From d3aa125d87944940080d9fe8816cd4a289d3e3a0 Mon Sep 17 00:00:00 2001
From: Dwight <dmerriman@gmail.com>
Date: Fri, 30 Jan 2009 14:49:28 -0500
Subject: [PATCH] implement resetError and make lasterror better

---
 client/dbclient.cpp            |  8 ++++----
 client/dbclient.h              | 18 ++++++++++++------
 client/examples/clientTest.cpp |  6 ++++--
 3 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/client/dbclient.cpp b/client/dbclient.cpp
index 1887de6bcbf..34595f021af 100644
--- a/client/dbclient.cpp
+++ b/client/dbclient.cpp
@@ -87,9 +87,9 @@ namespace mongo {
 
     BSONObj getlasterrorcmdobj = fromjson("{getlasterror:1}");
 
-    string DBClientWithCommands::getLastError(const char *dbname) { 
+    string DBClientWithCommands::getLastError() { 
         BSONObj info;
-        runCommand(dbname, getlasterrorcmdobj, info);
+        runCommand("admin", getlasterrorcmdobj, info);
         BSONElement e = info["err"];
         if( e.eoo() ) return "";
         if( e.type() == Object ) return e.toString();
@@ -98,9 +98,9 @@ namespace mongo {
 
     BSONObj getpreverrorcmdobj = fromjson("{getpreverror:1}");
 
-    BSONObj DBClientWithCommands::getPrevError(const char *dbname) { 
+    BSONObj DBClientWithCommands::getPrevError() { 
         BSONObj info;
-        runCommand(dbname, getpreverrorcmdobj, info);
+        runCommand("admin", getpreverrorcmdobj, info);
         return info;
     }
 
diff --git a/client/dbclient.h b/client/dbclient.h
index 4595214ce9d..520c759b7d1 100644
--- a/client/dbclient.h
+++ b/client/dbclient.h
@@ -281,23 +281,29 @@ namespace mongo {
         /** Get error result from the last operation on this connection. 
             @return error or empty string if no error.
         */
-        string getLastError(const char *dbname);
+        string getLastError();
 
 
-        /* Return the last error which has occurred, even if not the very last operation.
+        /** Return the last error which has occurred, even if not the very last operation.
 
-           Returns: 
-             { err : <error message>, nPrev : <how_many_ops_back_occurred>, ok : 1 }
+           @return { err : <error message>, nPrev : <how_many_ops_back_occurred>, ok : 1 }
 
            result.err will be null if no error has occurred.
         */        
-        BSONObj getPrevError(const char *dbname);
+        BSONObj getPrevError();
+
+        /** Reset the previous error state for this connection (accessed via getLastError and 
+            getPrevError).  Useful when performing several operations at once and then checking 
+            for an error after attempting all operations.
+        */
+        bool resetError() { return simpleCommand("admin", 0, "reseterror"); }
 
         /* Erase / drop an entire database */
         bool dropDatabase(const char *dbname, BSONObj *info = 0) {
             return simpleCommand(dbname, info, "dropDatabase");
         }
-        
+
+        /** Delete the specified collection. */        
         bool dropCollection( const string ns ){
             assert( ns.find( "." ) != string::npos );
             int pos = ns.find( "." );
diff --git a/client/examples/clientTest.cpp b/client/examples/clientTest.cpp
index ab4f8595955..8d1e36aea8c 100644
--- a/client/examples/clientTest.cpp
+++ b/client/examples/clientTest.cpp
@@ -112,11 +112,13 @@ int main() {
         assert( conn.findOne(ns, "{}")["name"].str() == "sara" );
 
         assert( conn.findOne(ns, "{ name : 'eliot' }")["name"].str() == "eliot" );
-        assert( conn.getLastError("test") == "" );
+        assert( conn.getLastError() == "" );
 
         // nonexistent index test
         assert( conn.findOne(ns, Query("{name:\"eliot\"}").hint("{foo:1}")).hasElement("$err") );
-        assert( conn.getLastError("test") == "hint index not found" );
+        assert( conn.getLastError() == "hint index not found" );
+        conn.resetError();
+        assert( conn.getLastError() == "" );
 
         //existing index
         assert( conn.findOne(ns, Query("{name:'eliot'}").hint("{name:1}")).hasElement("name") );