Files
remark42/app/rest/proxy/avatar_store.go
T

146 lines
4.2 KiB
Go

package proxy
//go:generate sh -c "mockery -inpkg -name AvatarStore -print > /tmp/mock.tmp && mv /tmp/mock.tmp avatar_store_mock.go"
import (
"bytes"
"fmt"
"hash/crc64"
"image"
"image/png"
"io"
"log"
"os"
"path"
"strings"
"sync"
// Initializing packages for supporting GIF and JPEG formats.
_ "image/gif"
_ "image/jpeg"
"github.com/pkg/errors"
"golang.org/x/image/draw"
"github.com/umputun/remark/app/store"
)
// AvatarStore defines interface to store and serve avatars
type AvatarStore interface {
Put(userID string, reader io.Reader) (avatar string, err error)
Get(avatar string) (reader io.ReadCloser, size int, err error)
}
// FSAvatarStore implements AvatarStore for local file system
type FSAvatarStore struct {
storePath string
resizeLimit int
ctcTable *crc64.Table
once sync.Once
}
// NewFSAvatarStore makes file-system avatar store
func NewFSAvatarStore(storePath string, resizeLimit int) *FSAvatarStore {
return &FSAvatarStore{storePath: storePath, resizeLimit: resizeLimit}
}
// Put avatar for userID to file and return avatar's file name (base), like 12345678.image
func (fs *FSAvatarStore) Put(userID string, reader io.Reader) (avatar string, err error) {
id := store.EncodeID(userID)
location := fs.location(id) // location adds partition to path
if _, err = os.Stat(location); os.IsNotExist(err) {
if e := os.Mkdir(location, 0700); e != nil {
return "", errors.Wrapf(e, "failed to mkdir avatar location %s", location)
}
}
avFile := path.Join(location, id+imgSfx)
fh, err := os.Create(avFile)
if err != nil {
return "", errors.Wrapf(err, "can't create file %s", avFile)
}
defer func() {
if e := fh.Close(); e != nil {
log.Printf("[WARN] can't close avatar file %s, %s", avFile, e)
}
}()
// Trying to resize avatar.
if reader = resize(reader, fs.resizeLimit); reader == nil {
return "", errors.New("avatar reader is nil")
}
if _, err = io.Copy(fh, reader); err != nil {
return "", errors.Wrapf(err, "can't save file %s", avFile)
}
return id + imgSfx, nil
}
// Get avatar reader for avatar id.image
func (fs *FSAvatarStore) Get(avatar string) (reader io.ReadCloser, size int, err error) {
location := fs.location(strings.TrimSuffix(avatar, imgSfx))
avFile := path.Join(location, avatar)
fh, err := os.Open(avFile)
if err != nil {
return nil, 0, errors.Wrapf(err, "can't load avatar %s, id")
}
if fi, e := fh.Stat(); e == nil {
size = int(fi.Size())
}
return fh, size, nil
}
// get location (directory) for user id by adding partition to final path in order to keep files
// in different subdirectories and avoid too many files in a single place.
// the end result is a full path like this - /tmp/avatars.test/92
func (fs *FSAvatarStore) location(id string) string {
fs.once.Do(func() { fs.ctcTable = crc64.MakeTable(crc64.ECMA) })
checksum64 := crc64.Checksum([]byte(id), fs.ctcTable)
partition := checksum64 % 100
return path.Join(fs.storePath, fmt.Sprintf("%02d", partition))
}
// Resizes an image of supported format (PNG, JPG, GIF) to the size of "limit" px of the biggest side
// (width or height) preserving aspect ratio.
// Returns original reader if resizing is not needed or failed.
func resize(reader io.Reader, limit int) io.Reader {
if reader == nil {
log.Print("[WARN] avatar resize(): reader is nil")
return nil
}
if limit <= 0 {
log.Print("[DEBUG] avatar resize(): limit should be greater than 0")
return reader
}
var teeBuf bytes.Buffer
tee := io.TeeReader(reader, &teeBuf)
src, _, err := image.Decode(tee)
if err != nil {
log.Printf("[WARN] avatar resize(): can't decode avatar image, %s", err)
return &teeBuf
}
bounds := src.Bounds()
w, h := bounds.Dx(), bounds.Dy()
if w <= limit && h <= limit || w <= 0 || h <= 0 {
log.Print("[DEBUG] resizing image is smaller that the limit or has 0 size")
return &teeBuf
}
newW, newH := w*limit/h, limit
if w > h {
newW, newH = limit, h*limit/w
}
m := image.NewRGBA(image.Rect(0, 0, newW, newH))
// Slower than `draw.ApproxBiLinear.Scale()` but better quality.
draw.BiLinear.Scale(m, m.Bounds(), src, src.Bounds(), draw.Src, nil)
var out bytes.Buffer
if err = png.Encode(&out, m); err != nil {
log.Printf("[WARN] avatar resize(): can't encode resized avatar to PNG, %s", err)
return &teeBuf
}
return &out
}