From cc41c560f2440305c1628cc5a552b53f6b953dbc Mon Sep 17 00:00:00 2001 From: Mateusz Bronk Date: Sun, 4 Oct 2020 15:27:03 +0200 Subject: [PATCH] [VolvoOnCall] Backported HTTP req. cache from 3.x This change is essential for not flooding VOC servers with requests on each channel update. Cache idea and timeout configuration copied from 3.x branch ('main', PR#8595) and adapted to 2.5.x codebase. Related to #8554 Also-by: clinique Signed-off-by: Mateusz Bronk --- .../handler/VolvoOnCallBridgeHandler.java | 31 +++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) diff --git a/bundles/org.openhab.binding.volvooncall/src/main/java/org/openhab/binding/volvooncall/internal/handler/VolvoOnCallBridgeHandler.java b/bundles/org.openhab.binding.volvooncall/src/main/java/org/openhab/binding/volvooncall/internal/handler/VolvoOnCallBridgeHandler.java index c9f7a9ac60e..de541761925 100644 --- a/bundles/org.openhab.binding.volvooncall/src/main/java/org/openhab/binding/volvooncall/internal/handler/VolvoOnCallBridgeHandler.java +++ b/bundles/org.openhab.binding.volvooncall/src/main/java/org/openhab/binding/volvooncall/internal/handler/VolvoOnCallBridgeHandler.java @@ -19,6 +19,7 @@ import java.io.IOException; import java.io.InputStream; import java.nio.charset.StandardCharsets; import java.time.ZonedDateTime; +import java.util.AbstractMap.SimpleImmutableEntry; import java.util.List; import java.util.Properties; import java.util.Stack; @@ -29,6 +30,7 @@ import org.apache.commons.lang.StringUtils; import org.eclipse.jdt.annotation.NonNullByDefault; import org.eclipse.jdt.annotation.Nullable; import org.eclipse.jetty.client.HttpClient; +import org.eclipse.smarthome.core.cache.ExpiringCacheMap; import org.eclipse.smarthome.core.library.types.OnOffType; import org.eclipse.smarthome.core.library.types.OpenClosedType; import org.eclipse.smarthome.core.thing.Bridge; @@ -60,6 +62,7 @@ import com.google.gson.JsonSyntaxException; * * @author Gaël L'hopital - Initial contribution * @author Mateusz Bronk - Backported (to 2.5.x line) a fix for #8554 (User-Agent header removed) + * @author Mateusz Bronk - Backported GET request cache from 3.x (to avoid flooding VOC servers) */ @NonNullByDefault public class VolvoOnCallBridgeHandler extends BaseBridgeHandler { @@ -68,6 +71,7 @@ public class VolvoOnCallBridgeHandler extends BaseBridgeHandler { private final Properties httpHeader = new Properties(); private final List> pendingActions = new Stack<>(); private final Gson gson; + private final ExpiringCacheMap> cache; private @NonNullByDefault({}) CustomerAccounts customerAccount; @@ -100,6 +104,8 @@ public class VolvoOnCallBridgeHandler extends BaseBridgeHandler { (JsonDeserializer) (json, type, jsonDeserializationContext) -> json.getAsBoolean() ? OnOffType.ON : OnOffType.OFF) .create(); + + this.cache = new ExpiringCacheMap<>(120 * 1000); } @Override @@ -140,8 +146,29 @@ public class VolvoOnCallBridgeHandler extends BaseBridgeHandler { public T getURL(String url, Class objectClass) throws VolvoOnCallException { try { - String jsonResponse = HttpUtil_VOC.executeUrl("GET", url, httpHeader, null, JSON_CONTENT_TYPE, - REQUEST_TIMEOUT); + // The cache stores pairs of: (Response(String), Exception) where only one of the elements is populated at + // any given time + // This is for backport purposes only, hence creation of a more proper abstraction has been omitted + // delibetatelly + // - the pair is there only to avoid storing 'Objects' and RTTI. + SimpleImmutableEntry<@Nullable String, @Nullable IOException> cacheResponse = cache.putIfAbsentAndGet(url, + () -> { + logger.trace("Cache MISS for URL: {}", url); + try { + return new SimpleImmutableEntry<@Nullable String, @Nullable IOException>(HttpUtil_VOC + .executeUrl("GET", url, httpHeader, null, JSON_CONTENT_TYPE, REQUEST_TIMEOUT), + null); + } catch (IOException e) { + return new SimpleImmutableEntry<@Nullable String, @Nullable IOException>(null, e); + } + }); + if (cacheResponse.getValue() != null) { // Exception ocurred while (re)populating cache + // -> invalidate the cache and rethrow + // ^- note this should really be handled by the cache internally + cache.invalidate(url); + throw cacheResponse.getValue(); + } + String jsonResponse = cacheResponse.getKey(); logger.debug("Request for : {}", url); logger.debug("Received : {}", jsonResponse); T response = gson.fromJson(jsonResponse, objectClass);