advertise new dbs for replication; handle user asserts on repl

13 files changed, 243 insertions, 169 deletions

diff --git a/db/db.cpp b/db/db.cpp
index 240a71c3480..ad62ed623ed 100644
--- a/db/db.cpp
+++ b/db/db.cpp
@@ -44,6 +44,7 @@ int dbLocked = 0;
 
 void closeAllSockets();
 void startReplication();
+void pairWith(const char *remoteEnd);
 
 struct MyStartupTests {
 	MyStartupTests() {
@@ -896,6 +897,9 @@ int main(int argc, char* argv[], char *envp[] )
 				master = true;
 			else if( s == "--slave" )
 				slave = true;
+			else if( s == "--pairwith" ) { 
+				pairWith( argv[++i] );
+			}
 			else if( s == "--dbpath" )
             	dbpath = argv[++i];
             else if( s == "--appsrvpath" )
@@ -930,6 +934,7 @@ int main(int argc, char* argv[], char *envp[] )
 	cout << " --port <portno>  --dbpath <root> --appsrvpath <root of appsrv>" << endl;
 	cout << " --nocursors  --nojni" << endl;
 	cout << " --oplog<n> 0=off 1=W 2=R 3=both 7=W+some reads" << endl;
+	cout << " --pairwith <server:port>" << endl;
 	cout << endl;
 	
 	return 0;
diff --git a/db/db.vcproj b/db/db.vcproj
index 7e6e0285868..6ab824bf3c7 100644
--- a/db/db.vcproj
+++ b/db/db.vcproj
@@ -361,6 +361,10 @@
 				>

 			</File>

 			<File

+				RelativePath=".\replset.h"

+				>

+			</File>

+			<File

 				RelativePath=".\resource.h"

 				>

 			</File>

diff --git a/db/pdfile.cpp b/db/pdfile.cpp
index 84b76b79978..712924b8f6e 100644
--- a/db/pdfile.cpp
+++ b/db/pdfile.cpp
@@ -152,15 +152,13 @@ void PhysicalDataFile::open(int fn, const char *filename) {
         
 	assert( length >= 64*1024*1024 );
 
-        if( strstr(filename, "_hudsonSmall") ) {
-          int mult = 1;
-          if ( fn > 1 && fn < 1000 )
-            mult = fn;
-          length = 1024 * 512 * mult;
-          cout << "Warning : using small files for _hudsonSmall" << endl;
-        }
-
-
+	if( strstr(filename, "_hudsonSmall") ) {
+		int mult = 1;
+		if ( fn > 1 && fn < 1000 )
+			mult = fn;
+		length = 1024 * 512 * mult;
+		cout << "Warning : using small files for _hudsonSmall" << endl;
+	}
 	assert( length % 4096 == 0 );
 
 	assert(fn == fileNo);
@@ -826,6 +824,9 @@ DiskLoc DataFileMgr::insert(const char *ns, const void *buf, int len, bool god)
 	return loc;
 }
 
+/* special version of insert for transaction logging -- streamlined a bit.
+   assumes ns is capped and no indexes
+*/
 Record* DataFileMgr::fast_oplog_insert(NamespaceDetails *d, const char *ns, int len) {
 	RARELY assert( d == nsdetails(ns) );
 
diff --git a/db/pdfile.h b/db/pdfile.h
index 9e7a8433d51..c0e9b2d44c1 100644
--- a/db/pdfile.h
+++ b/db/pdfile.h
@@ -209,7 +209,11 @@ public:
 
 	static int headerSize() { return sizeof(PDFHeader) - 4; }
 
-	bool uninitialized() { if( version == 0 ) return true; assert(version == VERSION); return false; }
+	bool uninitialized() { 
+		if( version == 0 ) return true; 
+		assert(version == VERSION); 
+		return false; 
+	}
 
 	Record* getRecord(DiskLoc dl) {
 		int ofs = dl.getOfs();
diff --git a/db/query.cpp b/db/query.cpp
index d35cab071ef..c39f38b1392 100644
--- a/db/query.cpp
+++ b/db/query.cpp
@@ -362,7 +362,7 @@ int _updateObjects(const char *ns, JSObj updateobj, JSObj pattern, bool upsert,
                     set<string>& idxKeys = ndt.indexKeys();
                     for( vector<Mod>::iterator i = mods.begin(); i != mods.end(); i++ ) { 
                         if( idxKeys.count(i->fieldName) ) {
-                            assert(false);
+                            uassert("can't $inc/$set an indexed field", false);
                         }
                     }
 
diff --git a/db/repl.cpp b/db/repl.cpp
index 12722b37377..ea6b693e21c 100644
--- a/db/repl.cpp
+++ b/db/repl.cpp
@@ -68,7 +68,7 @@ int test2() {
 
 /* --------------------------------------------------------------*/
 
-Source::Source(JSObj o) : nClonedThisPass(0) {
+ReplSource::ReplSource(JSObj o) : nClonedThisPass(0) {
 	only = o.getStringField("only");
 	hostName = o.getStringField("host");
 	sourceName = o.getStringField("source");
@@ -95,7 +95,7 @@ Source::Source(JSObj o) : nClonedThisPass(0) {
 }
 
 /* Turn our C++ Source object into a JSObj */
-JSObj Source::jsobj() {
+JSObj ReplSource::jsobj() {
 	JSObjBuilder b;
 	b.append("host", hostName);
 	b.append("source", sourceName);
@@ -112,7 +112,7 @@ JSObj Source::jsobj() {
 	return b.doneAndDecouple();
 }
 
-void Source::save() { 
+void ReplSource::save() { 
 	JSObjBuilder b;
 	b.append("host", hostName);
 	b.append("source", sourceName);
@@ -129,13 +129,13 @@ void Source::save() {
 	client = 0;
 }
 
-void Source::cleanup(vector<Source*>& v) { 
-	for( vector<Source*>::iterator i = v.begin(); i != v.end(); i++ )
+void ReplSource::cleanup(vector<ReplSource*>& v) { 
+	for( vector<ReplSource*>::iterator i = v.begin(); i != v.end(); i++ )
 		delete *i;
 }
 
-static void addSourceToList(vector<Source*>&v, Source& s, vector<Source*>&old) { 
-	for( vector<Source*>::iterator i = old.begin(); i != old.end();  ) {
+static void addSourceToList(vector<ReplSource*>&v, ReplSource& s, vector<ReplSource*>&old) { 
+	for( vector<ReplSource*>::iterator i = old.begin(); i != old.end();  ) {
 		if( s == **i ) {
 			v.push_back(*i);
 			old.erase(i);
@@ -144,32 +144,32 @@ static void addSourceToList(vector<Source*>&v, Source& s, vector<Source*>&old) {
 		i++;
 	}
 
-	v.push_back( new Source(s) );
+	v.push_back( new ReplSource(s) );
 }
 
 /* we reuse our existing objects so that we can keep our existing connection 
    and cursor in effect. 
 */
-void Source::loadAll(vector<Source*>& v) { 
-	vector<Source *> old = v;
+void ReplSource::loadAll(vector<ReplSource*>& v) { 
+	vector<ReplSource *> old = v;
     v.erase(v.begin(), v.end());
 
 	setClient("local.sources");
 	auto_ptr<Cursor> c = findTableScan("local.sources", emptyObj);
 	while( c->ok() ) { 
-		Source tmp(c->current());	
+		ReplSource tmp(c->current());	
 		addSourceToList(v, tmp, old);
 		c->advance();
 	}
 	client = 0;
 
-    for( vector<Source*>::iterator i = old.begin(); i != old.end(); i++ )
+    for( vector<ReplSource*>::iterator i = old.begin(); i != old.end(); i++ )
         delete *i;
 }
 
 JSObj opTimeQuery = fromjson("{getoptime:1}");
 
-bool Source::resync(string db) {
+bool ReplSource::resync(string db) {
 	{
 		log() << "resync: dropping database " << db << endl;
 		string dummyns = db + ".";
@@ -200,9 +200,11 @@ bool Source::resync(string db) {
 	return true;
 }
 
-/* { ts: ..., op: <optype>, ns: ..., o: <obj> , o2: <extraobj>, b: <boolflag> } 
+/* local.$oplog.main is of the form:
+     { ts: ..., op: <optype>, ns: ..., o: <obj> , o2: <extraobj>, b: <boolflag> } 
+     ...
 */
-void Source::applyOperation(JSObj& op) {
+void ReplSource::sync_pullOpLog_applyOperation(JSObj& op) {
 	char clientName[MaxClientLen];
 	const char *ns = op.getStringField("ns");
 	nsToClient(ns, clientName);
@@ -234,45 +236,53 @@ void Source::applyOperation(JSObj& op) {
 	stringstream ss;
 	const char *opType = op.getStringField("op");
 	JSObj o = op.getObjectField("o");
-	if( *opType == 'i' ) {
-        const char *p = strchr(ns, '.');
-        if( p && strcmp(p, ".system.indexes") == 0 ) { 
-            // updates aren't allowed for indexes -- so we will do a regular insert. if index already 
-            // exists, that is ok.
-            theDataFileMgr.insert(ns, (void*) o.objdata(), o.objsize());
-        }
-        else { 
-            // do upserts for inserts as we might get replayed more than once
-            OID *oid = o.getOID();
-            if( oid == 0 ) {
-                _updateObjects(ns, o, o, true, ss);
-            }
-            else { 
-                JSObjBuilder b;
-                b.appendOID("_id", oid);
-				RARELY ensureHaveIdIndex(ns); // otherwise updates will be super slow
-                _updateObjects(ns, o, b.done(), true, ss);
-            }
-        }
-	}
-	else if( *opType == 'u' ) { 
-		RARELY ensureHaveIdIndex(ns); // otherwise updates will be super slow
-		_updateObjects(ns, o, op.getObjectField("o2"), op.getBoolField("b"), ss);
-	}
-	else if( *opType == 'd' ) { 
-		deleteObjects(ns, o, op.getBoolField("b"));
+	try { 
+		if( *opType == 'i' ) {
+			const char *p = strchr(ns, '.');
+			if( p && strcmp(p, ".system.indexes") == 0 ) { 
+				// updates aren't allowed for indexes -- so we will do a regular insert. if index already 
+				// exists, that is ok.
+				theDataFileMgr.insert(ns, (void*) o.objdata(), o.objsize());
+			}
+			else { 
+				// do upserts for inserts as we might get replayed more than once
+				OID *oid = o.getOID();
+				if( oid == 0 ) {
+					_updateObjects(ns, o, o, true, ss);
+				}
+				else { 
+					JSObjBuilder b;
+					b.appendOID("_id", oid);
+					RARELY ensureHaveIdIndex(ns); // otherwise updates will be super slow
+					_updateObjects(ns, o, b.done(), true, ss);
+				}
+			}
+		}
+		else if( *opType == 'u' ) { 
+			RARELY ensureHaveIdIndex(ns); // otherwise updates will be super slow
+			_updateObjects(ns, o, op.getObjectField("o2"), op.getBoolField("b"), ss);
+		}
+		else if( *opType == 'd' ) { 
+			if( opType[1] == 0 )
+				deleteObjects(ns, o, op.getBoolField("b"));
+			else
+				assert( opType[1] == 'b' ); // "db" advertisement
+		}
+		else { 
+			BufBuilder bb;
+			JSObjBuilder ob;
+			assert( *opType == 'c' );
+			_runCommands(ns, o, ss, bb, ob);
+		}
 	}
-	else { 
-		BufBuilder bb;
-		JSObjBuilder ob;
-		assert( *opType == 'c' );
-		_runCommands(ns, o, ss, bb, ob);
+	catch( UserAssertionException e ) { 
+		log() << "sync: caught user assertion " << e.msg << '\n';
 	}
 	client = 0;
 }
 
 /* note: not yet in mutex at this point. */
-void Source::pullOpLog() { 
+void ReplSource::sync_pullOpLog() { 
 	string ns = string("local.oplog.$") + sourceName;
 
 	bool tailing = true;
@@ -323,7 +333,7 @@ void Source::pullOpLog() {
 			log() << "pull:   initial run\n";
 		}
         {
-            applyOperation(op);
+            sync_pullOpLog_applyOperation(op);
             n++;
         }
 	}
@@ -359,7 +369,7 @@ void Source::pullOpLog() {
 				uassert("bad 'ts' value in sources", false);
 			}
 
-			applyOperation(op);
+			sync_pullOpLog_applyOperation(op);
 			n++;
 		}
 	}
@@ -368,7 +378,7 @@ void Source::pullOpLog() {
 /* note: not yet in mutex at this point. 
    returns true if everything happy.  return false if you want to reconnect.
 */
-bool Source::sync() { 
+bool ReplSource::sync() { 
 	log() << "pull: " << sourceName << '@' << hostName << endl;
 	nClonedThisPass = 0;
 
@@ -402,7 +412,7 @@ bool Source::sync() {
 	OpTime serverCurTime;
 	serverCurTime.asDate() = e.date();
 */
-	pullOpLog();
+	sync_pullOpLog();
 	return true;
 }
 
@@ -416,7 +426,13 @@ Client *localOplogClient = 0;
      { ts : ..., op: ..., ns: ..., o: ... }
    ts: an OpTime timestamp
    op: 
-     'i' = insert
+    "i" insert
+    "u" update
+    "d" delete
+    "c" db cmd
+   bb:
+     if not null, specifies a boolean to pass along to the other side as b: param.
+     used for "justOne" or "upsert" flags on 'd', 'u'
 */
 void _logOp(const char *opstr, const char *ns, JSObj& obj, JSObj *o2, bool *bb) {
 	if( strncmp(ns, "local.", 6) == 0 )
@@ -471,19 +487,19 @@ _ reuse that cursor when we can
 */
 
 void replMain() { 
-	vector<Source*> sources;
+	vector<ReplSource*> sources;
 
 	while( 1 ) { 
 		{	
 			dblock lk;
-			Source::loadAll(sources);
+			ReplSource::loadAll(sources);
 		}
 		
 		if( sources.empty() )
 			sleepsecs(20);
 		
-		for( vector<Source*>::iterator i = sources.begin(); i != sources.end(); i++ ) {
-			Source *s = *i;	
+		for( vector<ReplSource*>::iterator i = sources.begin(); i != sources.end(); i++ ) {
+			ReplSource *s = *i;	
 			bool ok = false;	
 			try {
 				ok = s->sync();
@@ -503,7 +519,7 @@ void replMain() {
         sleepsecs(3);
 	}
 
-	Source::cleanup(sources);
+	ReplSource::cleanup(sources);
 }
 
 int debug_stop_repl = 0;
@@ -524,23 +540,75 @@ void replSlaveThread() {
 	}
 }
 
+/* used to verify that slave knows what databases we have */
+void logOurDbsPresence() { 
+	path dbs(dbpath);
+    directory_iterator end;
+    directory_iterator i(dbs);
+
+	dblock lk;
+
+	int k = 0;
+    while( i != end ) {
+      path p = *i;
+	  string f = p.leaf();
+	  if( endsWith(f.c_str(), ".ns") ) {
+		  /* note: we keep trailing "." so that when slave calls setClient(ns) everything is happy; e.g., 
+		           valid namespaces must always have a dot, even though here it is just a placeholder not 
+				   a real one
+				   */
+		  string dbname = string(f.c_str(), f.size() - 2);
+		  if( dbname != "local." )
+			  logOp("db", dbname.c_str(), emptyObj);
+	  }
+      i++;
+    }
+}
+
+/* we have to log the db presence periodically as that "advertisement" will roll out of the log
+   as it is of finite length.  also as we only do one db cloning per pass, we could skip over a bunch of 
+   advertisements and thus need to see them again later.  so this mechanism can actually be very slow to 
+   work, and should be improved.
+*/
+void replMasterThread() { 
+    sleepsecs(15);
+	while( 1 ) {
+		logOurDbsPresence();
+		sleepsecs(60 * 10);
+	}
+}
+
+#include "replset.h"
+
+ReplSet *replSet = 0;
+
 void startReplication() { 
 	if( slave ) {
 		log() << "slave=true" << endl;
 		boost::thread repl_thread(replSlaveThread);
 	}
 
-	if( master ) {  
+	if( master || replSet ) {
 		log() << "master=true" << endl;
-		dblock lk;
-		/* create an oplog collection, if it doesn't yet exist. */
-		JSObjBuilder b;
-		b.append("size", 254.0 * 1000 * 1000);
-		b.appendBool("capped", 1);
-		setClientTempNs("local.oplog.$main");
-		string err;
-		JSObj o = b.done();
-		userCreateNS("local.oplog.$main", o, err);
-		client = 0;
+		{
+			dblock lk;
+			/* create an oplog collection, if it doesn't yet exist. */
+			JSObjBuilder b;
+			b.append("size", 254.0 * 1000 * 1000);
+			b.appendBool("capped", 1);
+			setClientTempNs("local.oplog.$main");
+			string err;
+			JSObj o = b.done();
+			userCreateNS("local.oplog.$main", o, err);
+			client = 0;
+		}
+
+		boost::thread mt(replMasterThread);
 	}
 }
+
+/* called from main at server startup */
+void pairWith(const char *remoteEnd) {
+	replSet = new ReplSet(remoteEnd);
+//	uassert("not done yet!", false);
+}
diff --git a/db/repl.h b/db/repl.h
index d3708f56860..a95d5530115 100644
--- a/db/repl.h
+++ b/db/repl.h
@@ -85,10 +85,10 @@ struct SyncException {
 
       { host: ..., source: ..., syncedTo: ..., dbs: { ... } }
 */
-class Source {
+class ReplSource {
 	bool resync(string db);
-	void pullOpLog();
-	void applyOperation(JSObj& op);
+	void sync_pullOpLog();
+	void sync_pullOpLog_applyOperation(JSObj& op);
 
 	auto_ptr<DBClientConnection> conn;
 	auto_ptr<DBClientCursor> cursor;
@@ -108,9 +108,9 @@ public:
 
 	int nClonedThisPass;
 
-	static void loadAll(vector<Source*>&);
-	static void cleanup(vector<Source*>&);
-	Source(JSObj);
+	static void loadAll(vector<ReplSource*>&);
+	static void cleanup(vector<ReplSource*>&);
+	ReplSource(JSObj);
 	bool sync();
 	void save(); // write ourself to local.sources
 	void resetConnection() { conn = auto_ptr<DBClientConnection>(0); }
@@ -119,7 +119,7 @@ public:
 	//   { host: ..., source: ..., syncedTo: ... }
 	JSObj jsobj(); 
 	
-	bool operator==(const Source&r) const { 
+	bool operator==(const ReplSource&r) const { 
 		return hostName == r.hostName && sourceName == r.sourceName; 
 	}
 };
@@ -129,6 +129,7 @@ public:
    "u" update
    "d" delete
    "c" db cmd
+   "db" declares presence of a database (ns is set to the db name + '.')
 */
 void _logOp(const char *opstr, const char *ns, JSObj& obj, JSObj *patt, bool *b);
 inline void logOp(const char *opstr, const char *ns, JSObj& obj, JSObj *patt = 0, bool *b = 0) {
diff --git a/db/replset.h b/db/replset.h
new file mode 100644
index 00000000000..106b36c1189
--- /dev/null
+++ b/db/replset.h
@@ -0,0 +1,49 @@
+/**
+*    Copyright (C) 2008 10gen Inc.
+*  
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*  
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*  
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+/* ReplSet is a pair of db servers replicating to one another and cooperating.
+
+   Only one member of the pair is active at a time; so this is a smart master/slave
+   configuration basically.
+
+   You may read from the slave at anytime though (if you don't mind the slight lag).
+
+   todo: Could be extended to be more than a pair, thus the name 'Set' -- for example, 
+   a set of 3...
+*/
+
+class ReplSet { 
+
+public:
+	int remotePort;
+	string remoteHost;
+
+	ReplSet(const char *remoteEnd);
+
+};
+
+ReplSet::ReplSet(const char *remoteEnd) {
+	remotePort = DBPort;
+	remoteHost = remoteEnd;
+	const char *p = strchr(remoteEnd, ':');
+	if( p ) { 
+		remoteHost = string(remoteEnd, p-remoteEnd);
+		remotePort = atoi(p+1);
+		uassert("bad port #", remotePort > 0 && remotePort < 0x10000 );
+	}
+}
diff --git a/mongo.1 b/mongo.1
deleted file mode 100644
index 1ad5f8ffba9..00000000000
--- a/mongo.1
+++ /dev/null
@@ -1,79 +0,0 @@
-.\"Modified from man(1) of FreeBSD, the NetBSD mdoc.template, and mdoc.samples.

-.\"See Also:

-.\"man mdoc.samples for a complete listing of options

-.\"man mdoc for the short list of editing options

-.\"/usr/share/misc/mdoc.template

-.Dd 8/12/08               \" DATE 

-.Dt mongo 1      \" Program name and manual section number 

-.Os Darwin

-.Sh NAME                 \" Section Header - required - don't modify 

-.Nm mongo,

-.\" The following lines are read in generating the apropos(man -k) database. Use only key

-.\" words here as the database is built based on the words here and in the .ND line. 

-.Nm Other_name_for_same_program(),

-.Nm Yet another name for the same program.

-.\" Use .Nm macro to designate other names for the documented program.

-.Nd This line parsed for whatis database.

-.Sh SYNOPSIS             \" Section Header - required - don't modify

-.Nm

-.Op Fl abcd              \" [-abcd]

-.Op Fl a Ar path         \" [-a path] 

-.Op Ar file              \" [file]

-.Op Ar                   \" [file ...]

-.Ar arg0                 \" Underlined argument - use .Ar anywhere to underline

-arg2 ...                 \" Arguments

-.Sh DESCRIPTION          \" Section Header - required - don't modify

-Use the .Nm macro to refer to your program throughout the man page like such:

-.Nm

-Underlining is accomplished with the .Ar macro like this:

-.Ar underlined text .

-.Pp                      \" Inserts a space

-A list of items with descriptions:

-.Bl -tag -width -indent  \" Begins a tagged list 

-.It item a               \" Each item preceded by .It macro

-Description of item a

-.It item b

-Description of item b

-.El                      \" Ends the list

-.Pp

-A list of flags and their descriptions:

-.Bl -tag -width -indent  \" Differs from above in tag removed 

-.It Fl a                 \"-a flag as a list item

-Description of -a flag

-.It Fl b

-Description of -b flag

-.El                      \" Ends the list

-.Pp

-.\" .Sh ENVIRONMENT      \" May not be needed

-.\" .Bl -tag -width "ENV_VAR_1" -indent \" ENV_VAR_1 is width of the string ENV_VAR_1

-.\" .It Ev ENV_VAR_1

-.\" Description of ENV_VAR_1

-.\" .It Ev ENV_VAR_2

-.\" Description of ENV_VAR_2

-.\" .El                      

-.Sh FILES                \" File used or created by the topic of the man page

-.Bl -tag -width "/Users/joeuser/Library/really_long_file_name" -compact

-.It Pa /usr/share/file_name

-FILE_1 description

-.It Pa /Users/joeuser/Library/really_long_file_name

-FILE_2 description

-.El                      \" Ends the list

-.\" .Sh DIAGNOSTICS       \" May not be needed

-.\" .Bl -diag

-.\" .It Diagnostic Tag

-.\" Diagnostic informtion here.

-.\" .It Diagnostic Tag

-.\" Diagnostic informtion here.

-.\" .El

-.Sh SEE ALSO 

-.\" List links in ascending order by section, alphabetically within a section.

-.\" Please do not reference files that do not exist without filing a bug report

-.Xr a 1 , 

-.Xr b 1 ,

-.Xr c 1 ,

-.Xr a 2 ,

-.Xr b 2 ,

-.Xr a 3 ,

-.Xr b 3 

-.\" .Sh BUGS              \" Document known, unremedied bugs 

-.\" .Sh HISTORY           \" Document history if command behaves in a unique manner 
\ No newline at end of file
diff --git a/stdafx.cpp b/stdafx.cpp
index 89c5194be32..56ea439d52e 100644
--- a/stdafx.cpp
+++ b/stdafx.cpp
@@ -41,14 +41,14 @@ void wasserted(const char *msg, const char *file, unsigned line) {
 	sayDbContext();
 }
 
-void asserted(const char *msg, const char *file, unsigned line) { 
+void asserted(const char *msg, const char *file, unsigned line) {
 	wasserted(msg, file, line);
 	throw AssertionException();
 }
 
 void uasserted(const char *msg) { 
 	problem() << "User Assertion " << msg << endl;
-	throw AssertionException();
+	throw UserAssertionException(msg);
 }
 
 void msgasserted(const char *msg) {
diff --git a/stdafx.h b/stdafx.h
index 0612fa9f506..a74787d593f 100644
--- a/stdafx.h
+++ b/stdafx.h
@@ -53,7 +53,16 @@ inline void * ourrealloc(void *ptr, size_t size) {
 // you can catch these
 class AssertionException { 
 public:
-	AssertionException() { }
+	const char *msg;
+	AssertionException() { msg = ""; }
+	virtual bool isUserAssertion() { return false; }
+};
+
+/* we use the same mechanism for bad things the user does -- which are really just errors */
+class UserAssertionException : public AssertionException { 
+public:
+	UserAssertionException(const char *_msg) { msg = _msg; }
+	virtual bool isUserAssertion() { return true; }
 };
 
 void asserted(const char *msg, const char *file, unsigned line);
diff --git a/util/goodies.h b/util/goodies.h
index 631ed12b9f6..7c38f8d1e93 100644
--- a/util/goodies.h
+++ b/util/goodies.h
@@ -191,3 +191,11 @@ public:
 */
 
 //typedef boostlock lock;
+
+inline bool endsWith(const char *p, const char *suffix) { 
+	int a = strlen(p);
+	int b = strlen(suffix);
+	if( b > a ) return false;
+	return strcmp(p + a - b, suffix) == 0;
+}
+
diff --git a/util/util.cpp b/util/util.cpp
index 9c09267ae9c..51fb7dfc7f7 100644
--- a/util/util.cpp
+++ b/util/util.cpp
@@ -64,5 +64,9 @@ struct UtilTest {
 		assert( !isPrime(6) );
 		assert( nextPrime(4) == 5 );
 		assert( nextPrime(8) == 11 );
+
+		assert( endsWith("abcde", "de") );
+		assert( !endsWith("abcde", "dasdfasdfashkfde") );
+
 	}
 } utilTest;