micro-config-file/file.go
Vasiliy Tolstov 0112c44d7d config: minor changes to split config and watcher files
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2021-08-04 15:04:18 +03:00

159 lines
3.3 KiB
Go

package file
import (
"context"
"fmt"
"io"
"io/ioutil"
"os"
"github.com/imdario/mergo"
"github.com/unistack-org/micro/v3/codec"
"github.com/unistack-org/micro/v3/config"
rutil "github.com/unistack-org/micro/v3/util/reflect"
)
var (
DefaultStructTag = "file"
)
type fileConfig struct {
opts config.Options
path string
}
func (c *fileConfig) Options() config.Options {
return c.opts
}
func (c *fileConfig) Init(opts ...config.Option) error {
for _, o := range opts {
o(&c.opts)
}
if c.opts.Context != nil {
if v, ok := c.opts.Context.Value(pathKey{}).(string); ok {
c.path = v
}
}
if c.path == "" {
return fmt.Errorf("file path not exists: %v", c.path)
}
return nil
}
func (c *fileConfig) Load(ctx context.Context, opts ...config.LoadOption) error {
for _, fn := range c.opts.BeforeLoad {
if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
}
fp, err := os.OpenFile(c.path, os.O_RDONLY, os.FileMode(0400))
if err != nil && !c.opts.AllowFail {
return fmt.Errorf("failed to open: %s, error: %w", c.path, err)
} else if err == nil {
defer fp.Close()
var buf []byte
buf, err = ioutil.ReadAll(io.LimitReader(fp, int64(codec.DefaultMaxMsgSize)))
if err == nil {
src, err := rutil.Zero(c.opts.Struct)
if err == nil {
err = c.opts.Codec.Unmarshal(buf, src)
if err == nil {
options := config.NewLoadOptions(opts...)
mopts := []func(*mergo.Config){mergo.WithTypeCheck}
if options.Override {
mopts = append(mopts, mergo.WithOverride)
}
if options.Append {
mopts = append(mopts, mergo.WithAppendSlice)
}
err = mergo.Merge(c.opts.Struct, src, mopts...)
}
}
}
if err != nil && !c.opts.AllowFail {
return err
}
}
for _, fn := range c.opts.AfterLoad {
if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
}
return nil
}
func (c *fileConfig) Save(ctx context.Context, opts ...config.SaveOption) error {
for _, fn := range c.opts.BeforeSave {
if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
}
buf, err := c.opts.Codec.Marshal(c.opts.Struct)
if err == nil {
var fp *os.File
fp, err = os.OpenFile(c.path, os.O_RDONLY, os.FileMode(0400))
if err != nil && c.opts.AllowFail {
return nil
} else if err != nil && !c.opts.AllowFail {
return fmt.Errorf("failed to open: %s, error: %w", c.path, err)
}
if _, werr := fp.Write(buf); werr == nil {
err = fp.Close()
} else {
err = werr
}
}
if err != nil && !c.opts.AllowFail {
return err
}
for _, fn := range c.opts.AfterSave {
if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
}
return nil
}
func (c *fileConfig) String() string {
return "file"
}
func (c *fileConfig) Name() string {
return c.opts.Name
}
func (c *fileConfig) Watch(ctx context.Context, opts ...config.WatchOption) (config.Watcher, error) {
w := &fileWatcher{
path: c.path,
opts: c.opts,
wopts: config.NewWatchOptions(opts...),
done: make(chan struct{}),
vchan: make(chan map[string]interface{}),
echan: make(chan error),
}
go w.run()
return w, nil
}
func NewConfig(opts ...config.Option) config.Config {
options := config.NewOptions(opts...)
if len(options.StructTag) == 0 {
options.StructTag = DefaultStructTag
}
return &fileConfig{opts: options}
}