From 70dbbd50a3ec0a00b18dc7649eb6f1b6372fe39d Mon Sep 17 00:00:00 2001
From: Matt Mitchell <mmitche@microsoft.com>
Date: Thu, 21 Jul 2016 13:53:23 -0700
Subject: [PATCH] Implement an abuse handler

If too many requests are made within X amount of time (not the traditional hourly rate limit), github may begin returning 403.  Then we should wait for a bit to attempt to access the API again.  In this case, we parse out the Retry-After field returned and sleep until that (it's usually 60 seconds)
---
 src/main/java/org/kohsuke/github/GitHub.java  |  4 +++-
 .../org/kohsuke/github/GitHubBuilder.java     |  3 ++-
 .../org/kohsuke/github/RateLimitHandler.java  | 21 +++++++++++++++++++
 .../java/org/kohsuke/github/Requester.java    | 13 ++++++++++--
 4 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/src/main/java/org/kohsuke/github/GitHub.java b/src/main/java/org/kohsuke/github/GitHub.java
index 22792a8798..47388c93f2 100644
--- a/src/main/java/org/kohsuke/github/GitHub.java
+++ b/src/main/java/org/kohsuke/github/GitHub.java
@@ -83,6 +83,7 @@ public class GitHub {
     private final String apiUrl;
 
     /*package*/ final RateLimitHandler rateLimitHandler;
+    /*package*/ final RateLimitHandler abuseLimitHandler;
 
     private HttpConnector connector = HttpConnector.DEFAULT;
 
@@ -122,7 +123,7 @@ public class GitHub {
      * @param connector
      *      HttpConnector to use. Pass null to use default connector.
      */
-    /* package */ GitHub(String apiUrl, String login, String oauthAccessToken, String password, HttpConnector connector, RateLimitHandler rateLimitHandler) throws IOException {
+    /* package */ GitHub(String apiUrl, String login, String oauthAccessToken, String password, HttpConnector connector, RateLimitHandler rateLimitHandler, RateLimitHandler abuseLimitHandler) throws IOException {
         if (apiUrl.endsWith("/")) apiUrl = apiUrl.substring(0, apiUrl.length()-1); // normalize
         this.apiUrl = apiUrl;
         if (null != connector) this.connector = connector;
@@ -140,6 +141,7 @@ public class GitHub {
         }
 
         this.rateLimitHandler = rateLimitHandler;
+        this.abuseLimitHandler = abuseLimitHandler;
 
         if (login==null && encodedAuthorization!=null)
             login = getMyself().getLogin();
diff --git a/src/main/java/org/kohsuke/github/GitHubBuilder.java b/src/main/java/org/kohsuke/github/GitHubBuilder.java
index 2abe16f9c1..9ff603e199 100644
--- a/src/main/java/org/kohsuke/github/GitHubBuilder.java
+++ b/src/main/java/org/kohsuke/github/GitHubBuilder.java
@@ -30,6 +30,7 @@ public class GitHubBuilder {
     private HttpConnector connector;
 
     private RateLimitHandler rateLimitHandler = RateLimitHandler.WAIT;
+    private RateLimitHandler abuseLimitHandler = RateLimitHandler.ABUSE;
 
     public GitHubBuilder() {
     }
@@ -193,6 +194,6 @@ public HttpURLConnection connect(URL url) throws IOException {
     }
 
     public GitHub build() throws IOException {
-        return new GitHub(endpoint, user, oauthToken, password, connector, rateLimitHandler);
+        return new GitHub(endpoint, user, oauthToken, password, connector, rateLimitHandler, abuseLimitHandler);
     }
 }
diff --git a/src/main/java/org/kohsuke/github/RateLimitHandler.java b/src/main/java/org/kohsuke/github/RateLimitHandler.java
index b00624ce2b..8ff47a5ab4 100644
--- a/src/main/java/org/kohsuke/github/RateLimitHandler.java
+++ b/src/main/java/org/kohsuke/github/RateLimitHandler.java
@@ -48,6 +48,27 @@ private long parseWaitTime(HttpURLConnection uc) {
             return Math.max(10000, Long.parseLong(v)*1000 - System.currentTimeMillis());
         }
     };
+    
+    /**
+     * Wait until the API abuse "wait time" is passed.
+     */
+    public static final RateLimitHandler ABUSE = new RateLimitHandler() {
+        @Override
+        public void onError(IOException e, HttpURLConnection uc) throws IOException {
+            try {
+                Thread.sleep(parseWaitTime(uc));
+            } catch (InterruptedException _) {
+                throw (InterruptedIOException)new InterruptedIOException().initCause(e);
+            }
+        }
+
+        private long parseWaitTime(HttpURLConnection uc) {
+            String v = uc.getHeaderField("Retry-After");
+            if (v==null)    return 60 * 1000;   // can't tell, return 1 min
+
+            return Math.max(1000, Long.parseLong(v)*1000);
+        }
+    };
 
     /**
      * Fail immediately.
diff --git a/src/main/java/org/kohsuke/github/Requester.java b/src/main/java/org/kohsuke/github/Requester.java
index 62fb78339f..15f1f19afc 100644
--- a/src/main/java/org/kohsuke/github/Requester.java
+++ b/src/main/java/org/kohsuke/github/Requester.java
@@ -576,11 +576,20 @@ private InputStream wrapStream(InputStream in) throws IOException {
         InputStream es = wrapStream(uc.getErrorStream());
         try {
             if (es!=null) {
+                String errorString = IOUtils.toString(es, "UTF-8");
+                // Check to see whether we hit a 403, and the message indicates the
+                // abuse handler (occurs on too many concurrent requests)
+                if (responseCode == HttpURLConnection.HTTP_FORBIDDEN && 
+                    errorString.contains("You have triggered an abuse detection mechanism.")) {
+                    this.root.abuseLimitHandler.onError(e,uc);
+                    return;
+                }
+                
                 if (e instanceof FileNotFoundException) {
                     // pass through 404 Not Found to allow the caller to handle it intelligently
-                    throw (IOException) new FileNotFoundException(IOUtils.toString(es, "UTF-8")).initCause(e);
+                    throw (IOException) new FileNotFoundException(errorString).initCause(e);
                 } else
-                    throw (IOException) new IOException(IOUtils.toString(es, "UTF-8")).initCause(e);
+                    throw (IOException) new IOException(errorString).initCause(e);
             } else
                 throw e;
         } finally {