Package de.cxp.ocs.smartsuggest.limiter

Class ConfigurableShareLimiter

java.lang.Object

de.cxp.ocs.smartsuggest.limiter.ConfigurableShareLimiter

All Implemented Interfaces:

Limiter

public class ConfigurableShareLimiter
extends Object
implements Limiter

Limiter where you can configure, which group of suggestions should get which share in the result (e.g. keywords=0.5 (50%), brand=0.3 (30%), category=0.2 (20%)).

That configuration can be done by the Map given in the constructor or by defining system property or environment variables with the group values prefixed by "SUGGEST_GROUP_SHARE_" keyword, e.g. the group "brand" could be configured with environment variable "SUGGEST_GROUP_SHARE_BRAND=0.2". (It's also possible to combine these configuration possibilities, but why would you do that..).

The configured values should sum up to 1.0. If that's not the case, they are normalized accordingly.

The order of the returned groups is defined by the order in the configuration. This is why it must be a LinkedHashMap. Groups that are not configured or configured by environment variables, will be appended to that configuration according to their appearance in the results.

If one or more group are not configured at all, they either get the same weight as the lowest configured group, or - in case the configured shares sum up to a value lower 1, the remaining share will evenly be distributed over the not-configured groups.

To group the results properly, a "groupKey" has to be specified. It is then looked up at the pay-load of the suggestions. If a suggestion has no value for that key, "other" is used. This means you should also consider configuring the value of the "other" group.

If a result can't be distributed evenly, the remaining space will be filled up with suggestions according to the group priority order - or the value of the least important group will be truncated.

Field Summary

Fields

Modifier and Type	Field	Description
static String	OTHER_SHARE_KEY
static String	SHARE_KEY_ENV_PREFIX

Constructor Summary

Constructors

Constructor	Description
ConfigurableShareLimiter(String groupingKey, LinkedHashMap<String,Double> shareConfiguration, Optional<String[]> groupDeduplicationOrder)	The share limiter will group the results according to a particular payload value and uses the configured share values to distribute the limited space among those grouped suggestions.

Method Summary

Modifier and Type	Method	Description
List<Suggestion>	limit(List<Suggestion> suggestions, int limit)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SHARE_KEY_ENV_PREFIX

public static final String SHARE_KEY_ENV_PREFIX

See Also:

Constant Field Values

OTHER_SHARE_KEY

public static final String OTHER_SHARE_KEY

See Also:

Constant Field Values

Constructor Detail

ConfigurableShareLimiter

public ConfigurableShareLimiter(@Nonnull
                                String groupingKey,
                                LinkedHashMap<String,Double> shareConfiguration,
                                Optional<String[]> groupDeduplicationOrder)

The share limiter will group the results according to a particular payload value and uses the configured share values to distribute the limited space among those grouped suggestions.

Parameters:

groupingKey - which key to use to get the grouping key from the suggestions payload.

shareConfiguration - the share value (between 0 and 1) for each available group. The order of the groups matters. See java-doc of ConfigurableShareLimiter

groupDeduplicationOrder - If given (even with an empty array), the suggestions will be deduplicated. The array defines preferred groups. Suggestions of the groups defined first will be preferred over suggestions from other groups.

See Also:

ConfigurableShareLimiter

Method Detail

limit

public List<Suggestion> limit(List<Suggestion> suggestions,
                              int limit)

Specified by:

limit in interface Limiter