From fd87ce503c7927ba552b381b5c2d4b32fccb48dd Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Wed, 7 Oct 2015 10:45:28 +0200
Subject: [PATCH] logging: add special logging level "KEEP"

Without this, the user cannot configure only certain logging domains
without touching them all.

E.g.

  # nmcli general logging level DEBUG domains PLATFORM

will disable all non-PLATFORM domains.
Well, the user can do:

  # nmcli general logging level INFO domains PLATFORM:DEBUG
  # nmcli general logging level DEBUG domains ALL:INFO,PLATFORM

but in this case all non-PLATFORM domains are reset explicitly.

Now the user can:

  # nmcli general logging level KEEP domains PLATFORM:DEBUG
  # nmcli general logging level DEBUG domains ALL:KEEP,PLATFORM

which will only change the platform domain.
---
 introspection/nm-manager.xml |  8 +++++++-
 src/nm-logging.c             | 21 ++++++++++++++++-----
 src/nm-logging.h             |  1 +
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/introspection/nm-manager.xml b/introspection/nm-manager.xml
index 88f477d62f..36cbee3011 100644
--- a/introspection/nm-manager.xml
+++ b/introspection/nm-manager.xml
@@ -184,7 +184,13 @@
       </tp:docstring>
       <arg name="level" type="s" direction="in">
         <tp:docstring>
-          One of [ERR, WARN, INFO, DEBUG, TRACE].
+          One of [ERR, WARN, INFO, DEBUG, TRACE, OFF, KEEP].
+          This level is applied to the domains as specified in the domains
+          argument. Except for the special level "KEEP", all unmentioned
+          domains are disabled entirely. "KEEP" is special and allows
+          not to change the current setting except for the specified
+          domains. E.g. level=KEEP and domains=PLATFORM:DEBUG will only
+          touch the platform domain.
         </tp:docstring>
       </arg>
       <arg name="domains" type="s" direction="in">
diff --git a/src/nm-logging.c b/src/nm-logging.c
index 30c754d163..e58a5de384 100644
--- a/src/nm-logging.c
+++ b/src/nm-logging.c
@@ -79,6 +79,7 @@ static const LogLevelDesc level_desc[_LOGL_N] = {
 	[LOGL_WARN]  = { "WARN",  "<warn>",  LOG_WARNING, G_LOG_LEVEL_WARNING, FALSE },
 	[LOGL_ERR]   = { "ERR",   "<error>", LOG_ERR,     G_LOG_LEVEL_WARNING, TRUE  },
 	[_LOGL_OFF]  = { "OFF",   NULL,      0,           0,                   FALSE },
+	[_LOGL_KEEP] = { "KEEP",  NULL,      0,           0,                   FALSE },
 };
 
 static const LogDesc domain_descs[] = {
@@ -181,6 +182,11 @@ nm_logging_setup (const char  *level,
 	if (level && *level) {
 		if (!match_log_level (level, &new_log_level, error))
 			return FALSE;
+		if (new_log_level == _LOGL_KEEP) {
+			new_log_level = log_level;
+			for (i = 0; i < G_N_ELEMENTS (new_logging); i++)
+				new_logging[i] = logging[i];
+		}
 	}
 
 	/* domains */
@@ -249,11 +255,16 @@ nm_logging_setup (const char  *level,
 			}
 		}
 
-		for (i = 0; i < G_N_ELEMENTS (new_logging); i++) {
-			if (i < domain_log_level)
-				new_logging[i] &= ~bits;
-			else
-				new_logging[i] |= bits;
+		if (domain_log_level == _LOGL_KEEP) {
+			for (i = 0; i < G_N_ELEMENTS (new_logging); i++)
+				new_logging[i] = (new_logging[i] & ~bits) | (logging[i] & bits);
+		} else {
+			for (i = 0; i < G_N_ELEMENTS (new_logging); i++) {
+				if (i < domain_log_level)
+					new_logging[i] &= ~bits;
+				else
+					new_logging[i] |= bits;
+			}
 		}
 	}
 	g_strfreev (tmp);
diff --git a/src/nm-logging.h b/src/nm-logging.h
index db9f0b1557..b54078186e 100644
--- a/src/nm-logging.h
+++ b/src/nm-logging.h
@@ -94,6 +94,7 @@ typedef enum  { /*< skip >*/
 	_LOGL_N_REAL, /* the number of actual logging levels */
 
 	_LOGL_OFF = _LOGL_N_REAL, /* special logging level that is always disabled. */
+	_LOGL_KEEP,               /* special logging level to indicate that the logging level should not be changed. */
 
 	_LOGL_N, /* the number of logging levels including "OFF" */
 } NMLogLevel;