1 files changed, 192 insertions, 0 deletions
diff --git a/libs/xmpp-addr/src/main/java/rocks/xmpp/util/cache/DirectoryCache.java b/libs/xmpp-addr/src/main/java/rocks/xmpp/util/cache/DirectoryCache.java
new file mode 100644
index 000000000..9b7d66d04
--- /dev/null
+++ b/libs/xmpp-addr/src/main/java/rocks/xmpp/util/cache/DirectoryCache.java
@@ -0,0 +1,192 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014-2016 Christian Schudt
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package rocks.xmpp.util.cache;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.function.BiConsumer;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * A simple directory based cache for caching of persistent items like avatars or entity capabilities.
+ *
+ * @author Christian Schudt
+ */
+public final class DirectoryCache implements Map<String, byte[]> {
+
+    private final Path cacheDirectory;
+
+    public DirectoryCache(Path cacheDirectory) {
+        this.cacheDirectory = cacheDirectory;
+    }
+
+    @Override
+    public final int size() {
+        try (final Stream<Path> files = cacheContent()) {
+            return (int) Math.min(files.count(), Integer.MAX_VALUE);
+        }
+    }
+
+    @Override
+    public final boolean isEmpty() {
+        try (final Stream<Path> files = cacheContent()) {
+            return files.findAny().map(file -> Boolean.FALSE).orElse(Boolean.TRUE);
+        }
+    }
+
+    @Override
+    public final boolean containsKey(Object key) {
+        return Files.exists(cacheDirectory.resolve(key.toString()));
+    }
+
+    @Override
+    public final boolean containsValue(Object value) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public final byte[] get(final Object key) {
+        return Optional.ofNullable(key).map(Object::toString).filter(((Predicate<String>) String::isEmpty).negate()).map(cacheDirectory::resolve).filter(Files::isReadable).map(file -> {
+            try {
+                return Files.readAllBytes(file);
+            } catch (IOException e) {
+                throw new UncheckedIOException(e);
+            }
+        }).orElse(null);
+    }
+
+    @Override
+    public final byte[] put(String key, byte[] value) {
+        // Make sure the directory exists.
+        byte[] data = get(key);
+        if (!Arrays.equals(data, value))
+            try {
+                if (Files.notExists(cacheDirectory)) {
+                    Files.createDirectories(cacheDirectory);
+                }
+                Path file = cacheDirectory.resolve(key);
+                Files.write(file, value);
+            } catch (IOException e) {
+                throw new UncheckedIOException(e);
+            }
+        return data;
+    }
+
+    @Override
+    public final byte[] remove(Object key) {
+        byte[] data = get(key);
+        try {
+            Files.deleteIfExists(cacheDirectory.resolve(key.toString()));
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+        return data;
+    }
+
+    @Override
+    public final void putAll(Map<? extends String, ? extends byte[]> m) {
+        m.forEach(this::put);
+    }
+
+    @Override
+    public final void clear() {
+        try {
+            Files.walkFileTree(cacheDirectory, new SimpleFileVisitor<Path>() {
+                @Override
+                public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
+                    Files.deleteIfExists(file);
+                    return FileVisitResult.CONTINUE;
+                }
+
+                @Override
+                public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
+                    // Don't delete the cache directory itself.
+                    if (!Files.isSameFile(dir, cacheDirectory)) {
+                        Files.deleteIfExists(dir);
+                    }
+                    return FileVisitResult.CONTINUE;
+                }
+            });
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+    @Override
+    public final Set<String> keySet() {
+        try (final Stream<Path> files = Files.list(cacheDirectory)) {
+            return Collections.unmodifiableSet(files.map(Path::getFileName).map(Path::toString).collect(Collectors.toSet()));
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+    @Override
+    public final Collection<byte[]> values() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public final Set<Entry<String, byte[]>> entrySet() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public final void forEach(final BiConsumer<? super String, ? super byte[]> action) {
+        if (Files.exists(cacheDirectory))
+            try (final Stream<Path> files = cacheContent().filter(Files::isReadable)) {
+                files.forEach(file -> {
+                    try {
+                        action.accept(file.getFileName().toString(), Files.readAllBytes(file));
+                    } catch (final IOException e) {
+                        throw new UncheckedIOException(e);
+                    }
+                });
+            }
+    }
+
+    @SuppressWarnings("StreamResourceLeak")
+    private final Stream<Path> cacheContent() {
+        try {
+            return Files.walk(cacheDirectory).filter(Files::isRegularFile);
+        } catch (final IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+}