Github user geomacy commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/462#discussion_r94418145
--- Diff:
core/src/main/java/org/apache/brooklyn/core/config/BasicConfigInheritance.java
---
@@ -28,51 +32,188 @@
import org.apache.brooklyn.config.ConfigKey;
import org.apache.brooklyn.config.ConfigValueAtContainer;
import org.apache.brooklyn.util.collections.CollectionMerger;
+import org.apache.brooklyn.util.exceptions.Exceptions;
import org.apache.brooklyn.util.exceptions.ReferenceWithError;
import org.apache.brooklyn.util.guava.Maybe;
+import org.apache.brooklyn.util.text.Strings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+@SuppressWarnings("serial")
public class BasicConfigInheritance implements ConfigInheritance {
+ private static final Logger log =
LoggerFactory.getLogger(BasicConfigInheritance.class);
+
private static final long serialVersionUID = -5916548049057961051L;
public static final String CONFLICT_RESOLUTION_STRATEGY_DEEP_MERGE =
"deep_merge";
public static final String CONFLICT_RESOLUTION_STRATEGY_OVERWRITE =
"overwrite";
+ public static abstract class DelegatingConfigInheritance implements
ConfigInheritance {
+ protected abstract ConfigInheritance getDelegate();
+
+ @Override @Deprecated public InheritanceMode
isInherited(ConfigKey<?> key, Object from, Object to) {
+ return getDelegate().isInherited(key, from, to);
+ }
+ @Override public <TContainer, TValue> boolean
isReinheritable(ConfigValueAtContainer<TContainer, TValue> parent,
ConfigInheritanceContext context) {
+ return getDelegate().isReinheritable(parent, context);
+ }
+ @Override public <TContainer, TValue> boolean
considerParent(ConfigValueAtContainer<TContainer, TValue> local,
ConfigValueAtContainer<TContainer, TValue> parent, ConfigInheritanceContext
context) {
+ return getDelegate().considerParent(local, parent, context);
+ }
+ @Override
+ public <TContainer, TValue>
ReferenceWithError<ConfigValueAtContainer<TContainer, TValue>>
resolveWithParent(ConfigValueAtContainer<TContainer, TValue> local,
ConfigValueAtContainer<TContainer, TValue> resolvedParent,
ConfigInheritanceContext context) {
+ return getDelegate().resolveWithParent(local, resolvedParent,
context);
+ }
+ @Override
+ public boolean equals(Object obj) {
+ return super.equals(obj) || getDelegate().equals(obj);
+ }
+
+ // standard deserialization method
+ protected ConfigInheritance readResolve() {
+ return returnEquivalentConstant(this);
+ }
+ }
+
+ private static ConfigInheritance
returnEquivalentConstant(ConfigInheritance candidate) {
+ for (ConfigInheritance knownMode: Arrays.asList(
+ NOT_REINHERITED, NOT_REINHERITED_ELSE_DEEP_MERGE,
NEVER_INHERITED, OVERWRITE, BasicConfigInheritance.DEEP_MERGE)) {
+ if (candidate.equals(knownMode)) return knownMode;
+ }
+ if (candidate.equals(new BasicConfigInheritance(false,
CONFLICT_RESOLUTION_STRATEGY_OVERWRITE, true, true))) {
+ // ignore the ancestor flag for this mode
+ return NEVER_INHERITED;
+ }
+ return candidate;
+ }
+
+ /*
+ * use of delegate is so that stateless classes can be defined to make
the serialization nice,
+ * both the name and hiding the implementation detail (also making it
easier for that detail to change);
+ * with aliased type names the field names here could even be aliases
for the type names.
+ * (we could alternatively have an "alias-for-final-instance" mode in
serialization,
+ * to optimize where we know that a java instance is final.)
+ */
+
+ private static class NotReinherited extends
DelegatingConfigInheritance {
+ final static BasicConfigInheritance DELEGATE = new
BasicConfigInheritance(false, CONFLICT_RESOLUTION_STRATEGY_OVERWRITE, false,
true);
+ @Override protected ConfigInheritance getDelegate() { return
DELEGATE; }
+ }
/** Indicates that a config key value should not be passed down from a
container where it is defined.
* Unlike {@link #NEVER_INHERITED} these values can be passed down if
set as anonymous keys at a container
* (ie the container does not expect it) to a container which does
expect it, but it will not be passed down further.
* If the inheritor also defines a value the parent's value is ignored
irrespective
* (as in {@link #OVERWRITE}; see {@link
#NOT_REINHERITED_ELSE_DEEP_MERGE} if merging is desired). */
- public static BasicConfigInheritance NOT_REINHERITED = new
BasicConfigInheritance(false,CONFLICT_RESOLUTION_STRATEGY_OVERWRITE,false);
+ public static ConfigInheritance NOT_REINHERITED = new NotReinherited();
+
+ private static class NotReinheritedElseDeepMerge extends
DelegatingConfigInheritance {
+ final static BasicConfigInheritance DELEGATE = new
BasicConfigInheritance(false, CONFLICT_RESOLUTION_STRATEGY_DEEP_MERGE, false,
true);
+ @Override protected ConfigInheritance getDelegate() { return
DELEGATE; }
+ }
/** As {@link #NOT_REINHERITED} but in cases where a value is
inherited because a parent did not recognize it,
* if the inheritor also defines a value the two values should be
merged. */
- public static BasicConfigInheritance NOT_REINHERITED_ELSE_DEEP_MERGE =
new BasicConfigInheritance(false,CONFLICT_RESOLUTION_STRATEGY_DEEP_MERGE,false);
- /** Indicates that a key's value should never be inherited, even if
defined on a container that does not know the key.
- * Most usages will prefer {@link #NOT_REINHERITED}. */
- public static BasicConfigInheritance NEVER_INHERITED = new
BasicConfigInheritance(false,CONFLICT_RESOLUTION_STRATEGY_OVERWRITE,true);
+ public static ConfigInheritance NOT_REINHERITED_ELSE_DEEP_MERGE = new
NotReinheritedElseDeepMerge();
+
+ private static class NeverInherited extends
DelegatingConfigInheritance {
+ final static BasicConfigInheritance DELEGATE = new
BasicConfigInheritance(false, CONFLICT_RESOLUTION_STRATEGY_OVERWRITE, true,
false);
+ @Override protected ConfigInheritance getDelegate() { return
DELEGATE; }
+ }
+ /** Indicates that a key's value should never be inherited, even if
inherited from a value set on a container that does not know the key.
+ * (Most usages will prefer {@link #NOT_REINHERITED}.) */
+ public static ConfigInheritance NEVER_INHERITED = new NeverInherited();
+
+ private static class Overwrite extends DelegatingConfigInheritance {
+ final static BasicConfigInheritance DELEGATE = new
BasicConfigInheritance(true, CONFLICT_RESOLUTION_STRATEGY_OVERWRITE, false,
true);
+ @Override protected ConfigInheritance getDelegate() { return
DELEGATE; }
+ }
/** Indicates that if a key has a value at both an ancestor and a
descendant, the descendant and his descendants
* will prefer the value at the descendant. */
- public static BasicConfigInheritance OVERWRITE = new
BasicConfigInheritance(true,CONFLICT_RESOLUTION_STRATEGY_OVERWRITE,false);
+ public static ConfigInheritance OVERWRITE = new Overwrite();
+
+ private static class DeepMerge extends DelegatingConfigInheritance {
+ final static BasicConfigInheritance DELEGATE = new
BasicConfigInheritance(true, CONFLICT_RESOLUTION_STRATEGY_DEEP_MERGE, false,
true);
+ @Override protected ConfigInheritance getDelegate() { return
DELEGATE; }
+ }
/** Indicates that if a key has a value at both an ancestor and a
descendant, the descendant and his descendants
- * should attempt to merge the values. If the values are not mergable
behaviour is undefined
+ * should attempt to merge the values. If the values are not mergeable
behaviour is undefined
* (and often the descendant's value will simply overwrite). */
- public static BasicConfigInheritance DEEP_MERGE = new
BasicConfigInheritance(true,CONFLICT_RESOLUTION_STRATEGY_DEEP_MERGE,false);
+ public static ConfigInheritance DEEP_MERGE = new DeepMerge();
+
+ // support conversion from these legacy fields
+ @SuppressWarnings("deprecation")
+ private static void registerReplacements() {
+
ConfigInheritance.Legacy.registerReplacement(ConfigInheritance.DEEP_MERGE,
DEEP_MERGE);
+
ConfigInheritance.Legacy.registerReplacement(ConfigInheritance.ALWAYS,
OVERWRITE);
+
ConfigInheritance.Legacy.registerReplacement(ConfigInheritance.NONE,
NOT_REINHERITED);
+ }
+ static { registerReplacements(); }
- /** reinheritable? true/false; if false,
children/descendants/inheritors will never see it; default true */
+ /** whether a value on a key defined locally should be inheritable by
descendants.
+ * if false at a point where a key is defined,
+ * children/descendants/inheritors will not be able to see its value,
whether explicit or default.
+ * default true: things are normally reinherited.
+ * <p>
+ * note that this only takes effect where a key is defined locally.
+ * if a key is not defined at an ancestor, a descendant setting this
value false will not prevent it
+ * from inheriting values from ancestors.
+ * <p>
+ * typical use case for setting this is false is where a key is
consumed and descendants should not
+ * "reconsume" it. for example setting files to install on a VM need
only be applied once,
+ * and if it has <b>runtime management</b> hierarchy descendants which
also understand that field they
+ * should not install the same files.
+ * (there is normally no reason to set this false in the context of
<b>type hierarchy</b> inheritance because
+ * an ancestor type cannot "consume" a value.) */
protected final boolean isReinherited;
- /** conflict-resolution-strategy? in {@link BasicConfigInheritance}
supported values are
+
+ /** a symbol indicating a conflict-resolution-strategy understood by
the implementation.
+ * in {@link BasicConfigInheritance} supported values are
* {@link #CONFLICT_RESOLUTION_STRATEGY_DEEP_MERGE} and {@link
#CONFLICT_RESOLUTION_STRATEGY_OVERWRITE}.
- * subclasses may pass null if they provide a custom implementaton of
{@link #resolveWithParentCustomStrategy(ConfigValueAtContainer,
ConfigValueAtContainer,
org.apache.brooklyn.config.ConfigInheritance.ConfigInheritanceContext)} */
+ * subclasses may pass null or a different string if they provide a
custom implementaton
+ * of {@link #resolveWithParentCustomStrategy(ConfigValueAtContainer,
ConfigValueAtContainer,
org.apache.brooklyn.config.ConfigInheritance.ConfigInheritanceContext)} */
@Nullable protected final String conflictResolutionStrategy;
- /** use-local-default-value? true/false; if true, overwrite above
means "always ignore (even if null)"; default false
- * whereas merge means "use local default (if non-null)" */
- protected final boolean useLocalDefaultValue;
+
+ /** @deprecated since 0.10.0 when this was introduced, now renamed
{@link #localDefaultResolvesWithAncestorValue} */
+ @Deprecated protected final Boolean useLocalDefaultValue;
+ /** whether a local default value should be considered for resolution
in the presence of an ancestor value.
+ * can use true with overwrite to mean don't inherit, or true with
merge to mean local default merged on top of inherited
--- End diff --
add a link for clarity - "can use true with {@link
CONFLICT_RESOLUTION_STRATEGY_OVERWRITE} to mean..." etc. and same for merge
strategy.
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