From 8bd0664ba002d832f104f5207ef59da490669475 Mon Sep 17 00:00:00 2001
From: Brian Picciano <mediocregopher@gmail.com>
Date: Sat, 15 Jun 2019 17:35:17 -0600
Subject: [PATCH] mlog: refactor to use Components instead of Contexts for
 storing Logger

---
 mlog/cmp.go       | 28 +++++++++++++++++++++++
 mlog/ctx.go       | 58 -----------------------------------------------
 mlog/mlog.go      |  6 ++---
 mlog/mlog_test.go |  2 +-
 4 files changed, 32 insertions(+), 62 deletions(-)
 create mode 100644 mlog/cmp.go
 delete mode 100644 mlog/ctx.go

diff --git a/mlog/cmp.go b/mlog/cmp.go
new file mode 100644
index 0000000..03d3e4f
--- /dev/null
+++ b/mlog/cmp.go
@@ -0,0 +1,28 @@
+package mlog
+
+import (
+	"github.com/mediocregopher/mediocre-go-lib/mcmp"
+)
+
+type cmpKey int
+
+// SetLogger sets the given logger onto the Component. The logger can later be
+// retrieved from the Component, or any of its children, using From.
+func SetLogger(cmp *mcmp.Component, l *Logger) {
+	cmp.SetValue(cmpKey(0), l)
+}
+
+// DefaultLogger is an instance of Logger which is returned by From when a
+// Logger hasn't been previously set with SetLogger on the passed in Component.
+var DefaultLogger = NewLogger()
+
+// From returns the Logger which was set on the Component, or one of its
+// ancestors, using SetLogger. If no Logger was ever set then DefaultLogger is
+// returned.
+func From(cmp *mcmp.Component) *Logger {
+	l, _ := cmp.Value(cmpKey(0)).(*Logger)
+	if l == nil {
+		l = DefaultLogger
+	}
+	return l
+}
diff --git a/mlog/ctx.go b/mlog/ctx.go
deleted file mode 100644
index 8d07a80..0000000
--- a/mlog/ctx.go
+++ /dev/null
@@ -1,58 +0,0 @@
-package mlog
-
-import (
-	"context"
-)
-
-type ctxKey int
-
-// WithLogger returns the Context with the Logger carried by it.
-func WithLogger(ctx context.Context, l *Logger) context.Context {
-	return context.WithValue(ctx, ctxKey(0), l)
-}
-
-// DefaultLogger is an instance of Logger which is returned by From when a
-// Logger hasn't been previously WithLogger on the Contexts passed in.
-var DefaultLogger = NewLogger()
-
-// From looks at each context and returns the Logger from the first Context
-// which carries one via a WithLogger call. If none carry a Logger than
-// DefaultLogger is returned.
-func From(ctxs ...context.Context) *Logger {
-	for _, ctx := range ctxs {
-		if l, _ := ctx.Value(ctxKey(0)).(*Logger); l != nil {
-			return l
-		}
-	}
-	return DefaultLogger
-}
-
-// Debug is a shortcut for
-//	mlog.From(ctxs...).Debug(desc, ctxs...)
-func Debug(descr string, ctxs ...context.Context) {
-	From(ctxs...).Debug(descr, ctxs...)
-}
-
-// Info is a shortcut for
-//	mlog.From(ctxs...).Info(desc, ctxs...)
-func Info(descr string, ctxs ...context.Context) {
-	From(ctxs...).Info(descr, ctxs...)
-}
-
-// Warn is a shortcut for
-//	mlog.From(ctxs...).Warn(desc, ctxs...)
-func Warn(descr string, ctxs ...context.Context) {
-	From(ctxs...).Warn(descr, ctxs...)
-}
-
-// Error is a shortcut for
-//	mlog.From(ctxs...).Error(desc, ctxs...)
-func Error(descr string, ctxs ...context.Context) {
-	From(ctxs...).Error(descr, ctxs...)
-}
-
-// Fatal is a shortcut for
-//	mlog.From(ctxs...).Fatal(desc, ctxs...)
-func Fatal(descr string, ctxs ...context.Context) {
-	From(ctxs...).Fatal(descr, ctxs...)
-}
diff --git a/mlog/mlog.go b/mlog/mlog.go
index f5141e2..5eb9275 100644
--- a/mlog/mlog.go
+++ b/mlog/mlog.go
@@ -107,8 +107,8 @@ type MessageJSON struct {
 	Level       string `json:"level"`
 	Description string `json:"descr"`
 
-	// path -> key -> value
-	Annotations map[string]map[string]string `json:"annotations,omitempty"`
+	// key -> value
+	Annotations map[string]string `json:"annotations,omitempty"`
 }
 
 // DefaultHandler initializes and returns a Handler which will write all
@@ -131,7 +131,7 @@ func defaultHandler(out io.Writer) Handler {
 		}
 		if len(msg.Contexts) > 0 {
 			ctx := mctx.MergeAnnotations(msg.Contexts...)
-			msgJSON.Annotations = mctx.Annotations(ctx).StringMapByPath()
+			msgJSON.Annotations = mctx.Annotations(ctx).StringMap()
 		}
 
 		return enc.Encode(msgJSON)
diff --git a/mlog/mlog_test.go b/mlog/mlog_test.go
index 86aa8bd..cc23be0 100644
--- a/mlog/mlog_test.go
+++ b/mlog/mlog_test.go
@@ -60,7 +60,7 @@ func TestLogger(t *T) {
 	l.Error("buz", mctx.Annotate(ctx, "a", "b", "c", "d"))
 	massert.Require(t,
 		assertOut(`{"level":"WARN","descr":"baz"}`),
-		assertOut(`{"level":"ERROR","descr":"buz","annotations":{"/":{"a":"b","c":"d"}}}`),
+		assertOut(`{"level":"ERROR","descr":"buz","annotations":{"a":"b","c":"d"}}`),
 	)
 
 	l2 := l.Clone()