more refactoring and README updates

README.md

@@ -37,7 +37,31 @@ in the Ruby Kredis version.
 To enable debug logging, simply call:
 
 ```go
-kredis.SetCommandLogging(true)
+kredis.EnableDebugLogging()
+```
+
+### Failsafe
+
+Kredis wraps calls in Redis in a
+[failsafe](https://github.com/rails/kredis/blob/4fbb2f5613ed049f72cba337317c5eae2a6bba28/lib/kredis/types/proxy/failsafe.rb#L9-L13).
+To match this design, certain functions around reading values
+intentionally omit returning an error and will return zero values when a
+read fails.
+
+If you need to handle errors and do not want the "failsafe" behavior,
+most types also offer functions that end in `Result` that return the
+value and an error using standard Go idioms. For example:
+
+```go
+slot, _ := kredis.NewSlot("slot", 3)
+slot.Reserve()
+
+// some time later when Redis is down...
+
+t := slot.Taken()
+// 0
+t, err := slot.TakenResult() // func TakenResult() (int64, error)
+// 0, dial tcp [::1]:6379: connect: connection refused
 ```
 
 ## Types
@@ -58,7 +82,8 @@ Collection types:
 - [Ordered Set](#ordered-set)
 - [Unique List](#unique-list)
 
-All types accept the following option functions:
+All factory functions for the various types accept the following option
+functions:
 
 - `WithConfigName` sets the Redis config to use. The function accepts a
   `string` name and should match the value passed to `SetConfiguration`.
@@ -414,7 +439,11 @@ uniq.Clear()                      // DEL uniq
 
 - Other scalar types
     - Some sort of map type (serialized as json)
-- Add a way to call `HINCRBY` for `Hash[int]` type
+- `Hash` type
+    - Add a way to call `HINCRBY` (limited to `Hash[int]`)
+- `OrderedSet` type
+    - Let the user control the ranking
+    - Add a `Rank` function to call `ZRANK`
 - Explore support for [pipelining](https://redis.uptrace.dev/guide/go-redis-pipelines.html)
     - With only kredis commands?
     - With a shared redis client?

connections.go

@@ -16,15 +16,6 @@ type config struct {
 
 var configs map[string]*config = map[string]*config{}
 var connections map[string]*redis.Client = map[string]*redis.Client{}
-var connectionLogging bool
-
-func SetCommandLogging(v bool) {
-	connectionLogging = v
-}
-
-// TODO add a way to configure a user provided value that implements the
-// cmdLogging interface
-// func SetCommandLogger(userLogger cmdLogging)
 
 type RedisOption func(*redis.Options)
 
@@ -56,18 +47,18 @@ func getConnection(name string) (*redis.Client, *string, error) {
 	conn = redis.NewClient(config.options)
 	connections[name] = conn
 
-	if connectionLogging {
-		conn.AddHook(newCmdLoggingHook(NewStdoutLogger()))
+	if debugLogger != nil {
+		conn.AddHook(newCmdLoggingHook(debugLogger))
 	}
 
 	return conn, &config.namespace, nil
 }
 
 type cmdLoggingHook struct {
-	cmdLogger cmdLogging
+	cmdLogger logging
 }
 
-func newCmdLoggingHook(clog cmdLogging) *cmdLoggingHook {
+func newCmdLoggingHook(clog logging) *cmdLoggingHook {
 	return &cmdLoggingHook{clog}
 }
 

counter.go

@@ -60,6 +60,7 @@ func (c *Counter) Decrement(by int64) (int64, error) {
 	return decr.Val(), nil
 }
 
+// An empty value returned when there is a Redis error as a failsafe
 func (c *Counter) Value() (v int64) {
 	v, err := c.client.Get(c.ctx, c.key).Int64()
 	if err != nil && err != redis.Nil {

examples/counter/counter.go

@@ -6,7 +6,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	cntr, _ := kredis.NewCounter("counter")
 	cntr.Increment(1)

examples/cycle/cycle.go

@@ -8,7 +8,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	cycle, _ := kredis.NewCycle("cycle", []string{"ready", "set", "go"})
 	cycle.Index()

examples/enum/enum.go

@@ -8,7 +8,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	enum, _ := kredis.NewEnum("enum", "go", []string{"ready", "set", "go"})
 	enum.Is("go")

examples/flag/flag.go

@@ -9,7 +9,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	flag, _ := kredis.NewFlag("flag")
 	fmt.Println(flag.IsMarked())

examples/hash/hash.go

@@ -8,7 +8,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	dogs := map[string]kredis.KredisJSON{
 		"ollie": *kredis.NewKredisJSON(`{"weight":9.72}`),

examples/limiter/limiter.go

@@ -6,7 +6,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	limiter, _ := kredis.NewLimiter("limiter", 5)
 

examples/list/list.go

@@ -8,7 +8,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	l, _ := kredis.NewIntegerList("key")
 	l.Append(1, 2, 3)

examples/main.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/mjc-gh/kredis-go"
+)
+
+func main() {
+	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
+	kredis.EnableDebugLogging()
+
+	slot, err := kredis.NewSlot("slot", 3)
+	if err != nil {
+		panic(err)
+	}
+
+	slot.Reserve()
+	fmt.Println(slot.Taken())
+
+	// some time later when Redis is down...
+	time.Sleep(10 * time.Second)
+
+	fmt.Println(slot.Taken())
+	n, err := slot.TakenResult() // 0,
+	fmt.Println(n, err)
+
+	fmt.Println(err)
+}

examples/ordered_set/ordered_set.go

@@ -8,7 +8,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	oset, _ := kredis.NewStringOrderedSet("ranks", 4)
 	oset.Append("a", "b", "c")

examples/scalars/scalars.go

@@ -9,7 +9,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	k, _ := kredis.NewTime("sessionStart", kredis.WithExpiry("1ms"))
 	_ = k.SetValue(time.Now()) // SET sessionStart

examples/set/set.go

@@ -9,7 +9,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	t := time.Date(2021, 8, 28, 23, 0, 0, 0, time.UTC)
 	times := []time.Time{t, t.Add(1 * time.Hour), t.Add(2 * time.Hour), t.Add(3 * time.Hour)}

examples/slot/slot.go

@@ -4,7 +4,7 @@ import "github.com/mjc-gh/kredis-go"
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	slot, _ := kredis.NewSlot("slot", 3)
 	slot.Reserve()

examples/unique_list/unique_list.go

@@ -8,7 +8,7 @@ import (
 
 func main() {
 	kredis.SetConfiguration("shared", "ns", "redis://localhost:6379/2")
-	kredis.SetCommandLogging(true)
+	kredis.EnableDebugLogging()
 
 	uniq, _ := kredis.NewFloatUniqueList("uniq", 5)
 	uniq.Append(3.14, 2.718)

kredis_test.go

@@ -17,7 +17,7 @@ func (suite *KredisTestSuite) SetupTest() {
 	SetConfiguration("shared", "ns", "redis://localhost:6379/2")
 	SetConfiguration("badconn", "", "redis://localhost:1234/0")
 
-	SetCommandLogging(true)
+	EnableDebugLogging()
 }
 
 func (suite *KredisTestSuite) TearDownTest() {

logging.go

@@ -9,16 +9,30 @@ import (
 	"github.com/redis/go-redis/v9"
 )
 
-type cmdLogging interface {
+type logging interface {
 	Info(redis.Cmder, time.Duration)
+	Warn(string, error)
 }
 
 type stdLogger struct{}
 
-func NewStdoutLogger() stdLogger {
-	return stdLogger{}
+var debugLogger logging
+
+// Enable logging of Redis commands and errors that are ignored by functions
+// with failsafes. This is useful for development and tests. Logging is
+// disabled by default.
+func EnableDebugLogging() {
+	debugLogger = stdLogger{}
+}
+
+// Turn off debug logging.
+func DisableDebugLogging() {
+	debugLogger = nil
 }
 
+// TODO add a way to configure a user provided value that implements the logging interface
+// func SetCommandLogger(userLogger cmdLogging)
+
 func (log stdLogger) Info(cmd redis.Cmder, dur time.Duration) {
 	name, key, args := cmdLogParts(cmd)
 
@@ -31,6 +45,10 @@ func (log stdLogger) Info(cmd redis.Cmder, dur time.Duration) {
 	}
 }
 
+func (log stdLogger) Warn(msg string, err error) {
+
+}
+
 var cmdColor = color.New(color.FgYellow).SprintFunc()
 var keyColor = color.New(color.FgCyan).SprintFunc()
 var argsColor = color.New(color.FgGreen).SprintFunc()

ordered_set.go

@@ -274,10 +274,6 @@ func (s *OrderedSet[T]) SetLimit(limit uint64) {
 	s.limit = limit
 }
 
-// TODO
-//func (s OrderedSet[T]) Rank(member T) int64 {
-//}
-
 func (s *OrderedSet[T]) appendScore(index int) float64 {
 	baseScore := s.baseScore()
 	incrementalScore := float64(index) * 0.000001