# HG changeset patch
# User cin
# Date 2024-06-16 18:42:56
# Node ID 77543ddacb8db657d897e88889df2f22a640605d
# Parent  d3d34ee14dfe865991f6ba9c081347a40ba6000b

Added LazyValue, ExternalTask

diff --git a/common/build.gradle b/common/build.gradle
--- a/common/build.gradle
+++ b/common/build.gradle
@@ -12,6 +12,7 @@ java {
 }
 
 dependencies {
+    compileOnly "org.eclipse.jdt:org.eclipse.jdt.annotation:2.3.0"
     api gradleApi()
 }
 
diff --git a/common/src/main/java/org/implab/gradle/common/tasks/ExecuteTask.java b/common/src/main/java/org/implab/gradle/common/tasks/ExecuteTask.java
new file mode 100644
--- /dev/null
+++ b/common/src/main/java/org/implab/gradle/common/tasks/ExecuteTask.java
@@ -0,0 +1,52 @@
+package org.implab.gradle.common.tasks;
+
+import org.gradle.api.DefaultTask;
+import org.gradle.api.provider.ListProperty;
+import org.gradle.api.tasks.Internal;
+import org.implab.gradle.common.dsl.RedirectFromSpec;
+import org.implab.gradle.common.dsl.RedirectToSpec;
+
+public abstract class ExecuteTask extends DefaultTask  {
+
+    private final RedirectToSpec redirectStderr = new RedirectToSpec();
+
+    private final RedirectToSpec redirectStdout = new RedirectToSpec();
+
+    private final RedirectFromSpec redirectStdin = new RedirectFromSpec();
+
+    @Internal
+    public abstract ListProperty<String> getCommandLine();
+
+
+    /**
+     * STDIN redirection, if not specified, no input will be passed to the command
+     */
+    @Internal
+    public RedirectFromSpec getStdin() {
+        return redirectStdin;
+    }
+
+    /**
+     * STDOUT redirection, if not specified, redirected to logger::info
+     */
+    @Internal
+    public RedirectToSpec getStdout() {
+        return redirectStdout;
+    }
+
+    /**
+     * STDERR redirection, if not specified, redirected to logger::error
+     */
+    @Internal
+    public RedirectToSpec getStderr() {
+        return redirectStderr;
+    }
+
+
+        /** Appends specified parameters to the command line */
+        void commandLine(String... args) {
+            getCommandLine().addAll(args);
+        }
+    
+    
+}
diff --git a/common/src/main/java/org/implab/gradle/common/tasks/ExternalTask.java b/common/src/main/java/org/implab/gradle/common/tasks/ExternalTask.java
new file mode 100644
--- /dev/null
+++ b/common/src/main/java/org/implab/gradle/common/tasks/ExternalTask.java
@@ -0,0 +1,104 @@
+package org.implab.gradle.common.tasks;
+
+import java.io.IOException;
+import java.util.Optional;
+import java.util.concurrent.ExecutionException;
+
+import org.gradle.api.DefaultTask;
+import org.implab.gradle.common.dsl.ProcessSpec;
+import org.implab.gradle.common.exec.Executor;
+import org.implab.gradle.common.exec.RedirectFrom;
+import org.implab.gradle.common.exec.RedirectTo;
+
+public abstract class ExternalTask extends DefaultTask {
+
+    /**
+     * A default redirection to the build log when loglevel is set to INFO,
+     * otherwise returns an empty redirection.
+     */
+    protected Optional<RedirectTo> loggerInfoRedirect() {
+        return getLogger().isInfoEnabled()
+                ? Optional.of(RedirectTo.consumer(getLogger()::info))
+                : Optional.empty();
+    }
+
+    /**
+     * A default redirection to the build log when loglevel is set to ERROR,
+     * otherwise returns an empty redirection. Note that ERROR level is set
+     * by default for a build runs.
+     */
+    protected Optional<RedirectTo> loggerErrorRedirect() {
+        return getLogger().isErrorEnabled()
+                ? Optional.of(RedirectTo.consumer(getLogger()::error))
+                : Optional.empty();
+    }
+
+    /**
+     * Stdout redirection for {@link #exec(ProcessSpec)}, default implementation
+     * will forward stdout to the build log through {@link #loggerErrorRedirect()}
+     */
+    protected Optional<RedirectTo> stdoutRedirection() {
+        return loggerInfoRedirect();
+    }
+
+    /**
+     * Stderr redirection for {@link #exec(ProcessSpec)}, default implementation
+     * will forward stderr to build log through {@link #loggerErrorRedirect()}.
+     */
+    protected Optional<RedirectTo> stderrRedirection() {
+        return loggerErrorRedirect();
+    }
+
+    /**
+     * Stdin redirection for {@link #exec(ProcessSpec)}, empty by default.
+     */
+    protected Optional<RedirectFrom> stdinRedirection() {
+        return Optional.empty();
+    }
+
+    /**
+     * Executes the specified process specification
+     * 
+     * @param spec
+     * @throws InterruptedException
+     * @throws ExecutionException
+     * @throws IOException
+     */
+    protected void exec(ProcessSpec spec) throws InterruptedException, ExecutionException, IOException {
+        var executor = exec();
+
+        stdoutRedirection().ifPresent(executor::stdout);
+        stderrRedirection().ifPresent(executor::stderr);
+        stdinRedirection().ifPresent(executor::stdin);
+
+        getLogger().info("Staring: {}", spec.command());
+
+        spec.accept(executor);
+
+        // runs the command and checks the error code
+        var code = executor.start().get();
+
+        // check success code
+        if (code != 0)
+            throw new IOException("The process exited with error code " + code);
+    }
+
+    protected boolean checkRetCode(ProcessSpec proc, int code)
+            throws InterruptedException, ExecutionException, IOException {
+
+        var executor = exec();
+
+        if (getLogger().isInfoEnabled()) {
+            loggerInfoRedirect().ifPresent(executor::stdout);
+            loggerInfoRedirect().ifPresent(executor::stderr);
+        }
+
+        getLogger().info("Starting: {}", proc.command());
+
+        proc.accept(executor);
+
+        return executor.start().get() == code;
+    }
+
+    protected abstract Executor exec();
+}
diff --git a/common/src/main/java/org/implab/gradle/common/utils/LazyValue.java b/common/src/main/java/org/implab/gradle/common/utils/LazyValue.java
new file mode 100644
--- /dev/null
+++ b/common/src/main/java/org/implab/gradle/common/utils/LazyValue.java
@@ -0,0 +1,29 @@
+package org.implab.gradle.common.utils;
+
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Supplier;
+
+public class LazyValue<T> implements Supplier<T> {
+    private final AtomicReference<T> reference = new AtomicReference<>();
+
+    private final Supplier<T> innerSupplier;
+
+    public LazyValue(Supplier<T> supplier) {
+        this.innerSupplier = supplier;
+    }
+
+    @Override
+    public T get() {
+        var t = reference.get();
+        if (t != null)
+            return t;
+        return updateValue();
+    }
+
+    private T updateValue() {
+        var v = innerSupplier.get();
+        var t = reference.compareAndExchange(null, v);
+        return t != null ? t : v;
+    }
+
+}
diff --git a/settings.gradle b/settings.gradle
--- a/settings.gradle
+++ b/settings.gradle
@@ -8,6 +8,16 @@
  * in the user guide at https://docs.gradle.org/3.5/userguide/multi_project_builds.html
  */
 
+dependencyResolutionManagement {
+    repositories {
+        mavenCentral()
+        mavenLocal()
+        ivy {
+            url "${System.properties["user.home"]}/ivy-repo"
+        }
+    }
+}
+
 rootProject.name = 'gradle-common'
 
 include 'common'