more work

src/com/typesafe/config/Config.java

@@ -1,13 +1,150 @@
 package com.typesafe.config;
 
+import java.util.concurrent.TimeUnit;
+
 import com.typesafe.config.impl.ConfigFactory;
 
-public class Config {
+public final class Config {
     public static ConfigObject load(ConfigConfig configConfig) {
-        return ConfigFactory.getConfig(configConfig);
+        return ConfigFactory.loadConfig(configConfig);
     }
 
     public static ConfigObject load(String rootPath) {
-        return ConfigFactory.getConfig(new ConfigConfig(rootPath, null));
+        return ConfigFactory.loadConfig(new ConfigConfig(rootPath, null));
+    }
+
+    private static String getUnits(String s) {
+        int i = s.length() - 1;
+        while (i >= 0) {
+            char c = s.charAt(i);
+            if (!Character.isLetter(c))
+                break;
+            i -= 1;
+        }
+        return s.substring(i + 1);
+    }
+
+    /**
+     * Parses a duration string. If no units are specified in the string, it is
+     * assumed to be in milliseconds. The returned duration is in nanoseconds.
+     *
+     * @param input
+     *            the string to parse
+     * @param originForException
+     *            origin of the value being parsed
+     * @param pathForException
+     *            path to include in exceptions
+     * @return duration in nanoseconds
+     * @throws ConfigException
+     *             if string is invalid
+     */
+    public static long parseDuration(String input,
+            ConfigOrigin originForException, String pathForException) {
+        String s = input.trim();
+        String unitString = getUnits(s);
+        String numberString = s.substring(0, s.length() - unitString.length()).trim();
+        TimeUnit units = null;
+
+        // note that this is deliberately case-sensitive
+        if (unitString == "" || unitString == "ms" || unitString == "milliseconds") {
+            units = TimeUnit.MILLISECONDS;
+        } else if (unitString == "us" || unitString == "microseconds") {
+            units = TimeUnit.MICROSECONDS;
+        } else if (unitString == "ns" || unitString == "nanoseconds") {
+            units = TimeUnit.NANOSECONDS;
+        } else if (unitString == "d" || unitString == "days") {
+            units = TimeUnit.DAYS;
+        } else if (unitString == "s" || unitString == "seconds") {
+            units = TimeUnit.SECONDS;
+        } else if (unitString == "m" || unitString == "minutes") {
+            units = TimeUnit.MINUTES;
+        } else {
+            throw new ConfigException.BadValue(originForException,
+                    pathForException, "Could not parse time unit '"
+                            + unitString + "' (try ns, us, ms, s, m, d)");
+        }
+
+        try {
+            // if the string is purely digits, parse as an integer to avoid possible precision loss;
+            // otherwise as a double.
+            if (numberString.matches("[0-9]+")) {
+                return units.toNanos(Long.parseLong(numberString));
+            } else {
+                long nanosInUnit = units.toNanos(1);
+                return (new Double(Double.parseDouble(numberString) * nanosInUnit)).longValue();
+            }
+        } catch (NumberFormatException e) {
+            throw new ConfigException.BadValue(originForException, pathForException,
+ "Could not parse duration number '"
+                            + numberString + "'");
+        }
+    }
+
+    private static enum MemoryUnit {
+        BYTES(1), KILOBYTES(1024), MEGABYTES(1024 * 1024), GIGABYTES(
+                1024 * 1024 * 1024);
+
+        int bytes;
+        MemoryUnit(int bytes) {
+            this.bytes = bytes;
+        }
+    }
+
+    /**
+     * Parses a memory-size string. If no units are specified in the string, it
+     * is assumed to be in bytes. The returned value is in bytes.
+     *
+     * @param input
+     *            the string to parse
+     * @param originForException
+     *            origin of the value being parsed
+     * @param pathForException
+     *            path to include in exceptions
+     * @return size in bytes
+     * @throws ConfigException
+     *             if string is invalid
+     */
+    public static long parseMemorySize(String input,
+            ConfigOrigin originForException, String pathForException) {
+        String s = input.trim();
+        String unitString = getUnits(s);
+        String unitStringLower = unitString.toLowerCase();
+        String numberString = s.substring(0, s.length() - unitString.length())
+                .trim();
+        MemoryUnit units = null;
+
+        // the short abbreviations are case-insensitive but you can't write the
+        // long form words in all caps.
+        if (unitString == "" || unitStringLower == "b"
+                || unitString == "bytes") {
+            units = MemoryUnit.BYTES;
+        } else if (unitStringLower == "k" || unitString == "kilobytes") {
+            units = MemoryUnit.KILOBYTES;
+        } else if (unitStringLower == "m" || unitString == "megabytes") {
+            units = MemoryUnit.MEGABYTES;
+        } else if (unitStringLower == "g" || unitString == "gigabytes") {
+            units = MemoryUnit.GIGABYTES;
+        } else {
+            throw new ConfigException.BadValue(originForException,
+                    pathForException, "Could not parse size unit '"
+                            + unitString + "' (try b, k, m, g)");
+        }
+
+        try {
+            // if the string is purely digits, parse as an integer to avoid
+            // possible precision loss;
+            // otherwise as a double.
+            if (numberString.matches("[0-9]+")) {
+                return Long.parseLong(numberString) * units.bytes;
+            } else {
+                return (new Double(Double.parseDouble(numberString)
+                        * units.bytes)).longValue();
+            }
+        } catch (NumberFormatException e) {
+            throw new ConfigException.BadValue(originForException,
+                    pathForException, "Could not parse memory size number '"
+                            + numberString
+                            + "'");
+        }
     }
 }

src/com/typesafe/config/ConfigConfig.java

@@ -3,7 +3,7 @@ package com.typesafe.config;
 /**
  * Configuration for a configuration!
  */
-public class ConfigConfig {
+public final class ConfigConfig {
 
     private String rootPath;
     private ConfigTransformer extraTransformer;

src/com/typesafe/config/ConfigException.java

@@ -81,6 +81,27 @@ public class ConfigException extends RuntimeException {
         }
     }
 
+    public static class BadValue extends ConfigException {
+        private static final long serialVersionUID = 1L;
+
+        public BadValue(ConfigOrigin origin, String path, String message,
+                Throwable cause) {
+            super(origin, "Invalid value at '" + path + "': " + message, cause);
+        }
+
+        public BadValue(ConfigOrigin origin, String path, String message) {
+            this(origin, path, message, null);
+        }
+
+        public BadValue(String path, String message, Throwable cause) {
+            super("Invalid value at '" + path + "': " + message, cause);
+        }
+
+        public BadValue(String path, String message) {
+            this(path, message, null);
+        }
+    }
+
     public static class BadPath extends ConfigException {
         private static final long serialVersionUID = 1L;
 

src/com/typesafe/config/ConfigObject.java

@@ -30,6 +30,23 @@ public interface ConfigObject extends ConfigValue {
 
     ConfigValue get(String path);
 
+    /** Get value as a size in bytes (parses special strings like "128M") */
+    Long getMemorySize(String path);
+
+    /**
+     * Get value as a duration in milliseconds. If the value is already a
+     * number, then it's left alone; if it's a string, it's parsed understanding
+     * units suffixes like "10m" or "5ns"
+     */
+    Long getMilliseconds(String path);
+
+    /**
+     * Get value as a duration in nanoseconds. If the value is already a number
+     * it's taken as milliseconds. If it's a string, it's parsed understanding
+     * unit suffixes.
+     */
+    Long getNanoseconds(String path);
+
     List<ConfigValue> getList(String path);
 
     List<Boolean> getBooleanList(String path);
@@ -46,6 +63,12 @@ public interface ConfigObject extends ConfigValue {
 
     List<Object> getAnyList(String path);
 
+    List<Long> getMemorySizeList(String path);
+
+    List<Long> getMillisecondsList(String path);
+
+    List<Long> getNanosecondsList(String path);
+
     boolean containsKey(String key);
 
     Set<String> keySet();

src/com/typesafe/config/impl/AbstractConfigObject.java

@@ -1,7 +1,13 @@
 package com.typesafe.config.impl;
 
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+import com.typesafe.config.Config;
 import com.typesafe.config.ConfigException;
 import com.typesafe.config.ConfigObject;
 import com.typesafe.config.ConfigOrigin;
@@ -19,6 +25,13 @@ abstract class AbstractConfigObject extends AbstractConfigValue implements
         this.transformer = transformer;
     }
 
+    /**
+     * This looks up the key with no transformation or type conversion of any
+     * kind, and returns null if the key is not present.
+     *
+     * @param key
+     * @return the unmodified raw value or null
+     */
     protected abstract ConfigValue peek(String key);
 
     @Override
@@ -26,6 +39,18 @@ abstract class AbstractConfigObject extends AbstractConfigValue implements
         return ConfigValueType.OBJECT;
     }
 
+    static AbstractConfigObject transformed(AbstractConfigObject obj,
+            ConfigTransformer transformer) {
+        if (obj.transformer != transformer)
+            return new TransformedConfigObject(transformer, obj);
+        else
+            return obj;
+    }
+
+    private AbstractConfigObject transformed(AbstractConfigObject obj) {
+        return transformed(obj, transformer);
+    }
+
     static private ConfigValue resolve(AbstractConfigObject self, String path,
             ConfigValueType expected, ConfigTransformer transformer,
             String originalPath) {
@@ -59,6 +84,58 @@ abstract class AbstractConfigObject extends AbstractConfigValue implements
         return resolve(this, path, expected, transformer, originalPath);
     }
 
+    /**
+     * Stack should be from overrides to fallbacks (earlier items win). Test
+     * suite should check: merging of objects with a non-object in the middle.
+     * Override of object with non-object, override of non-object with object.
+     * Merging 0, 1, N objects.
+     */
+    static AbstractConfigObject merge(ConfigOrigin origin,
+            List<AbstractConfigObject> stack,
+            ConfigTransformer transformer) {
+        if (stack.isEmpty()) {
+            return new SimpleConfigObject(origin, transformer,
+                    Collections.<String, ConfigValue> emptyMap());
+        } else if (stack.size() == 1) {
+            return transformed(stack.get(0), transformer);
+        } else {
+            // for non-objects, we just take the first value; but for objects we
+            // have to do work to combine them.
+            Map<String, ConfigValue> merged = new HashMap<String, ConfigValue>();
+            Map<String, List<AbstractConfigObject>> objects = new HashMap<String, List<AbstractConfigObject>>();
+            for (AbstractConfigObject obj : stack) {
+                for (String key : obj.keySet()) {
+                    ConfigValue v = obj.peek(key);
+                    if (!merged.containsKey(key)) {
+                        if (v.valueType() == ConfigValueType.OBJECT) {
+                            // requires recursive merge and transformer fixup
+                            List<AbstractConfigObject> stackForKey = null;
+                            if (objects.containsKey(key)) {
+                                stackForKey = objects.get(key);
+                            } else {
+                                stackForKey = new ArrayList<AbstractConfigObject>();
+                            }
+                            stackForKey.add(transformed(
+                                    (AbstractConfigObject) v,
+                                    transformer));
+                        } else {
+                            if (!objects.containsKey(key)) {
+                                merged.put(key, v);
+                            }
+                        }
+                    }
+                }
+            }
+            for (String key : objects.keySet()) {
+                List<AbstractConfigObject> stackForKey = objects.get(key);
+                AbstractConfigObject obj = merge(origin, stackForKey, transformer);
+                merged.put(key, obj);
+            }
+
+            return new SimpleConfigObject(origin, transformer, merged);
+        }
+    }
+
     @Override
     public ConfigValue get(String path) {
         return resolve(path, null, path);
@@ -105,8 +182,9 @@ abstract class AbstractConfigObject extends AbstractConfigValue implements
 
     @Override
     public AbstractConfigObject getObject(String path) {
-        ConfigValue v = resolve(path, ConfigValueType.OBJECT, path);
-        return (AbstractConfigObject) v;
+        AbstractConfigObject obj = (AbstractConfigObject) resolve(path,
+                ConfigValueType.OBJECT, path);
+        return transformed(obj);
     }
 
     @Override
@@ -115,6 +193,36 @@ abstract class AbstractConfigObject extends AbstractConfigValue implements
         return v.unwrapped();
     }
 
+    @Override
+    public Long getMemorySize(String path) {
+        Long size = null;
+        try {
+            size = getLong(path);
+        } catch (ConfigException.WrongType e) {
+            ConfigValue v = resolve(path, ConfigValueType.STRING, path);
+            size = Config.parseMemorySize((String) v.unwrapped(), v.origin(),
+                    path);
+        }
+        return size;
+    }
+
+    @Override
+    public Long getMilliseconds(String path) {
+        return TimeUnit.NANOSECONDS.toMillis(getNanoseconds(path));
+    }
+
+    @Override
+    public Long getNanoseconds(String path) {
+        Long ns = null;
+        try {
+            ns = getLong(path);
+        } catch (ConfigException.WrongType e) {
+            ConfigValue v = resolve(path, ConfigValueType.STRING, path);
+            ns = Config.parseDuration((String) v.unwrapped(), v.origin(), path);
+        }
+        return ns;
+    }
+
     @SuppressWarnings("unchecked")
     private <T> List<T> getHomogeneousUnwrappedList(String path,
             ConfigValueType expected) {
@@ -177,7 +285,7 @@ abstract class AbstractConfigObject extends AbstractConfigValue implements
             if (v.valueType() != ConfigValueType.OBJECT)
                 throw new ConfigException.WrongType(v.origin(), path,
                         ConfigValueType.OBJECT.name(), v.valueType().name());
-            l.add((ConfigObject) v);
+            l.add(transformed((AbstractConfigObject) v));
         }
         return l;
     }
@@ -191,4 +299,55 @@ abstract class AbstractConfigObject extends AbstractConfigValue implements
         }
         return l;
     }
+
+    @Override
+    public List<Long> getMemorySizeList(String path) {
+        List<Long> l = new ArrayList<Long>();
+        List<ConfigValue> list = getList(path);
+        for (ConfigValue v : list) {
+            if (v.valueType() == ConfigValueType.NUMBER) {
+                l.add(((Number) v.unwrapped()).longValue());
+            } else if (v.valueType() == ConfigValueType.STRING) {
+                String s = (String) v.unwrapped();
+                Long n = Config.parseMemorySize(s, v.origin(), path);
+                l.add(n);
+            } else {
+                throw new ConfigException.WrongType(v.origin(), path,
+                        "memory size string or number of bytes", v.valueType()
+                                .name());
+            }
+        }
+        return l;
+    }
+
+    @Override
+    public List<Long> getMillisecondsList(String path) {
+        List<Long> nanos = getNanosecondsList(path);
+        List<Long> l = new ArrayList<Long>();
+        for (Long n : nanos) {
+            l.add(TimeUnit.NANOSECONDS.toMillis(n));
+        }
+        return l;
+    }
+
+    @Override
+    public List<Long> getNanosecondsList(String path) {
+        List<Long> l = new ArrayList<Long>();
+        List<ConfigValue> list = getList(path);
+        for (ConfigValue v : list) {
+            if (v.valueType() == ConfigValueType.NUMBER) {
+                l.add(((Number) v.unwrapped()).longValue());
+            } else if (v.valueType() == ConfigValueType.STRING) {
+                String s = (String) v.unwrapped();
+                Long n = Config.parseDuration(s, v.origin(), path);
+                l.add(n);
+            } else {
+                throw new ConfigException.WrongType(v.origin(), path,
+                        "duration string or number of nanoseconds", v
+                                .valueType().name());
+            }
+        }
+        return l;
+    }
+
 }

src/com/typesafe/config/impl/ConfigFactory.java

@@ -15,7 +15,7 @@ import com.typesafe.config.ConfigValue;
 
 /** This is public but is only supposed to be used by the "config" package */
 public class ConfigFactory {
-    public static ConfigObject getConfig(ConfigConfig configConfig) {
+    public static ConfigObject loadConfig(ConfigConfig configConfig) {
         AbstractConfigObject system = null;
         try {
             system = systemPropertiesConfig()
@@ -29,23 +29,36 @@ public class ConfigFactory {
         if (system != null)
             stack.add(system);
 
-        List<ConfigTransformer> transformerStack = new ArrayList<ConfigTransformer>();
-        transformerStack.add(defaultConfigTransformer());
-        ConfigTransformer extraTransformer = configConfig.extraTransformer();
-        if (extraTransformer != null)
-            transformerStack.add(extraTransformer);
-        ConfigTransformer transformer = new StackTransformer(transformerStack);
+        ConfigTransformer transformer = withExtraTransformer(configConfig
+                .extraTransformer());
 
-        StackConfigObject stackConfig = new StackConfigObject(
-                new SimpleConfigOrigin("config for " + configConfig.rootPath()),
-                transformer,
-                stack);
+        AbstractConfigObject merged = AbstractConfigObject
+                .merge(new SimpleConfigOrigin("config for "
+                        + configConfig.rootPath()), stack, transformer);
 
-        return stackConfig;
+        return merged;
     }
 
-    public static ConfigObject getEnvironmentAsConfig() {
-        return envVariablesConfig();
+    public static ConfigObject getEnvironmentAsConfig(
+            ConfigTransformer extraTransformer) {
+        // This should not need to create a new config object
+        // as long as the transformer is just the default transformer.
+        return AbstractConfigObject.transformed(envVariablesConfig(),
+                withExtraTransformer(extraTransformer));
+    }
+
+    private static ConfigTransformer withExtraTransformer(
+            ConfigTransformer extraTransformer) {
+        // idea is to avoid creating a new, unique transformer if there's no
+        // extraTransformer
+        if (extraTransformer != null) {
+            List<ConfigTransformer> transformerStack = new ArrayList<ConfigTransformer>();
+            transformerStack.add(defaultConfigTransformer());
+            transformerStack.add(extraTransformer);
+            return new StackTransformer(transformerStack);
+        } else {
+            return defaultConfigTransformer();
+        }
     }
 
     private static ConfigTransformer defaultTransformer = null;

src/com/typesafe/config/impl/StackConfigObject.java

@@ -11,6 +11,10 @@ import com.typesafe.config.ConfigOrigin;
 import com.typesafe.config.ConfigTransformer;
 import com.typesafe.config.ConfigValue;
 
+/**
+ * This is unused for now, decided that it was too annoying to "lazy merge" and
+ * better to do the full merge up-front.
+ */
 final class StackConfigObject extends AbstractConfigObject {
 
     private List<AbstractConfigObject> stack;