Expand documentation for SetGlobalVLogLevel and SetVLogLevel.
PiperOrigin-RevId: 646031348
Change-Id: I212e34a0b89293bd9f0081047bb5a1eba5d04bcb
diff --git a/absl/log/globals.h b/absl/log/globals.h
index b36e47e..4feec40 100644
--- a/absl/log/globals.h
+++ b/absl/log/globals.h
@@ -140,7 +140,7 @@
//
// This option tells the logging library that every logged message
// should include the prefix (severity, date, time, PID, etc.)
-
+//
// ShouldPrependLogPrefix()
//
// Returns the value of the Prepend Log Prefix option.
@@ -154,25 +154,38 @@
void EnableLogPrefix(bool on_off);
//------------------------------------------------------------------------------
-// Set Global VLOG Level
+// `VLOG` Configuration
//------------------------------------------------------------------------------
//
-// Sets the global `(ABSL_)VLOG(_IS_ON)` level to `log_level`. This level is
-// applied to any sites whose filename doesn't match any `module_pattern`.
-// Returns the prior value.
-inline int SetGlobalVLogLevel(int log_level) {
- return absl::log_internal::UpdateGlobalVLogLevel(log_level);
+// These methods set the `(ABSL_)VLOG(_IS_ON)` threshold. They allow
+// programmatic control of the thresholds set by the --v and --vmodule flags.
+//
+// Only `VLOG`s with a severity level LESS THAN OR EQUAL TO the threshold will
+// be evaluated.
+//
+// For example, if the threshold is 2, then:
+//
+// VLOG(2) << "This message will be logged.";
+// VLOG(3) << "This message will NOT be logged.";
+//
+// The default threshold is 0. Since `VLOG` levels must not be negative, a
+// negative threshold value will turn off all VLOGs.
+
+// SetGlobalVLogLevel()
+//
+// Sets the global `VLOG` level to threshold. Returns the previous global
+// threshold.
+inline int SetGlobalVLogLevel(int threshold) {
+ return absl::log_internal::UpdateGlobalVLogLevel(threshold);
}
-//------------------------------------------------------------------------------
-// Set VLOG Level
-//------------------------------------------------------------------------------
+// SetVLogLevel()
//
-// Sets `(ABSL_)VLOG(_IS_ON)` level for `module_pattern` to `log_level`. This
-// allows programmatic control of what is normally set by the --vmodule flag.
-// Returns the level that previously applied to `module_pattern`.
-inline int SetVLogLevel(absl::string_view module_pattern, int log_level) {
- return absl::log_internal::PrependVModule(module_pattern, log_level);
+// Sets the `VLOG` threshold for all files that match `module_pattern`,
+// overwriting any prior value. Files that don't match aren't affected.
+// Returns the threshold that previously applied to `module_pattern`.
+inline int SetVLogLevel(absl::string_view module_pattern, int threshold) {
+ return absl::log_internal::PrependVModule(module_pattern, threshold);
}
//------------------------------------------------------------------------------
