reduce_limit error is thrown when the reduce function output is not small enough compared to the input. Errors can be switched off using the config API.

git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@771466 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 18 insertions, 4 deletions

diff --git a/share/server/loop.js b/share/server/loop.js
index 170a8dc8..db6a9702 100644
--- a/share/server/loop.js
+++ b/share/server/loop.js
@@ -28,7 +28,7 @@ try {
 //
 // Responses are json values followed by a new line ("\n")
 
-var cmd, cmdkey;
+var line, cmd, cmdkey;
 
 var dispatch = {
   "reset"      : State.reset,
@@ -43,7 +43,9 @@ var dispatch = {
   "list_tail"  : Render.listTail 
 };
 
-while (cmd = eval(readline())) {
+while (line = eval(readline())) {
+  cmd = eval(line)
+  line_length = line.length
   try {
     cmdkey = cmd.shift();
     if (dispatch[cmdkey]) {
diff --git a/share/server/state.js b/share/server/state.js
index 05c55a1b..6c7d63b9 100644
--- a/share/server/state.js
+++ b/share/server/state.js
@@ -13,12 +13,14 @@
 // globals used by other modules and functions
 var funs = [];        // holds functions used for computation
 var funsrc = [];      // holds function source for debug info
+var query_config = {};
 var State = (function() {
   return {
-    reset : function() {
+    reset : function(config) {
       // clear the globals and run gc
       funs = [];
       funsrc = [];
+      query_config = config;
       gc();
       print("true"); // indicates success
     },
diff --git a/share/server/views.js b/share/server/views.js
index c6d71579..de728ac2 100644
--- a/share/server/views.js
+++ b/share/server/views.js
@@ -46,7 +46,17 @@ var Views = (function() {
         reductions[i] = null;
       }
     }
-    print("[true," + toJSON(reductions) + "]");
+    var reduce_line = toJSON(reductions);
+    var reduce_length = reduce_line.length;
+    if (query_config && query_config.reduce_limit &&
+          reduce_length > 200 && ((reduce_length * 2) > line.length)) {
+      throw {
+        error:"reduce_overflow_error",
+        reason: "Reduce output must shrink more rapidly. Current output: '"+reduce_line+"'"
+      };
+    } else {
+      print("[true," + reduce_line + "]");
+    }
   };
   
   return {