Handle 429 responses

untested

apps/i2psnark/java/src/org/klomp/snark/web/RemoteSearch.java

@@ -19,6 +19,7 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
 
 import net.i2p.CoreVersion;
@@ -57,6 +58,7 @@ class RemoteSearch {
     private static final AtomicInteger _lastSent = new AtomicInteger();
     private static final AtomicInteger _lastRcvd = new AtomicInteger();
     private static final AtomicReference<String> _currentSearch = new AtomicReference<String>();
+    private static final AtomicLong _bannedUntil = new AtomicLong();
     // positive/negative cache, Result.result may be null
     private static final Map<String, Result> _cache = new LHMCache<String, Result>(16);
     //private static final List<Thread> _waiting = new ArrayList<Thread>(16);
@@ -175,6 +177,19 @@ class RemoteSearch {
             return null;
         }
 
+        long currentBan = _bannedUntil.get();
+        if (currentBan > 0) {
+            long now = _ctx.clock().now();
+            if (currentBan > now) {
+                long retry = currentBan - now;
+                if (retry <= 10*60*1000)
+                    return _t("Rate limited for {0}", DataHelper.formatDuration(retry));
+                else
+                    return _t("Rate limited until {0}", DataHelper.formatTime(currentBan));
+            }
+            _bannedUntil.compareAndSet(currentBan, 0);
+        }
+
         // if a new search comes in within 650 ms, interrupt the old one
         if (isXHR) {
             Thread us = Thread.currentThread();
@@ -239,7 +254,11 @@ class RemoteSearch {
                 code = -1;
             if (code > 0) {
                 buf.append(code);
-                String text = get.getStatusText();
+                String text;
+                if (code == 429)
+                    text = process429(out);
+                else
+                    text = get.getStatusText();
                 if (text != null)
                     buf.append(' ').append(DataHelper.escapeHTML(text));
             } else {
@@ -304,6 +323,27 @@ class RemoteSearch {
         return buf.toString();
     }
 
+    private String process429(ByteArrayStream out) {
+        try {
+            Reader in = new InputStreamReader(out.asInputStream(), "UTF-8");
+            JsonObject map = (JsonObject) Jsoner.deserialize(in);
+            long retry = map.getIntegerOrDefault(RETRY) * 1000L;
+            long until = _ctx.clock().now() + retry;
+            long currentBan = _bannedUntil.get();
+            while (until > currentBan && !_bannedUntil.compareAndSet(currentBan, until)) {
+                currentBan = _bannedUntil.get();
+            }
+            if (retry <= 10*60*1000)
+                return _t("Rate limited for {0}", DataHelper.formatDuration(retry));
+            else
+                return _t("Rate limited until {0}", DataHelper.formatTime(until));
+        } catch (Exception e) {
+            if (_log.shouldWarn())
+                _log.warn("json error input=\"" + DataHelper.getUTF8(out.toByteArray()), e);
+            return null;
+        }
+    }
+
     // keys with defaults
     private static final JsonKey ADDED = Jsoner.mintJsonKey("added", "");
     private static final JsonKey ALIVE = Jsoner.mintJsonKey("is_alive", Integer.valueOf(0));
@@ -319,6 +359,7 @@ class RemoteSearch {
     private static final JsonKey LINK = Jsoner.mintJsonKey("download_link", "");
     private static final JsonKey NAME = Jsoner.mintJsonKey("name", "");
     private static final JsonKey OWNER = Jsoner.mintJsonKey("owner", "");
+    private static final JsonKey RETRY = Jsoner.mintJsonKey("retry_after", Integer.valueOf(60));
     private static final JsonKey SEEDS = Jsoner.mintJsonKey("seeders", Integer.valueOf(0));
     private static final JsonKey SIZE = Jsoner.mintJsonKey("size", Long.valueOf(0));
     private static final JsonKey TORRENTS = Jsoner.mintJsonKey("torrents", null);