Add some array types support

Add some utility functions to ease migration from other logger API.

README.md

@@ -189,6 +189,15 @@ c = c.Append(hlog.NewHandler(log))
 
 // Install some provided extra handler to set some request's context fields.
 // Thanks to those handler, all our logs will come with some pre-populated fields.
+c = c.Append(hlog.AccessHandler(func(r *http.Request, status, size int, duration time.Duration) {
+    hlog.FromRequest(r).Info().
+        Str("method", r.Method).
+        Str("url", r.URL.String()).
+        Int("status", status).
+        Int("size", size).
+        Dur("duration", duration).
+        Msg("")
+}))
 c = c.Append(hlog.RemoteAddrHandler("ip"))
 c = c.Append(hlog.UserAgentHandler("user_agent"))
 c = c.Append(hlog.RefererHandler("referer"))
@@ -255,11 +264,11 @@ Some settings can be changed and will by applied to all loggers:
 All operations are allocation free (those numbers *include* JSON encoding):
 
 ```
-BenchmarkLogEmpty-8        100000000	    19.1 ns/op	   0 B/op       0 allocs/op
-BenchmarkDisabled-8        500000000	     4.07 ns/op	   0 B/op       0 allocs/op
-BenchmarkInfo-8            30000000	    46.3 ns/op	   0 B/op       0 allocs/op
-BenchmarkContextFields-8   30000000	    47.1 ns/op	   0 B/op       0 allocs/op
-BenchmarkLogFields-8       10000000	   186 ns/op	   0 B/op       0 allocs/op
+BenchmarkLogEmpty-8        100000000    19.1 ns/op	   0 B/op       0 allocs/op
+BenchmarkDisabled-8        500000000     4.07 ns/op	   0 B/op       0 allocs/op
+BenchmarkInfo-8            30000000	    42.5 ns/op	   0 B/op       0 allocs/op
+BenchmarkContextFields-8   30000000	    44.9 ns/op	   0 B/op       0 allocs/op
+BenchmarkLogFields-8       10000000	   184 ns/op	   0 B/op       0 allocs/op
 ```
 
 Using Uber's zap [comparison benchmark](https://github.com/uber-go/zap#performance):

context.go

@@ -12,6 +12,12 @@ func (c Context) Logger() Logger {
 	return c.l
 }
 
+// Fields is a helper function to use a map to set fields using type assertion.
+func (c Context) Fields(fields map[string]interface{}) Context {
+	c.l.context = appendFields(c.l.context, fields)
+	return c
+}
+
 // 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, '}')
@@ -26,12 +32,30 @@ func (c Context) Str(key, val string) Context {
 	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 = appendStrings(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 = appendBytes(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 {
 	c.l.context = appendErrorKey(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 = appendErrorsKey(c.l.context, key, errs)
+	return c
+}
+
 // Err adds the field "error" with err as a string to the logger context.
 // To customize the key name, change zerolog.ErrorFieldName.
 func (c Context) Err(err error) Context {
@@ -39,84 +63,162 @@ func (c Context) Err(err error) Context {
 	return c
 }
 
-// Bool adds the field key with val as a Boolean to the logger context.
+// 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 = appendBool(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 = appendBools(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 = appendInt(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 = appendInts(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 = appendInt8(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 = appendInts8(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 = appendInt16(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 = appendInts16(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 = appendInt32(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 = appendInts32(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 = appendInt64(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 = appendInts64(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 = appendUint(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 = appendUints(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 = appendUint8(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 = appendUints8(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 = appendUint16(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 = appendUints16(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 = appendUint32(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 = appendUints32(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 = appendUint64(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 = appendUints64(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 = appendFloat32(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 = appendFloats32(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 = appendFloat64(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 = appendFloats64(c.l.context, key, f)
+	return c
+}
+
 // 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 {
@@ -134,12 +236,24 @@ func (c Context) Time(key string, t time.Time) Context {
 	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 = appendTimes(c.l.context, key, t)
+	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 = appendDuration(c.l.context, key, d)
 	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 = appendDurations(c.l.context, key, d)
+	return c
+}
+
 // Interface adds the field key with obj marshaled using reflection.
 func (c Context) Interface(key string, i interface{}) Context {
 	c.l.context = appendInterface(c.l.context, key, i)

event.go

@@ -94,6 +94,15 @@ func (e *Event) Msgf(format string, v ...interface{}) {
 	}
 }
 
+// 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 {
+		return e
+	}
+	e.buf = appendFields(e.buf, fields)
+	return e
+}
+
 // 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 {
@@ -121,6 +130,24 @@ func (e *Event) Str(key, val string) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendStrings(e.buf, key, vals)
+	return e
+}
+
+// Bytes adds the field key with val as a []byte to the *Event context.
+func (e *Event) Bytes(key string, val []byte) *Event {
+	if !e.enabled {
+		return e
+	}
+	e.buf = appendBytes(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 {
@@ -131,6 +158,16 @@ func (e *Event) AnErr(key string, err error) *Event {
 	return e
 }
 
+// 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 {
+		return e
+	}
+	e.buf = appendErrorsKey(e.buf, key, errs)
+	return e
+}
+
 // Err adds the field "error" with err as a string to the *Event context.
 // If err is nil, no field is added.
 // To customize the key name, change zerolog.ErrorFieldName.
@@ -142,7 +179,7 @@ func (e *Event) Err(err error) *Event {
 	return e
 }
 
-// Bool adds the field key with val as a Boolean to the *Event context.
+// 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 {
 		return e
@@ -151,6 +188,15 @@ func (e *Event) Bool(key string, b bool) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendBools(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 {
@@ -160,6 +206,15 @@ func (e *Event) Int(key string, i int) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendInts(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 {
@@ -169,6 +224,15 @@ func (e *Event) Int8(key string, i int8) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendInts8(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 {
@@ -178,6 +242,15 @@ func (e *Event) Int16(key string, i int16) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendInts16(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 {
@@ -187,6 +260,15 @@ func (e *Event) Int32(key string, i int32) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendInts32(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 {
@@ -196,6 +278,15 @@ func (e *Event) Int64(key string, i int64) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendInts64(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 {
@@ -205,6 +296,15 @@ func (e *Event) Uint(key string, i uint) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendUints(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 {
@@ -214,6 +314,15 @@ func (e *Event) Uint8(key string, i uint8) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendUints8(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 {
@@ -223,6 +332,15 @@ func (e *Event) Uint16(key string, i uint16) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendUints16(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 {
@@ -232,6 +350,15 @@ func (e *Event) Uint32(key string, i uint32) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendUints32(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 {
@@ -241,6 +368,15 @@ func (e *Event) Uint64(key string, i uint64) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendUints64(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 {
@@ -250,6 +386,15 @@ func (e *Event) Float32(key string, f float32) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendFloats32(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 {
@@ -259,6 +404,15 @@ func (e *Event) Float64(key string, f float64) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendFloats64(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 {
@@ -278,6 +432,15 @@ func (e *Event) Time(key string, t time.Time) *Event {
 	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 {
+		return e
+	}
+	e.buf = appendTimes(e.buf, key, t)
+	return e
+}
+
 // Dur adds the field key with duration d stored as zerolog.DurationFieldUnit.
 // If zerolog.DurationFieldInteger is true, durations are rendered as integer
 // instead of float.
@@ -289,6 +452,17 @@ func (e *Event) Dur(key string, d time.Duration) *Event {
 	return e
 }
 
+// Durs adds the field key with duration d stored as zerolog.DurationFieldUnit.
+// 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 {
+		return e
+	}
+	e.buf = appendDurations(e.buf, key, d)
+	return e
+}
+
 // TimeDiff adds the field key with positive duration between time t and start.
 // If time t is not greater than start, duration will be 0.
 // Duration format follows the same principle as Dur().

field.go

@@ -3,10 +3,98 @@ package zerolog
 import (
 	"encoding/json"
 	"fmt"
+	"sort"
 	"strconv"
 	"time"
 )
 
+func appendFields(dst []byte, fields map[string]interface{}) []byte {
+	keys := make([]string, 0, len(fields))
+	for key, _ := range fields {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+	for _, key := range keys {
+		switch val := fields[key].(type) {
+		case string:
+			dst = appendString(dst, key, val)
+		case []byte:
+			dst = appendBytes(dst, key, val)
+		case error:
+			dst = appendErrorKey(dst, key, val)
+		case []error:
+			dst = appendErrorsKey(dst, key, val)
+		case bool:
+			dst = appendBool(dst, key, val)
+		case int:
+			dst = appendInt(dst, key, val)
+		case int8:
+			dst = appendInt8(dst, key, val)
+		case int16:
+			dst = appendInt16(dst, key, val)
+		case int32:
+			dst = appendInt32(dst, key, val)
+		case int64:
+			dst = appendInt64(dst, key, val)
+		case uint:
+			dst = appendUint(dst, key, val)
+		case uint8:
+			dst = appendUint8(dst, key, val)
+		case uint16:
+			dst = appendUint16(dst, key, val)
+		case uint32:
+			dst = appendUint32(dst, key, val)
+		case uint64:
+			dst = appendUint64(dst, key, val)
+		case float32:
+			dst = appendFloat32(dst, key, val)
+		case float64:
+			dst = appendFloat64(dst, key, val)
+		case time.Time:
+			dst = appendTime(dst, key, val)
+		case time.Duration:
+			dst = appendDuration(dst, key, val)
+		case []string:
+			dst = appendStrings(dst, key, val)
+		case []bool:
+			dst = appendBools(dst, key, val)
+		case []int:
+			dst = appendInts(dst, key, val)
+		case []int8:
+			dst = appendInts8(dst, key, val)
+		case []int16:
+			dst = appendInts16(dst, key, val)
+		case []int32:
+			dst = appendInts32(dst, key, val)
+		case []int64:
+			dst = appendInts64(dst, key, val)
+		case []uint:
+			dst = appendUints(dst, key, val)
+		// case []uint8:
+		// 	dst = appendUints8(dst, key, val)
+		case []uint16:
+			dst = appendUints16(dst, key, val)
+		case []uint32:
+			dst = appendUints32(dst, key, val)
+		case []uint64:
+			dst = appendUints64(dst, key, val)
+		case []float32:
+			dst = appendFloats32(dst, key, val)
+		case []float64:
+			dst = appendFloats64(dst, key, val)
+		case []time.Time:
+			dst = appendTimes(dst, key, val)
+		case []time.Duration:
+			dst = appendDurations(dst, key, val)
+		case nil:
+			dst = append(appendKey(dst, key), "null"...)
+		default:
+			dst = appendInterface(dst, key, val)
+		}
+	}
+	return dst
+}
+
 func appendKey(dst []byte, key string) []byte {
 	if len(dst) > 1 {
 		dst = append(dst, ',')
@@ -19,6 +107,25 @@ func appendString(dst []byte, key, val string) []byte {
 	return appendJSONString(appendKey(dst, key), val)
 }
 
+func appendStrings(dst []byte, key string, vals []string) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = appendJSONString(dst, vals[0])
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = appendJSONString(append(dst, ','), val)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
+func appendBytes(dst []byte, key string, val []byte) []byte {
+	return appendJSONBytes(appendKey(dst, key), val)
+}
+
 func appendErrorKey(dst []byte, key string, err error) []byte {
 	if err == nil {
 		return dst
@@ -26,6 +133,29 @@ func appendErrorKey(dst []byte, key string, err error) []byte {
 	return appendJSONString(appendKey(dst, key), err.Error())
 }
 
+func appendErrorsKey(dst []byte, key string, errs []error) []byte {
+	if len(errs) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	if errs[0] != nil {
+		dst = appendJSONString(dst, errs[0].Error())
+	} else {
+		dst = append(dst, "null"...)
+	}
+	if len(errs) > 1 {
+		for _, err := range errs[1:] {
+			if err == nil {
+				dst = append(dst, ",null"...)
+				continue
+			}
+			dst = appendJSONString(append(dst, ','), err.Error())
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendError(dst []byte, err error) []byte {
 	return appendErrorKey(dst, ErrorFieldName, err)
 }
@@ -34,52 +164,247 @@ func appendBool(dst []byte, key string, val bool) []byte {
 	return strconv.AppendBool(appendKey(dst, key), val)
 }
 
+func appendBools(dst []byte, key string, vals []bool) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendBool(dst, vals[0])
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendBool(append(dst, ','), val)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendInt(dst []byte, key string, val int) []byte {
 	return strconv.AppendInt(appendKey(dst, key), int64(val), 10)
 }
 
+func appendInts(dst []byte, key string, vals []int) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendInt(dst, int64(vals[0]), 10)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendInt(append(dst, ','), int64(val), 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendInt8(dst []byte, key string, val int8) []byte {
 	return strconv.AppendInt(appendKey(dst, key), int64(val), 10)
 }
 
+func appendInts8(dst []byte, key string, vals []int8) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendInt(dst, int64(vals[0]), 10)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendInt(append(dst, ','), int64(val), 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendInt16(dst []byte, key string, val int16) []byte {
 	return strconv.AppendInt(appendKey(dst, key), int64(val), 10)
 }
 
+func appendInts16(dst []byte, key string, vals []int16) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendInt(dst, int64(vals[0]), 10)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendInt(append(dst, ','), int64(val), 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendInt32(dst []byte, key string, val int32) []byte {
 	return strconv.AppendInt(appendKey(dst, key), int64(val), 10)
 }
 
+func appendInts32(dst []byte, key string, vals []int32) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendInt(dst, int64(vals[0]), 10)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendInt(append(dst, ','), int64(val), 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendInt64(dst []byte, key string, val int64) []byte {
-	return strconv.AppendInt(appendKey(dst, key), int64(val), 10)
+	return strconv.AppendInt(appendKey(dst, key), val, 10)
+}
+
+func appendInts64(dst []byte, key string, vals []int64) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendInt(dst, vals[0], 10)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendInt(append(dst, ','), val, 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
 }
 
 func appendUint(dst []byte, key string, val uint) []byte {
 	return strconv.AppendUint(appendKey(dst, key), uint64(val), 10)
 }
 
+func appendUints(dst []byte, key string, vals []uint) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendUint(dst, uint64(vals[0]), 10)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendUint(append(dst, ','), uint64(val), 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendUint8(dst []byte, key string, val uint8) []byte {
 	return strconv.AppendUint(appendKey(dst, key), uint64(val), 10)
 }
 
+func appendUints8(dst []byte, key string, vals []uint8) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendUint(dst, uint64(vals[0]), 10)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendUint(append(dst, ','), uint64(val), 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendUint16(dst []byte, key string, val uint16) []byte {
 	return strconv.AppendUint(appendKey(dst, key), uint64(val), 10)
 }
 
+func appendUints16(dst []byte, key string, vals []uint16) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendUint(dst, uint64(vals[0]), 10)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendUint(append(dst, ','), uint64(val), 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendUint32(dst []byte, key string, val uint32) []byte {
 	return strconv.AppendUint(appendKey(dst, key), uint64(val), 10)
 }
 
+func appendUints32(dst []byte, key string, vals []uint32) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendUint(dst, uint64(vals[0]), 10)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendUint(append(dst, ','), uint64(val), 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendUint64(dst []byte, key string, val uint64) []byte {
 	return strconv.AppendUint(appendKey(dst, key), uint64(val), 10)
 }
 
+func appendUints64(dst []byte, key string, vals []uint64) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendUint(dst, vals[0], 10)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendUint(append(dst, ','), val, 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendFloat32(dst []byte, key string, val float32) []byte {
 	return strconv.AppendFloat(appendKey(dst, key), float64(val), 'f', -1, 32)
 }
 
+func appendFloats32(dst []byte, key string, vals []float32) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendFloat(dst, float64(vals[0]), 'f', -1, 32)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendFloat(append(dst, ','), float64(val), 'f', -1, 32)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendFloat64(dst []byte, key string, val float64) []byte {
-	return strconv.AppendFloat(appendKey(dst, key), float64(val), 'f', -1, 32)
+	return strconv.AppendFloat(appendKey(dst, key), val, 'f', -1, 32)
+}
+
+func appendFloats64(dst []byte, key string, vals []float64) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendFloat(dst, vals[0], 'f', -1, 32)
+	if len(vals) > 1 {
+		for _, val := range vals[1:] {
+			dst = strconv.AppendFloat(append(dst, ','), val, 'f', -1, 32)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
 }
 
 func appendTime(dst []byte, key string, t time.Time) []byte {
@@ -89,6 +414,39 @@ func appendTime(dst []byte, key string, t time.Time) []byte {
 	return append(t.AppendFormat(append(appendKey(dst, key), '"'), TimeFieldFormat), '"')
 }
 
+func appendTimes(dst []byte, key string, vals []time.Time) []byte {
+	if TimeFieldFormat == "" {
+		return appendUnixTimes(dst, key, vals)
+	}
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = append(vals[0].AppendFormat(append(dst, '"'), TimeFieldFormat), '"')
+	if len(vals) > 1 {
+		for _, t := range vals[1:] {
+			dst = append(t.AppendFormat(append(dst, ',', '"'), TimeFieldFormat), '"')
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
+func appendUnixTimes(dst []byte, key string, vals []time.Time) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendInt(dst, vals[0].Unix(), 10)
+	if len(vals) > 1 {
+		for _, t := range vals[1:] {
+			dst = strconv.AppendInt(dst, t.Unix(), 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendTimestamp(dst []byte) []byte {
 	return appendTime(dst, TimestampFieldName, TimestampFunc())
 }
@@ -100,6 +458,39 @@ func appendDuration(dst []byte, key string, d time.Duration) []byte {
 	return appendFloat64(dst, key, float64(d)/float64(DurationFieldUnit))
 }
 
+func appendDurations(dst []byte, key string, vals []time.Duration) []byte {
+	if DurationFieldInteger {
+		return appendIntDurations(dst, key, vals)
+	}
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendFloat(dst, float64(vals[0])/float64(DurationFieldUnit), 'f', -1, 32)
+	if len(vals) > 1 {
+		for _, d := range vals[1:] {
+			dst = strconv.AppendFloat(append(dst, ','), float64(d)/float64(DurationFieldUnit), 'f', -1, 32)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
+func appendIntDurations(dst []byte, key string, vals []time.Duration) []byte {
+	if len(vals) == 0 {
+		return append(appendKey(dst, key), '[', ']')
+	}
+	dst = append(appendKey(dst, key), '[')
+	dst = strconv.AppendInt(dst, int64(vals[0]/DurationFieldUnit), 10)
+	if len(vals) > 1 {
+		for _, d := range vals[1:] {
+			dst = strconv.AppendInt(append(dst, ','), int64(d/DurationFieldUnit), 10)
+		}
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
 func appendInterface(dst []byte, key string, i interface{}) []byte {
 	marshaled, err := json.Marshal(i)
 	if err != nil {

globals.go

@@ -63,5 +63,5 @@ func DisableSampling(v bool) {
 }
 
 func samplingDisabled() bool {
-	return atomic.LoadUint32(gLevel) == 1
+	return atomic.LoadUint32(disableSampling) == 1
 }

hlog/hlog.go

@@ -5,10 +5,12 @@ import (
 	"context"
 	"net"
 	"net/http"
+	"time"
 
 	"github.com/rs/xid"
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
+	"github.com/zenazn/goji/web/mutil"
 )
 
 // FromRequest gets the logger in the request's context.
@@ -152,3 +154,15 @@ func RequestIDHandler(fieldKey, headerName string) func(next http.Handler) http.
 		})
 	}
 }
+
+// AccessHandler returns a handler that call f after each request.
+func AccessHandler(f func(r *http.Request, status, size int, duration time.Duration)) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			start := time.Now()
+			lw := mutil.WrapWriter(w)
+			next.ServeHTTP(lw, r)
+			f(r, lw.Status(), lw.BytesWritten(), time.Since(start))
+		})
+	}
+}

json.go

@@ -21,48 +21,10 @@ func appendJSONString(dst []byte, s string) []byte {
 		// Check if the character needs encoding. Control characters, slashes,
 		// and the double quote need json encoding. Bytes above the ascii
 		// boundary needs utf8 encoding.
-		if s[i] < ' ' || s[i] == '\\' || s[i] == '"' || s[i] > 126 {
-			// We encountered a character that needs to be encoded. Let's
-			// append the previous simple characters to the byte slice
-			// and switch our operation to read and encode the remainder
-			// characters byte-by-byte.
-			dst = append(dst, s[:i]...)
-			for i < len(s) {
-				if b := s[i]; b < utf8.RuneSelf {
-					switch b {
-					case '"', '\\':
-						dst = append(dst, '\\', b)
-					case '\b':
-						dst = append(dst, '\\', 'b')
-					case '\f':
-						dst = append(dst, '\\', 'f')
-					case '\n':
-						dst = append(dst, '\\', 'n')
-					case '\r':
-						dst = append(dst, '\\', 'r')
-					case '\t':
-						dst = append(dst, '\\', 't')
-					default:
-						if b >= 0x20 {
-							dst = append(dst, b)
-						} else {
-							dst = append(dst, '\\', 'u', '0', '0',
-								hex[b>>4], hex[b&0xF])
-						}
-					}
-					i++
-					continue
-				}
-				r, size := utf8.DecodeRuneInString(s[i:])
-				if r == utf8.RuneError && size == 1 {
-					dst = append(dst, `\ufffd`...)
-					i++
-					continue
-				}
-				dst = append(dst, s[i:i+size]...)
-				i += size
-			}
-			// End with a double quote
+		if s[i] < 0x20 || s[i] > 0x7e || s[i] == '\\' || s[i] == '"' {
+			// We encountered a character that needs to be encoded. Switch
+			// to complex version of the algorithm.
+			dst = appendJSONStringComplex(dst, s, i)
 			return append(dst, '"')
 		}
 	}
@@ -72,3 +34,132 @@ func appendJSONString(dst []byte, s string) []byte {
 	// End with a double quote
 	return append(dst, '"')
 }
+
+// appendJSONStringComplex is used by appendJSONString to take over an in
+// progress JSON string encoding that encountered a character that needs
+// to be encoded.
+func appendJSONStringComplex(dst []byte, s string, i int) []byte {
+	start := 0
+	for i < len(s) {
+		b := s[i]
+		if b >= utf8.RuneSelf {
+			r, size := utf8.DecodeRuneInString(s[i:])
+			if r == utf8.RuneError && size == 1 {
+				// In case of error, first append previous simple characters to
+				// the byte slice if any and append a remplacement character code
+				// in place of the invalid sequence.
+				if start < i {
+					dst = append(dst, s[start:i]...)
+				}
+				dst = append(dst, `\ufffd`...)
+				i += size
+				start = i
+				continue
+			}
+			i += size
+			continue
+		}
+		if b >= 0x20 && b <= 0x7e && b != '\\' && b != '"' {
+			i++
+			continue
+		}
+		// We encountered a character that needs to be encoded.
+		// Let's append the previous simple characters to the byte slice
+		// and switch our operation to read and encode the remainder
+		// characters byte-by-byte.
+		if start < i {
+			dst = append(dst, s[start:i]...)
+		}
+		switch b {
+		case '"', '\\':
+			dst = append(dst, '\\', b)
+		case '\b':
+			dst = append(dst, '\\', 'b')
+		case '\f':
+			dst = append(dst, '\\', 'f')
+		case '\n':
+			dst = append(dst, '\\', 'n')
+		case '\r':
+			dst = append(dst, '\\', 'r')
+		case '\t':
+			dst = append(dst, '\\', 't')
+		default:
+			dst = append(dst, '\\', 'u', '0', '0', hex[b>>4], hex[b&0xF])
+		}
+		i++
+		start = i
+	}
+	if start < len(s) {
+		dst = append(dst, s[start:]...)
+	}
+	return dst
+}
+
+// appendJSONBytes is a mirror of appendJSONString with []byte arg
+func appendJSONBytes(dst, s []byte) []byte {
+	dst = append(dst, '"')
+	for i := 0; i < len(s); i++ {
+		if s[i] < 0x20 || s[i] > 0x7e || s[i] == '\\' || s[i] == '"' {
+			dst = appendJSONBytesComplex(dst, s, i)
+			return append(dst, '"')
+		}
+	}
+	dst = append(dst, s...)
+	return append(dst, '"')
+}
+
+// appendJSONBytesComplex is a mirror of the appendJSONStringComplex
+// with []byte arg
+func appendJSONBytesComplex(dst, s []byte, i int) []byte {
+	start := 0
+	for i < len(s) {
+		b := s[i]
+		if b >= utf8.RuneSelf {
+			r, size := utf8.DecodeRune(s[i:])
+			if r == utf8.RuneError && size == 1 {
+				if start < i {
+					dst = append(dst, s[start:i]...)
+				}
+				dst = append(dst, `\ufffd`...)
+				i += size
+				start = i
+				continue
+			}
+			i += size
+			continue
+		}
+		if b >= 0x20 && b <= 0x7e && b != '\\' && b != '"' {
+			i++
+			continue
+		}
+		// We encountered a character that needs to be encoded.
+		// Let's append the previous simple characters to the byte slice
+		// and switch our operation to read and encode the remainder
+		// characters byte-by-byte.
+		if start < i {
+			dst = append(dst, s[start:i]...)
+		}
+		switch b {
+		case '"', '\\':
+			dst = append(dst, '\\', b)
+		case '\b':
+			dst = append(dst, '\\', 'b')
+		case '\f':
+			dst = append(dst, '\\', 'f')
+		case '\n':
+			dst = append(dst, '\\', 'n')
+		case '\r':
+			dst = append(dst, '\\', 'r')
+		case '\t':
+			dst = append(dst, '\\', 't')
+		default:
+			dst = append(dst, '\\', 'u', '0', '0', hex[b>>4], hex[b&0xF])
+		}
+		i++
+		start = i
+	}
+	if start < len(s) {
+		dst = append(dst, s[start:]...)
+	}
+	return dst
+}

json_test.go

@@ -1,49 +1,59 @@
 package zerolog
 
-import "testing"
+import (
+	"testing"
+	"unicode"
+)
+
+var encodeStringTests = []struct {
+	in  string
+	out string
+}{
+	{"", `""`},
+	{"\\", `"\\"`},
+	{"\x00", `"\u0000"`},
+	{"\x01", `"\u0001"`},
+	{"\x02", `"\u0002"`},
+	{"\x03", `"\u0003"`},
+	{"\x04", `"\u0004"`},
+	{"\x05", `"\u0005"`},
+	{"\x06", `"\u0006"`},
+	{"\x07", `"\u0007"`},
+	{"\x08", `"\b"`},
+	{"\x09", `"\t"`},
+	{"\x0a", `"\n"`},
+	{"\x0b", `"\u000b"`},
+	{"\x0c", `"\f"`},
+	{"\x0d", `"\r"`},
+	{"\x0e", `"\u000e"`},
+	{"\x0f", `"\u000f"`},
+	{"\x10", `"\u0010"`},
+	{"\x11", `"\u0011"`},
+	{"\x12", `"\u0012"`},
+	{"\x13", `"\u0013"`},
+	{"\x14", `"\u0014"`},
+	{"\x15", `"\u0015"`},
+	{"\x16", `"\u0016"`},
+	{"\x17", `"\u0017"`},
+	{"\x18", `"\u0018"`},
+	{"\x19", `"\u0019"`},
+	{"\x1a", `"\u001a"`},
+	{"\x1b", `"\u001b"`},
+	{"\x1c", `"\u001c"`},
+	{"\x1d", `"\u001d"`},
+	{"\x1e", `"\u001e"`},
+	{"\x1f", `"\u001f"`},
+	{"✭", `"✭"`},
+	{"foo\xc2\x7fbar", `"foo\ufffd\u007fbar"`}, // invalid sequence
+	{"ascii", `"ascii"`},
+	{"\"a", `"\"a"`},
+	{"\x1fa", `"\u001fa"`},
+	{"foo\"bar\"baz", `"foo\"bar\"baz"`},
+	{"\x1ffoo\x1fbar\x1fbaz", `"\u001ffoo\u001fbar\u001fbaz"`},
+	{"emoji \u2764\ufe0f!", `"emoji ❤️!"`},
+}
 
 func TestAppendJSONString(t *testing.T) {
-	encodeStringTests := []struct {
-		in  string
-		out string
-	}{
-		{"\\", `"\\"`},
-		{"\x00", `"\u0000"`},
-		{"\x01", `"\u0001"`},
-		{"\x02", `"\u0002"`},
-		{"\x03", `"\u0003"`},
-		{"\x04", `"\u0004"`},
-		{"\x05", `"\u0005"`},
-		{"\x06", `"\u0006"`},
-		{"\x07", `"\u0007"`},
-		{"\x08", `"\b"`},
-		{"\x09", `"\t"`},
-		{"\x0a", `"\n"`},
-		{"\x0b", `"\u000b"`},
-		{"\x0c", `"\f"`},
-		{"\x0d", `"\r"`},
-		{"\x0e", `"\u000e"`},
-		{"\x0f", `"\u000f"`},
-		{"\x10", `"\u0010"`},
-		{"\x11", `"\u0011"`},
-		{"\x12", `"\u0012"`},
-		{"\x13", `"\u0013"`},
-		{"\x14", `"\u0014"`},
-		{"\x15", `"\u0015"`},
-		{"\x16", `"\u0016"`},
-		{"\x17", `"\u0017"`},
-		{"\x18", `"\u0018"`},
-		{"\x19", `"\u0019"`},
-		{"\x1a", `"\u001a"`},
-		{"\x1b", `"\u001b"`},
-		{"\x1c", `"\u001c"`},
-		{"\x1d", `"\u001d"`},
-		{"\x1e", `"\u001e"`},
-		{"\x1f", `"\u001f"`},
-		{"ascii", `"ascii"`},
-		{"emoji \u2764\ufe0f!", `"emoji ❤️!"`},
-	}
-
 	for _, tt := range encodeStringTests {
 		b := appendJSONString([]byte{}, tt.in)
 		if got, want := string(b), tt.out; got != want {
@@ -51,3 +61,90 @@ func TestAppendJSONString(t *testing.T) {
 		}
 	}
 }
+
+func TestAppendJSONBytes(t *testing.T) {
+	for _, tt := range encodeStringTests {
+		b := appendJSONBytes([]byte{}, []byte(tt.in))
+		if got, want := string(b), tt.out; got != want {
+			t.Errorf("appendJSONBytes(%q) = %#q, want %#q", tt.in, got, want)
+		}
+	}
+}
+
+func TestStringBytes(t *testing.T) {
+	t.Parallel()
+	// Test that encodeState.stringBytes and encodeState.string use the same encoding.
+	var r []rune
+	for i := '\u0000'; i <= unicode.MaxRune; i++ {
+		r = append(r, i)
+	}
+	s := string(r) + "\xff\xff\xffhello" // some invalid UTF-8 too
+
+	enc := string(appendJSONString([]byte{}, s))
+	encBytes := string(appendJSONBytes([]byte{}, []byte(s)))
+
+	if enc != encBytes {
+		i := 0
+		for i < len(enc) && i < len(encBytes) && enc[i] == encBytes[i] {
+			i++
+		}
+		enc = enc[i:]
+		encBytes = encBytes[i:]
+		i = 0
+		for i < len(enc) && i < len(encBytes) && enc[len(enc)-i-1] == encBytes[len(encBytes)-i-1] {
+			i++
+		}
+		enc = enc[:len(enc)-i]
+		encBytes = encBytes[:len(encBytes)-i]
+
+		if len(enc) > 20 {
+			enc = enc[:20] + "..."
+		}
+		if len(encBytes) > 20 {
+			encBytes = encBytes[:20] + "..."
+		}
+
+		t.Errorf("encodings differ at %#q vs %#q", enc, encBytes)
+	}
+}
+
+func BenchmarkAppendJSONString(b *testing.B) {
+	tests := map[string]string{
+		"NoEncoding":       `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`,
+		"EncodingFirst":    `"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`,
+		"EncodingMiddle":   `aaaaaaaaaaaaaaaaaaaaaaaaa"aaaaaaaaaaaaaaaaaaaaaaaa`,
+		"EncodingLast":     `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"`,
+		"MultiBytesFirst":  `❤️aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`,
+		"MultiBytesMiddle": `aaaaaaaaaaaaaaaaaaaaaaaaa❤️aaaaaaaaaaaaaaaaaaaaaaaa`,
+		"MultiBytesLast":   `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa❤️`,
+	}
+	for name, str := range tests {
+		b.Run(name, func(b *testing.B) {
+			buf := make([]byte, 0, 100)
+			for i := 0; i < b.N; i++ {
+				_ = appendJSONString(buf, str)
+			}
+		})
+	}
+}
+
+func BenchmarkAppendJSONBytes(b *testing.B) {
+	tests := map[string]string{
+		"NoEncoding":       `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`,
+		"EncodingFirst":    `"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`,
+		"EncodingMiddle":   `aaaaaaaaaaaaaaaaaaaaaaaaa"aaaaaaaaaaaaaaaaaaaaaaaa`,
+		"EncodingLast":     `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"`,
+		"MultiBytesFirst":  `❤️aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`,
+		"MultiBytesMiddle": `aaaaaaaaaaaaaaaaaaaaaaaaa❤️aaaaaaaaaaaaaaaaaaaaaaaa`,
+		"MultiBytesLast":   `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa❤️`,
+	}
+	for name, str := range tests {
+		byt := []byte(str)
+		b.Run(name, func(b *testing.B) {
+			buf := make([]byte, 0, 100)
+			for i := 0; i < b.N; i++ {
+				_ = appendJSONBytes(buf, byt)
+			}
+		})
+	}
+}

log.go

@@ -71,6 +71,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"strconv"
 	"sync/atomic"
 )
 
@@ -246,6 +247,30 @@ func (l Logger) Panic() *Event {
 	return l.newEvent(PanicLevel, true, 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 {
+	switch level {
+	case DebugLevel:
+		return l.Debug()
+	case InfoLevel:
+		return l.Info()
+	case WarnLevel:
+		return l.Warn()
+	case ErrorLevel:
+		return l.Error()
+	case FatalLevel:
+		return l.Fatal()
+	case PanicLevel:
+		return l.Panic()
+	case Disabled:
+		return disabledEvent
+	default:
+		panic("zerolog: WithLevel(): invalid level: " + strconv.Itoa(int(level)))
+	}
+}
+
 // Log starts a new message with no level. Setting GlobalLevel to Disabled
 // will still disable events produced by this method.
 //

log_example_test.go

@@ -91,6 +91,15 @@ func ExampleLogger_Error() {
 	// Output: {"level":"error","error":"some error","message":"error doing something"}
 }
 
+func ExampleLogger_WithLevel() {
+	log := zerolog.New(os.Stdout)
+
+	log.WithLevel(zerolog.InfoLevel).
+		Msg("hello world")
+
+	// Output: {"level":"info","message":"hello world"}
+}
+
 func ExampleLogger_Write() {
 	log := zerolog.New(os.Stdout).With().
 		Str("foo", "bar").
@@ -159,6 +168,22 @@ func ExampleEvent_Dur() {
 	// Output: {"foo":"bar","dur":10000,"message":"hello world"}
 }
 
+func ExampleEvent_Durs() {
+	d := []time.Duration{
+		time.Duration(10 * time.Second),
+		time.Duration(20 * time.Second),
+	}
+
+	log := zerolog.New(os.Stdout)
+
+	log.Log().
+		Str("foo", "bar").
+		Durs("durs", d).
+		Msg("hello world")
+
+	// Output: {"foo":"bar","durs":[10000,20000],"message":"hello world"}
+}
+
 func ExampleContext_Dict() {
 	log := zerolog.New(os.Stdout).With().
 		Str("foo", "bar").
@@ -201,3 +226,19 @@ func ExampleContext_Dur() {
 
 	// Output: {"foo":"bar","dur":10000,"message":"hello world"}
 }
+
+func ExampleContext_Durs() {
+	d := []time.Duration{
+		time.Duration(10 * time.Second),
+		time.Duration(20 * time.Second),
+	}
+
+	log := zerolog.New(os.Stdout).With().
+		Str("foo", "bar").
+		Durs("durs", d).
+		Logger()
+
+	log.Log().Msg("hello world")
+
+	// Output: {"foo":"bar","durs":[10000,20000],"message":"hello world"}
+}

log_test.go

@@ -14,7 +14,7 @@ func TestLog(t *testing.T) {
 		log := New(out)
 		log.Log().Msg("")
 		if got, want := out.String(), "{}\n"; got != want {
-			t.Errorf("invalid log output: got %q, want %q", got, want)
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 		}
 	})
 
@@ -23,7 +23,7 @@ func TestLog(t *testing.T) {
 		log := New(out)
 		log.Log().Str("foo", "bar").Msg("")
 		if got, want := out.String(), `{"foo":"bar"}`+"\n"; got != want {
-			t.Errorf("invalid log output: got %q, want %q", got, want)
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 		}
 	})
 
@@ -35,7 +35,7 @@ func TestLog(t *testing.T) {
 			Int("n", 123).
 			Msg("")
 		if got, want := out.String(), `{"foo":"bar","n":123}`+"\n"; got != want {
-			t.Errorf("invalid log output: got %q, want %q", got, want)
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 		}
 	})
 }
@@ -46,7 +46,7 @@ func TestInfo(t *testing.T) {
 		log := New(out)
 		log.Info().Msg("")
 		if got, want := out.String(), `{"level":"info"}`+"\n"; got != want {
-			t.Errorf("invalid log output: got %q, want %q", got, want)
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 		}
 	})
 
@@ -55,7 +55,7 @@ func TestInfo(t *testing.T) {
 		log := New(out)
 		log.Info().Str("foo", "bar").Msg("")
 		if got, want := out.String(), `{"level":"info","foo":"bar"}`+"\n"; got != want {
-			t.Errorf("invalid log output: got %q, want %q", got, want)
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 		}
 	})
 
@@ -67,7 +67,7 @@ func TestInfo(t *testing.T) {
 			Int("n", 123).
 			Msg("")
 		if got, want := out.String(), `{"level":"info","foo":"bar","n":123}`+"\n"; got != want {
-			t.Errorf("invalid log output: got %q, want %q", got, want)
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 		}
 	})
 }
@@ -95,15 +95,46 @@ func TestWith(t *testing.T) {
 		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 {
-		t.Errorf("invalid log output: got %q, want %q", got, want)
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+	}
+}
+
+func TestFieldsMap(t *testing.T) {
+	out := &bytes.Buffer{}
+	log := New(out)
+	log.Log().Fields(map[string]interface{}{
+		"nil":     nil,
+		"string":  "foo",
+		"bytes":   []byte("bar"),
+		"error":   errors.New("some error"),
+		"bool":    true,
+		"int":     int(1),
+		"int8":    int8(2),
+		"int16":   int16(3),
+		"int32":   int32(4),
+		"int64":   int64(5),
+		"uint":    uint(6),
+		"uint8":   uint8(7),
+		"uint16":  uint16(8),
+		"uint32":  uint32(9),
+		"uint64":  uint64(10),
+		"float32": float32(11),
+		"float64": float64(12),
+		"dur":     1 * time.Second,
+		"time":    time.Time{},
+	}).Msg("")
+	if got, want := out.String(), `{"bool":true,"bytes":"bar","dur":1000,"error":"some error","float32":11,"float64":12,"int":1,"int16":3,"int32":4,"int64":5,"int8":2,"nil":null,"string":"foo","time":"0001-01-01T00:00:00Z","uint":6,"uint16":8,"uint32":9,"uint64":10,"uint8":7}`+"\n"; got != want {
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
 
 func TestFields(t *testing.T) {
 	out := &bytes.Buffer{}
 	log := New(out)
+	now := time.Now()
 	log.Log().
-		Str("foo", "bar").
+		Str("string", "foo").
+		Bytes("bytes", []byte("bar")).
 		AnErr("some_err", nil).
 		Err(errors.New("some error")).
 		Bool("bool", true).
@@ -121,18 +152,101 @@ func TestFields(t *testing.T) {
 		Float64("float64", 12).
 		Dur("dur", 1*time.Second).
 		Time("time", time.Time{}).
-		TimeDiff("diff", time.Now(), time.Now().Add(-10*time.Second)).
+		TimeDiff("diff", now, now.Add(-10*time.Second)).
 		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,"dur":1000,"time":"0001-01-01T00:00:00Z","diff":10000}`+"\n"; got != want {
-		t.Errorf("invalid log output: got %q, want %q", got, want)
+	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 {
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+	}
+}
+
+func TestFieldsArrayEmpty(t *testing.T) {
+	out := &bytes.Buffer{}
+	log := New(out)
+	log.Log().
+		Strs("string", []string{}).
+		Errs("err", []error{}).
+		Bools("bool", []bool{}).
+		Ints("int", []int{}).
+		Ints8("int8", []int8{}).
+		Ints16("int16", []int16{}).
+		Ints32("int32", []int32{}).
+		Ints64("int64", []int64{}).
+		Uints("uint", []uint{}).
+		Uints8("uint8", []uint8{}).
+		Uints16("uint16", []uint16{}).
+		Uints32("uint32", []uint32{}).
+		Uints64("uint64", []uint64{}).
+		Floats32("float32", []float32{}).
+		Floats64("float64", []float64{}).
+		Durs("dur", []time.Duration{}).
+		Times("time", []time.Time{}).
+		Msg("")
+	if got, want := out.String(), `{"string":[],"err":[],"bool":[],"int":[],"int8":[],"int16":[],"int32":[],"int64":[],"uint":[],"uint8":[],"uint16":[],"uint32":[],"uint64":[],"float32":[],"float64":[],"dur":[],"time":[]}`+"\n"; got != want {
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+	}
+}
+
+func TestFieldsArraySingleElement(t *testing.T) {
+	out := &bytes.Buffer{}
+	log := New(out)
+	log.Log().
+		Strs("string", []string{"foo"}).
+		Errs("err", []error{errors.New("some error")}).
+		Bools("bool", []bool{true}).
+		Ints("int", []int{1}).
+		Ints8("int8", []int8{2}).
+		Ints16("int16", []int16{3}).
+		Ints32("int32", []int32{4}).
+		Ints64("int64", []int64{5}).
+		Uints("uint", []uint{6}).
+		Uints8("uint8", []uint8{7}).
+		Uints16("uint16", []uint16{8}).
+		Uints32("uint32", []uint32{9}).
+		Uints64("uint64", []uint64{10}).
+		Floats32("float32", []float32{11}).
+		Floats64("float64", []float64{12}).
+		Durs("dur", []time.Duration{1 * time.Second}).
+		Times("time", []time.Time{time.Time{}}).
+		Msg("")
+	if got, want := out.String(), `{"string":["foo"],"err":["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"]}`+"\n"; got != want {
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
+	}
+}
+
+func TestFieldsArrayMultipleElement(t *testing.T) {
+	out := &bytes.Buffer{}
+	log := New(out)
+	log.Log().
+		Strs("string", []string{"foo", "bar"}).
+		Errs("err", []error{errors.New("some error"), nil}).
+		Bools("bool", []bool{true, false}).
+		Ints("int", []int{1, 0}).
+		Ints8("int8", []int8{2, 0}).
+		Ints16("int16", []int16{3, 0}).
+		Ints32("int32", []int32{4, 0}).
+		Ints64("int64", []int64{5, 0}).
+		Uints("uint", []uint{6, 0}).
+		Uints8("uint8", []uint8{7, 0}).
+		Uints16("uint16", []uint16{8, 0}).
+		Uints32("uint32", []uint32{9, 0}).
+		Uints64("uint64", []uint64{10, 0}).
+		Floats32("float32", []float32{11, 0}).
+		Floats64("float64", []float64{12, 0}).
+		Durs("dur", []time.Duration{1 * time.Second, 0}).
+		Times("time", []time.Time{time.Time{}, time.Time{}}).
+		Msg("")
+	if got, want := out.String(), `{"string":["foo","bar"],"err":["some error",null],"bool":[true,false],"int":[1,0],"int8":[2,0],"int16":[3,0],"int32":[4,0],"int64":[5,0],"uint":[6,0],"uint8":[7,0],"uint16":[8,0],"uint32":[9,0],"uint64":[10,0],"float32":[11,0],"float64":[12,0],"dur":[1000,0],"time":["0001-01-01T00:00:00Z","0001-01-01T00:00:00Z"]}`+"\n"; got != want {
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
 
 func TestFieldsDisabled(t *testing.T) {
 	out := &bytes.Buffer{}
 	log := New(out).Level(InfoLevel)
+	now := time.Now()
 	log.Debug().
-		Str("foo", "bar").
+		Str("string", "foo").
+		Bytes("bytes", []byte("bar")).
 		AnErr("some_err", nil).
 		Err(errors.New("some error")).
 		Bool("bool", true).
@@ -150,10 +264,10 @@ func TestFieldsDisabled(t *testing.T) {
 		Float64("float64", 12).
 		Dur("dur", 1*time.Second).
 		Time("time", time.Time{}).
-		TimeDiff("diff", time.Now(), time.Now().Add(-10*time.Second)).
+		TimeDiff("diff", now, now.Add(-10*time.Second)).
 		Msg("")
 	if got, want := out.String(), ""; got != want {
-		t.Errorf("invalid log output: got %q, want %q", got, want)
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
 
@@ -161,7 +275,7 @@ func TestMsgf(t *testing.T) {
 	out := &bytes.Buffer{}
 	New(out).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: got %q, want %q", got, want)
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
 
@@ -170,7 +284,7 @@ func TestWithAndFieldsCombined(t *testing.T) {
 	log := New(out).With().Str("f1", "val").Str("f2", "val").Logger()
 	log.Log().Str("f3", "val").Msg("")
 	if got, want := out.String(), `{"f1":"val","f2":"val","f3":"val"}`+"\n"; got != want {
-		t.Errorf("invalid log output: got %q, want %q", got, want)
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
 
@@ -180,7 +294,7 @@ func TestLevel(t *testing.T) {
 		log := New(out).Level(Disabled)
 		log.Info().Msg("test")
 		if got, want := out.String(), ""; got != want {
-			t.Errorf("invalid log output: got %q, want %q", got, want)
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 		}
 	})
 
@@ -189,7 +303,7 @@ func TestLevel(t *testing.T) {
 		log := New(out).Level(InfoLevel)
 		log.Info().Msg("test")
 		if got, want := out.String(), `{"level":"info","message":"test"}`+"\n"; got != want {
-			t.Errorf("invalid log output: got %q, want %q", got, want)
+			t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 		}
 	})
 }
@@ -202,7 +316,7 @@ func TestSampling(t *testing.T) {
 	log.Log().Int("i", 3).Msg("")
 	log.Log().Int("i", 4).Msg("")
 	if got, want := out.String(), "{\"sample\":2,\"i\":2}\n{\"sample\":2,\"i\":4}\n"; got != want {
-		t.Errorf("invalid log output: got %q, want %q", got, want)
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
 
@@ -237,6 +351,11 @@ func TestLevelWriter(t *testing.T) {
 	log.Info().Msg("2")
 	log.Warn().Msg("3")
 	log.Error().Msg("4")
+	log.WithLevel(DebugLevel).Msg("5")
+	log.WithLevel(InfoLevel).Msg("6")
+	log.WithLevel(WarnLevel).Msg("7")
+	log.WithLevel(ErrorLevel).Msg("8")
+
 	want := []struct {
 		l Level
 		p string
@@ -245,6 +364,10 @@ func TestLevelWriter(t *testing.T) {
 		{InfoLevel, `{"level":"info","message":"2"}` + "\n"},
 		{WarnLevel, `{"level":"warn","message":"3"}` + "\n"},
 		{ErrorLevel, `{"level":"error","message":"4"}` + "\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"},
 	}
 	if got := lw.ops; !reflect.DeepEqual(got, want) {
 		t.Errorf("invalid ops:\ngot:\n%v\nwant:\n%v", got, want)
@@ -263,7 +386,7 @@ func TestContextTimestamp(t *testing.T) {
 	log.Log().Msg("hello world")
 
 	if got, want := out.String(), `{"time":"2001-02-03T04:05:06Z","foo":"bar","message":"hello world"}`+"\n"; got != want {
-		t.Errorf("invalid log output: got %q, want %q", got, want)
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }
 
@@ -279,6 +402,6 @@ func TestEventTimestamp(t *testing.T) {
 	log.Log().Timestamp().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: got %q, want %q", got, want)
+		t.Errorf("invalid log output:\ngot:  %v\nwant: %v", got, want)
 	}
 }