cache rules

bubble-server/src/main/java/bubble/service/stream/RuleEngine.java

@@ -49,10 +49,12 @@ import java.util.List;
 import java.util.Map;
 
 import static bubble.client.BubbleApiClient.newHttpClientBuilder;
+import static java.util.concurrent.TimeUnit.HOURS;
 import static java.util.concurrent.TimeUnit.MINUTES;
 import static javax.ws.rs.core.HttpHeaders.CONTENT_LENGTH;
 import static org.apache.commons.lang3.ArrayUtils.EMPTY_BYTE_ARRAY;
 import static org.cobbzilla.util.daemon.ZillaRuntime.empty;
+import static org.cobbzilla.util.daemon.ZillaRuntime.hashOf;
 import static org.cobbzilla.util.http.HttpStatusCodes.OK;
 import static org.cobbzilla.util.io.StreamUtil.DEFAULT_BUFFER_SIZE;
 import static org.cobbzilla.wizard.resources.ResourceUtil.send;
@@ -149,7 +151,7 @@ public class RuleEngine {
         if (empty(matcherIds)) return passthru(request);
 
         // have we seen this request before?
-        ActiveStreamState state = activeProcessors.computeIfAbsent(requestId, k -> new ActiveStreamState(initRules(account, device, matcherIds)));
+        final ActiveStreamState state = activeProcessors.computeIfAbsent(requestId, k -> new ActiveStreamState(initRules(account, device, matcherIds)));
         final byte[] chunk = toBytes(request.getEntityStream());
         if (last) {
             if (log.isDebugEnabled()) log.debug("applyRulesToChunkAndSendResponse: adding LAST stream");
@@ -171,22 +173,26 @@ public class RuleEngine {
         return bout.toByteArray();
     }
 
+    private ExpirationMap<String, List<AppRuleHarness>> ruleCache = new ExpirationMap<>(HOURS.toMillis(1), ExpirationEvictionPolicy.atime);
+
     private List<AppRuleHarness> initRules(Account account, Device device, String[] matcherIds) {
-        final List<AppMatcher> matchers = matcherDAO.findByUuids(matcherIds);
-        if (matchers.size() != matcherIds.length) {
-            log.warn("initRules: duplicate rules, or could not resolve some rule(s)");
-        }
-        List<AppRuleHarness> ruleHarnesses = new ArrayList<>();
-        for (AppMatcher m : matchers) {
-            final AppRule rule = ruleDAO.findByUuid(m.getRule());
-            if (rule == null) {
-                log.warn("initRules: rule not found ("+m.getRule()+") for matcher: "+m.getUuid());
-                continue;
+        final String cacheKey = hashOf(account.getUuid(), device.getUuid(), matcherIds);
+        return ruleCache.computeIfAbsent(cacheKey, k -> {
+            final List<AppMatcher> matchers = matcherDAO.findByUuids(matcherIds);
+            if (matchers.size() != matcherIds.length) {
+                log.warn("initRules: duplicate rules, or could not resolve some rule(s)");
             }
-            ruleHarnesses.add(new AppRuleHarness(m, rule));
-        }
-        ruleHarnesses = initRules(account, device, ruleHarnesses);
-        return ruleHarnesses;
+            final List<AppRuleHarness> ruleHarnesses = new ArrayList<>();
+            for (AppMatcher m : matchers) {
+                final AppRule rule = ruleDAO.findByUuid(m.getRule());
+                if (rule == null) {
+                    log.warn("initRules: rule not found ("+m.getRule()+") for matcher: "+m.getUuid());
+                    continue;
+                }
+                ruleHarnesses.add(new AppRuleHarness(m, rule));
+            }
+            return initRules(account, device, ruleHarnesses);
+        });
     }
 
     private List<AppRuleHarness> initRules(Account account, Device device, List<AppRuleHarness> rules) {