micro-config-file/file.go
Vasiliy Tolstov 6b27204711
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add text transform support
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2024-04-17 14:57:30 +03:00

346 lines
7.1 KiB
Go

package file // import "go.unistack.org/micro-config-file/v3"
import (
"context"
"fmt"
"io"
"os"
"regexp"
"dario.cat/mergo"
"go.unistack.org/micro/v3/codec"
"go.unistack.org/micro/v3/config"
rutil "go.unistack.org/micro/v3/util/reflect"
"golang.org/x/text/transform"
)
var DefaultStructTag = "file"
type fileConfig struct {
opts config.Options
path string
reader io.Reader
transformer transform.Transformer
}
func (c *fileConfig) Options() config.Options {
return c.opts
}
func (c *fileConfig) Init(opts ...config.Option) error {
if err := config.DefaultBeforeInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
return err
}
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 v, ok := c.opts.Context.Value(transformerKey{}).(transform.Transformer); ok {
c.transformer = v
}
if v, ok := c.opts.Context.Value(readerKey{}).(io.Reader); ok {
c.reader = v
}
}
if c.opts.Codec == nil {
return fmt.Errorf("Codec must be specified")
}
if c.path == "" && c.reader == nil {
err := fmt.Errorf("Path or Reader must be specified")
if !c.opts.AllowFail {
return err
}
}
if err := config.DefaultAfterInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
return err
}
return nil
}
func (c *fileConfig) Load(ctx context.Context, opts ...config.LoadOption) error {
if c.opts.SkipLoad != nil && c.opts.SkipLoad(ctx, c) {
return nil
}
if err := config.DefaultBeforeLoad(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
path := c.path
options := config.NewLoadOptions(opts...)
if options.Context != nil {
if v, ok := options.Context.Value(pathKey{}).(string); ok && v != "" {
path = v
}
}
var fp io.Reader
var err error
if c.path != "" {
fp, err = os.OpenFile(path, os.O_RDONLY, os.FileMode(0o400))
} else if c.reader != nil {
fp = c.reader
} else {
err = fmt.Errorf("Path or Reader must be specified")
}
if err != nil {
if !c.opts.AllowFail {
if c.path != "" {
return fmt.Errorf("file load path %s error: %w", path, err)
} else {
return fmt.Errorf("file load error: %w", err)
}
}
if err = config.DefaultAfterLoad(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
return nil
}
if fpc, ok := fp.(io.Closer); ok {
defer fpc.Close()
}
var r io.Reader
if c.transformer != nil {
r = transform.NewReader(fp, c.transformer)
} else {
r = fp
}
buf, err := io.ReadAll(io.LimitReader(r, int64(codec.DefaultMaxMsgSize)))
if err != nil {
if !c.opts.AllowFail {
return err
}
if err = config.DefaultAfterLoad(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
return nil
}
dst := c.opts.Struct
if options.Struct != nil {
dst = options.Struct
}
src, err := rutil.Zero(dst)
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(dst, src, mopts...)
}
}
if err != nil && !c.opts.AllowFail {
return err
}
if err := config.DefaultAfterLoad(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
return nil
}
func (c *fileConfig) Save(ctx context.Context, opts ...config.SaveOption) error {
if c.opts.SkipSave != nil && c.opts.SkipSave(ctx, c) {
return nil
}
if err := config.DefaultBeforeSave(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
path := c.path
options := config.NewSaveOptions(opts...)
if options.Context != nil {
if v, ok := options.Context.Value(pathKey{}).(string); ok && v != "" {
path = v
}
}
dst := c.opts.Struct
if options.Struct != nil {
dst = options.Struct
}
buf, err := c.opts.Codec.Marshal(dst)
if err != nil {
if !c.opts.AllowFail {
return err
}
if err = config.DefaultAfterSave(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
return nil
}
fp, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE, os.FileMode(0o600))
if err != nil {
if !c.opts.AllowFail {
return err
}
if err = config.DefaultAfterSave(ctx, c); err != nil && !c.opts.AllowFail {
return err
}
return nil
}
defer fp.Close()
if _, err = fp.Write(buf); err == nil {
err = fp.Close()
}
if err != nil && !c.opts.AllowFail {
return err
}
if err := config.DefaultAfterSave(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) {
path := c.path
options := config.NewWatchOptions(opts...)
if options.Context != nil {
if v, ok := options.Context.Value(pathKey{}).(string); ok && v != "" {
path = v
}
}
w := &fileWatcher{
path: 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}
}
type EnvTransformer struct {
maxMatchSize int
Regexp *regexp.Regexp
TransformerFunc TransformerFunc
overflow []byte
}
var _ transform.Transformer = (*EnvTransformer)(nil)
// Transform implements golang.org/x/text/transform#Transformer
func (t *EnvTransformer) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
t.maxMatchSize = 1024
var n int
// copy any overflow from the last call
if len(t.overflow) > 0 {
n, err = fullcopy(dst, t.overflow)
nDst += n
if err != nil {
t.overflow = t.overflow[n:]
return
}
t.overflow = nil
}
for _, index := range t.Regexp.FindAllSubmatchIndex(src, -1) {
// copy everything up to the match
n, err = fullcopy(dst[nDst:], src[nSrc:index[0]])
nSrc += n
nDst += n
if err != nil {
return
}
// skip the match if it ends at the end the src buffer.
// it could potentially match more
if index[1] == len(src) && !atEOF {
break
}
// copy the replacement
rep := t.TransformerFunc(src, index)
n, err = fullcopy(dst[nDst:], rep)
nDst += n
nSrc = index[1]
if err != nil {
t.overflow = rep[n:]
return
}
}
// if we're at the end, tack on any remaining bytes
if atEOF {
n, err = fullcopy(dst[nDst:], src[nSrc:])
nDst += n
nSrc += n
return
}
// skip any bytes which exceede the max match size
if skip := len(src[nSrc:]) - t.maxMatchSize; skip > 0 {
n, err = fullcopy(dst[nDst:], src[nSrc:nSrc+skip])
nSrc += n
nDst += n
if err != nil {
return
}
}
err = transform.ErrShortSrc
return
}
// Reset resets the state and allows a Transformer to be reused.
func (t *EnvTransformer) Reset() {
t.overflow = nil
}
func fullcopy(dst, src []byte) (n int, err error) {
n = copy(dst, src)
if n < len(src) {
err = transform.ErrShortDst
}
return
}