feat: add independent platform modules and multi-provider storage

config/file.go

@@ -0,0 +1,203 @@
+package config
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"git.yuntuo.hk/k2safe/go-omni/logx"
+	"gopkg.in/yaml.v3"
+	"io"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"sync"
+	"time"
+)
+
+// DecodeFile merges a bounded JSON/YAML document into defaults. It uses JSON
+// field names for both formats, rejects unknown fields and accepts durations
+// such as "3s". Application-specific validation remains with the caller.
+func DecodeFile[T any](path string, defaults T) (T, error) {
+	var zero T
+	f, err := os.Open(path)
+	if err != nil {
+		return zero, err
+	}
+	defer f.Close()
+	data, err := io.ReadAll(io.LimitReader(f, (1<<20)+1))
+	if err != nil {
+		return zero, err
+	}
+	if len(data) > 1<<20 {
+		return zero, errors.New("config: file exceeds 1 MiB")
+	}
+	var value any
+	switch strings.ToLower(filepath.Ext(path)) {
+	case ".yaml", ".yml":
+		dec := yaml.NewDecoder(bytes.NewReader(data))
+		if err := dec.Decode(&value); err != nil {
+			return zero, err
+		}
+		var extra any
+		if err := dec.Decode(&extra); err != io.EOF {
+			return zero, errors.New("config: one YAML document required")
+		}
+	case ".json":
+		dec := json.NewDecoder(bytes.NewReader(data))
+		dec.UseNumber()
+		if err := dec.Decode(&value); err != nil {
+			return zero, err
+		}
+		var extra any
+		if err := dec.Decode(&extra); err != io.EOF {
+			return zero, errors.New("config: one JSON document required")
+		}
+	default:
+		return zero, errors.New("config: expected .json, .yaml or .yml")
+	}
+	if _, ok := value.(map[string]any); !ok {
+		return zero, errors.New("config: root must be an object")
+	}
+	value, err = durations(value, reflect.TypeOf(defaults))
+	if err != nil {
+		return zero, err
+	}
+	encoded, err := json.Marshal(value)
+	if err != nil {
+		return zero, err
+	}
+	// Deep copy defaults so errors cannot partially mutate caller-owned maps.
+	original, err := json.Marshal(defaults)
+	if err != nil {
+		return zero, err
+	}
+	var result T
+	if err = json.Unmarshal(original, &result); err != nil {
+		return zero, err
+	}
+	dec := json.NewDecoder(bytes.NewReader(encoded))
+	dec.DisallowUnknownFields()
+	if err = dec.Decode(&result); err != nil {
+		return zero, err
+	}
+	return result, nil
+}
+func durations(v any, t reflect.Type) (any, error) {
+	if t == nil {
+		return v, nil
+	}
+	for t.Kind() == reflect.Pointer {
+		t = t.Elem()
+	}
+	if t == reflect.TypeOf(time.Duration(0)) {
+		if s, ok := v.(string); ok {
+			d, err := time.ParseDuration(s)
+			return int64(d), err
+		}
+		return v, nil
+	}
+	if t.Kind() == reflect.Struct {
+		if m, ok := v.(map[string]any); ok {
+			for n := 0; n < t.NumField(); n++ {
+				field := t.Field(n)
+				name := strings.Split(field.Tag.Get("json"), ",")[0]
+				if name == "-" {
+					continue
+				}
+				if name == "" {
+					name = field.Name
+				}
+				if item, exists := m[name]; exists {
+					converted, err := durations(item, field.Type)
+					if err != nil {
+						return nil, err
+					}
+					m[name] = converted
+				}
+			}
+		}
+	}
+	if t.Kind() == reflect.Slice {
+		if items, ok := v.([]any); ok {
+			for n, item := range items {
+				converted, err := durations(item, t.Elem())
+				if err != nil {
+					return nil, err
+				}
+				items[n] = converted
+			}
+		}
+	}
+	return v, nil
+}
+func LoadFile(path, prefix string) (Config, error) {
+	cfg, err := DecodeFile(path, Default())
+	if err != nil {
+		return Config{}, err
+	}
+	return applyEnv(cfg, prefix)
+}
+
+// Reloader only accepts log.level changes. Static changes and invalid files
+// leave the current snapshot and logger untouched. Watch does not own a goroutine.
+type Reloader struct {
+	mu           sync.Mutex
+	path, prefix string
+	current      Config
+	logger       *logx.Logger
+}
+
+func NewReloader(path, prefix string, logger *logx.Logger) (*Reloader, error) {
+	cfg, err := LoadFile(path, prefix)
+	if err != nil {
+		return nil, err
+	}
+	if err = logger.SetLevel(cfg.Log.Level); err != nil {
+		return nil, err
+	}
+	return &Reloader{path: path, prefix: prefix, current: cfg, logger: logger}, nil
+}
+func (r *Reloader) Reload() error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	next, err := LoadFile(r.path, r.prefix)
+	if err != nil {
+		return err
+	}
+	comparable := next
+	comparable.Log.Level = r.current.Log.Level
+	if !reflect.DeepEqual(comparable, r.current) {
+		return errors.New("config: static fields changed; restart required")
+	}
+	if err = r.logger.SetLevel(next.Log.Level); err != nil {
+		return err
+	}
+	r.current = next
+	return nil
+}
+func (r *Reloader) Snapshot() Config {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cfg := r.current
+	cfg.TrustedProxies = append([]string(nil), cfg.TrustedProxies...)
+	return cfg
+}
+func (r *Reloader) Watch(ctx context.Context, interval time.Duration, onError func(error)) error {
+	if ctx == nil || interval < 100*time.Millisecond {
+		return errors.New("config: context and interval >=100ms required")
+	}
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case <-ticker.C:
+			if err := r.Reload(); err != nil && onError != nil {
+				onError(err)
+			}
+		}
+	}
+}