From e01120a46a6f74c5b71a5dc3c477f518a2073f51 Mon Sep 17 00:00:00 2001
From: Colin Jones <trptcolin@gmail.com>
Date: Sat, 28 Apr 2012 13:11:46 -0500
Subject: [PATCH] Flush output after session/*out-limit* characters

Defaults to 1024, but can easily be rebound on a per-evaluation
basis, e.g. (binding [session/*out-limit* Long/MAX_VALUE] ...)
---
 .../clojure/tools/nrepl/middleware/session.clj     |    6 +++++-
 .../java/clojure/tools/nrepl/StdOutBuffer.java     |   10 +++++++---
 .../clojure/clojure/tools/nrepl/sanity_test.clj    |   20 +++++++++++++-------
 3 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/src/main/clojure/clojure/tools/nrepl/middleware/session.clj b/src/main/clojure/clojure/tools/nrepl/middleware/session.clj
index 9081c90..b129a0e 100644
--- a/src/main/clojure/clojure/tools/nrepl/middleware/session.clj
+++ b/src/main/clojure/clojure/tools/nrepl/middleware/session.clj
@@ -18,6 +18,8 @@
 ;; depending upon the expectations of the client/user.  I'm not sure at the moment
 ;; how best to make it configurable though...
 
+(def ^{:dynamic true} *out-limit* 1024)
+
 (defn- session-out
   "Returns a PrintWriter suitable for binding as *out* or *err*.  All of
    the content written to that PrintWriter will (when .flush-ed) be sent on the
@@ -33,7 +35,9 @@
                           (number? x) (.append buf (char x))
                           (not off) #(.append buf x)
                           (instance? CharSequence x) (.append buf ^CharSequence x off len)
-                          :else (.append buf ^chars x off len))))
+                          :else (.append buf ^chars x off len))
+                        (when (<= *out-limit* (.length buf))
+                          (.flush ^Writer this))))
                     (flush []
                       (let [text (locking buf (let [text (str buf)]
                                                 (.setLength buf 0)
diff --git a/src/main/java/clojure/tools/nrepl/StdOutBuffer.java b/src/main/java/clojure/tools/nrepl/StdOutBuffer.java
index d85f519..4a66a06 100644
--- a/src/main/java/clojure/tools/nrepl/StdOutBuffer.java
+++ b/src/main/java/clojure/tools/nrepl/StdOutBuffer.java
@@ -3,9 +3,9 @@ package clojure.tools.nrepl;
 /**
  * This class exists solely so that the clojure side can call .setLength under JDK 1.5.
  * Doing so with a StringBuilder/StringBuffer fails with:
- * 
+ *
  * Can't call public method of non-public class: public void java.lang.AbstractStringBuilder.setLength(int)
- * 
+ *
  * ...as documented in these outstanding bugs:
  * http://dev.clojure.org/jira/browse/CLJ-126
  * http://dev.clojure.org/jira/browse/CLJ-259
@@ -16,7 +16,11 @@ public class StdOutBuffer {
     public void setLength (int x) {
         sb.setLength(x);
     }
-    
+
+    public int length() {
+        return sb.length();
+    }
+
     public void append(Object x) {
         sb.append(x);
     }
diff --git a/src/test/clojure/clojure/tools/nrepl/sanity_test.clj b/src/test/clojure/clojure/tools/nrepl/sanity_test.clj
index a28d6cc..0edb1be 100644
--- a/src/test/clojure/clojure/tools/nrepl/sanity_test.clj
+++ b/src/test/clojure/clojure/tools/nrepl/sanity_test.clj
@@ -46,11 +46,11 @@
   (try
     (are [result expr] (= result (internal-eval expr))
          ["" 3] '(+ 1 2)
-         
+
          ["" nil] '*1
          ["" nil] '(do (def ^{:dynamic true} ++ +) nil)
          ["" 5] '(binding [++ -] (++ 8 3))
-         
+
          ["" 42] '(set! *print-length* 42)
          ["" nil] '*print-length*)
     (finally (ns-unmap *ns* '++))))
@@ -60,12 +60,12 @@
     (are [ns result expr] (= result (internal-eval ns expr))
          (ns-name *ns*) ["" [(str (ns-name *ns*)) 3]]
          '(+ 1 2)
-         
+
          'user ["" ["user" '("user" "++")]]
          '(do
             (def ^{:dynamic true} ++ +)
             (map #(-> #'++ meta % str) [:ns :name]))
-         
+
          (ns-name *ns*) ["" [(str (ns-name *ns*)) 5]]
          '(binding [user/++ -]
             (user/++ 8 3)))
@@ -104,11 +104,17 @@
       (binding [*out* out]
         (newline)
         (prn #{})
+        (flush)
+        (binding [session/*out-limit* 10]
+          (print (range 11)))
         (flush)))
-    
+
     (is (= ["abcdefghij "
             "no writes\nkeyed on linebreaks"
-            "\n#{}\n"]
+            "\n#{}\n"
+            "(0 1 2 3 4"
+            " 5 6 7 8 9"
+            " 10)"]
           (->> (repl/response-seq local 0)
             (map :out))))))
 
@@ -133,4 +139,4 @@
                (throw (Exception. "foo")))
           full-response
           :err))))
-)
\ No newline at end of file
+)
-- 
1.7.1.1