message: relocate from container

This package is quite useful. This change allows it to be imported without importing container.

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 0 insertions, 110 deletions

diff --git a/container/msg.go b/container/msg.go
deleted file mode 100644
index 38c38ecd..00000000
--- a/container/msg.go
+++ /dev/null
@@ -1,110 +0,0 @@
-package container
-
-import (
-	"errors"
-	"log"
-	"sync/atomic"
-)
-
-// MessageError is an error with a user-facing message.
-type MessageError interface {
-	// Message returns a user-facing error message.
-	Message() string
-
-	error
-}
-
-// GetErrorMessage returns whether an error implements [MessageError], and the message if it does.
-func GetErrorMessage(err error) (string, bool) {
-	var e MessageError
-	if !errors.As(err, &e) || e == nil {
-		return zeroString, false
-	}
-	return e.Message(), true
-}
-
-// Msg is used for package-wide verbose logging.
-type Msg interface {
-	// GetLogger returns the address of the underlying [log.Logger].
-	GetLogger() *log.Logger
-
-	// IsVerbose atomically loads and returns whether [Msg] has verbose logging enabled.
-	IsVerbose() bool
-	// SwapVerbose atomically stores a new verbose state and returns the previous value held by [Msg].
-	SwapVerbose(verbose bool) bool
-	// Verbose passes its argument to the Println method of the underlying [log.Logger] if IsVerbose returns true.
-	Verbose(v ...any)
-	// Verbosef passes its argument to the Printf method of the underlying [log.Logger] if IsVerbose returns true.
-	Verbosef(format string, v ...any)
-
-	// Suspend causes the embedded [Suspendable] to withhold writes to its downstream [io.Writer].
-	// Suspend returns false and is a noop if called between calls to Suspend and Resume.
-	Suspend() bool
-
-	// Resume dumps the entire buffer held by the embedded [Suspendable] and stops withholding future writes.
-	// Resume returns false and is a noop if a call to Suspend does not precede it.
-	Resume() bool
-
-	// BeforeExit runs implementation-specific cleanup code, and optionally prints warnings.
-	// BeforeExit is called before [os.Exit].
-	BeforeExit()
-}
-
-// defaultMsg is the default implementation of the [Msg] interface.
-// The zero value is not safe for use. Callers should use the [NewMsg] function instead.
-type defaultMsg struct {
-	verbose atomic.Bool
-
-	logger *log.Logger
-	Suspendable
-}
-
-// NewMsg initialises a downstream [log.Logger] for a new [Msg].
-// The [log.Logger] should no longer be configured after NewMsg returns.
-// If downstream is nil, a new logger is initialised in its place.
-func NewMsg(downstream *log.Logger) Msg {
-	if downstream == nil {
-		downstream = log.New(log.Writer(), "container: ", 0)
-	}
-
-	m := defaultMsg{logger: downstream}
-	m.Suspendable.Downstream = downstream.Writer()
-	downstream.SetOutput(&m.Suspendable)
-	return &m
-}
-
-func (msg *defaultMsg) GetLogger() *log.Logger { return msg.logger }
-
-func (msg *defaultMsg) IsVerbose() bool               { return msg.verbose.Load() }
-func (msg *defaultMsg) SwapVerbose(verbose bool) bool { return msg.verbose.Swap(verbose) }
-func (msg *defaultMsg) Verbose(v ...any) {
-	if msg.verbose.Load() {
-		msg.logger.Println(v...)
-	}
-}
-func (msg *defaultMsg) Verbosef(format string, v ...any) {
-	if msg.verbose.Load() {
-		msg.logger.Printf(format, v...)
-	}
-}
-
-// Resume calls [Suspendable.Resume] and prints a message if buffer was filled
-// between calls to [Suspendable.Suspend] and Resume.
-func (msg *defaultMsg) Resume() bool {
-	resumed, dropped, _, err := msg.Suspendable.Resume()
-	if err != nil {
-		// probably going to result in an error as well, so this message is as good as unreachable
-		msg.logger.Printf("cannot dump buffer on resume: %v", err)
-	}
-	if resumed && dropped > 0 {
-		msg.logger.Printf("dropped %d bytes while output is suspended", dropped)
-	}
-	return resumed
-}
-
-// BeforeExit prints a message if called between calls to [Suspendable.Suspend] and Resume.
-func (msg *defaultMsg) BeforeExit() {
-	if msg.Resume() {
-		msg.logger.Printf("beforeExit reached on suspended output")
-	}
-}