Add sangria-core module.

3 files changed, 263 insertions, 0 deletions

diff --git a/sangria-core/src/main/java/com/tavianator/sangria/core/DelayedError.java b/sangria-core/src/main/java/com/tavianator/sangria/core/DelayedError.java
new file mode 100644
index 0000000..4fa9eab
--- /dev/null
+++ b/sangria-core/src/main/java/com/tavianator/sangria/core/DelayedError.java
@@ -0,0 +1,91 @@
+/*********************************************************************
+ * Sangria                                                           *
+ * Copyright (C) 2014 Tavian Barnes <tavianator@tavianator.com>      *
+ *                                                                   *
+ * This library is free software. It comes without any warranty, to  *
+ * the extent permitted by applicable law. You can redistribute it   *
+ * and/or modify it under the terms of the Do What The Fuck You Want *
+ * To Public License, Version 2, as published by Sam Hocevar. See    *
+ * the COPYING file or http://www.wtfpl.net/ for more details.       *
+ *********************************************************************/
+
+package com.tavianator.sangria.core;
+
+import javax.inject.Inject;
+
+import com.google.common.collect.ImmutableList;
+import com.google.inject.Binder;
+import com.google.inject.CreationException;
+import com.google.inject.Injector;
+import com.google.inject.spi.Message;
+
+/**
+ * Similar to {@link Binder#addError(String, Object...)}, but can be canceled later. Useful for enforcing correct usage
+ * of fluent APIs.
+ *
+ * @author Tavian Barnes (tavianator@tavianator.com)
+ * @version 1.0
+ * @since 1.0
+ */
+public class DelayedError {
+    private Throwable error;
+
+    /**
+     * Create a {@link DelayedError}.
+     *
+     * @param binder  The binder to attach the error to.
+     * @param message The format string for the message.
+     * @param args    Arguments that will be passed to the format string.
+     * @return A {@link DelayedError} token that can be canceled later.
+     * @see Binder#addError(String, Object...)
+     */
+    public static DelayedError create(Binder binder, String message, Object... args) {
+        return create(binder, new Message(PrettyTypes.format(message, args)));
+    }
+
+    /**
+     * Create a {@link DelayedError}.
+     *
+     * @param binder The binder to attach the error to.
+     * @param t      The {@link Throwable} that caused this potential error.
+     * @return A {@link DelayedError} token that can be canceled later.
+     * @see Binder#addError(Throwable)
+     */
+    public static DelayedError create(Binder binder, Throwable t) {
+        DelayedError error = new DelayedError(t);
+        binder.skipSources(DelayedError.class)
+                .requestInjection(error);
+        return error;
+    }
+
+    /**
+     * Create a {@link DelayedError}.
+     *
+     * @param binder  The binder to attach the error to.
+     * @param message The error message.
+     * @return A {@link DelayedError} token that can be canceled later.
+     * @see Binder#addError(Message)
+     */
+    public static DelayedError create(Binder binder, Message message) {
+        // Using CreationException allows Guice to extract the Message and format it nicely
+        return create(binder, new CreationException(ImmutableList.of(message)));
+    }
+
+    private DelayedError(Throwable error) {
+        this.error = error;
+    }
+
+    /**
+     * Cancel this error.
+     */
+    public void cancel() {
+        this.error = null;
+    }
+
+    @Inject
+    void inject(Injector injector) throws Throwable {
+        if (error != null) {
+            throw error;
+        }
+    }
+}
diff --git a/sangria-core/src/main/java/com/tavianator/sangria/core/PrettyTypes.java b/sangria-core/src/main/java/com/tavianator/sangria/core/PrettyTypes.java
new file mode 100644
index 0000000..12721a4
--- /dev/null
+++ b/sangria-core/src/main/java/com/tavianator/sangria/core/PrettyTypes.java
@@ -0,0 +1,75 @@
+/*********************************************************************
+ * Sangria                                                           *
+ * Copyright (C) 2014 Tavian Barnes <tavianator@tavianator.com>      *
+ *                                                                   *
+ * This library is free software. It comes without any warranty, to  *
+ * the extent permitted by applicable law. You can redistribute it   *
+ * and/or modify it under the terms of the Do What The Fuck You Want *
+ * To Public License, Version 2, as published by Sam Hocevar. See    *
+ * the COPYING file or http://www.wtfpl.net/ for more details.       *
+ *********************************************************************/
+
+package com.tavianator.sangria.core;
+
+import com.google.inject.Key;
+
+/**
+ * Utility class for pretty-printing messages containing types.
+ *
+ * @author Tavian Barnes (tavianator@tavianator.com)
+ * @version 1.0
+ * @since 1.0
+ */
+public class PrettyTypes {
+    private PrettyTypes() {
+        // Not for instantiating
+    }
+
+    /**
+     * Format a message.
+     *
+     * @param message The format string.
+     * @param args    The format arguments, possibly containing {@link Class} or {@link Key} instances to be
+     *                pretty-printed.
+     * @return A formatted message.
+     * @see String#format(String, Object...)
+     */
+    public static String format(String message, Object... args) {
+        // This is like Guice's internal Errors.format()
+        Object[] prettyArgs = new Object[args.length];
+        for (int i = 0; i < args.length; ++i) {
+            Object arg = args[i];
+            Object prettyArg;
+
+            if (arg instanceof Class) {
+                prettyArg = format((Class<?>)arg);
+            } else if (arg instanceof Key) {
+                prettyArg = format((Key<?>)arg);
+            } else {
+                prettyArg = arg;
+            }
+
+            prettyArgs[i] = prettyArg;
+        }
+
+        return String.format(message, prettyArgs);
+    }
+
+    private static String format(Class<?> type) {
+        return type.getCanonicalName();
+    }
+
+    private static String format(Key<?> key) {
+        StringBuilder builder = new StringBuilder(key.getTypeLiteral().toString());
+        if (key.getAnnotationType() != null) {
+            builder.append(" annotated with ");
+            if (key.getAnnotation() != null) {
+                builder.append(key.getAnnotation());
+            } else {
+                builder.append("@")
+                        .append(format(key.getAnnotationType()));
+            }
+        }
+        return builder.toString();
+    }
+}
diff --git a/sangria-core/src/main/java/com/tavianator/sangria/core/UniqueAnnotations.java b/sangria-core/src/main/java/com/tavianator/sangria/core/UniqueAnnotations.java
new file mode 100644
index 0000000..bfdfe6b
--- /dev/null
+++ b/sangria-core/src/main/java/com/tavianator/sangria/core/UniqueAnnotations.java
@@ -0,0 +1,97 @@
+/*********************************************************************
+ * Sangria                                                           *
+ * Copyright (C) 2014 Tavian Barnes <tavianator@tavianator.com>      *
+ *                                                                   *
+ * This library is free software. It comes without any warranty, to  *
+ * the extent permitted by applicable law. You can redistribute it   *
+ * and/or modify it under the terms of the Do What The Fuck You Want *
+ * To Public License, Version 2, as published by Sam Hocevar. See    *
+ * the COPYING file or http://www.wtfpl.net/ for more details.       *
+ *********************************************************************/
+
+package com.tavianator.sangria.core;
+
+import java.lang.annotation.Annotation;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.util.concurrent.atomic.AtomicLong;
+import javax.inject.Qualifier;
+
+import com.google.common.annotations.VisibleForTesting;
+
+/**
+ * Re-implementation of Guice's internal UniqueAnnotations utility.
+ *
+ * @author Tavian Barnes (tavianator@tavianator.com)
+ * @version 1.0
+ * @since 1.0
+ */
+public class UniqueAnnotations {
+    private static final AtomicLong SEQUENCE = new AtomicLong();
+
+    private UniqueAnnotations() {
+        // Not for instantiating
+    }
+
+    @Retention(RetentionPolicy.RUNTIME)
+    @Qualifier
+    @VisibleForTesting
+    @interface UniqueAnnotation {
+        long value();
+    }
+
+    /**
+     * Actual implementation of {@link UniqueAnnotation}.
+     */
+    @SuppressWarnings("ClassExplicitlyAnnotation")
+    private static class UniqueAnnotationImpl implements UniqueAnnotation {
+        private final long value;
+
+        UniqueAnnotationImpl(long value) {
+            this.value = value;
+        }
+
+        @Override
+        public long value() {
+            return value;
+        }
+
+        public Class<? extends Annotation> annotationType() {
+            return UniqueAnnotation.class;
+        }
+
+        @Override
+        public String toString() {
+            return "@" + UniqueAnnotation.class.getName() + "(value=" + value + ")";
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (obj == this) {
+                return true;
+            } else if (!(obj instanceof UniqueAnnotation)) {
+                return false;
+            }
+
+            UniqueAnnotation other = (UniqueAnnotation)obj;
+            return value == other.value();
+        }
+
+        @Override
+        public int hashCode() {
+            return (127*"value".hashCode()) ^ Long.valueOf(value).hashCode();
+        }
+    }
+
+    /**
+     * @return An {@link Annotation} that will be unequal to every other annotation.
+     */
+    public static Annotation create() {
+        return create(SEQUENCE.getAndIncrement());
+    }
+
+    @VisibleForTesting
+    static Annotation create(long value) {
+        return new UniqueAnnotationImpl(value);
+    }
+}