simplify java api (#155)

Author: erdos

java-src/io/github/erdos/stencil/API.java

@@ -1,7 +1,7 @@
 package io.github.erdos.stencil;
 
 import io.github.erdos.stencil.functions.Function;
-import io.github.erdos.stencil.impl.NativeEvaluator;
+import io.github.erdos.stencil.functions.FunctionEvaluator;
 import io.github.erdos.stencil.impl.NativeTemplateFactory;
 
 import java.io.File;
@@ -57,10 +57,10 @@ public static EvaluatedDocument render(PreparedTemplate template, Map<String, Pr
     }
 
     public static EvaluatedDocument render(PreparedTemplate template, Map<String, PreparedFragment> fragments, TemplateData data, Collection<Function> customFunctions) {
-        final NativeEvaluator evaluator = new NativeEvaluator();
+        FunctionEvaluator function = new FunctionEvaluator();
         if (customFunctions != null) {
-            evaluator.getFunctionEvaluator().registerFunctions(customFunctions.toArray(new Function[0]));
+            function.registerFunctions(customFunctions.toArray(new Function[0]));
         }
-        return evaluator.render(template, fragments, data);
+        return template.render(fragments, function, data);
     }
 }

java-src/io/github/erdos/stencil/EvaluatedDocument.java

@@ -4,17 +4,14 @@
 
 import java.io.*;
 import java.util.concurrent.ExecutorService;
-import java.util.function.Consumer;
 
 /**
  * An evaluated document ready to be converted to the final output format.
  */
 @SuppressWarnings("unused")
 public interface EvaluatedDocument {
 
-    TemplateDocumentFormats getFormat();
-
-    Consumer<OutputStream> getWriter();
+    void write(OutputStream target);
 
     /**
      * Writes output of this document to a file
@@ -24,14 +21,10 @@ default void writeToFile(File output) throws IOException {
             throw new IllegalArgumentException("Output file already exists: " + output);
         }
         try (FileOutputStream fos = new FileOutputStream(output)) {
-            writeToStream(fos);
+            write(fos);
         }
     }
 
-    default void writeToStream(OutputStream outputStream) {
-        getWriter().accept(outputStream);
-    }
-
     /**
      * Creates a blocking input stream that can be used to render generated document.
      *
@@ -59,7 +52,7 @@ default InputStream toInputStream(ExecutorService executorService) {
                 throw new IllegalStateException("The supplied executor must submit jobs to new threads!");
             } else {
                 try {
-                    writeToStream(outputStream);
+                    write(outputStream);
                 } catch (Throwable e) {
                     inputStreamErrors.fail(e);
                     throw e;

java-src/io/github/erdos/stencil/PreparedFragment.java

@@ -1,43 +1,13 @@
 package io.github.erdos.stencil;
 
-import io.github.erdos.stencil.impl.FileHelper;
-
-import java.io.File;
-import java.util.concurrent.atomic.AtomicBoolean;
-
-public final class PreparedFragment implements AutoCloseable {
-
-    private final Object content;
-    private final File zipDirResource;
-    private final AtomicBoolean alive = new AtomicBoolean(true);
-
-    public PreparedFragment(Object content, File zipDirResource) {
-        this.content = content;
-        this.zipDirResource = zipDirResource;
-    }
-
-    public Object getImpl() {
-        if (!alive.get()) {
-            throw new IllegalStateException("Can not render destroyed fragment!");
-        } else {
-            return content;
-        }
-    }
+public interface PreparedFragment extends AutoCloseable {
 
     /**
-     * Makes the template clean up any resources allocated for it.
+     * Makes the template clean up resources allocated for it.
      * <p>
      * Subsequent invocations of this method have no effects. Rendering the template after this method call will throw
      * an IllegalStateException.
      */
-    public void cleanup() {
-        if (alive.compareAndSet(true, false)) {
-            FileHelper.forceDelete(zipDirResource);
-        }
-    }
-
     @Override
-    public void close() {
-        cleanup();
-    }
+    void close();
 }

java-src/io/github/erdos/stencil/PreparedTemplate.java

@@ -1,15 +1,18 @@
 package io.github.erdos.stencil;
 
+import io.github.erdos.stencil.functions.FunctionEvaluator;
+
 import java.io.File;
 import java.time.LocalDateTime;
+import java.util.Map;
 
 /**
  * Represents an already preprocessed template file.
  * <p>
  * These files may be serialized or cached for later use.
  */
 @SuppressWarnings("unused")
-public interface PreparedTemplate extends AutoCloseable{
+public interface PreparedTemplate extends AutoCloseable {
 
     /**
      * Original template file that was preprocessed.
@@ -32,16 +35,7 @@ default TemplateDocumentFormats getTemplateFormat() {
      *
      * @return template preprocess call time
      */
-    LocalDateTime creationDateTime();
-
-    /**
-     * Contains the preprocess result.
-     * <p>
-     * Implementation detail. May be used for serializing these objects. May be used for debugging too.
-     *
-     * @return inner representation of prepared template
-     */
-    Object getSecretObject();
+    LocalDateTime creationDateTime(); // TODO: remove?
 
 
     /**
@@ -50,20 +44,15 @@ default TemplateDocumentFormats getTemplateFormat() {
     TemplateVariables getVariables();
 
     /**
-     * Makes the template clean up any resources allocated for it. Subsequential invocations of this method have no
-     * effects. Rendering the template after this method call will throw an IllegalStateException.
+     * Makes the template clean up any resources allocated for it.
+     * Subsequent invocations of this method have no effects.
+     * Rendering the template after this method call will throw an IllegalStateException.
      */
-    void cleanup();
+    @Override
+    void close();
 
     /**
      * Renders the current prepared template file with the given template data.
      */
-    default EvaluatedDocument render(TemplateData templateData) {
-        return API.render(this, templateData);
-    }
-
-    @Override
-    default void close() {
-        cleanup();
-    }
+    EvaluatedDocument render(Map<String, PreparedFragment> fragments, FunctionEvaluator function, TemplateData templateData);
 }

java-src/io/github/erdos/stencil/TemplateVariables.java

@@ -35,7 +35,7 @@ private TemplateVariables(Set<String> variables, Set<String> fragmentNames) {
         root = r;
     }
 
-    private Node reduce(Node originalNode, String path) {
+    private static Node reduce(Node originalNode, String path) {
         if (path.isEmpty())
             return LEAF;
         else if (originalNode == null)
@@ -151,7 +151,7 @@ private List<SchemaError> validate(Object data, Node schema) {
         return validateImpl("", data, schema).collect(toList());
     }
 
-    private Stream<SchemaError> validateImpl(String path, Object data, Node schema) {
+    private static Stream<SchemaError> validateImpl(String path, Object data, Node schema) {
         return schema.accept(new NodeVisitor<Stream<SchemaError>>() {
             @Override
             public Stream<SchemaError> visitArray(Node wrapped) {

java-src/io/github/erdos/stencil/impl/CachingTemplateFactory.java

@@ -37,7 +37,7 @@ public PreparedTemplate prepareTemplateFile(File templateFile, PrepareOptions op
             PreparedTemplate stored = cache.get(templateFile);
             if (stored.creationDateTime().toEpochSecond(ZoneOffset.UTC) <= templateFile.lastModified()) {
                 // TODO: this is so not thread safe.
-                stored.cleanup();
+                stored.close();
                 stored = templateFactory.prepareTemplateFile(templateFile, options);
                 cache.put(templateFile, stored);
             }

java-src/io/github/erdos/stencil/impl/ClojureHelper.java

@@ -1,12 +1,9 @@
 package io.github.erdos.stencil.impl;
 
 import clojure.lang.IFn;
-import clojure.lang.Keyword;
 import clojure.lang.RT;
 import clojure.lang.Symbol;
 
-import java.util.Map;
-
 /**
  * Clojure utilities.
  */
@@ -15,20 +12,6 @@ public final class ClojureHelper {
 
     private ClojureHelper() {}
 
-    enum Keywords {
-        DATA, FUNCTION, FRAGMENTS, TEMPLATE, VARIABLES, SOURCE_FOLDER, WRITER;
-
-        public final Keyword kw = Keyword.intern(name().toLowerCase().replace('_', '-'));
-
-        public final <V> V getOrThrow(Map<?, V> m) {
-            if (!m.containsKey(kw)) {
-                throw new IllegalArgumentException("Map does not contain keyword " + kw);
-            } else {
-                return m.get(kw);
-            }
-        }
-    }
-
     // requires stencil.process namespace so stencil is loaded.
     static {
         final IFn req = RT.var("clojure.core", "require");

java-src/io/github/erdos/stencil/impl/DeleteOnCloseFileInputStream.java

@@ -101,22 +101,6 @@ public static void forceDelete(final File file) {
         file.delete();
     }
 
-    /**
-     * Recursively marks a directory or a file for deletion on exit.
-     *
-     * @param file to delete, not null
-     * @throws NullPointerException on null or invalid file
-     */
-    @SuppressWarnings({"ConstantConditions"})
-    public static void forceDeleteOnExit(final File file) {
-        file.deleteOnExit();
-        if (file.isDirectory()) {
-            for (File child : file.listFiles()) {
-                forceDeleteOnExit(child);
-            }
-        }
-    }
-
     /**
      * Returns a string representation of path with unix separators ("/") instead of the
      * system-dependent separators (which is backslash on Windows).

java-src/io/github/erdos/stencil/impl/FileHelper.java

@@ -0,0 +1,59 @@
+package io.github.erdos.stencil.impl;
+
+import java.util.*;
+import java.util.concurrent.Callable;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+public final class LifecycleLock implements AutoCloseable {
+
+    private final ReadWriteLock lock;
+    private final AtomicBoolean alive;
+    private final Runnable cleanup;
+
+    public LifecycleLock(Runnable cleanup) {
+        this.lock = new ReentrantReadWriteLock();
+        this.alive = new AtomicBoolean(true);
+        this.cleanup = Objects.requireNonNull(cleanup);
+    }
+
+    public static <T> T execute(List<LifecycleLock> locks, Callable<T> supplier) throws Exception {
+        if (locks.isEmpty()) {
+            return supplier.call();
+        } else {
+            ListIterator<LifecycleLock> iterator = locks.listIterator();
+            try {
+                while (iterator.hasNext()) {
+                    iterator.next().acquireReadLockAndCheck();
+                }
+                return supplier.call();
+            } finally {
+                while (iterator.hasPrevious()) {
+                    iterator.previous().lock.readLock().unlock();
+                }
+            }
+        }
+    }
+
+    private void acquireReadLockAndCheck() {
+        lock.readLock().lock();
+        if (!alive.get()) { // we DO NOT release read lock, because it will be released in finally block!
+            throw new IllegalStateException("Component has already been closed.");
+        }
+    }
+
+    @Override
+    public void close() throws Exception {
+        if (alive.get()) {
+            lock.writeLock().lock();
+            try {
+                if (alive.getAndSet(false)) {
+                    cleanup.run();
+                }
+            } finally {
+                lock.writeLock().unlock();
+            }
+        }
+    }
+}