check error URL cache before adding errorDoc to index

- del obsolete related switchboardconstant

source/net/yacy/search/SwitchboardConstants.java

@@ -189,11 +189,6 @@ public final class SwitchboardConstants {
      * <p>Name of the setting how much memory in bytes should be assigned to the Noticed URLs DB for caching purposes</p>
      */
     public static final String RAM_CACHE_NURL_TIME      = "ramCacheNURL_time";
-    /**
-     * <p><code>public static final String <strong>RAM_CACHE_EURL</strong> = "ramCacheEURL"</code></p>
-     * <p>Name of the setting how much memory in bytes should be assigned to the Erroneous URLs DB for caching purposes</p>
-     */
-    public static final String RAM_CACHE_EURL_TIME      = "ramCacheEURL_time";
     /**
      * <p><code>public static final String <strong>RAM_CACHE_RWI</strong> = "ramCacheRWI"</code></p>
      * <p>Name of the setting how much memory in bytes should be assigned to the RWIs DB for caching purposes</p>

source/net/yacy/search/index/ErrorCache.java

@@ -106,12 +106,25 @@ public class ErrorCache {
         }
     }
 
+    /**
+     * Adds a error document to the Solr index (marked as failed by httpstatus_i <> 200)
+     * and caches recently added failed docs (up to maxStackSize = 1000)
+     *
+     * @param url  failed url
+     * @param crawldepth info crawldepth
+     * @param profile info of collection
+     * @param failCategory .store to index otherwise cache only
+     * @param anycause info cause-string
+     * @param httpcode http response code
+     */
     public void push(final DigestURL url, final int crawldepth, final CrawlProfile profile, final FailCategory failCategory, String anycause, final int httpcode) {
         // assert executor != null; // null == proxy !
         assert failCategory.store || httpcode == -1 : "failCategory=" + failCategory.name();
         if (anycause == null) anycause = "unknown";
         final String reason = anycause + ((httpcode >= 0) ? " (http return code = " + httpcode + ")" : "");
         if (!reason.startsWith("double")) log.info(url.toNormalform(true) + " - " + reason);
+
+        if (!this.cache.containsKey(ASCII.String(url.hash()))) { // no further action if in error-cache
             CollectionConfiguration.FailDoc failDoc = new CollectionConfiguration.FailDoc(
                     url, profile == null ? null : profile.collections(),
                     failCategory.name() + " " + reason, failCategory.failType,
@@ -136,6 +149,7 @@ public class ErrorCache {
             }
             checkStackSize();
         }
+    }
     
     private void checkStackSize() {
         synchronized (this.cache) {