common: Make code Java 7 friendly

We can eventually use retrolambda to generate Java 7-compatible class bytecode. Change the few places that currently use Java 8 API.
kohlschutter · Sep 25, 2023 · 87a86d1 · 87a86d1
1 parent f5fabc0
commit 87a86d1
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Showing 8 changed files with 35 additions and 22 deletions.
diff --git a/junixsocket-common/src/main/java/org/newsclub/net/unix/AFFunction.java b/junixsocket-common/src/main/java/org/newsclub/net/unix/AFFunction.java
@@ -0,0 +1,13 @@
+package org.newsclub.net.unix;
+
+@FunctionalInterface
+public interface AFFunction<T, R> {
+
+  /**
+   * Applies this function to the given argument.
+   *
+   * @param t the function argument
+   * @return the function result
+   */
+  R apply(T t);
+}
diff --git a/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSocketAddress.java b/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSocketAddress.java
@@ -37,7 +37,6 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
-import java.util.function.Supplier;
 
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
@@ -647,7 +646,7 @@ static final int unwrapAddressDirectBufferInternal(ByteBuffer socketAddressBuffe
     Objects.requireNonNull(address);
 
     if (!(address instanceof AFSocketAddress)) {
-      Supplier<? extends AFSocketAddress> supp = AFUNIXSocketAddress.supportedAddressSupplier(
+      AFSupplier<? extends AFSocketAddress> supp = AFUNIXSocketAddress.supportedAddressSupplier(
           address);
       address = supp == null ? null : supp.get();
       if (address == null) {

diff --git a/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSupplier.java b/junixsocket-common/src/main/java/org/newsclub/net/unix/AFSupplier.java
@@ -0,0 +1,12 @@
+package org.newsclub.net.unix;
+
+@FunctionalInterface
+interface AFSupplier<T> {
+
+    /**
+     * Gets a result.
+     *
+     * @return a result
+     */
+    T get();
+}
diff --git a/junixsocket-common/src/main/java/org/newsclub/net/unix/AFUNIXSocketAddress.java b/junixsocket-common/src/main/java/org/newsclub/net/unix/AFUNIXSocketAddress.java
@@ -35,7 +35,6 @@
 import java.util.Locale;
 import java.util.Objects;
 import java.util.Set;
-import java.util.function.Supplier;
 
 import org.eclipse.jdt.annotation.NonNull;
 
@@ -331,7 +330,7 @@ public static AFUNIXSocketAddress unwrap(InetAddress address, int port) throws S
   public static AFUNIXSocketAddress unwrap(SocketAddress address) throws SocketException {
     // FIXME: add support for UnixDomainSocketAddress
     Objects.requireNonNull(address);
-    Supplier<AFUNIXSocketAddress> supplier = supportedAddressSupplier(address);
+    AFSupplier<AFUNIXSocketAddress> supplier = supportedAddressSupplier(address);
     if (supplier == null) {
       throw new SocketException("Unsupported address");
     }
@@ -527,7 +526,7 @@ public static boolean isSupportedAddress(SocketAddress addr) {
    * @param addr The address.
    * @return The supplier, or {@code null}.
    */
-  static Supplier<AFUNIXSocketAddress> supportedAddressSupplier(SocketAddress addr) {
+  static AFSupplier<AFUNIXSocketAddress> supportedAddressSupplier(SocketAddress addr) {
     if (addr == null) {
       return null;
     } else if (addr instanceof AFUNIXSocketAddress) {

diff --git a/junixsocket-common/src/main/java/org/newsclub/net/unix/FileDescriptorCast.java b/junixsocket-common/src/main/java/org/newsclub/net/unix/FileDescriptorCast.java
@@ -32,7 +32,6 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
-import java.util.function.Function;
 
 import org.eclipse.jdt.annotation.NonNull;
 
@@ -73,7 +72,7 @@ public final class FileDescriptorCast implements FileDescriptorAccess {
   private static final Map<Class<?>, CastingProviderMap> PRIMARY_TYPE_PROVIDERS_MAP = Collections
       .synchronizedMap(new HashMap<>());
 
-  private static final Function<FileDescriptor, FileInputStream> FD_IS_PROVIDER = System
+  private static final AFFunction<FileDescriptor, FileInputStream> FD_IS_PROVIDER = System
       .getProperty("osv.version") != null ? LenientFileInputStream::new : FileInputStream::new;
 
   private static final CastingProviderMap GLOBAL_PROVIDERS_FINAL = new CastingProviderMap() {

diff --git a/junixsocket-common/src/main/java/org/newsclub/net/unix/NativeUnixSocket.java b/junixsocket-common/src/main/java/org/newsclub/net/unix/NativeUnixSocket.java
@@ -29,8 +29,7 @@
 import java.nio.ByteBuffer;
 import java.nio.channels.SelectionKey;
 import java.nio.channels.spi.AbstractSelectableChannel;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ExecutionException;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.newsclub.net.unix.AFSelector.PollFd;
 
@@ -43,7 +42,7 @@
  * @author Christian Kohlschütter
  */
 final class NativeUnixSocket {
-  private static final CompletableFuture<Boolean> LOADED = new CompletableFuture<>();
+  private static final AtomicBoolean LOADED = new AtomicBoolean(false);
 
   static final int DOMAIN_UNIX = 1;
   static final int DOMAIN_TIPC = 30;
@@ -105,13 +104,7 @@ private NativeUnixSocket() {
   }
 
   static boolean isLoaded() {
-    boolean loadSuccessful;
-    try {
-      loadSuccessful = LOADED.get();
-    } catch (InterruptedException | ExecutionException e) {
-      loadSuccessful = false;
-    }
-    return loadSuccessful;
+    return LOADED.get();
   }
 
   static void ensureSupported() throws UnsupportedOperationException {
@@ -319,6 +312,6 @@ static native boolean initPipe(FileDescriptor source, FileDescriptor sink, boole
   static native int systemResolveCtlId(FileDescriptor fd, String ctlName) throws IOException;
 
   static void setLoaded(boolean successful) {
-    LOADED.complete(successful);
+    LOADED.compareAndSet(false, successful);
   }
 }
diff --git a/junixsocket-common/src/main/java/org/newsclub/net/unix/SocketAddressUtil.java b/junixsocket-common/src/main/java/org/newsclub/net/unix/SocketAddressUtil.java
@@ -20,7 +20,6 @@
 import java.net.SocketAddress;
 import java.net.SocketException;
 import java.net.UnixDomainSocketAddress;
-import java.util.function.Supplier;
 
 /**
  * {@link SocketAddress}-related helper methods.
@@ -38,7 +37,7 @@ private SocketAddressUtil() {
    * @param address The address.
    * @return A supplier for the given address, or {@code null}.
    */
-  static Supplier<AFUNIXSocketAddress> supplyAFUNIXSocketAddress(SocketAddress address) {
+  static AFSupplier<AFUNIXSocketAddress> supplyAFUNIXSocketAddress(SocketAddress address) {
     if (address instanceof UnixDomainSocketAddress) {
       UnixDomainSocketAddress udsa = (UnixDomainSocketAddress) address;
 

diff --git a/junixsocket-common/src/main/java15/org/newsclub/net/unix/SocketAddressUtil.java b/junixsocket-common/src/main/java15/org/newsclub/net/unix/SocketAddressUtil.java
@@ -19,7 +19,6 @@
 
 import java.net.SocketAddress;
 import java.net.SocketException;
-import java.util.function.Supplier;
 
 /**
  * {@link SocketAddress}-related helper methods.
@@ -37,7 +36,7 @@ private SocketAddressUtil() {
    * @param address The address.
    * @return A supplier for the given address, or {@code null}.
    */
-  static Supplier<AFUNIXSocketAddress> supplyAFUNIXSocketAddress(SocketAddress address) {
+  static AFSupplier<AFUNIXSocketAddress> supplyAFUNIXSocketAddress(SocketAddress address) {
     return null;
   }
 }