diff -r d84d25d6cdbb -r e55a17cdabd2 Logging.m
--- a/Logging.m	Sat Mar 08 21:04:41 2008 -0800
+++ b/Logging.m	Thu Mar 20 09:05:58 2008 -0700
@@ -23,7 +23,9 @@
 }
 
 
-int gShouldLog = -1;
+int _gShouldLog = -1;
+static BOOL sConsole;
+static NSMutableSet *sEnabledDomains;
 
 
 static BOOL isConsole( int fd )
@@ -37,9 +39,65 @@
 }
 
 
-static void _Logv( NSString *msg, va_list args )
+static void InitLogging()
 {
-    if( isConsole(STDERR_FILENO) ) {
+    if( _gShouldLog != -1 )
+        return;
+
+    NSAutoreleasePool *pool = [NSAutoreleasePool new];
+    _gShouldLog = NO;
+    sEnabledDomains = [[NSMutableSet alloc] init];
+    NSDictionary *dflts = [[NSUserDefaults standardUserDefaults] dictionaryRepresentation];
+    for( NSString *key in dflts ) {
+        if( [key hasPrefix: @"Log"] ) {
+            BOOL value = [[NSUserDefaults standardUserDefaults] boolForKey: key];
+            if( key.length==3 )
+                _gShouldLog = value;
+            else if( value )
+                [sEnabledDomains addObject: [key substringFromIndex: 3]];
+        }
+    }
+    sConsole = isConsole(STDERR_FILENO);
+    
+    Log(@"Logging enabled in domains: {%@}", 
+        [[[sEnabledDomains allObjects] sortedArrayUsingSelector: @selector(caseInsensitiveCompare:)] 
+                componentsJoinedByString: @", "]);
+    [pool drain];
+}
+
+
+BOOL EnableLog( BOOL enable )
+{
+    if( _gShouldLog == -1 )
+        InitLogging();
+    BOOL old = _gShouldLog;
+    _gShouldLog = enable;
+    return old;
+}
+
+BOOL _WillLogTo( NSString *domain )
+{
+    if( _gShouldLog == -1 )
+        InitLogging();
+    return _gShouldLog && [sEnabledDomains containsObject: domain];
+}
+
+BOOL _EnableLogTo( NSString *domain, BOOL enable )
+{
+    if( _gShouldLog == -1 )
+        InitLogging();
+    BOOL old = [sEnabledDomains containsObject: domain];
+    if( enable )
+        [sEnabledDomains addObject: domain];
+    else
+        [sEnabledDomains removeObject: domain];
+    return old;
+}
+
+
+static void _Logv( NSString *prefix, NSString *msg, va_list args )
+{
+    if( sConsole ) {
         NSAutoreleasePool *pool = [NSAutoreleasePool new];
         static NSDateFormatter *sTimestampFormat;
         if( ! sTimestampFormat ) {
@@ -49,8 +107,10 @@
         NSDate *now = [[NSDate alloc] init];
         NSString *timestamp = [sTimestampFormat stringFromDate: now];
         [now release];
+        NSString *separator = prefix.length ?@": " :@"";
         msg = [[NSString alloc] initWithFormat: msg arguments: args];
-        NSString *finalMsg = [[NSString alloc] initWithFormat: @"%@| %@\n", timestamp,msg];
+        NSString *finalMsg = [[NSString alloc] initWithFormat: @"%@| %@%@%@\n", 
+                              timestamp,prefix,separator,msg];
         fputs([finalMsg UTF8String], stderr);
         [finalMsg release];
         [msg release];
@@ -64,32 +124,42 @@
 {
     va_list args;
     va_start(args,msg);
-    _Logv(msg,args);
+    _Logv(@"",msg,args);
     va_end(args);
 }
 
 
 void _Log( NSString *msg, ... )
 {
-    if( gShouldLog == -1 )
-        gShouldLog = [[NSUserDefaults standardUserDefaults] boolForKey: @"Log"];
-    
-    if( gShouldLog ) {
+    if( _gShouldLog == -1 )
+        InitLogging();
+    if( _gShouldLog ) {
         va_list args;
         va_start(args,msg);
-        _Logv(msg,args);
+        _Logv(@"",msg,args);
         va_end(args);
     }
 }
 
 
+void _LogTo( NSString *domain, NSString *msg, ... )
+{
+    if( _gShouldLog == -1 )
+        InitLogging();
+    if( _gShouldLog && [sEnabledDomains containsObject: domain] ) {
+        va_list args;
+        va_start(args,msg);
+        _Logv(domain, msg, args);
+        va_end(args);
+    }
+}
+
+
 void Warn( NSString *msg, ... )
 {
-    msg = [@"WARNING*** " stringByAppendingString: msg];
-    
     va_list args;
     va_start(args,msg);
-    _Logv(msg,args);
+    _Logv(@"WARNING*** ",msg,args);
     va_end(args);
 }