[filecache] add CacheDir Option, and copy to pkg/ directory (#175)

## Summary

I added an Option to make CacheDir configurable in `filecache`. This
would enable Devbox to continue using the xdg dirs.

I also copied the `filecache` to `pkgs/` directory. Once that is
published, I'll send another PR so `envsec` can reference that and
delete the `envsec/internal/filecache`.

## How was it tested?

`devbox run -c envsec/ build`

Author: savil

.gitignore

@@ -0,0 +1 @@
+*.idea

envsec/internal/filecache/filecache.go

@@ -14,18 +14,39 @@ var NotFound = errors.New("not found")
 var Expired = errors.New("expired")
 
 type cache struct {
-	domain string
-}
-
-func New(domain string) *cache {
-	return &cache{domain: domain}
+	domain   string
+	cacheDir string
 }
 
 type data struct {
 	Val []byte
 	Exp time.Time
 }
 
+type Option func(*cache)
+
+func New(domain string, opts ...Option) *cache {
+	result := &cache{domain: domain}
+
+	var err error
+	result.cacheDir, err = os.UserCacheDir()
+	if err != nil {
+		result.cacheDir = "~/.cache"
+	}
+
+	for _, opt := range opts {
+		opt(result)
+	}
+
+	return result
+}
+
+func WithCacheDir(dir string) Option {
+	return func(c *cache) {
+		c.cacheDir = dir
+	}
+}
+
 func (c *cache) Set(key string, val []byte, dur time.Duration) error {
 	d, err := json.Marshal(data{Val: val, Exp: time.Now().Add(dur)})
 	if err != nil {
@@ -65,11 +86,7 @@ func (c *cache) Get(key string) ([]byte, error) {
 }
 
 func (c *cache) filename(key string) string {
-	cacheDir, err := os.UserCacheDir()
-	if err != nil {
-		cacheDir = "~/.cache"
-	}
-	dir := filepath.Join(cacheDir, c.domain)
+	dir := filepath.Join(c.cacheDir, c.domain)
 	_ = os.MkdirAll(dir, 0755)
 	return filepath.Join(dir, key)
 }

go.work.sum

@@ -1,16 +1,21 @@
+cloud.google.com/go/compute v1.20.1 h1:6aKEtlUiwEpJzM001l0yFkpXmUVXaN8W+fbkb2AZNbg=
 cloud.google.com/go/compute v1.20.1/go.mod h1:4tCnrn48xsqlwSAiLf1HXMQk8CONslYbdiEZc9FEIbM=
 cloud.google.com/go/compute/metadata v0.2.0/go.mod h1:zFmK7XCadkQkj6TtorcaGlCW1hT1fIilQDwofLpJ20k=
+cloud.google.com/go/compute/metadata v0.2.3 h1:mg4jlk7mCAj6xXp9UJ4fjI9VUI5rubuGBW5aJ7UnBMY=
 cloud.google.com/go/compute/metadata v0.2.3/go.mod h1:VAV5nSsACxMJvgaAuX6Pk2AawlZn8kiOGuCv6gTkwuA=
 github.com/BurntSushi/toml v1.2.1/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/CloudyKit/fastprinter v0.0.0-20200109182630-33d98a066a53/go.mod h1:+3IMCy2vIlbG1XG/0ggNQv0SvxCAIpPM5b1nCz56Xno=
 github.com/adrg/xdg v0.4.0 h1:RzRqFcjH4nE5C6oTAxhBtoE2IRyjBSa62SCbyPidvls=
 github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
 github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869/go.mod h1:Ekp36dRnpXw/yCqJaO+ZrUyxD+3VXMFFr56k5XYrpB4=
+github.com/bwesterb/go-ristretto v1.2.3 h1:1w53tCkGhCQ5djbat3+MH0BAQ5Kfgbt56UZQ/JMzngw=
+github.com/bwesterb/go-ristretto v1.2.3/go.mod h1:fUIoIZaG73pV5biE2Blr2xEzDoMj7NFEuV9ekS419A0=
 github.com/cloudflare/ahocorasick v0.0.0-20210425175752-730270c3e184/go.mod h1:tGWUZLZp9ajsxUOnHmFFLnqnlKXsCn6GReG4jAD59H0=
 github.com/cockroachdb/apd v1.1.0 h1:3LFP3629v+1aKXU5Q37mxmRxX/pIu1nijXydLShEq5I=
 github.com/cockroachdb/apd v1.1.0/go.mod h1:8Sl8LxpKi29FqWXR16WEFZRNSz3SoPzUzeMeY4+DwBQ=
 github.com/codegangsta/inject v0.0.0-20150114235600-33e0aa1cb7c0/go.mod h1:4Zcjuz89kmFXt9morQgcfYZAYZ5n8WHjt81YYWIwtTM=
 github.com/cpuguy83/go-md2man/v2 v2.0.2 h1:p1EgwI/C7NhT0JmVkwCD2ZBK8j4aeHQX2pMHHBfMQ6w=
+github.com/creack/pty v1.1.9 h1:uDmaGzcdjhF4i/plgjmEsriH11Y0o7RKapEf/LDaM3w=
 github.com/dop251/goja_nodejs v0.0.0-20210225215109-d91c329300e7 h1:tYwu/z8Y0NkkzGEh3z21mSWggMg4LwLRFucLS7TjARg=
 github.com/eknkc/amber v0.0.0-20171010120322-cdade1c07385/go.mod h1:0vRUJqYpeSZifjYj7uP3BG/gKcuzL9xWVV/Y+cK33KM=
 github.com/fatih/structs v1.1.0/go.mod h1:9NiDSp5zOcgEDl+j00MP/WkGVPOlPRLejGD8Ga6PJ7M=
@@ -44,6 +49,7 @@ github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf
 github.com/schollz/closestmatch v2.1.0+incompatible/go.mod h1:RtP1ddjLong6gTkbtmuhtR2uUrrJOpYzYRvbcPAid+g=
 github.com/sirupsen/logrus v1.9.0/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/stretchr/objx v0.5.0 h1:1zr/of2m5FGMsad5YfcqgdqdWrIhu+EBEJRhR1U7z/c=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
 github.com/urfave/negroni v1.0.0/go.mod h1:Meg73S6kFm/4PpbYdq35yYWoCZ9mS/YSx+lKnmiohz4=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
 github.com/valyala/fasthttp v1.40.0/go.mod h1:t/G+3rLek+CyY9bnIE+YlMRddxVAAGjhxndDB4i4C0I=
@@ -54,13 +60,19 @@ golang.org/x/crypto v0.12.0 h1:tFM/ta59kqch6LlvYnPa0yx5a83cL2nHflFhYKvv9Yk=
 golang.org/x/crypto v0.12.0/go.mod h1:NF0Gs7EO5K4qLn+Ylc+fih8BSTeIjAP05siRnAh98yw=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/mod v0.9.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/mod v0.12.0 h1:rmsUpXtvNzj340zd98LZ4KntptpfRHwpFOHG188oHXc=
 golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
 golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
+golang.org/x/net v0.15.0 h1:ugBLEUaxABaB5AJqW9enI0ACdci2RUd4eP51NTBvuJ8=
+golang.org/x/net v0.15.0/go.mod h1:idbUs1IY1+zTqbi8yxTbhexhEEk5ur9LInksu6HrEpk=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
 golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
 golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.11.0/go.mod h1:zC9APTIj3jG3FdV/Ons+XE1riIZXG4aZ4GTHiPZJPIU=
+golang.org/x/term v0.12.0 h1:/ZfYdc3zq+q02Rv9vGqTeSItdzZTSNDmfTi0mBAuidU=
 golang.org/x/term v0.12.0/go.mod h1:owVbMEjm3cBLCHdkQu9b1opXd4ETQWc3BhuQGKgXgvU=
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
-golang.org/x/tools v0.13.0/go.mod h1:HvlwmtVNQAhOuCjW7xxvovg8wbNq7LwfXh/k7wXUl58=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
+gopkg.in/errgo.v2 v2.1.0 h1:0vLT13EuvQ0hNvakwLuFZ/jYrLp5F3kcWHXdRggjCE8=

pkg/filecache/filecache.go

@@ -0,0 +1,92 @@
+// filecache is a simple local file-based cache
+package filecache
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+var NotFound = errors.New("not found")
+var Expired = errors.New("expired")
+
+type cache struct {
+	domain   string
+	cacheDir string
+}
+
+type data struct {
+	Val []byte
+	Exp time.Time
+}
+
+type Option func(*cache)
+
+func New(domain string, opts ...Option) *cache {
+	result := &cache{domain: domain}
+
+	var err error
+	result.cacheDir, err = os.UserCacheDir()
+	if err != nil {
+		result.cacheDir = "~/.cache"
+	}
+
+	for _, opt := range opts {
+		opt(result)
+	}
+
+	return result
+}
+
+func WithCacheDir(dir string) Option {
+	return func(c *cache) {
+		c.cacheDir = dir
+	}
+}
+
+func (c *cache) Set(key string, val []byte, dur time.Duration) error {
+	d, err := json.Marshal(data{Val: val, Exp: time.Now().Add(dur)})
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	return errors.WithStack(os.WriteFile(c.filename(key), d, 0644))
+}
+
+func (c *cache) SetT(key string, val []byte, t time.Time) error {
+	d, err := json.Marshal(data{Val: val, Exp: t})
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	return errors.WithStack(os.WriteFile(c.filename(key), d, 0644))
+}
+
+func (c *cache) Get(key string) ([]byte, error) {
+	path := c.filename(key)
+	if _, err := os.Stat(path); errors.Is(err, os.ErrNotExist) {
+		return nil, NotFound
+	}
+
+	content, err := os.ReadFile(path)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+	d := data{}
+	if err := json.Unmarshal(content, &d); err != nil {
+		return nil, errors.WithStack(err)
+	}
+	if time.Now().After(d.Exp) {
+		return nil, Expired
+	}
+	return d.Val, nil
+}
+
+func (c *cache) filename(key string) string {
+	dir := filepath.Join(c.cacheDir, c.domain)
+	_ = os.MkdirAll(dir, 0755)
+	return filepath.Join(dir, key)
+}