treewide: rename to hakurei

Fortify makes little sense for a container tool.

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

4 files changed, 202 insertions, 0 deletions

diff --git a/internal/hlog/errors.go b/internal/hlog/errors.go
new file mode 100644
index 00000000..d731f57f
--- /dev/null
+++ b/internal/hlog/errors.go
@@ -0,0 +1,81 @@
+package hlog
+
+import (
+	"fmt"
+	"log"
+	"reflect"
+	"strings"
+)
+
+// baseError implements a basic error container
+type baseError struct {
+	Err error
+}
+
+func (e *baseError) Error() string { return e.Err.Error() }
+func (e *baseError) Unwrap() error { return e.Err }
+
+// BaseError implements an error container with a user-facing message
+type BaseError struct {
+	message string
+	baseError
+}
+
+// Message returns a user-facing error message
+func (e *BaseError) Message() string { return e.message }
+
+// WrapErr wraps an error with a corresponding message.
+func WrapErr(err error, a ...any) error {
+	if err == nil {
+		return nil
+	}
+	return wrapErr(err, fmt.Sprintln(a...))
+}
+
+// WrapErrSuffix wraps an error with a corresponding message with err at the end of the message.
+func WrapErrSuffix(err error, a ...any) error {
+	if err == nil {
+		return nil
+	}
+	return wrapErr(err, fmt.Sprintln(append(a, err)...))
+}
+
+// WrapErrFunc wraps an error with a corresponding message returned by f.
+func WrapErrFunc(err error, f func(err error) string) error {
+	if err == nil {
+		return nil
+	}
+	return wrapErr(err, f(err))
+}
+
+func wrapErr(err error, message string) *BaseError {
+	return &BaseError{message, baseError{err}}
+}
+
+var (
+	baseErrorType = reflect.TypeFor[*BaseError]()
+)
+
+func AsBaseError(err error, target **BaseError) bool {
+	v := reflect.ValueOf(err)
+	if !v.CanConvert(baseErrorType) {
+		return false
+	}
+
+	*target = v.Convert(baseErrorType).Interface().(*BaseError)
+	return true
+}
+
+func PrintBaseError(err error, fallback string) {
+	var e *BaseError
+
+	if AsBaseError(err, &e) {
+		if msg := e.Message(); strings.TrimSpace(msg) != "" {
+			log.Print(msg)
+			return
+		}
+		Verbose("*"+fallback, err)
+		return
+	}
+	log.Println(fallback, err)
+}
diff --git a/internal/hlog/hlog.go b/internal/hlog/hlog.go
new file mode 100644
index 00000000..415d16bf
--- /dev/null
+++ b/internal/hlog/hlog.go
@@ -0,0 +1,86 @@
+// Package hlog provides various functions for output messages.
+package hlog
+
+import (
+	"bytes"
+	"io"
+	"log"
+	"os"
+	"sync"
+	"sync/atomic"
+	"syscall"
+)
+
+const (
+	bufSize    = 4 * 1024
+	bufSizeMax = 16 * 1024 * 1024
+)
+
+var o = &suspendable{w: os.Stderr}
+
+// Prepare configures the system logger for [Suspend] and [Resume] to take effect.
+func Prepare(prefix string) { log.SetPrefix(prefix + ": "); log.SetFlags(0); log.SetOutput(o) }
+
+type suspendable struct {
+	w io.Writer
+	s atomic.Bool
+
+	buf     bytes.Buffer
+	bufOnce sync.Once
+	bufMu   sync.Mutex
+	dropped int
+}
+
+func (s *suspendable) Write(p []byte) (n int, err error) {
+	if !s.s.Load() {
+		return s.w.Write(p)
+	}
+	s.bufOnce.Do(func() { s.prepareBuf() })
+
+	s.bufMu.Lock()
+	defer s.bufMu.Unlock()
+
+	if l := len(p); s.buf.Len()+l > bufSizeMax {
+		s.dropped += l
+		return 0, syscall.ENOMEM
+	}
+	return s.buf.Write(p)
+}
+
+func (s *suspendable) prepareBuf()   { s.buf.Grow(bufSize) }
+func (s *suspendable) Suspend() bool { return o.s.CompareAndSwap(false, true) }
+func (s *suspendable) Resume() (resumed bool, dropped uintptr, n int64, err error) {
+	if o.s.CompareAndSwap(true, false) {
+		o.bufMu.Lock()
+		defer o.bufMu.Unlock()
+
+		resumed = true
+		dropped = uintptr(o.dropped)
+
+		o.dropped = 0
+		n, err = io.Copy(s.w, &s.buf)
+		s.buf = bytes.Buffer{}
+		s.prepareBuf()
+	}
+	return
+}
+
+func Suspend() bool { return o.Suspend() }
+func Resume() bool {
+	resumed, dropped, _, err := o.Resume()
+	if err != nil {
+		// probably going to result in an error as well,
+		// so this call is as good as unreachable
+		log.Printf("cannot dump buffer on resume: %v", err)
+	}
+	if resumed && dropped > 0 {
+		log.Fatalf("dropped %d bytes while output is suspended", dropped)
+	}
+	return resumed
+}
+
+func BeforeExit() {
+	if Resume() {
+		log.Printf("beforeExit reached on suspended output")
+	}
+}
diff --git a/internal/hlog/msg.go b/internal/hlog/msg.go
new file mode 100644
index 00000000..dd37fdbf
--- /dev/null
+++ b/internal/hlog/msg.go
@@ -0,0 +1,12 @@
+package hlog
+
+type Output struct{}
+
+func (Output) IsVerbose() bool                         { return Load() }
+func (Output) Verbose(v ...any)                        { Verbose(v...) }
+func (Output) Verbosef(format string, v ...any)        { Verbosef(format, v...) }
+func (Output) WrapErr(err error, a ...any) error       { return WrapErr(err, a...) }
+func (Output) PrintBaseErr(err error, fallback string) { PrintBaseError(err, fallback) }
+func (Output) Suspend()                                { Suspend() }
+func (Output) Resume() bool                            { return Resume() }
+func (Output) BeforeExit()                             { BeforeExit() }
diff --git a/internal/hlog/verbose.go b/internal/hlog/verbose.go
new file mode 100644
index 00000000..d6fcd94d
--- /dev/null
+++ b/internal/hlog/verbose.go
@@ -0,0 +1,23 @@
+package hlog
+
+import (
+	"log"
+	"sync/atomic"
+)
+
+var verbose = new(atomic.Bool)
+
+func Load() bool   { return verbose.Load() }
+func Store(v bool) { verbose.Store(v) }
+
+func Verbosef(format string, v ...any) {
+	if verbose.Load() {
+		log.Printf(format, v...)
+	}
+}
+
+func Verbose(v ...any) {
+	if verbose.Load() {
+		log.Println(v...)
+	}
+}