Switch encoder using build tags

* Added missed >m< in github.com
* Added backquotes to denote "code" where appropriate
* Cleanup based on feedback
* Added three examples from README
* Removed Output for 3 examples
* Updated Setting Global Log Level section w/ flags
* Removed unnecessary blank lines
* Moved flags from init into main
* Update log_example_test.go
* Cosmetic change based on Olivier's feedback
* Pushed back to original
* New Examples for Log package
* Removed extra spaces
* Reorganized file and added examples

.travis.yml

@@ -2,6 +2,7 @@ language: go
 go:
 - 1.7
 - 1.8
+- 1.9
 - tip
 matrix:
   allow_failures:

README.md

@@ -4,9 +4,9 @@
 
 The zerolog package provides a fast and simple logger dedicated to JSON output.
 
-Zerolog's API is designed to provide both a great developer experience and stunning [performance](#performance). Its unique chaining API allows zerolog to write JSON log events by avoiding allocations and reflection.
+Zerolog's API is designed to provide both a great developer experience and stunning [performance](#benchmarks). Its unique chaining API allows zerolog to write JSON log events by avoiding allocations and reflection.
 
-The uber's [zap](https://godoc.org/go.uber.org/zap) library pioneered this approach. Zerolog is taking this concept to the next level with simpler to use API and even better performance.
+Uber's [zap](https://godoc.org/go.uber.org/zap) library pioneered this approach. Zerolog is taking this concept to the next level with a simpler to use API and even better performance.
 
 To keep the code base and the API simple, zerolog focuses on JSON logging only. Pretty logging on the console is made possible using the provided (but inefficient) `zerolog.ConsoleWriter`.
 
@@ -18,48 +18,150 @@ To keep the code base and the API simple, zerolog focuses on JSON logging only.
 * Low to zero allocation
 * Level logging
 * Sampling
+* Hooks
 * Contextual fields
 * `context.Context` integration
 * `net/http` helpers
 * Pretty logging for development
 
-## Usage
+## Installation
+```go
+go get -u github.com/rs/zerolog/log
+```
+## Getting Started
+### Simple Logging Example
+For simple logging, import the global logger package **github.com/rs/zerolog/log**
+```go
+package main
+
+import (
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+)
+
+func main() {
+	// UNIX Time is faster and smaller than most timestamps
+	// If you set zerolog.TimeFieldFormat to an empty string,
+	// logs will write with UNIX time
+	zerolog.TimeFieldFormat = ""
+
+	log.Print("hello world")
+}
+
+// Output: {"time":1516134303,"level":"debug","message":"hello world"}
+```
+> Note: The default log level for `log.Print` is *debug*
+----
+### Leveled Logging
+
+#### Simple Leveled Logging Example
 
 ```go
-import "github.com/rs/zerolog/log"
+package main
+
+import (
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+)
+
+func main() {
+	zerolog.TimeFieldFormat = ""
+
+	log.Info().Msg("hello world")
+}
+
+// Output: {"time":1516134303,"level":"info","message":"hello world"}
 ```
 
-### A global logger can be use for simple logging
+**zerolog** allows for logging at the following levels (from highest to lowest):
+- panic (`zerolog.PanicLevel`, 5)
+- fatal (`zerolog.FatalLevel`, 4)
+- error (`zerolog.ErrorLevel`, 3)
+- warn (`zerolog.WarnLevel`, 2)
+- info (`zerolog.InfoLevel`, 1)
+- debug (`zerolog.DebugLevel`, 0)
 
+You can set the Global logging level to any of these options using the `SetGlobalLevel` function in the zerolog package, passing in one of the given constants above, e.g. `zerolog.InfoLevel` would be the "info" level.  Whichever level is chosen, all logs with a level greater than or equal to that level will be written. To turn off logging entirely, pass the `zerolog.Disabled` constant.
+
+#### Setting Global Log Level
+This example uses command-line flags to demonstrate various outputs depending on the chosen log level.
 ```go
-log.Print("hello world")
+package main
 
-// Output: {"level":"debug","time":1494567715,"message":"hello world"}
+import (
+	"flag"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+)
+
+func main() {
+	zerolog.TimeFieldFormat = ""
+	debug := flag.Bool("debug", false, "sets log level to debug")
+
+	flag.Parse()
+
+	// Default level for this example is info, unless debug flag is present
+	zerolog.SetGlobalLevel(zerolog.InfoLevel)
+	if *debug {
+		zerolog.SetGlobalLevel(zerolog.DebugLevel)
+	}
+
+	log.Debug().Msg("This message appears only when log level set to Debug")
+	log.Info().Msg("This message appears when log level set to Debug or Info")
+
+	if e := log.Debug(); e.Enabled() {
+		// Compute log output only if enabled.
+		value := "bar"
+		e.Str("foo", value).Msg("some debug message")
+	}
+}
+```
+Info Output (no flag)
+```bash
+$ ./logLevelExample
+{"time":1516387492,"level":"info","message":"This message appears when log level set to Debug or Info"}
 ```
 
+Debug Output (debug flag set)
+```bash
+$ ./logLevelExample -debug
+{"time":1516387573,"level":"debug","message":"This message appears only when log level set to Debug"}
+{"time":1516387573,"level":"info","message":"This message appears when log level set to Debug or Info"}
+{"time":1516387573,"level":"debug","foo":"bar","message":"some debug message"}
+```
 
+#### Logging Fatal Messages
 ```go
-log.Info().Msg("hello world")
+package main
 
-// Output: {"level":"info","time":1494567715,"message":"hello world"}
+import (
+	"errors"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+)
+
+func main() {
+	err := errors.New("A repo man spends his life getting into tense situations")
+	service := "myservice"
+
+	zerolog.TimeFieldFormat = ""
+
+	log.Fatal().
+		Err(err).
+		Str("service", service).
+		Msgf("Cannot start %s", service)
+}
+
+// Output: {"time":1516133263,"level":"fatal","error":"A repo man spends his life getting into tense situations","service":"myservice","message":"Cannot start myservice"}
+//         exit status 1
 ```
+> NOTE: Using `Msgf` generates one allocation even when the logger is disabled.
+----------------
+### Contextual Logging
 
-NOTE: To import the global logger, import the `log` subpackage `github.com/rs/zerolog/log`.
-
-```go
-log.Fatal().
-    Err(err).
-    Str("service", service).
-    Msgf("Cannot start %s", service)
-
-// Output: {"level":"fatal","time":1494567715,"message":"Cannot start myservice","error":"some error","service":"myservice"}
-// Exit 1
-```
-
-NOTE: Using `Msgf` generates one allocation even when the logger is disabled.
-
-### Fields can be added to log messages
-
+#### Fields can be added to log messages
 ```go
 log.Info().
     Str("foo", "bar").
@@ -90,22 +192,7 @@ sublogger.Info().Msg("hello world")
 // Output: {"level":"info","time":1494567715,"message":"hello world","component":"foo"}
 ```
 
-### Level logging
 
-```go
-zerolog.SetGlobalLevel(zerolog.InfoLevel)
-
-log.Debug().Msg("filtered out message")
-log.Info().Msg("routed message")
-
-if e := log.Debug(); e.Enabled() {
-    // Compute log output only if enabled.
-    value := compute()
-    e.Str("foo": value).Msg("some debug message")
-}
-
-// Output: {"level":"info","time":1494567715,"message":"routed message"}
-```
 
 ### Pretty logging
 
@@ -185,6 +272,22 @@ sampled.Debug().Msg("hello world")
 // Output: {"time":1494567715,"level":"debug","message":"hello world"}
 ```
 
+### Hooks
+
+```go
+type SeverityHook struct{}
+
+func (h SeverityHook) Run(e *zerolog.Event, level zerolog.Level, msg string) {
+    if level != zerolog.NoLevel {
+        e.Str("severity", level.String())
+    }
+}
+
+hooked := log.Hook(SeverityHook{})
+hooked.Warn().Msg("")
+
+// Output: {"level":"warn","severity":"warn"}
+```
 
 ### Pass a sub-logger by context
 
@@ -358,4 +461,3 @@ Log a static string, without any context or `printf`-style templating:
 | logrus | 1244 ns/op | 1505 B/op | 27 allocs/op |
 | apex/log | 2751 ns/op | 584 B/op | 11 allocs/op |
 | log15 | 5181 ns/op | 1592 B/op | 26 allocs/op |
-

array.go

@@ -3,8 +3,6 @@ package zerolog
 import (
 	"sync"
 	"time"
-
-	"github.com/rs/zerolog/internal/json"
 )
 
 var arrayPool = &sync.Pool{
@@ -53,109 +51,109 @@ func (a *Array) Object(obj LogObjectMarshaler) *Array {
 
 // Str append the val as a string to the array.
 func (a *Array) Str(val string) *Array {
-	a.buf = json.AppendString(append(a.buf, ','), val)
+	a.buf = appendString(append(a.buf, ','), val)
 	return a
 }
 
 // Bytes append the val as a string to the array.
 func (a *Array) Bytes(val []byte) *Array {
-	a.buf = json.AppendBytes(append(a.buf, ','), val)
+	a.buf = appendBytes(append(a.buf, ','), val)
 	return a
 }
 
 // Err append the err as a string to the array.
 func (a *Array) Err(err error) *Array {
-	a.buf = json.AppendError(append(a.buf, ','), err)
+	a.buf = appendError(append(a.buf, ','), err)
 	return a
 }
 
 // Bool append the val as a bool to the array.
 func (a *Array) Bool(b bool) *Array {
-	a.buf = json.AppendBool(append(a.buf, ','), b)
+	a.buf = appendBool(append(a.buf, ','), b)
 	return a
 }
 
 // Int append i as a int to the array.
 func (a *Array) Int(i int) *Array {
-	a.buf = json.AppendInt(append(a.buf, ','), i)
+	a.buf = appendInt(append(a.buf, ','), i)
 	return a
 }
 
 // Int8 append i as a int8 to the array.
 func (a *Array) Int8(i int8) *Array {
-	a.buf = json.AppendInt8(append(a.buf, ','), i)
+	a.buf = appendInt8(append(a.buf, ','), i)
 	return a
 }
 
 // Int16 append i as a int16 to the array.
 func (a *Array) Int16(i int16) *Array {
-	a.buf = json.AppendInt16(append(a.buf, ','), i)
+	a.buf = appendInt16(append(a.buf, ','), i)
 	return a
 }
 
 // Int32 append i as a int32 to the array.
 func (a *Array) Int32(i int32) *Array {
-	a.buf = json.AppendInt32(append(a.buf, ','), i)
+	a.buf = appendInt32(append(a.buf, ','), i)
 	return a
 }
 
 // Int64 append i as a int64 to the array.
 func (a *Array) Int64(i int64) *Array {
-	a.buf = json.AppendInt64(append(a.buf, ','), i)
+	a.buf = appendInt64(append(a.buf, ','), i)
 	return a
 }
 
 // Uint append i as a uint to the array.
 func (a *Array) Uint(i uint) *Array {
-	a.buf = json.AppendUint(append(a.buf, ','), i)
+	a.buf = appendUint(append(a.buf, ','), i)
 	return a
 }
 
 // Uint8 append i as a uint8 to the array.
 func (a *Array) Uint8(i uint8) *Array {
-	a.buf = json.AppendUint8(append(a.buf, ','), i)
+	a.buf = appendUint8(append(a.buf, ','), i)
 	return a
 }
 
 // Uint16 append i as a uint16 to the array.
 func (a *Array) Uint16(i uint16) *Array {
-	a.buf = json.AppendUint16(append(a.buf, ','), i)
+	a.buf = appendUint16(append(a.buf, ','), i)
 	return a
 }
 
 // Uint32 append i as a uint32 to the array.
 func (a *Array) Uint32(i uint32) *Array {
-	a.buf = json.AppendUint32(append(a.buf, ','), i)
+	a.buf = appendUint32(append(a.buf, ','), i)
 	return a
 }
 
 // Uint64 append i as a uint64 to the array.
 func (a *Array) Uint64(i uint64) *Array {
-	a.buf = json.AppendUint64(append(a.buf, ','), i)
+	a.buf = appendUint64(append(a.buf, ','), i)
 	return a
 }
 
 // Float32 append f as a float32 to the array.
 func (a *Array) Float32(f float32) *Array {
-	a.buf = json.AppendFloat32(append(a.buf, ','), f)
+	a.buf = appendFloat32(append(a.buf, ','), f)
 	return a
 }
 
 // Float64 append f as a float64 to the array.
 func (a *Array) Float64(f float64) *Array {
-	a.buf = json.AppendFloat64(append(a.buf, ','), f)
+	a.buf = appendFloat64(append(a.buf, ','), f)
 	return a
 }
 
 // Time append t formated as string using zerolog.TimeFieldFormat.
 func (a *Array) Time(t time.Time) *Array {
-	a.buf = json.AppendTime(append(a.buf, ','), t, TimeFieldFormat)
+	a.buf = appendTime(append(a.buf, ','), t, TimeFieldFormat)
 	return a
 }
 
 // Dur append d to the array.
 func (a *Array) Dur(d time.Duration) *Array {
-	a.buf = json.AppendDuration(append(a.buf, ','), d, DurationFieldUnit, DurationFieldInteger)
+	a.buf = appendDuration(append(a.buf, ','), d, DurationFieldUnit, DurationFieldInteger)
 	return a
 }
 
@@ -164,6 +162,6 @@ func (a *Array) Interface(i interface{}) *Array {
 	if obj, ok := i.(LogObjectMarshaler); ok {
 		return a.Object(obj)
 	}
-	a.buf = json.AppendInterface(append(a.buf, ','), i)
+	a.buf = appendInterface(append(a.buf, ','), i)
 	return a
 }

benchmark_test.go

@@ -215,3 +215,130 @@ func BenchmarkLogFieldType(b *testing.B) {
 		})
 	}
 }
+
+func BenchmarkContextFieldType(b *testing.B) {
+	oldFormat := TimeFieldFormat
+	TimeFieldFormat = ""
+	defer func() { TimeFieldFormat = oldFormat }()
+	bools := []bool{true, false, true, false, true, false, true, false, true, false}
+	ints := []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+	floats := []float64{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+	strings := []string{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j"}
+	durations := []time.Duration{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+	times := []time.Time{
+		time.Unix(0, 0),
+		time.Unix(1, 0),
+		time.Unix(2, 0),
+		time.Unix(3, 0),
+		time.Unix(4, 0),
+		time.Unix(5, 0),
+		time.Unix(6, 0),
+		time.Unix(7, 0),
+		time.Unix(8, 0),
+		time.Unix(9, 0),
+	}
+	interfaces := []struct {
+		Pub  string
+		Tag  string `json:"tag"`
+		priv int
+	}{
+		{"a", "a", 0},
+		{"a", "a", 0},
+		{"a", "a", 0},
+		{"a", "a", 0},
+		{"a", "a", 0},
+		{"a", "a", 0},
+		{"a", "a", 0},
+		{"a", "a", 0},
+		{"a", "a", 0},
+		{"a", "a", 0},
+	}
+	objects := []obj{
+		obj{"a", "a", 0},
+		obj{"a", "a", 0},
+		obj{"a", "a", 0},
+		obj{"a", "a", 0},
+		obj{"a", "a", 0},
+		obj{"a", "a", 0},
+		obj{"a", "a", 0},
+		obj{"a", "a", 0},
+		obj{"a", "a", 0},
+		obj{"a", "a", 0},
+	}
+	errs := []error{errors.New("a"), errors.New("b"), errors.New("c"), errors.New("d"), errors.New("e")}
+	types := map[string]func(c Context) Context{
+		"Bool": func(c Context) Context {
+			return c.Bool("k", bools[0])
+		},
+		"Bools": func(c Context) Context {
+			return c.Bools("k", bools)
+		},
+		"Int": func(c Context) Context {
+			return c.Int("k", ints[0])
+		},
+		"Ints": func(c Context) Context {
+			return c.Ints("k", ints)
+		},
+		"Float": func(c Context) Context {
+			return c.Float64("k", floats[0])
+		},
+		"Floats": func(c Context) Context {
+			return c.Floats64("k", floats)
+		},
+		"Str": func(c Context) Context {
+			return c.Str("k", strings[0])
+		},
+		"Strs": func(c Context) Context {
+			return c.Strs("k", strings)
+		},
+		"Err": func(c Context) Context {
+			return c.Err(errs[0])
+		},
+		"Errs": func(c Context) Context {
+			return c.Errs("k", errs)
+		},
+		"Time": func(c Context) Context {
+			return c.Time("k", times[0])
+		},
+		"Times": func(c Context) Context {
+			return c.Times("k", times)
+		},
+		"Dur": func(c Context) Context {
+			return c.Dur("k", durations[0])
+		},
+		"Durs": func(c Context) Context {
+			return c.Durs("k", durations)
+		},
+		"Interface": func(c Context) Context {
+			return c.Interface("k", interfaces[0])
+		},
+		"Interfaces": func(c Context) Context {
+			return c.Interface("k", interfaces)
+		},
+		"Interface(Object)": func(c Context) Context {
+			return c.Interface("k", objects[0])
+		},
+		"Interface(Objects)": func(c Context) Context {
+			return c.Interface("k", objects)
+		},
+		"Object": func(c Context) Context {
+			return c.Object("k", objects[0])
+		},
+		"Timestamp": func(c Context) Context {
+			return c.Timestamp()
+		},
+	}
+	logger := New(ioutil.Discard)
+	b.ResetTimer()
+	for name := range types {
+		f := types[name]
+		b.Run(name, func(b *testing.B) {
+			b.RunParallel(func(pb *testing.PB) {
+				for pb.Next() {
+					l := f(logger.With()).Logger()
+					l.Info().Msg("")
+				}
+			})
+		})
+	}
+}

context.go

@@ -3,8 +3,6 @@ package zerolog
 import (
 	"io/ioutil"
 	"time"
-
-	"github.com/rs/zerolog/internal/json"
 )
 
 // Context configures a new sub-logger with contextual fields.
@@ -26,7 +24,7 @@ func (c Context) Fields(fields map[string]interface{}) Context {
 // Dict adds the field key with the dict to the logger context.
 func (c Context) Dict(key string, dict *Event) Context {
 	dict.buf = append(dict.buf, '}')
-	c.l.context = append(json.AppendKey(c.l.context, key), dict.buf...)
+	c.l.context = append(appendKey(c.l.context, key), dict.buf...)
 	eventPool.Put(dict)
 	return c
 }
@@ -35,7 +33,7 @@ func (c Context) Dict(key string, dict *Event) Context {
 // Use zerolog.Arr() to create the array or pass a type that
 // implement the LogArrayMarshaler interface.
 func (c Context) Array(key string, arr LogArrayMarshaler) Context {
-	c.l.context = json.AppendKey(c.l.context, key)
+	c.l.context = appendKey(c.l.context, key)
 	if arr, ok := arr.(*Array); ok {
 		c.l.context = arr.write(c.l.context)
 		return c
@@ -63,33 +61,33 @@ func (c Context) Object(key string, obj LogObjectMarshaler) Context {
 
 // Str adds the field key with val as a string to the logger context.
 func (c Context) Str(key, val string) Context {
-	c.l.context = json.AppendString(json.AppendKey(c.l.context, key), val)
+	c.l.context = appendString(appendKey(c.l.context, key), val)
 	return c
 }
 
 // Strs adds the field key with val as a string to the logger context.
 func (c Context) Strs(key string, vals []string) Context {
-	c.l.context = json.AppendStrings(json.AppendKey(c.l.context, key), vals)
+	c.l.context = appendStrings(appendKey(c.l.context, key), vals)
 	return c
 }
 
 // Bytes adds the field key with val as a []byte to the logger context.
 func (c Context) Bytes(key string, val []byte) Context {
-	c.l.context = json.AppendBytes(json.AppendKey(c.l.context, key), val)
+	c.l.context = appendBytes(appendKey(c.l.context, key), val)
 	return c
 }
 
 // AnErr adds the field key with err as a string to the logger context.
 func (c Context) AnErr(key string, err error) Context {
 	if err != nil {
-		c.l.context = json.AppendError(json.AppendKey(c.l.context, key), err)
+		c.l.context = appendError(appendKey(c.l.context, key), err)
 	}
 	return c
 }
 
 // Errs adds the field key with errs as an array of strings to the logger context.
 func (c Context) Errs(key string, errs []error) Context {
-	c.l.context = json.AppendErrors(json.AppendKey(c.l.context, key), errs)
+	c.l.context = appendErrors(appendKey(c.l.context, key), errs)
 	return c
 }
 
@@ -97,204 +95,222 @@ func (c Context) Errs(key string, errs []error) Context {
 // To customize the key name, change zerolog.ErrorFieldName.
 func (c Context) Err(err error) Context {
 	if err != nil {
-		c.l.context = json.AppendError(json.AppendKey(c.l.context, ErrorFieldName), err)
+		c.l.context = appendError(appendKey(c.l.context, ErrorFieldName), err)
 	}
 	return c
 }
 
 // Bool adds the field key with val as a bool to the logger context.
 func (c Context) Bool(key string, b bool) Context {
-	c.l.context = json.AppendBool(json.AppendKey(c.l.context, key), b)
+	c.l.context = appendBool(appendKey(c.l.context, key), b)
 	return c
 }
 
 // Bools adds the field key with val as a []bool to the logger context.
 func (c Context) Bools(key string, b []bool) Context {
-	c.l.context = json.AppendBools(json.AppendKey(c.l.context, key), b)
+	c.l.context = appendBools(appendKey(c.l.context, key), b)
 	return c
 }
 
 // Int adds the field key with i as a int to the logger context.
 func (c Context) Int(key string, i int) Context {
-	c.l.context = json.AppendInt(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInt(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Ints adds the field key with i as a []int to the logger context.
 func (c Context) Ints(key string, i []int) Context {
-	c.l.context = json.AppendInts(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInts(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Int8 adds the field key with i as a int8 to the logger context.
 func (c Context) Int8(key string, i int8) Context {
-	c.l.context = json.AppendInt8(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInt8(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Ints8 adds the field key with i as a []int8 to the logger context.
 func (c Context) Ints8(key string, i []int8) Context {
-	c.l.context = json.AppendInts8(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInts8(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Int16 adds the field key with i as a int16 to the logger context.
 func (c Context) Int16(key string, i int16) Context {
-	c.l.context = json.AppendInt16(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInt16(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Ints16 adds the field key with i as a []int16 to the logger context.
 func (c Context) Ints16(key string, i []int16) Context {
-	c.l.context = json.AppendInts16(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInts16(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Int32 adds the field key with i as a int32 to the logger context.
 func (c Context) Int32(key string, i int32) Context {
-	c.l.context = json.AppendInt32(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInt32(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Ints32 adds the field key with i as a []int32 to the logger context.
 func (c Context) Ints32(key string, i []int32) Context {
-	c.l.context = json.AppendInts32(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInts32(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Int64 adds the field key with i as a int64 to the logger context.
 func (c Context) Int64(key string, i int64) Context {
-	c.l.context = json.AppendInt64(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInt64(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Ints64 adds the field key with i as a []int64 to the logger context.
 func (c Context) Ints64(key string, i []int64) Context {
-	c.l.context = json.AppendInts64(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInts64(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Uint adds the field key with i as a uint to the logger context.
 func (c Context) Uint(key string, i uint) Context {
-	c.l.context = json.AppendUint(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendUint(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Uints adds the field key with i as a []uint to the logger context.
 func (c Context) Uints(key string, i []uint) Context {
-	c.l.context = json.AppendUints(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendUints(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Uint8 adds the field key with i as a uint8 to the logger context.
 func (c Context) Uint8(key string, i uint8) Context {
-	c.l.context = json.AppendUint8(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendUint8(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Uints8 adds the field key with i as a []uint8 to the logger context.
 func (c Context) Uints8(key string, i []uint8) Context {
-	c.l.context = json.AppendUints8(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendUints8(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Uint16 adds the field key with i as a uint16 to the logger context.
 func (c Context) Uint16(key string, i uint16) Context {
-	c.l.context = json.AppendUint16(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendUint16(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Uints16 adds the field key with i as a []uint16 to the logger context.
 func (c Context) Uints16(key string, i []uint16) Context {
-	c.l.context = json.AppendUints16(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendUints16(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Uint32 adds the field key with i as a uint32 to the logger context.
 func (c Context) Uint32(key string, i uint32) Context {
-	c.l.context = json.AppendUint32(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendUint32(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Uints32 adds the field key with i as a []uint32 to the logger context.
 func (c Context) Uints32(key string, i []uint32) Context {
-	c.l.context = json.AppendUints32(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendUints32(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Uint64 adds the field key with i as a uint64 to the logger context.
 func (c Context) Uint64(key string, i uint64) Context {
-	c.l.context = json.AppendUint64(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendUint64(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Uints64 adds the field key with i as a []uint64 to the logger context.
 func (c Context) Uints64(key string, i []uint64) Context {
-	c.l.context = json.AppendUints64(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendUints64(appendKey(c.l.context, key), i)
 	return c
 }
 
 // Float32 adds the field key with f as a float32 to the logger context.
 func (c Context) Float32(key string, f float32) Context {
-	c.l.context = json.AppendFloat32(json.AppendKey(c.l.context, key), f)
+	c.l.context = appendFloat32(appendKey(c.l.context, key), f)
 	return c
 }
 
 // Floats32 adds the field key with f as a []float32 to the logger context.
 func (c Context) Floats32(key string, f []float32) Context {
-	c.l.context = json.AppendFloats32(json.AppendKey(c.l.context, key), f)
+	c.l.context = appendFloats32(appendKey(c.l.context, key), f)
 	return c
 }
 
 // Float64 adds the field key with f as a float64 to the logger context.
 func (c Context) Float64(key string, f float64) Context {
-	c.l.context = json.AppendFloat64(json.AppendKey(c.l.context, key), f)
+	c.l.context = appendFloat64(appendKey(c.l.context, key), f)
 	return c
 }
 
 // Floats64 adds the field key with f as a []float64 to the logger context.
 func (c Context) Floats64(key string, f []float64) Context {
-	c.l.context = json.AppendFloats64(json.AppendKey(c.l.context, key), f)
+	c.l.context = appendFloats64(appendKey(c.l.context, key), f)
 	return c
 }
 
+type timestampHook struct{}
+
+func (ts timestampHook) Run(e *Event, level Level, msg string) {
+	e.Timestamp()
+}
+
+var th = timestampHook{}
+
 // Timestamp adds the current local time as UNIX timestamp to the logger context with the "time" key.
 // To customize the key name, change zerolog.TimestampFieldName.
 func (c Context) Timestamp() Context {
-	if len(c.l.context) > 0 {
-		c.l.context[0] = 1
-	} else {
-		c.l.context = append(c.l.context, 1)
-	}
+	c.l = c.l.Hook(th)
 	return c
 }
 
 // Time adds the field key with t formated as string using zerolog.TimeFieldFormat.
 func (c Context) Time(key string, t time.Time) Context {
-	c.l.context = json.AppendTime(json.AppendKey(c.l.context, key), t, TimeFieldFormat)
+	c.l.context = appendTime(appendKey(c.l.context, key), t, TimeFieldFormat)
 	return c
 }
 
 // Times adds the field key with t formated as string using zerolog.TimeFieldFormat.
 func (c Context) Times(key string, t []time.Time) Context {
-	c.l.context = json.AppendTimes(json.AppendKey(c.l.context, key), t, TimeFieldFormat)
+	c.l.context = appendTimes(appendKey(c.l.context, key), t, TimeFieldFormat)
 	return c
 }
 
 // Dur adds the fields key with d divided by unit and stored as a float.
 func (c Context) Dur(key string, d time.Duration) Context {
-	c.l.context = json.AppendDuration(json.AppendKey(c.l.context, key), d, DurationFieldUnit, DurationFieldInteger)
+	c.l.context = appendDuration(appendKey(c.l.context, key), d, DurationFieldUnit, DurationFieldInteger)
 	return c
 }
 
 // Durs adds the fields key with d divided by unit and stored as a float.
 func (c Context) Durs(key string, d []time.Duration) Context {
-	c.l.context = json.AppendDurations(json.AppendKey(c.l.context, key), d, DurationFieldUnit, DurationFieldInteger)
+	c.l.context = appendDurations(appendKey(c.l.context, key), d, DurationFieldUnit, DurationFieldInteger)
 	return c
 }
 
 // Interface adds the field key with obj marshaled using reflection.
 func (c Context) Interface(key string, i interface{}) Context {
-	c.l.context = json.AppendInterface(json.AppendKey(c.l.context, key), i)
+	c.l.context = appendInterface(appendKey(c.l.context, key), i)
+	return c
+}
+
+type callerHook struct{}
+
+func (ch callerHook) Run(e *Event, level Level, msg string) {
+	e.caller(4)
+}
+
+var ch = callerHook{}
+
+// Caller adds the file:line of the caller with the zerolog.CallerFieldName key.
+func (c Context) Caller() Context {
+	c.l = c.l.Hook(ch)
 	return c
 }

encoder.go

@@ -0,0 +1,161 @@
+// +build !zerolog_binary
+
+package zerolog
+
+import (
+	"time"
+
+	"github.com/rs/zerolog/internal/json"
+)
+
+func appendKey(dst []byte, key string) []byte {
+	return json.AppendKey(dst, key)
+}
+
+func appendError(dst []byte, err error) []byte {
+	return json.AppendError(dst, err)
+}
+
+func appendErrors(dst []byte, errs []error) []byte {
+	return json.AppendErrors(dst, errs)
+}
+
+func appendStrings(dst []byte, vals []string) []byte {
+	return json.AppendStrings(dst, vals)
+}
+
+func appendString(dst []byte, s string) []byte {
+	return json.AppendString(dst, s)
+}
+
+func appendBytes(dst, b []byte) []byte {
+	return json.AppendBytes(dst, b)
+}
+
+func appendTime(dst []byte, t time.Time, format string) []byte {
+	return json.AppendTime(dst, t, format)
+}
+
+func appendTimes(dst []byte, vals []time.Time, format string) []byte {
+	return json.AppendTimes(dst, vals, format)
+}
+
+func appendDuration(dst []byte, d time.Duration, unit time.Duration, useInt bool) []byte {
+	return json.AppendDuration(dst, d, unit, useInt)
+}
+
+func appendDurations(dst []byte, vals []time.Duration, unit time.Duration, useInt bool) []byte {
+	return json.AppendDurations(dst, vals, unit, useInt)
+}
+
+func appendBool(dst []byte, val bool) []byte {
+	return json.AppendBool(dst, val)
+}
+
+func appendBools(dst []byte, vals []bool) []byte {
+	return json.AppendBools(dst, vals)
+}
+
+func appendInt(dst []byte, val int) []byte {
+	return json.AppendInt(dst, val)
+}
+
+func appendInts(dst []byte, vals []int) []byte {
+	return json.AppendInts(dst, vals)
+}
+
+func appendInt8(dst []byte, val int8) []byte {
+	return json.AppendInt8(dst, val)
+}
+
+func appendInts8(dst []byte, vals []int8) []byte {
+	return json.AppendInts8(dst, vals)
+}
+
+func appendInt16(dst []byte, val int16) []byte {
+	return json.AppendInt16(dst, val)
+}
+
+func appendInts16(dst []byte, vals []int16) []byte {
+	return json.AppendInts16(dst, vals)
+}
+
+func appendInt32(dst []byte, val int32) []byte {
+	return json.AppendInt32(dst, val)
+}
+
+func appendInts32(dst []byte, vals []int32) []byte {
+	return json.AppendInts32(dst, vals)
+}
+
+func appendInt64(dst []byte, val int64) []byte {
+	return json.AppendInt64(dst, val)
+}
+
+func appendInts64(dst []byte, vals []int64) []byte {
+	return json.AppendInts64(dst, vals)
+}
+
+func appendUint(dst []byte, val uint) []byte {
+	return json.AppendUint(dst, val)
+}
+
+func appendUints(dst []byte, vals []uint) []byte {
+	return json.AppendUints(dst, vals)
+}
+
+func appendUint8(dst []byte, val uint8) []byte {
+	return json.AppendUint8(dst, val)
+}
+
+func appendUints8(dst []byte, vals []uint8) []byte {
+	return json.AppendUints8(dst, vals)
+}
+
+func appendUint16(dst []byte, val uint16) []byte {
+	return json.AppendUint16(dst, val)
+}
+
+func appendUints16(dst []byte, vals []uint16) []byte {
+	return json.AppendUints16(dst, vals)
+}
+
+func appendUint32(dst []byte, val uint32) []byte {
+	return json.AppendUint32(dst, val)
+}
+
+func appendUints32(dst []byte, vals []uint32) []byte {
+	return json.AppendUints32(dst, vals)
+}
+
+func appendUint64(dst []byte, val uint64) []byte {
+	return json.AppendUint64(dst, val)
+}
+
+func appendUints64(dst []byte, vals []uint64) []byte {
+	return json.AppendUints64(dst, vals)
+}
+
+func appendFloat(dst []byte, val float64, bitSize int) []byte {
+	return json.AppendFloat(dst, val, bitSize)
+}
+
+func appendFloat32(dst []byte, val float32) []byte {
+	return json.AppendFloat32(dst, val)
+}
+
+func appendFloats32(dst []byte, vals []float32) []byte {
+	return json.AppendFloats32(dst, vals)
+}
+
+func appendFloat64(dst []byte, val float64) []byte {
+	return json.AppendFloat64(dst, val)
+}
+
+func appendFloats64(dst []byte, vals []float64) []byte {
+	return json.AppendFloats64(dst, vals)
+}
+
+func appendInterface(dst []byte, i interface{}) []byte {
+	return json.AppendInterface(dst, i)
+}

encoder_binary.go

@@ -0,0 +1,161 @@
+// +build zerolog_binary
+
+package zerolog
+
+import (
+	"time"
+
+	"github.com/rs/zerolog/internal/cbor"
+)
+
+func appendKey(dst []byte, key string) []byte {
+	return cbor.AppendKey(dst, key)
+}
+
+func appendError(dst []byte, err error) []byte {
+	return cbor.AppendError(dst, err)
+}
+
+func appendErrors(dst []byte, errs []error) []byte {
+	return cbor.AppendErrors(dst, errs)
+}
+
+func appendStrings(dst []byte, vals []string) []byte {
+	return cbor.AppendStrings(dst, vals)
+}
+
+func appendString(dst []byte, s string) []byte {
+	return cbor.AppendString(dst, s)
+}
+
+func appendBytes(dst, b []byte) []byte {
+	return cbor.AppendBytes(dst, b)
+}
+
+func appendTime(dst []byte, t time.Time, format string) []byte {
+	return cbor.AppendTime(dst, t, format)
+}
+
+func appendTimes(dst []byte, vals []time.Time, format string) []byte {
+	return cbor.AppendTimes(dst, vals, format)
+}
+
+func appendDuration(dst []byte, d time.Duration, unit time.Duration, useInt bool) []byte {
+	return cbor.AppendDuration(dst, d, unit, useInt)
+}
+
+func appendDurations(dst []byte, vals []time.Duration, unit time.Duration, useInt bool) []byte {
+	return cbor.AppendDurations(dst, vals, unit, useInt)
+}
+
+func appendBool(dst []byte, val bool) []byte {
+	return cbor.AppendBool(dst, val)
+}
+
+func appendBools(dst []byte, vals []bool) []byte {
+	return cbor.AppendBools(dst, vals)
+}
+
+func appendInt(dst []byte, val int) []byte {
+	return cbor.AppendInt(dst, val)
+}
+
+func appendInts(dst []byte, vals []int) []byte {
+	return cbor.AppendInts(dst, vals)
+}
+
+func appendInt8(dst []byte, val int8) []byte {
+	return cbor.AppendInt8(dst, val)
+}
+
+func appendInts8(dst []byte, vals []int8) []byte {
+	return cbor.AppendInts8(dst, vals)
+}
+
+func appendInt16(dst []byte, val int16) []byte {
+	return cbor.AppendInt16(dst, val)
+}
+
+func appendInts16(dst []byte, vals []int16) []byte {
+	return cbor.AppendInts16(dst, vals)
+}
+
+func appendInt32(dst []byte, val int32) []byte {
+	return cbor.AppendInt32(dst, val)
+}
+
+func appendInts32(dst []byte, vals []int32) []byte {
+	return cbor.AppendInts32(dst, vals)
+}
+
+func appendInt64(dst []byte, val int64) []byte {
+	return cbor.AppendInt64(dst, val)
+}
+
+func appendInts64(dst []byte, vals []int64) []byte {
+	return cbor.AppendInts64(dst, vals)
+}
+
+func appendUint(dst []byte, val uint) []byte {
+	return cbor.AppendUint(dst, val)
+}
+
+func appendUints(dst []byte, vals []uint) []byte {
+	return cbor.AppendUints(dst, vals)
+}
+
+func appendUint8(dst []byte, val uint8) []byte {
+	return cbor.AppendUint8(dst, val)
+}
+
+func appendUints8(dst []byte, vals []uint8) []byte {
+	return cbor.AppendUints8(dst, vals)
+}
+
+func appendUint16(dst []byte, val uint16) []byte {
+	return cbor.AppendUint16(dst, val)
+}
+
+func appendUints16(dst []byte, vals []uint16) []byte {
+	return cbor.AppendUints16(dst, vals)
+}
+
+func appendUint32(dst []byte, val uint32) []byte {
+	return cbor.AppendUint32(dst, val)
+}
+
+func appendUints32(dst []byte, vals []uint32) []byte {
+	return cbor.AppendUints32(dst, vals)
+}
+
+func appendUint64(dst []byte, val uint64) []byte {
+	return cbor.AppendUint64(dst, val)
+}
+
+func appendUints64(dst []byte, vals []uint64) []byte {
+	return cbor.AppendUints64(dst, vals)
+}
+
+func appendFloat(dst []byte, val float64, bitSize int) []byte {
+	return cbor.AppendFloat(dst, val, bitSize)
+}
+
+func appendFloat32(dst []byte, val float32) []byte {
+	return cbor.AppendFloat32(dst, val)
+}
+
+func appendFloats32(dst []byte, vals []float32) []byte {
+	return cbor.AppendFloats32(dst, vals)
+}
+
+func appendFloat64(dst []byte, val float64) []byte {
+	return cbor.AppendFloat64(dst, val)
+}
+
+func appendFloats64(dst []byte, vals []float64) []byte {
+	return cbor.AppendFloats64(dst, vals)
+}
+
+func appendInterface(dst []byte, i interface{}) []byte {
+	return cbor.AppendInterface(dst, i)
+}

event.go

@@ -4,10 +4,10 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"runtime"
+	"strconv"
 	"sync"
 	"time"
-
-	"github.com/rs/zerolog/internal/json"
 )
 
 var eventPool = &sync.Pool{
@@ -21,11 +21,12 @@ var eventPool = &sync.Pool{
 // Event represents a log event. It is instanced by one of the level method of
 // Logger and finalized by the Msg or Msgf method.
 type Event struct {
-	buf     []byte
-	w       LevelWriter
-	level   Level
-	enabled bool
-	done    func(msg string)
+	buf   []byte
+	w     LevelWriter
+	level Level
+	done  func(msg string)
+	ch    []Hook // hooks from context
+	h     []Hook
 }
 
 // LogObjectMarshaler provides a strongly-typed and encoding-agnostic interface
@@ -46,15 +47,15 @@ func newEvent(w LevelWriter, level Level, enabled bool) *Event {
 	}
 	e := eventPool.Get().(*Event)
 	e.buf = e.buf[:1]
+	e.h = e.h[:0]
 	e.buf[0] = '{'
 	e.w = w
 	e.level = level
-	e.enabled = true
 	return e
 }
 
 func (e *Event) write() (err error) {
-	if !e.enabled {
+	if e == nil {
 		return nil
 	}
 	e.buf = append(e.buf, '}', '\n')
@@ -66,7 +67,7 @@ func (e *Event) write() (err error) {
 // Enabled return false if the *Event is going to be filtered out by
 // log level or sampling.
 func (e *Event) Enabled() bool {
-	return e.enabled
+	return e != nil
 }
 
 // Msg sends the *Event with msg added as the message field if not empty.
@@ -74,11 +75,27 @@ func (e *Event) Enabled() bool {
 // NOTICE: once this method is called, the *Event should be disposed.
 // Calling Msg twice can have unexpected result.
 func (e *Event) Msg(msg string) {
-	if !e.enabled {
+	if e == nil {
 		return
 	}
+	if len(e.ch) > 0 {
+		e.ch[0].Run(e, e.level, msg)
+		if len(e.ch) > 1 {
+			for _, hook := range e.ch[1:] {
+				hook.Run(e, e.level, msg)
+			}
+		}
+	}
+	if len(e.h) > 0 {
+		e.h[0].Run(e, e.level, msg)
+		if len(e.h) > 1 {
+			for _, hook := range e.h[1:] {
+				hook.Run(e, e.level, msg)
+			}
+		}
+	}
 	if msg != "" {
-		e.buf = json.AppendString(json.AppendKey(e.buf, MessageFieldName), msg)
+		e.buf = appendString(appendKey(e.buf, MessageFieldName), msg)
 	}
 	if e.done != nil {
 		defer e.done(msg)
@@ -93,24 +110,15 @@ func (e *Event) Msg(msg string) {
 // NOTICE: once this methid is called, the *Event should be disposed.
 // Calling Msg twice can have unexpected result.
 func (e *Event) Msgf(format string, v ...interface{}) {
-	if !e.enabled {
+	if e == nil {
 		return
 	}
-	msg := fmt.Sprintf(format, v...)
-	if msg != "" {
-		e.buf = json.AppendString(json.AppendKey(e.buf, MessageFieldName), msg)
-	}
-	if e.done != nil {
-		defer e.done(msg)
-	}
-	if err := e.write(); err != nil {
-		fmt.Fprintf(os.Stderr, "zerolog: could not write event: %v", err)
-	}
+	e.Msg(fmt.Sprintf(format, v...))
 }
 
 // Fields is a helper function to use a map to set fields using type assertion.
 func (e *Event) Fields(fields map[string]interface{}) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
 	e.buf = appendFields(e.buf, fields)
@@ -120,10 +128,10 @@ func (e *Event) Fields(fields map[string]interface{}) *Event {
 // Dict adds the field key with a dict to the event context.
 // Use zerolog.Dict() to create the dictionary.
 func (e *Event) Dict(key string, dict *Event) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = append(append(json.AppendKey(e.buf, key), dict.buf...), '}')
+	e.buf = append(append(appendKey(e.buf, key), dict.buf...), '}')
 	eventPool.Put(dict)
 	return e
 }
@@ -139,10 +147,10 @@ func Dict() *Event {
 // Use zerolog.Arr() to create the array or pass a type that
 // implement the LogArrayMarshaler interface.
 func (e *Event) Array(key string, arr LogArrayMarshaler) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendKey(e.buf, key)
+	e.buf = appendKey(e.buf, key)
 	var a *Array
 	if aa, ok := arr.(*Array); ok {
 		a = aa
@@ -170,29 +178,29 @@ func (e *Event) appendObject(obj LogObjectMarshaler) {
 
 // Object marshals an object that implement the LogObjectMarshaler interface.
 func (e *Event) Object(key string, obj LogObjectMarshaler) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendKey(e.buf, key)
+	e.buf = appendKey(e.buf, key)
 	e.appendObject(obj)
 	return e
 }
 
 // Str adds the field key with val as a string to the *Event context.
 func (e *Event) Str(key, val string) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendString(json.AppendKey(e.buf, key), val)
+	e.buf = appendString(appendKey(e.buf, key), val)
 	return e
 }
 
 // Strs adds the field key with vals as a []string to the *Event context.
 func (e *Event) Strs(key string, vals []string) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendStrings(json.AppendKey(e.buf, key), vals)
+	e.buf = appendStrings(appendKey(e.buf, key), vals)
 	return e
 }
 
@@ -201,21 +209,21 @@ func (e *Event) Strs(key string, vals []string) *Event {
 // Runes outside of normal ASCII ranges will be hex-encoded in the resulting
 // JSON.
 func (e *Event) Bytes(key string, val []byte) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendBytes(json.AppendKey(e.buf, key), val)
+	e.buf = appendBytes(appendKey(e.buf, key), val)
 	return e
 }
 
 // AnErr adds the field key with err as a string to the *Event context.
 // If err is nil, no field is added.
 func (e *Event) AnErr(key string, err error) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
 	if err != nil {
-		e.buf = json.AppendError(json.AppendKey(e.buf, key), err)
+		e.buf = appendError(appendKey(e.buf, key), err)
 	}
 	return e
 }
@@ -223,10 +231,10 @@ func (e *Event) AnErr(key string, err error) *Event {
 // Errs adds the field key with errs as an array of strings to the *Event context.
 // If err is nil, no field is added.
 func (e *Event) Errs(key string, errs []error) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendErrors(json.AppendKey(e.buf, key), errs)
+	e.buf = appendErrors(appendKey(e.buf, key), errs)
 	return e
 }
 
@@ -234,274 +242,274 @@ func (e *Event) Errs(key string, errs []error) *Event {
 // If err is nil, no field is added.
 // To customize the key name, change zerolog.ErrorFieldName.
 func (e *Event) Err(err error) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
 	if err != nil {
-		e.buf = json.AppendError(json.AppendKey(e.buf, ErrorFieldName), err)
+		e.buf = appendError(appendKey(e.buf, ErrorFieldName), err)
 	}
 	return e
 }
 
 // Bool adds the field key with val as a bool to the *Event context.
 func (e *Event) Bool(key string, b bool) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendBool(json.AppendKey(e.buf, key), b)
+	e.buf = appendBool(appendKey(e.buf, key), b)
 	return e
 }
 
 // Bools adds the field key with val as a []bool to the *Event context.
 func (e *Event) Bools(key string, b []bool) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendBools(json.AppendKey(e.buf, key), b)
+	e.buf = appendBools(appendKey(e.buf, key), b)
 	return e
 }
 
 // Int adds the field key with i as a int to the *Event context.
 func (e *Event) Int(key string, i int) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendInt(json.AppendKey(e.buf, key), i)
+	e.buf = appendInt(appendKey(e.buf, key), i)
 	return e
 }
 
 // Ints adds the field key with i as a []int to the *Event context.
 func (e *Event) Ints(key string, i []int) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendInts(json.AppendKey(e.buf, key), i)
+	e.buf = appendInts(appendKey(e.buf, key), i)
 	return e
 }
 
 // Int8 adds the field key with i as a int8 to the *Event context.
 func (e *Event) Int8(key string, i int8) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendInt8(json.AppendKey(e.buf, key), i)
+	e.buf = appendInt8(appendKey(e.buf, key), i)
 	return e
 }
 
 // Ints8 adds the field key with i as a []int8 to the *Event context.
 func (e *Event) Ints8(key string, i []int8) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendInts8(json.AppendKey(e.buf, key), i)
+	e.buf = appendInts8(appendKey(e.buf, key), i)
 	return e
 }
 
 // Int16 adds the field key with i as a int16 to the *Event context.
 func (e *Event) Int16(key string, i int16) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendInt16(json.AppendKey(e.buf, key), i)
+	e.buf = appendInt16(appendKey(e.buf, key), i)
 	return e
 }
 
 // Ints16 adds the field key with i as a []int16 to the *Event context.
 func (e *Event) Ints16(key string, i []int16) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendInts16(json.AppendKey(e.buf, key), i)
+	e.buf = appendInts16(appendKey(e.buf, key), i)
 	return e
 }
 
 // Int32 adds the field key with i as a int32 to the *Event context.
 func (e *Event) Int32(key string, i int32) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendInt32(json.AppendKey(e.buf, key), i)
+	e.buf = appendInt32(appendKey(e.buf, key), i)
 	return e
 }
 
 // Ints32 adds the field key with i as a []int32 to the *Event context.
 func (e *Event) Ints32(key string, i []int32) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendInts32(json.AppendKey(e.buf, key), i)
+	e.buf = appendInts32(appendKey(e.buf, key), i)
 	return e
 }
 
 // Int64 adds the field key with i as a int64 to the *Event context.
 func (e *Event) Int64(key string, i int64) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendInt64(json.AppendKey(e.buf, key), i)
+	e.buf = appendInt64(appendKey(e.buf, key), i)
 	return e
 }
 
 // Ints64 adds the field key with i as a []int64 to the *Event context.
 func (e *Event) Ints64(key string, i []int64) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendInts64(json.AppendKey(e.buf, key), i)
+	e.buf = appendInts64(appendKey(e.buf, key), i)
 	return e
 }
 
 // Uint adds the field key with i as a uint to the *Event context.
 func (e *Event) Uint(key string, i uint) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendUint(json.AppendKey(e.buf, key), i)
+	e.buf = appendUint(appendKey(e.buf, key), i)
 	return e
 }
 
 // Uints adds the field key with i as a []int to the *Event context.
 func (e *Event) Uints(key string, i []uint) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendUints(json.AppendKey(e.buf, key), i)
+	e.buf = appendUints(appendKey(e.buf, key), i)
 	return e
 }
 
 // Uint8 adds the field key with i as a uint8 to the *Event context.
 func (e *Event) Uint8(key string, i uint8) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendUint8(json.AppendKey(e.buf, key), i)
+	e.buf = appendUint8(appendKey(e.buf, key), i)
 	return e
 }
 
 // Uints8 adds the field key with i as a []int8 to the *Event context.
 func (e *Event) Uints8(key string, i []uint8) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendUints8(json.AppendKey(e.buf, key), i)
+	e.buf = appendUints8(appendKey(e.buf, key), i)
 	return e
 }
 
 // Uint16 adds the field key with i as a uint16 to the *Event context.
 func (e *Event) Uint16(key string, i uint16) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendUint16(json.AppendKey(e.buf, key), i)
+	e.buf = appendUint16(appendKey(e.buf, key), i)
 	return e
 }
 
 // Uints16 adds the field key with i as a []int16 to the *Event context.
 func (e *Event) Uints16(key string, i []uint16) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendUints16(json.AppendKey(e.buf, key), i)
+	e.buf = appendUints16(appendKey(e.buf, key), i)
 	return e
 }
 
 // Uint32 adds the field key with i as a uint32 to the *Event context.
 func (e *Event) Uint32(key string, i uint32) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendUint32(json.AppendKey(e.buf, key), i)
+	e.buf = appendUint32(appendKey(e.buf, key), i)
 	return e
 }
 
 // Uints32 adds the field key with i as a []int32 to the *Event context.
 func (e *Event) Uints32(key string, i []uint32) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendUints32(json.AppendKey(e.buf, key), i)
+	e.buf = appendUints32(appendKey(e.buf, key), i)
 	return e
 }
 
 // Uint64 adds the field key with i as a uint64 to the *Event context.
 func (e *Event) Uint64(key string, i uint64) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendUint64(json.AppendKey(e.buf, key), i)
+	e.buf = appendUint64(appendKey(e.buf, key), i)
 	return e
 }
 
 // Uints64 adds the field key with i as a []int64 to the *Event context.
 func (e *Event) Uints64(key string, i []uint64) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendUints64(json.AppendKey(e.buf, key), i)
+	e.buf = appendUints64(appendKey(e.buf, key), i)
 	return e
 }
 
 // Float32 adds the field key with f as a float32 to the *Event context.
 func (e *Event) Float32(key string, f float32) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendFloat32(json.AppendKey(e.buf, key), f)
+	e.buf = appendFloat32(appendKey(e.buf, key), f)
 	return e
 }
 
 // Floats32 adds the field key with f as a []float32 to the *Event context.
 func (e *Event) Floats32(key string, f []float32) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendFloats32(json.AppendKey(e.buf, key), f)
+	e.buf = appendFloats32(appendKey(e.buf, key), f)
 	return e
 }
 
 // Float64 adds the field key with f as a float64 to the *Event context.
 func (e *Event) Float64(key string, f float64) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendFloat64(json.AppendKey(e.buf, key), f)
+	e.buf = appendFloat64(appendKey(e.buf, key), f)
 	return e
 }
 
 // Floats64 adds the field key with f as a []float64 to the *Event context.
 func (e *Event) Floats64(key string, f []float64) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendFloats64(json.AppendKey(e.buf, key), f)
+	e.buf = appendFloats64(appendKey(e.buf, key), f)
 	return e
 }
 
 // Timestamp adds the current local time as UNIX timestamp to the *Event context with the "time" key.
 // To customize the key name, change zerolog.TimestampFieldName.
 func (e *Event) Timestamp() *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendTime(json.AppendKey(e.buf, TimestampFieldName), TimestampFunc(), TimeFieldFormat)
+	e.buf = appendTime(appendKey(e.buf, TimestampFieldName), TimestampFunc(), TimeFieldFormat)
 	return e
 }
 
 // Time adds the field key with t formated as string using zerolog.TimeFieldFormat.
 func (e *Event) Time(key string, t time.Time) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendTime(json.AppendKey(e.buf, key), t, TimeFieldFormat)
+	e.buf = appendTime(appendKey(e.buf, key), t, TimeFieldFormat)
 	return e
 }
 
 // Times adds the field key with t formated as string using zerolog.TimeFieldFormat.
 func (e *Event) Times(key string, t []time.Time) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendTimes(json.AppendKey(e.buf, key), t, TimeFieldFormat)
+	e.buf = appendTimes(appendKey(e.buf, key), t, TimeFieldFormat)
 	return e
 }
 
@@ -509,10 +517,10 @@ func (e *Event) Times(key string, t []time.Time) *Event {
 // If zerolog.DurationFieldInteger is true, durations are rendered as integer
 // instead of float.
 func (e *Event) Dur(key string, d time.Duration) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendDuration(json.AppendKey(e.buf, key), d, DurationFieldUnit, DurationFieldInteger)
+	e.buf = appendDuration(appendKey(e.buf, key), d, DurationFieldUnit, DurationFieldInteger)
 	return e
 }
 
@@ -520,10 +528,10 @@ func (e *Event) Dur(key string, d time.Duration) *Event {
 // If zerolog.DurationFieldInteger is true, durations are rendered as integer
 // instead of float.
 func (e *Event) Durs(key string, d []time.Duration) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
-	e.buf = json.AppendDurations(json.AppendKey(e.buf, key), d, DurationFieldUnit, DurationFieldInteger)
+	e.buf = appendDurations(appendKey(e.buf, key), d, DurationFieldUnit, DurationFieldInteger)
 	return e
 }
 
@@ -531,25 +539,42 @@ func (e *Event) Durs(key string, d []time.Duration) *Event {
 // If time t is not greater than start, duration will be 0.
 // Duration format follows the same principle as Dur().
 func (e *Event) TimeDiff(key string, t time.Time, start time.Time) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
 	var d time.Duration
 	if t.After(start) {
 		d = t.Sub(start)
 	}
-	e.buf = json.AppendDuration(json.AppendKey(e.buf, key), d, DurationFieldUnit, DurationFieldInteger)
+	e.buf = appendDuration(appendKey(e.buf, key), d, DurationFieldUnit, DurationFieldInteger)
 	return e
 }
 
 // Interface adds the field key with i marshaled using reflection.
 func (e *Event) Interface(key string, i interface{}) *Event {
-	if !e.enabled {
+	if e == nil {
 		return e
 	}
 	if obj, ok := i.(LogObjectMarshaler); ok {
 		return e.Object(key, obj)
 	}
-	e.buf = json.AppendInterface(json.AppendKey(e.buf, key), i)
+	e.buf = appendInterface(appendKey(e.buf, key), i)
+	return e
+}
+
+// Caller adds the file:line of the caller with the zerolog.CallerFieldName key.
+func (e *Event) Caller() *Event {
+	return e.caller(2)
+}
+
+func (e *Event) caller(skip int) *Event {
+	if e == nil {
+		return e
+	}
+	_, file, line, ok := runtime.Caller(skip)
+	if !ok {
+		return e
+	}
+	e.buf = appendString(appendKey(e.buf, CallerFieldName), file+":"+strconv.Itoa(line))
 	return e
 }

fields.go

@@ -3,8 +3,6 @@ package zerolog
 import (
 	"sort"
 	"time"
-
-	"github.com/rs/zerolog/internal/json"
 )
 
 func appendFields(dst []byte, fields map[string]interface{}) []byte {
@@ -14,82 +12,82 @@ func appendFields(dst []byte, fields map[string]interface{}) []byte {
 	}
 	sort.Strings(keys)
 	for _, key := range keys {
-		dst = json.AppendKey(dst, key)
+		dst = appendKey(dst, key)
 		switch val := fields[key].(type) {
 		case string:
-			dst = json.AppendString(dst, val)
+			dst = appendString(dst, val)
 		case []byte:
-			dst = json.AppendBytes(dst, val)
+			dst = appendBytes(dst, val)
 		case error:
-			dst = json.AppendError(dst, val)
+			dst = appendError(dst, val)
 		case []error:
-			dst = json.AppendErrors(dst, val)
+			dst = appendErrors(dst, val)
 		case bool:
-			dst = json.AppendBool(dst, val)
+			dst = appendBool(dst, val)
 		case int:
-			dst = json.AppendInt(dst, val)
+			dst = appendInt(dst, val)
 		case int8:
-			dst = json.AppendInt8(dst, val)
+			dst = appendInt8(dst, val)
 		case int16:
-			dst = json.AppendInt16(dst, val)
+			dst = appendInt16(dst, val)
 		case int32:
-			dst = json.AppendInt32(dst, val)
+			dst = appendInt32(dst, val)
 		case int64:
-			dst = json.AppendInt64(dst, val)
+			dst = appendInt64(dst, val)
 		case uint:
-			dst = json.AppendUint(dst, val)
+			dst = appendUint(dst, val)
 		case uint8:
-			dst = json.AppendUint8(dst, val)
+			dst = appendUint8(dst, val)
 		case uint16:
-			dst = json.AppendUint16(dst, val)
+			dst = appendUint16(dst, val)
 		case uint32:
-			dst = json.AppendUint32(dst, val)
+			dst = appendUint32(dst, val)
 		case uint64:
-			dst = json.AppendUint64(dst, val)
+			dst = appendUint64(dst, val)
 		case float32:
-			dst = json.AppendFloat32(dst, val)
+			dst = appendFloat32(dst, val)
 		case float64:
-			dst = json.AppendFloat64(dst, val)
+			dst = appendFloat64(dst, val)
 		case time.Time:
-			dst = json.AppendTime(dst, val, TimeFieldFormat)
+			dst = appendTime(dst, val, TimeFieldFormat)
 		case time.Duration:
-			dst = json.AppendDuration(dst, val, DurationFieldUnit, DurationFieldInteger)
+			dst = appendDuration(dst, val, DurationFieldUnit, DurationFieldInteger)
 		case []string:
-			dst = json.AppendStrings(dst, val)
+			dst = appendStrings(dst, val)
 		case []bool:
-			dst = json.AppendBools(dst, val)
+			dst = appendBools(dst, val)
 		case []int:
-			dst = json.AppendInts(dst, val)
+			dst = appendInts(dst, val)
 		case []int8:
-			dst = json.AppendInts8(dst, val)
+			dst = appendInts8(dst, val)
 		case []int16:
-			dst = json.AppendInts16(dst, val)
+			dst = appendInts16(dst, val)
 		case []int32:
-			dst = json.AppendInts32(dst, val)
+			dst = appendInts32(dst, val)
 		case []int64:
-			dst = json.AppendInts64(dst, val)
+			dst = appendInts64(dst, val)
 		case []uint:
-			dst = json.AppendUints(dst, val)
+			dst = appendUints(dst, val)
 		// case []uint8:
 		// 	dst = appendUints8(dst, val)
 		case []uint16:
-			dst = json.AppendUints16(dst, val)
+			dst = appendUints16(dst, val)
 		case []uint32:
-			dst = json.AppendUints32(dst, val)
+			dst = appendUints32(dst, val)
 		case []uint64:
-			dst = json.AppendUints64(dst, val)
+			dst = appendUints64(dst, val)
 		case []float32:
-			dst = json.AppendFloats32(dst, val)
+			dst = appendFloats32(dst, val)
 		case []float64:
-			dst = json.AppendFloats64(dst, val)
+			dst = appendFloats64(dst, val)
 		case []time.Time:
-			dst = json.AppendTimes(dst, val, TimeFieldFormat)
+			dst = appendTimes(dst, val, TimeFieldFormat)
 		case []time.Duration:
-			dst = json.AppendDurations(dst, val, DurationFieldUnit, DurationFieldInteger)
+			dst = appendDurations(dst, val, DurationFieldUnit, DurationFieldInteger)
 		case nil:
 			dst = append(dst, "null"...)
 		default:
-			dst = json.AppendInterface(dst, val)
+			dst = appendInterface(dst, val)
 		}
 	}
 	return dst

globals.go

@@ -16,6 +16,9 @@ var (
 	// ErrorFieldName is the field name used for error fields.
 	ErrorFieldName = "error"
 
+	// CallerFieldName is the field name used for caller field.
+	CallerFieldName = "caller"
+
 	// TimeFieldFormat defines the time format of the Time field type.
 	// If set to an empty string, the time is formatted as an UNIX timestamp
 	// as integer.

hlog/hlog.go

@@ -124,7 +124,7 @@ func RefererHandler(fieldKey string) func(next http.Handler) http.Handler {
 
 type idKey struct{}
 
-// IDFromRequest returns the unique id accociated to the request if any.
+// IDFromRequest returns the unique id associated to the request if any.
 func IDFromRequest(r *http.Request) (id xid.ID, ok bool) {
 	if r == nil {
 		return

hlog/hlog_example_test.go

@@ -67,5 +67,5 @@ func Example_handler() {
 
 	h.ServeHTTP(httptest.NewRecorder(), &http.Request{})
 
-	// Output: {"time":"2001-02-03T04:05:06Z","level":"info","role":"my-service","host":"local-hostname","user":"current user","status":"ok","message":"Something happend"}
+	// Output: {"level":"info","role":"my-service","host":"local-hostname","user":"current user","status":"ok","time":"2001-02-03T04:05:06Z","message":"Something happend"}
 }

hook.go

@@ -0,0 +1,51 @@
+package zerolog
+
+// Hook defines an interface to a log hook.
+type Hook interface {
+	// Run runs the hook with the event.
+	Run(e *Event, level Level, message string)
+}
+
+// LevelHook applies a different hook for each level.
+type LevelHook struct {
+	NoLevelHook, DebugHook, InfoHook, WarnHook, ErrorHook, FatalHook, PanicHook Hook
+}
+
+// Run implements the Hook interface.
+func (h LevelHook) Run(e *Event, level Level, message string) {
+	switch level {
+	case DebugLevel:
+		if h.DebugHook != nil {
+			h.DebugHook.Run(e, level, message)
+		}
+	case InfoLevel:
+		if h.InfoHook != nil {
+			h.InfoHook.Run(e, level, message)
+		}
+	case WarnLevel:
+		if h.WarnHook != nil {
+			h.WarnHook.Run(e, level, message)
+		}
+	case ErrorLevel:
+		if h.ErrorHook != nil {
+			h.ErrorHook.Run(e, level, message)
+		}
+	case FatalLevel:
+		if h.FatalHook != nil {
+			h.FatalHook.Run(e, level, message)
+		}
+	case PanicLevel:
+		if h.PanicHook != nil {
+			h.PanicHook.Run(e, level, message)
+		}
+	case NoLevel:
+		if h.NoLevelHook != nil {
+			h.NoLevelHook.Run(e, level, message)
+		}
+	}
+}
+
+// NewLevelHook returns a new LevelHook.
+func NewLevelHook() LevelHook {
+	return LevelHook{}
+}

hook_test.go

@@ -0,0 +1,236 @@
+package zerolog
+
+import (
+	"testing"
+	"bytes"
+	"io/ioutil"
+)
+
+type LevelNameHook struct{}
+
+func (h LevelNameHook) Run(e *Event, level Level, msg string) {
+	levelName := level.String()
+	if level == NoLevel {
+		levelName = "nolevel"
+	}
+	e.Str("level_name", levelName)
+}
+
+type SimpleHook struct{}
+
+func (h SimpleHook) Run(e *Event, level Level, msg string) {
+	e.Bool("has_level", level != NoLevel)
+	e.Str("test", "logged")
+}
+
+type CopyHook struct{}
+
+func (h CopyHook) Run(e *Event, level Level, msg string) {
+	hasLevel := level != NoLevel
+	e.Bool("copy_has_level", hasLevel)
+	if hasLevel {
+		e.Str("copy_level", level.String())
+	}
+	e.Str("copy_msg", msg)
+}
+
+type NopHook struct{}
+
+func (h NopHook) Run(e *Event, level Level, msg string) {
+}
+
+var (
+	levelNameHook LevelNameHook
+	simpleHook    SimpleHook
+	copyHook      CopyHook
+	nopHook       NopHook
+)
+
+func TestHook(t *testing.T) {
+	t.Run("Message", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(levelNameHook)
+		log.Log().Msg("test message")
+		if got, want := out.String(), `{"level_name":"nolevel","message":"test message"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("NoLevel", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(levelNameHook)
+		log.Log().Msg("")
+		if got, want := out.String(), `{"level_name":"nolevel"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Print", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(levelNameHook)
+		log.Print("")
+		if got, want := out.String(), `{"level":"debug","level_name":"debug"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Error", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(levelNameHook)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","level_name":"error"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Copy/1", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(copyHook)
+		log.Log().Msg("")
+		if got, want := out.String(), `{"copy_has_level":false,"copy_msg":""}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Copy/2", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(copyHook)
+		log.Info().Msg("a message")
+		if got, want := out.String(), `{"level":"info","copy_has_level":true,"copy_level":"info","copy_msg":"a message","message":"a message"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Multi", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(levelNameHook).Hook(simpleHook)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","level_name":"error","has_level":true,"test":"logged"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Multi/Message", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(levelNameHook).Hook(simpleHook)
+		log.Error().Msg("a message")
+		if got, want := out.String(), `{"level":"error","level_name":"error","has_level":true,"test":"logged","message":"a message"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Output/single/pre", func(t *testing.T) {
+		ignored := &bytes.Buffer{}
+		out := &bytes.Buffer{}
+		log := New(ignored).Hook(levelNameHook).Output(out)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","level_name":"error"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Output/single/post", func(t *testing.T) {
+		ignored := &bytes.Buffer{}
+		out := &bytes.Buffer{}
+		log := New(ignored).Output(out).Hook(levelNameHook)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","level_name":"error"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Output/multi/pre", func(t *testing.T) {
+		ignored := &bytes.Buffer{}
+		out := &bytes.Buffer{}
+		log := New(ignored).Hook(levelNameHook).Hook(simpleHook).Output(out)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","level_name":"error","has_level":true,"test":"logged"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Output/multi/post", func(t *testing.T) {
+		ignored := &bytes.Buffer{}
+		out := &bytes.Buffer{}
+		log := New(ignored).Output(out).Hook(levelNameHook).Hook(simpleHook)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","level_name":"error","has_level":true,"test":"logged"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("Output/mixed", func(t *testing.T) {
+		ignored := &bytes.Buffer{}
+		out := &bytes.Buffer{}
+		log := New(ignored).Hook(levelNameHook).Output(out).Hook(simpleHook)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","level_name":"error","has_level":true,"test":"logged"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("With/single/pre", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(levelNameHook).With().Str("with", "pre").Logger()
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","with":"pre","level_name":"error"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("With/single/post", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).With().Str("with", "post").Logger().Hook(levelNameHook)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","with":"post","level_name":"error"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("With/multi/pre", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(levelNameHook).Hook(simpleHook).With().Str("with", "pre").Logger()
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","with":"pre","level_name":"error","has_level":true,"test":"logged"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("With/multi/post", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).With().Str("with", "post").Logger().Hook(levelNameHook).Hook(simpleHook)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","with":"post","level_name":"error","has_level":true,"test":"logged"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("With/mixed", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Hook(levelNameHook).With().Str("with", "mixed").Logger().Hook(simpleHook)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error","with":"mixed","level_name":"error","has_level":true,"test":"logged"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+	t.Run("None", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out)
+		log.Error().Msg("")
+		if got, want := out.String(), `{"level":"error"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+}
+
+func BenchmarkHooks(b *testing.B) {
+	logger := New(ioutil.Discard)
+	b.ResetTimer()
+	b.Run("Nop/Single", func(b *testing.B) {
+		log := logger.Hook(nopHook)
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				log.Log().Msg("")
+			}
+		})
+	})
+	b.Run("Nop/Multi", func(b *testing.B) {
+		log := logger.Hook(nopHook).Hook(nopHook)
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				log.Log().Msg("")
+			}
+		})
+	})
+	b.Run("Simple", func(b *testing.B) {
+		log := logger.Hook(simpleHook)
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				log.Log().Msg("")
+			}
+		})
+	})
+}

log.go

@@ -65,6 +65,23 @@
 //     sampled := log.Sample(&zerolog.BasicSampler{N: 10})
 //     sampled.Info().Msg("will be logged every 10 messages")
 //
+// Log with contextual hooks:
+//
+//     // Create the hook:
+//     type SeverityHook struct{}
+//
+//     func (h SeverityHook) Run(e *zerolog.Event, level zerolog.Level, msg string) {
+//          if level != zerolog.NoLevel {
+//              e.Str("severity", level.String())
+//          }
+//     }
+//
+//     // And use it:
+//     var h SeverityHook
+//     log := zerolog.New(os.Stdout).Hook(h)
+//     log.Warn().Msg("")
+//     // Output: {"level":"warn","severity":"warn"}
+//
 package zerolog
 
 import (
@@ -73,8 +90,6 @@ import (
 	"io/ioutil"
 	"os"
 	"strconv"
-
-	"github.com/rs/zerolog/internal/json"
 )
 
 // Level defines log levels.
@@ -93,6 +108,8 @@ const (
 	FatalLevel
 	// PanicLevel defines panic log level.
 	PanicLevel
+	// NoLevel defines an absent log level.
+	NoLevel
 	// Disabled disables the logger.
 	Disabled
 )
@@ -111,12 +128,12 @@ func (l Level) String() string {
 		return "fatal"
 	case PanicLevel:
 		return "panic"
+	case NoLevel:
+		return ""
 	}
 	return ""
 }
 
-var disabledEvent = newEvent(levelWriterAdapter{ioutil.Discard}, 0, false)
-
 // A Logger represents an active logging object that generates lines
 // of JSON output to an io.Writer. Each logging operation makes a single
 // call to the Writer's Write method. There is no guaranty on access
@@ -127,6 +144,7 @@ type Logger struct {
 	level   Level
 	sampler Sampler
 	context []byte
+	hooks   []Hook
 }
 
 // New creates a root logger with given output writer. If the output writer implements
@@ -157,8 +175,13 @@ func (l Logger) Output(w io.Writer) Logger {
 	l2 := New(w)
 	l2.level = l.level
 	l2.sampler = l.sampler
-	l2.context = make([]byte, len(l.context), cap(l.context))
-	copy(l2.context, l.context)
+	if len(l.hooks) > 0 {
+		l2.hooks = append(l2.hooks, l.hooks...)
+	}
+	if l.context != nil {
+		l2.context = make([]byte, len(l.context), cap(l.context))
+		copy(l2.context, l.context)
+	}
 	return l2
 }
 
@@ -168,9 +191,6 @@ func (l Logger) With() Context {
 	l.context = make([]byte, 0, 500)
 	if context != nil {
 		l.context = append(l.context, context...)
-	} else {
-		// first byte of context is presence of timestamp or not
-		l.context = append(l.context, 0)
 	}
 	return Context{l}
 }
@@ -183,7 +203,7 @@ func (l *Logger) UpdateContext(update func(c Context) Context) {
 		return
 	}
 	if cap(l.context) == 0 {
-		l.context = make([]byte, 1, 500) // first byte is timestamp flag
+		l.context = make([]byte, 0, 500)
 	}
 	c := update(Context{*l})
 	l.context = c.l.context
@@ -201,54 +221,60 @@ func (l Logger) Sample(s Sampler) Logger {
 	return l
 }
 
+// Hook returns a logger with the h Hook.
+func (l Logger) Hook(h Hook) Logger {
+	l.hooks = append(l.hooks, h)
+	return l
+}
+
 // Debug starts a new message with debug level.
 //
 // You must call Msg on the returned event in order to send the event.
-func (l Logger) Debug() *Event {
-	return l.newEvent(DebugLevel, true, nil)
+func (l *Logger) Debug() *Event {
+	return l.newEvent(DebugLevel, nil)
 }
 
 // Info starts a new message with info level.
 //
 // You must call Msg on the returned event in order to send the event.
-func (l Logger) Info() *Event {
-	return l.newEvent(InfoLevel, true, nil)
+func (l *Logger) Info() *Event {
+	return l.newEvent(InfoLevel, nil)
 }
 
 // Warn starts a new message with warn level.
 //
 // You must call Msg on the returned event in order to send the event.
-func (l Logger) Warn() *Event {
-	return l.newEvent(WarnLevel, true, nil)
+func (l *Logger) Warn() *Event {
+	return l.newEvent(WarnLevel, nil)
 }
 
 // Error starts a new message with error level.
 //
 // You must call Msg on the returned event in order to send the event.
-func (l Logger) Error() *Event {
-	return l.newEvent(ErrorLevel, true, nil)
+func (l *Logger) Error() *Event {
+	return l.newEvent(ErrorLevel, nil)
 }
 
 // Fatal starts a new message with fatal level. The os.Exit(1) function
 // is called by the Msg method.
 //
 // You must call Msg on the returned event in order to send the event.
-func (l Logger) Fatal() *Event {
-	return l.newEvent(FatalLevel, true, func(msg string) { os.Exit(1) })
+func (l *Logger) Fatal() *Event {
+	return l.newEvent(FatalLevel, func(msg string) { os.Exit(1) })
 }
 
 // Panic starts a new message with panic level. The message is also sent
 // to the panic function.
 //
 // You must call Msg on the returned event in order to send the event.
-func (l Logger) Panic() *Event {
-	return l.newEvent(PanicLevel, true, func(msg string) { panic(msg) })
+func (l *Logger) Panic() *Event {
+	return l.newEvent(PanicLevel, func(msg string) { panic(msg) })
 }
 
 // WithLevel starts a new message with level.
 //
 // You must call Msg on the returned event in order to send the event.
-func (l Logger) WithLevel(level Level) *Event {
+func (l *Logger) WithLevel(level Level) *Event {
 	switch level {
 	case DebugLevel:
 		return l.Debug()
@@ -262,8 +288,10 @@ func (l Logger) WithLevel(level Level) *Event {
 		return l.Fatal()
 	case PanicLevel:
 		return l.Panic()
+	case NoLevel:
+		return l.Log()
 	case Disabled:
-		return disabledEvent
+		return nil
 	default:
 		panic("zerolog: WithLevel(): invalid level: " + strconv.Itoa(int(level)))
 	}
@@ -273,15 +301,13 @@ func (l Logger) WithLevel(level Level) *Event {
 // will still disable events produced by this method.
 //
 // You must call Msg on the returned event in order to send the event.
-func (l Logger) Log() *Event {
-	// We use panic level with addLevelField=false to make Log passthrough all
-	// levels except Disabled.
-	return l.newEvent(PanicLevel, false, nil)
+func (l *Logger) Log() *Event {
+	return l.newEvent(NoLevel, nil)
 }
 
 // Print sends a log event using debug level and no extra field.
 // Arguments are handled in the manner of fmt.Print.
-func (l Logger) Print(v ...interface{}) {
+func (l *Logger) Print(v ...interface{}) {
 	if e := l.Debug(); e.Enabled() {
 		e.Msg(fmt.Sprint(v...))
 	}
@@ -289,7 +315,7 @@ func (l Logger) Print(v ...interface{}) {
 
 // Printf sends a log event using debug level and no extra field.
 // Arguments are handled in the manner of fmt.Printf.
-func (l Logger) Printf(format string, v ...interface{}) {
+func (l *Logger) Printf(format string, v ...interface{}) {
 	if e := l.Debug(); e.Enabled() {
 		e.Msg(fmt.Sprintf(format, v...))
 	}
@@ -307,35 +333,28 @@ func (l Logger) Write(p []byte) (n int, err error) {
 	return
 }
 
-func (l Logger) newEvent(level Level, addLevelField bool, done func(string)) *Event {
+func (l *Logger) newEvent(level Level, done func(string)) *Event {
 	enabled := l.should(level)
 	if !enabled {
-		return disabledEvent
+		return nil
 	}
-	lvl := InfoLevel
-	if addLevelField {
-		lvl = level
-	}
-	e := newEvent(l.w, lvl, true)
+	e := newEvent(l.w, level, true)
 	e.done = done
-	if l.context != nil && len(l.context) > 0 && l.context[0] > 0 {
-		// first byte of context is ts flag
-		e.buf = json.AppendTime(json.AppendKey(e.buf, TimestampFieldName), TimestampFunc(), TimeFieldFormat)
-	}
-	if addLevelField {
+	e.ch = l.hooks
+	if level != NoLevel {
 		e.Str(LevelFieldName, level.String())
 	}
-	if l.context != nil && len(l.context) > 1 {
+	if len(l.context) > 0 {
 		if len(e.buf) > 1 {
 			e.buf = append(e.buf, ',')
 		}
-		e.buf = append(e.buf, l.context[1:]...)
+		e.buf = append(e.buf, l.context...)
 	}
 	return e
 }
 
 // should returns true if the log event should be logged.
-func (l Logger) should(lvl Level) bool {
+func (l *Logger) should(lvl Level) bool {
 	if lvl < l.level || lvl < globalLevel() {
 		return false
 	}

log/log.go

@@ -22,7 +22,7 @@ func With() zerolog.Context {
 	return Logger.With()
 }
 
-// Level crestes a child logger with the minium accepted level set to level.
+// Level creates a child logger with the minimum accepted level set to level.
 func Level(level zerolog.Level) zerolog.Logger {
 	return Logger.Level(level)
 }
@@ -32,6 +32,11 @@ func Sample(s zerolog.Sampler) zerolog.Logger {
 	return Logger.Sample(s)
 }
 
+// Hook returns a logger with the h Hook.
+func Hook(h zerolog.Hook) zerolog.Logger {
+	return Logger.Hook(h)
+}
+
 // Debug starts a new message with debug level.
 //
 // You must call Msg on the returned event in order to send the event.
@@ -76,8 +81,15 @@ func Panic() *zerolog.Event {
 	return Logger.Panic()
 }
 
+// WithLevel starts a new message with level.
+//
+// You must call Msg on the returned event in order to send the event.
+func WithLevel(level zerolog.Level) *zerolog.Event {
+	return Logger.WithLevel(level)
+}
+
 // Log starts a new message with no level. Setting zerolog.GlobalLevel to
-// zerlog.Disabled will still disable events produced by this method.
+// zerolog.Disabled will still disable events produced by this method.
 //
 // You must call Msg on the returned event in order to send the event.
 func Log() *zerolog.Event {

log/log_example_test.go

@@ -0,0 +1,141 @@
+package log_test
+
+import (
+	"errors"
+	"flag"
+	"os"
+	"time"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+)
+
+// setup would normally be an init() function, however, there seems
+// to be something awry with the testing framework when we set the
+// global Logger from an init()
+func setup() {
+	// UNIX Time is faster and smaller than most timestamps
+	// If you set zerolog.TimeFieldFormat to an empty string,
+	// logs will write with UNIX time
+	zerolog.TimeFieldFormat = ""
+	// In order to always output a static time to stdout for these
+	// examples to pass, we need to override zerolog.TimestampFunc
+	// and log.Logger globals -- you would not normally need to do this
+	zerolog.TimestampFunc = func() time.Time {
+		return time.Date(2008, 1, 8, 17, 5, 05, 0, time.UTC)
+	}
+	log.Logger = zerolog.New(os.Stdout).With().Timestamp().Logger()
+}
+
+// Simple logging example using the Print function in the log package
+// Note that both Print and Printf are at the debug log level by default
+func ExamplePrint() {
+	setup()
+
+	log.Print("hello world")
+	// Output: {"level":"debug","time":1199811905,"message":"hello world"}
+}
+
+// Simple logging example using the Printf function in the log package
+func ExamplePrintf() {
+	setup()
+
+	log.Printf("hello %s", "world")
+	// Output: {"level":"debug","time":1199811905,"message":"hello world"}
+}
+
+// Example of a log with no particular "level"
+func ExampleLog() {
+	setup()
+	log.Log().Msg("hello world")
+
+	// Output: {"time":1199811905,"message":"hello world"}
+}
+
+// Example of a log at a particular "level" (in this case, "debug")
+func ExampleDebug() {
+	setup()
+	log.Debug().Msg("hello world")
+
+	// Output: {"level":"debug","time":1199811905,"message":"hello world"}
+}
+
+// Example of a log at a particular "level" (in this case, "info")
+func ExampleInfo() {
+	setup()
+	log.Info().Msg("hello world")
+
+	// Output: {"level":"info","time":1199811905,"message":"hello world"}
+}
+
+// Example of a log at a particular "level" (in this case, "warn")
+func ExampleWarn() {
+	setup()
+	log.Warn().Msg("hello world")
+
+	// Output: {"level":"warn","time":1199811905,"message":"hello world"}
+}
+
+// Example of a log at a particular "level" (in this case, "error")
+func ExampleError() {
+	setup()
+	log.Error().Msg("hello world")
+
+	// Output: {"level":"error","time":1199811905,"message":"hello world"}
+}
+
+// Example of a log at a particular "level" (in this case, "fatal")
+func ExampleFatal() {
+	setup()
+	err := errors.New("A repo man spends his life getting into tense situations")
+	service := "myservice"
+
+	log.Fatal().
+		Err(err).
+		Str("service", service).
+		Msgf("Cannot start %s", service)
+
+	// Outputs: {"level":"fatal","time":1199811905,"error":"A repo man spends his life getting into tense situations","service":"myservice","message":"Cannot start myservice"}
+}
+
+// TODO: Panic
+
+// This example uses command-line flags to demonstrate various outputs
+// depending on the chosen log level.
+func Example_LevelFlag() {
+	setup()
+	debug := flag.Bool("debug", false, "sets log level to debug")
+
+	flag.Parse()
+
+	// Default level for this example is info, unless debug flag is present
+	zerolog.SetGlobalLevel(zerolog.InfoLevel)
+	if *debug {
+		zerolog.SetGlobalLevel(zerolog.DebugLevel)
+	}
+
+	log.Debug().Msg("This message appears only when log level set to Debug")
+	log.Info().Msg("This message appears when log level set to Debug or Info")
+
+	if e := log.Debug(); e.Enabled() {
+		// Compute log output only if enabled.
+		value := "bar"
+		e.Str("foo", value).Msg("some debug message")
+	}
+
+	// Output: {"level":"info","time":1199811905,"message":"This message appears when log level set to Debug or Info"}
+}
+
+// TODO: Output
+
+// TODO: With
+
+// TODO: Level
+
+// TODO: Sample
+
+// TODO: Hook
+
+// TODO: WithLevel
+
+// TODO: Ctx

log_example_test.go

@@ -49,6 +49,33 @@ func ExampleLogger_Sample() {
 	// {"level":"info","message":"message 4"}
 }
 
+type LevelNameHook struct{}
+
+func (h LevelNameHook) Run(e *zerolog.Event, l zerolog.Level, msg string) {
+	if l != zerolog.NoLevel {
+		e.Str("level_name", l.String())
+	} else {
+		e.Str("level_name", "NoLevel")
+	}
+}
+
+type MessageHook string
+
+func (h MessageHook) Run(e *zerolog.Event, l zerolog.Level, msg string) {
+	e.Str("the_message", msg)
+}
+
+func ExampleLogger_Hook() {
+	var levelNameHook LevelNameHook
+	var messageHook MessageHook = "The message"
+
+	log := zerolog.New(os.Stdout).Hook(levelNameHook).Hook(messageHook)
+
+	log.Info().Msg("hello world")
+
+	// Output: {"level":"info","level_name":"info","the_message":"hello world","message":"hello world"}
+}
+
 func ExampleLogger_Print() {
 	log := zerolog.New(os.Stdout)
 

log_test.go

@@ -3,7 +3,9 @@ package zerolog
 import (
 	"bytes"
 	"errors"
+	"fmt"
 	"reflect"
+	"runtime"
 	"testing"
 	"time"
 )
@@ -74,7 +76,7 @@ func TestInfo(t *testing.T) {
 
 func TestWith(t *testing.T) {
 	out := &bytes.Buffer{}
-	log := New(out).With().
+	ctx := New(out).With().
 		Str("foo", "bar").
 		AnErr("some_err", nil).
 		Err(errors.New("some error")).
@@ -91,10 +93,12 @@ func TestWith(t *testing.T) {
 		Uint64("uint64", 10).
 		Float32("float32", 11).
 		Float64("float64", 12).
-		Time("time", time.Time{}).
-		Logger()
+		Time("time", time.Time{})
+	_, file, line, _ := runtime.Caller(0)
+	caller := fmt.Sprintf("%s:%d", file, line+3)
+	log := ctx.Caller().Logger()
 	log.Log().Msg("")
-	if got, want := out.String(), `{"foo":"bar","error":"some error","bool":true,"int":1,"int8":2,"int16":3,"int32":4,"int64":5,"uint":6,"uint8":7,"uint16":8,"uint32":9,"uint64":10,"float32":11,"float64":12,"time":"0001-01-01T00:00:00Z"}`+"\n"; got != want {
+	if got, want := out.String(), `{"foo":"bar","error":"some error","bool":true,"int":1,"int8":2,"int16":3,"int32":4,"int64":5,"uint":6,"uint8":7,"uint16":8,"uint32":9,"uint64":10,"float32":11,"float64":12,"time":"0001-01-01T00:00:00Z","caller":"`+caller+`"}`+"\n"; got != want {
 		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
@@ -132,7 +136,10 @@ func TestFields(t *testing.T) {
 	out := &bytes.Buffer{}
 	log := New(out)
 	now := time.Now()
+	_, file, line, _ := runtime.Caller(0)
+	caller := fmt.Sprintf("%s:%d", file, line+3)
 	log.Log().
+		Caller().
 		Str("string", "foo").
 		Bytes("bytes", []byte("bar")).
 		AnErr("some_err", nil).
@@ -154,7 +161,7 @@ func TestFields(t *testing.T) {
 		Time("time", time.Time{}).
 		TimeDiff("diff", now, now.Add(-10*time.Second)).
 		Msg("")
-	if got, want := out.String(), `{"string":"foo","bytes":"bar","error":"some error","bool":true,"int":1,"int8":2,"int16":3,"int32":4,"int64":5,"uint":6,"uint8":7,"uint16":8,"uint32":9,"uint64":10,"float32":11,"float64":12,"dur":1000,"time":"0001-01-01T00:00:00Z","diff":10000}`+"\n"; got != want {
+	if got, want := out.String(), `{"caller":"`+caller+`","string":"foo","bytes":"bar","error":"some error","bool":true,"int":1,"int8":2,"int16":3,"int32":4,"int64":5,"uint":6,"uint8":7,"uint16":8,"uint32":9,"uint64":10,"float32":11,"float64":12,"dur":1000,"time":"0001-01-01T00:00:00Z","diff":10000}`+"\n"; got != want {
 		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
@@ -273,7 +280,8 @@ func TestFieldsDisabled(t *testing.T) {
 
 func TestMsgf(t *testing.T) {
 	out := &bytes.Buffer{}
-	New(out).Log().Msgf("one %s %.1f %d %v", "two", 3.4, 5, errors.New("six"))
+	log := New(out)
+	log.Log().Msgf("one %s %.1f %d %v", "two", 3.4, 5, errors.New("six"))
 	if got, want := out.String(), `{"message":"one two 3.4 5 six"}`+"\n"; got != want {
 		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
@@ -298,6 +306,42 @@ func TestLevel(t *testing.T) {
 		}
 	})
 
+	t.Run("NoLevel/Disabled", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Level(Disabled)
+		log.Log().Msg("test")
+		if got, want := out.String(), ""; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+
+	t.Run("NoLevel/Info", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Level(InfoLevel)
+		log.Log().Msg("test")
+		if got, want := out.String(), `{"message":"test"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+
+	t.Run("NoLevel/Panic", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Level(PanicLevel)
+		log.Log().Msg("test")
+		if got, want := out.String(), `{"message":"test"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+
+	t.Run("NoLevel/WithLevel", func(t *testing.T) {
+		out := &bytes.Buffer{}
+		log := New(out).Level(InfoLevel)
+		log.WithLevel(NoLevel).Msg("test")
+		if got, want := out.String(), `{"message":"test"}`+"\n"; got != want {
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+		}
+	})
+
 	t.Run("Info", func(t *testing.T) {
 		out := &bytes.Buffer{}
 		log := New(out).Level(InfoLevel)
@@ -351,10 +395,12 @@ func TestLevelWriter(t *testing.T) {
 	log.Info().Msg("2")
 	log.Warn().Msg("3")
 	log.Error().Msg("4")
+	log.Log().Msg("nolevel-1")
 	log.WithLevel(DebugLevel).Msg("5")
 	log.WithLevel(InfoLevel).Msg("6")
 	log.WithLevel(WarnLevel).Msg("7")
 	log.WithLevel(ErrorLevel).Msg("8")
+	log.WithLevel(NoLevel).Msg("nolevel-2")
 
 	want := []struct {
 		l Level
@@ -364,10 +410,12 @@ func TestLevelWriter(t *testing.T) {
 		{InfoLevel, `{"level":"info","message":"2"}` + "\n"},
 		{WarnLevel, `{"level":"warn","message":"3"}` + "\n"},
 		{ErrorLevel, `{"level":"error","message":"4"}` + "\n"},
+		{NoLevel, `{"message":"nolevel-1"}` + "\n"},
 		{DebugLevel, `{"level":"debug","message":"5"}` + "\n"},
 		{InfoLevel, `{"level":"info","message":"6"}` + "\n"},
 		{WarnLevel, `{"level":"warn","message":"7"}` + "\n"},
 		{ErrorLevel, `{"level":"error","message":"8"}` + "\n"},
+		{NoLevel, `{"message":"nolevel-2"}` + "\n"},
 	}
 	if got := lw.ops; !reflect.DeepEqual(got, want) {
 		t.Errorf("invalid ops:\ngot:\n%v\nwant:\n%v", got, want)
@@ -385,7 +433,7 @@ func TestContextTimestamp(t *testing.T) {
 	log := New(out).With().Timestamp().Str("foo", "bar").Logger()
 	log.Log().Msg("hello world")
 
-	if got, want := out.String(), `{"time":"2001-02-03T04:05:06Z","foo":"bar","message":"hello world"}`+"\n"; got != want {
+	if got, want := out.String(), `{"foo":"bar","time":"2001-02-03T04:05:06Z","message":"hello world"}`+"\n"; got != want {
 		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
@@ -405,3 +453,31 @@ func TestEventTimestamp(t *testing.T) {
 		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
+
+func TestOutputWithoutTimestamp(t *testing.T) {
+	ignoredOut := &bytes.Buffer{}
+	out := &bytes.Buffer{}
+	log := New(ignoredOut).Output(out).With().Str("foo", "bar").Logger()
+	log.Log().Msg("hello world")
+
+	if got, want := out.String(), `{"foo":"bar","message":"hello world"}`+"\n"; got != want {
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+	}
+}
+
+func TestOutputWithTimestamp(t *testing.T) {
+	TimestampFunc = func() time.Time {
+		return time.Date(2001, time.February, 3, 4, 5, 6, 7, time.UTC)
+	}
+	defer func() {
+		TimestampFunc = time.Now
+	}()
+	ignoredOut := &bytes.Buffer{}
+	out := &bytes.Buffer{}
+	log := New(ignoredOut).Output(out).With().Timestamp().Str("foo", "bar").Logger()
+	log.Log().Msg("hello world")
+
+	if got, want := out.String(), `{"foo":"bar","time":"2001-02-03T04:05:06Z","message":"hello world"}`+"\n"; got != want {
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+	}
+}

sampler.go

@@ -31,10 +31,8 @@ func (s RandomSampler) Sample(lvl Level) bool {
 	if s <= 0 {
 		return false
 	}
-	if s > 0 {
-		if rand.Intn(int(s)) != 0 {
-			return false
-		}
+	if rand.Intn(int(s)) != 0 {
+		return false
 	}
 	return true
 }
@@ -70,7 +68,7 @@ type BurstSampler struct {
 
 // Sample implements the Sampler interface.
 func (s *BurstSampler) Sample(lvl Level) bool {
-	if s.Burst > 9 && s.Period > 0 {
+	if s.Burst > 0 && s.Period > 0 {
 		if s.inc() <= s.Burst {
 			return true
 		}

syslog.go

@@ -44,6 +44,8 @@ func (sw syslogWriter) WriteLevel(level Level, p []byte) (n int, err error) {
 		err = sw.w.Emerg(string(p))
 	case PanicLevel:
 		err = sw.w.Crit(string(p))
+	case NoLevel:
+		err = sw.w.Info(string(p))
 	default:
 		panic("invalid level")
 	}

syslog_test.go

@@ -1,3 +1,5 @@
+// +build !windows
+
 package zerolog
 
 import "testing"
@@ -46,11 +48,13 @@ func TestSyslogWriter(t *testing.T) {
 	log.Info().Msg("info")
 	log.Warn().Msg("warn")
 	log.Error().Msg("error")
+	log.Log().Msg("nolevel")
 	want := []syslogEvent{
 		{"Debug", `{"level":"debug","message":"debug"}` + "\n"},
 		{"Info", `{"level":"info","message":"info"}` + "\n"},
 		{"Warning", `{"level":"warn","message":"warn"}` + "\n"},
 		{"Err", `{"level":"error","message":"error"}` + "\n"},
+		{"Info", `{"message":"nolevel"}` + "\n"},
 	}
 	if got := sw.events; !reflect.DeepEqual(got, want) {
 		t.Errorf("Invalid syslog message routing: want %v, got %v", want, got)

writer_test.go

@@ -1,3 +1,5 @@
+// +build !windows
+
 package zerolog
 
 import (
@@ -12,11 +14,13 @@ func TestMultiSyslogWriter(t *testing.T) {
 	log.Info().Msg("info")
 	log.Warn().Msg("warn")
 	log.Error().Msg("error")
+	log.Log().Msg("nolevel")
 	want := []syslogEvent{
 		{"Debug", `{"level":"debug","message":"debug"}` + "\n"},
 		{"Info", `{"level":"info","message":"info"}` + "\n"},
 		{"Warning", `{"level":"warn","message":"warn"}` + "\n"},
 		{"Err", `{"level":"error","message":"error"}` + "\n"},
+		{"Info", `{"message":"nolevel"}` + "\n"},
 	}
 	if got := sw.events; !reflect.DeepEqual(got, want) {
 		t.Errorf("Invalid syslog message routing: want %v, got %v", want, got)