Add log adapters for testing and log15

Make LogLevel a type for Stringer interface.

log/log15adapter/adapter.go

@@ -0,0 +1,42 @@
+// Package log15adapter provides a logger that writes to a github.com/inconshreveable/log15.Logger
+// log.
+package log15adapter
+
+import (
+	"github.com/jackc/pgx"
+)
+
+// Log15Logger interface defines the subset of
+// github.com/inconshreveable/log15.Logger that this adapter uses.
+type Log15Logger interface {
+	Debug(msg string, ctx ...interface{})
+	Info(msg string, ctx ...interface{})
+	Warn(msg string, ctx ...interface{})
+	Error(msg string, ctx ...interface{})
+	Crit(msg string, ctx ...interface{})
+}
+
+type Logger struct {
+	l Log15Logger
+}
+
+func NewLogger(l Log15Logger) *Logger {
+	return &Logger{l: l}
+}
+
+func (l *Logger) Log(level pgx.LogLevel, msg string, ctx ...interface{}) {
+	switch level {
+	case pgx.LogLevelTrace:
+		l.l.Debug(msg, append(ctx, "PGX_LOG_LEVEL", level)...)
+	case pgx.LogLevelDebug:
+		l.l.Debug(msg, ctx...)
+	case pgx.LogLevelInfo:
+		l.l.Info(msg, ctx...)
+	case pgx.LogLevelWarn:
+		l.l.Warn(msg, ctx...)
+	case pgx.LogLevelError:
+		l.l.Error(msg, ctx...)
+	default:
+		l.l.Error(msg, append(ctx, "INVALID_PGX_LOG_LEVEL", level)...)
+	}
+}

log/testingadapter/adapter.go

@@ -0,0 +1,25 @@
+// Package testingadapter provides a logger that writes to a test or benchmark
+// log.
+package testingadapter
+
+import (
+	"github.com/jackc/pgx"
+)
+
+// TestingLogger interface defines the subset of testing.TB methods used by this
+// adapter.
+type TestingLogger interface {
+	Log(args ...interface{})
+}
+
+type Logger struct {
+	l TestingLogger
+}
+
+func NewLogger(l TestingLogger) *Logger {
+	return &Logger{l: l}
+}
+
+func (l *Logger) Log(level pgx.LogLevel, msg string, ctx ...interface{}) {
+	l.l.Log(level, msg, ctx)
+}