control has since been yielded to Rust code and the
+ * address we had may have been invalidated by it.
+ */
+public class Ptr {
+
+  private static final HashSet<Long> validAddresses = new HashSet<>();
+
+  protected final long addr;
+  private final String clazz;
+  private final String trace;
+
+  /**
+   * Associate a class instance with a native pointer
+   */
+  public static Ptr register(Class c, long addr) {
+    var trace = Thread.currentThread().getStackTrace();
+    var traceStr = Arrays
+      .asList(trace)
+      .stream()
+      .skip(2)
+      .map(StackTraceElement::toString)
+      .reduce("", (s, tr) -> s == "" ? tr : s + "\n\t" + tr);
+
+    Ptr.validAddresses.add(addr);
+    return new Ptr(addr, c.toString(), traceStr);
+  }
+
+  private Ptr(long addr, String clazz, String trace) {
+    this.clazz = clazz;
+    this.addr = addr;
+    this.trace = trace;
+  }
+
+  /**
+   * Invokes the cleaning action on the object associated with an address
+   */
+  public void release() {
+    Ptr.validAddresses.remove(this.addr);
+  }
+
+  /**
+   * Throw `ExpiredError` if object has been leaked
+   * outside of its appropriate context.
+   */
+  public void ensureValid() {
+    if (!Ptr.validAddresses.contains(this.addr)) {
+      throw new ExpiredError(this);
+    }
+  }
+
+  public long addr() {
+    this.ensureValid();
+    return this.addr;
+  }
+
+  public static class ExpiredError extends Error {
+
+    private static final String fmt =
+      "Instance of %s may not be stored by user code.\n" +
+      "Object was registered by:\n" +
+      ">>>>>>\n" +
+      "%s\n" +
+      "<<<<<<\n";
+
+    ExpiredError(Ptr ptr) {
+      super(String.format(fmt, ptr.clazz, ptr.trace));
+    }
+  }
+}

src/main/java/dev.toad/msg/MessageOptionRef.java

@@ -1,7 +1,6 @@
 package dev.toad.msg;
 
-import dev.toad.RefHawk;
-import dev.toad.RefHawk.Ptr;
+import dev.toad.ffi.Ptr;
 import java.util.Arrays;
 import java.util.List;
 
@@ -13,7 +12,7 @@ public class MessageOptionRef implements MessageOption, AutoCloseable {
   private native MessageOptionValueRef[] values(long ptr);
 
   public MessageOptionRef(long addr, long number) {
-    this.ptr = RefHawk.register(this.getClass(), addr);
+    this.ptr = Ptr.register(this.getClass(), addr);
     this.number = number;
   }
 
@@ -35,6 +34,6 @@ public class MessageOptionRef implements MessageOption, AutoCloseable {
 
   @Override
   public void close() {
-    RefHawk.release(this.ptr);
+    this.ptr.release();
   }
 }

src/main/java/dev.toad/msg/MessageOptionValueRef.java

@@ -1,7 +1,6 @@
 package dev.toad.msg;
 
-import dev.toad.RefHawk;
-import dev.toad.RefHawk.Ptr;
+import dev.toad.ffi.Ptr;
 
 public class MessageOptionValueRef
   implements MessageOptionValue, AutoCloseable {
@@ -11,7 +10,7 @@ public class MessageOptionValueRef
   private native byte[] bytes(long addr);
 
   public MessageOptionValueRef(long addr) {
-    this.ptr = RefHawk.register(this.getClass(), addr);
+    this.ptr = Ptr.register(this.getClass(), addr);
   }
 
   public byte[] asBytes() {
@@ -28,6 +27,6 @@ public class MessageOptionValueRef
 
   @Override
   public void close() {
-    RefHawk.release(this.ptr);
+    this.ptr.release();
   }
 }

src/main/java/dev.toad/msg/MessageRef.java

@@ -1,7 +1,6 @@
 package dev.toad.msg;
 
-import dev.toad.RefHawk;
-import dev.toad.RefHawk.Ptr;
+import dev.toad.ffi.Ptr;
 import java.util.Arrays;
 import java.util.List;
 
@@ -29,7 +28,7 @@ public class MessageRef implements Message, AutoCloseable {
   private static native MessageOptionRef[] opts(long addr);
 
   public MessageRef(long addr) {
-    this.ptr = RefHawk.register(this.getClass(), addr);
+    this.ptr = Ptr.register(this.getClass(), addr);
   }
 
   public Message clone() {
@@ -70,6 +69,6 @@ public class MessageRef implements Message, AutoCloseable {
 
   @Override
   public void close() {
-    RefHawk.release(this.ptr);
+    this.ptr.release();
   }
 }