Add log.level(...) and log.levels(...) API for changing logger stream levels.

CHANGES.md

@@ -2,6 +2,9 @@
 
 ## bunyan 0.5.0 (not yet released)
 
+- Add `log.level(...)` and `log.levels(...)` API for changing logger stream
+  levels.
+- Add `TRACE|DEBUG|INFO|WARN|ERROR|FATAL` level constants to exports.
 - Add `log.info(err)` special case for logging an `Error` instance. For
   example `log.info(new TypeError("boom")` will produce:
 

README.md

@@ -220,6 +220,22 @@ Integers are used for the actual level values (1 for "trace", ..., 6 for
 "fatal") and constants are defined for the (Logger.TRACE ... Logger.DEBUG).
 The lowercase level names are aliases supported in the API.
 
+Here is the API for changing levels in an existing logger:
+
+    log.level() -> INFO   // gets current level (lowest level of all streams)
+ 
+    log.level(INFO)       // set all streams to level INFO
+    log.level("info")     // set all streams to level INFO
+
+    log.levels() -> [DEBUG, INFO]   // get array of levels of all streams
+    log.levels(0) -> DEBUG          // get level of stream at index 0
+    log.levels("foo")               // get level of stream with name "foo"
+ 
+    log.levels(0, INFO)             // set level of stream 0 to INFO
+    log.levels(0, "info")           // can use "info" et al aliases
+    log.levels("foo", WARN)         // set stream named "foo" to WARN
+
+
 
 # Log Record Fields
 

TODO.md

@@ -1,8 +1,8 @@
-- line/file: possible to get quickly with v8? Yunong asked.
-    file/line/func (?)
 - Logger.setLevel()? How to change level for a given stream. Default all,
   else, give an index... or type ... or support stream "names". Some positives
   to stream names.
+- service -> name
+- 10, 20,...
 - bunyan cli: more layouts (http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/EnhancedPatternLayout.html)
   Custom log formats (in config file? in '-f' arg) using printf or hogan.js
   or whatever. Dap wants field width control for lining up. Hogan.js is

examples/level.js

@@ -0,0 +1,47 @@
+// Play with setting levels.
+//
+// TODO: put this in a damn test suite
+
+var Logger = require('../lib/bunyan'),
+  DEBUG = Logger.DEBUG,
+  INFO = Logger.INFO,
+  WARN = Logger.WARN;
+var assert = require('assert');
+
+// Basic usage.
+var log = new Logger({
+  service: 'example-level',
+  streams: [
+    {
+      name: 'stdout',
+      stream: process.stdout,
+      level: 'debug'
+    },
+    {
+      name: 'stderr',
+      stream: process.stderr
+    }
+  ]
+});
+
+assert.equal(log.level(), DEBUG);
+assert.equal(log.levels()[0], DEBUG);
+assert.equal(log.levels()[1], INFO);
+assert.equal(log.levels(0), DEBUG);
+assert.equal(log.levels(1), INFO);
+
+assert.equal(log.levels('stdout'), DEBUG)
+try {
+  log.levels('foo')
+} catch (e) {
+  assert.ok(e.message.indexOf('name') !== -1)
+}
+
+log.trace("no one should see this")
+log.debug("should see this once (on stdout)")
+log.info("should see this twice")
+log.levels('stdout', INFO)
+log.debug("no one should see this either")
+log.level('trace')
+log.trace('should see this twice as 4th and 5th emitted log messages')
+

lib/bunyan.js

@@ -22,6 +22,7 @@ var xxx = function xxx() {};  // uncomment to turn of debug logging
 var os = require('os');
 var fs = require('fs');
 var util = require('util');
+var assert = require('assert');
 
 
 
@@ -201,7 +202,7 @@ function Logger(options, _childOptions, _childSimple) {
     // streams.
     this._isSimpleChild = true;
 
-    this.level = parent.level;
+    this._level = parent._level;
     this.streams = parent.streams;
     this.serializers = parent.serializers;
     this.src = parent.src;
@@ -217,7 +218,7 @@ function Logger(options, _childOptions, _childSimple) {
   // Null values.
   var self = this;
   if (parent) {
-    this.level = parent.level;
+    this._level = parent._level;
     this.streams = [];
     for (var i = 0; i < parent.streams.length; i++) {
       var s = objCopy(parent.streams[i]);
@@ -228,7 +229,7 @@ function Logger(options, _childOptions, _childSimple) {
     this.src = parent.src;
     this.fields = objCopy(parent.fields);
   } else {
-    this.level = Number.POSITIVE_INFINITY;
+    this._level = Number.POSITIVE_INFINITY;
     this.streams = [];
     this.serializers = null;
     this.src = false;
@@ -254,8 +255,8 @@ function Logger(options, _childOptions, _childSimple) {
     } else {
       s.level = INFO;
     }
-    if (s.level < self.level) {
+    if (s.level < self._level) {
-      self.level = s.level;
+      self._level = s.level;
     }
 
     switch (s.type) {
@@ -399,6 +400,98 @@ Logger.prototype.child = function (options, simple) {
 //}
 
 
+/**
+ * Get/set the level of all streams on this logger.
+ *
+ * Get Usage:
+ *    // Returns the current log level (lowest level of all its streams).
+ *    log.level() -> INFO
+ *
+ * Set Usage:
+ *    log.level(INFO)       // set all streams to level INFO
+ *    log.level("info")     // can use "info" et al aliases
+ */
+Logger.prototype.level = function level(value) {
+  if (value === undefined) {
+    return this._level;
+  }
+  var newLevel = resolveLevel(value);
+  var len = this.streams.length;
+  for (var i = 0; i < len; i++) {
+    this.streams[i].level = newLevel;
+  }
+  this._level = newLevel;
+}
+
+
+/**
+ * Get/set the level of a particular stream on this logger.
+ *
+ * Get Usage:
+ *    // Returns an array of the levels of each stream.
+ *    log.levels() -> [TRACE, INFO]
+ *
+ *    // Returns a level of the identified stream.
+ *    log.levels(0) -> TRACE      // level of stream at index 0
+ *    log.levels("foo")           // level of stream with name "foo"
+ *
+ * Set Usage:
+ *    log.levels(0, INFO)         // set level of stream 0 to INFO
+ *    log.levels(0, "info")       // can use "info" et al aliases
+ *    log.levels("foo", WARN)     // set stream named "foo" to WARN
+ *
+ * Stream names: When streams are defined, they can optionally be given
+ * a name. For example,
+ *       log = new Logger({
+ *         streams: [
+ *           {
+ *             name: 'foo',    // <--- proposed new option, yucky controlling uniqueness
+ *             path: '/var/log/my-service/foo.log'
+ *             level: 'trace'
+ *           },
+ *         ...
+ *
+ * @param name {String|Number} The stream index or name.
+ * @param value {Number|String} The level value (INFO) or alias ("info").
+ *    If not given, this is a 'get' operation.
+ * @throws {Error} If there is no stream with the given name.
+ */
+Logger.prototype.levels = function levels(name, value) {
+  if (name === undefined) {
+    assert.equal(value, undefined);
+    return this.streams.map(function (s) { return s.level });
+  }
+  var stream;
+  if (typeof name === 'number') {
+    stream = this.streams[name];
+    if (stream === undefined) {
+      throw new Error('invalid stream index: ' + name);
+    }
+  } else {
+    var len = this.streams.length;
+    for (var i = 0; i < len; i++) {
+      var s = this.streams[i];
+      if (s.name === name) {
+        stream = s;
+        break;
+      }
+    }
+    if (!stream) {
+      throw new Error(format('no stream with name "%s"', name));
+    }
+  }
+  if (value === undefined) {
+    return stream.level;
+  } else {
+    var newLevel = resolveLevel(value);
+    stream.level = newLevel;
+    if (newLevel < this._level) {
+      this._level = newLevel;
+    }
+  }
+}
+
+
 /**
  * Apply registered serializers to the appropriate keys in the given fields.
  *
@@ -760,7 +853,13 @@ var errSerializer = Logger.stdSerializers.err = function err(err) {
 //---- Exports
 
 module.exports = Logger;
+
+module.exports.TRACE = TRACE;
+module.exports.DEBUG = DEBUG;
+module.exports.INFO = INFO;
+module.exports.WARN = WARN;
+module.exports.ERROR = ERROR;
+module.exports.FATAL = FATAL;
+
 module.exports.VERSION = VERSION;
 module.exports.LOG_VERSION = LOG_VERSION;
-
-