完善 cache 相关内容

pkg/core/backend.go

@@ -0,0 +1,81 @@
+package core
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+
+	"code.d7z.net/d7z-project/gitea-pages/pkg/utils"
+)
+
+type Backend interface {
+	// Repos return repo name + default branch
+	Repos(owner string) (map[string]string, error)
+	// Branches return branch + commit id
+	Branches(owner, repo string) (map[string]string, error)
+	// Open return file or error
+	Open(client *http.Client, owner, repo, commit, path string, headers map[string]string) (*http.Response, error)
+}
+
+type CacheBackend struct {
+	backend Backend
+	config  utils.Config
+	ttl     time.Duration
+}
+
+func NewCacheBackend(backend Backend, config utils.Config, ttl time.Duration) *CacheBackend {
+	return &CacheBackend{backend: backend, config: config, ttl: ttl}
+}
+
+func (c *CacheBackend) Repos(owner string) (map[string]string, error) {
+	ret := make(map[string]string)
+	key := fmt.Sprintf("repos/%s", owner)
+	data, err := c.config.Get(key)
+	if err != nil {
+		ret, err = c.backend.Repos(owner)
+		if err != nil {
+			return nil, err
+		}
+		data, err := json.Marshal(data)
+		if err != nil {
+			return nil, err
+		}
+		if err = c.config.Put(key, string(data), c.ttl); err != nil {
+			return nil, err
+		}
+	} else {
+		if err := json.Unmarshal([]byte(data), &ret); err != nil {
+			return nil, err
+		}
+	}
+	return ret, nil
+}
+
+func (c *CacheBackend) Branches(owner, repo string) (map[string]string, error) {
+	ret := make(map[string]string)
+	key := fmt.Sprintf("branches/%s/%s", owner, repo)
+	data, err := c.config.Get(key)
+	if err != nil {
+		ret, err = c.backend.Branches(owner, repo)
+		if err != nil {
+			return nil, err
+		}
+		data, err := json.Marshal(data)
+		if err != nil {
+			return nil, err
+		}
+		if err = c.config.Put(key, string(data), c.ttl); err != nil {
+			return nil, err
+		}
+	} else {
+		if err := json.Unmarshal([]byte(data), &ret); err != nil {
+			return nil, err
+		}
+	}
+	return ret, nil
+}
+
+func (c *CacheBackend) Open(client *http.Client, owner, repo, commit, path string, headers map[string]string) (*http.Response, error) {
+	return c.backend.Open(client, owner, repo, commit, path, headers)
+}