重构 page

pkg/core/backend_cache.go

@@ -0,0 +1,157 @@
+package core
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"strconv"
+	"time"
+
+	"github.com/pkg/errors"
+	"go.uber.org/zap"
+	"gopkg.d7z.net/gitea-pages/pkg/utils"
+	"gopkg.d7z.net/middleware/cache"
+	"gopkg.d7z.net/middleware/kv"
+	"gopkg.d7z.net/middleware/tools"
+)
+
+type CacheBackend struct {
+	backend     Backend
+	cacheRepo   *tools.Cache[map[string]string]
+	cacheBranch *tools.Cache[map[string]*BranchInfo]
+}
+
+func (c *CacheBackend) Close() error {
+	return c.backend.Close()
+}
+
+func NewCacheBackend(backend Backend, cache kv.KV, ttl time.Duration) *CacheBackend {
+	repoCache := tools.NewCache[map[string]string](cache, "repos", ttl)
+	branchCache := tools.NewCache[map[string]*BranchInfo](cache, "branches", ttl)
+	return &CacheBackend{
+		backend:     backend,
+		cacheRepo:   repoCache,
+		cacheBranch: branchCache,
+	}
+}
+
+func (c *CacheBackend) Repos(ctx context.Context, owner string) (map[string]string, error) {
+	if load, b := c.cacheRepo.Load(ctx, owner); b {
+		return load, nil
+	}
+	ret, err := c.backend.Repos(ctx, owner)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			_ = c.cacheRepo.Store(ctx, owner, map[string]string{})
+		}
+		return nil, err
+	}
+	err = c.cacheRepo.Store(ctx, owner, ret)
+	if len(ret) == 0 {
+		return nil, os.ErrNotExist
+	}
+	return ret, err
+}
+
+func (c *CacheBackend) Branches(ctx context.Context, owner, repo string) (map[string]*BranchInfo, error) {
+	ret := make(map[string]*BranchInfo)
+	key := fmt.Sprintf("%s/%s", owner, repo)
+	if load, b := c.cacheBranch.Load(ctx, key); b {
+		return load, nil
+	}
+	ret, err := c.backend.Branches(ctx, owner, repo)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			_ = c.cacheBranch.Store(ctx, key, map[string]*BranchInfo{})
+		}
+		return nil, err
+	}
+	err = c.cacheBranch.Store(ctx, key, ret)
+	if len(ret) == 0 {
+		return nil, os.ErrNotExist
+	}
+	return ret, err
+}
+
+func (c *CacheBackend) Open(ctx context.Context, client *http.Client, owner, repo, commit, path string, headers http.Header) (*http.Response, error) {
+	return c.backend.Open(ctx, client, owner, repo, commit, path, headers)
+}
+
+type CacheBackendBlobReader struct {
+	client *http.Client
+	cache  cache.Cache
+	base   Backend
+	limit  uint64
+}
+
+func NewCacheBackendBlobReader(
+	client *http.Client,
+	base Backend,
+	cache cache.Cache,
+	limit uint64,
+) *CacheBackendBlobReader {
+	return &CacheBackendBlobReader{client: client, base: base, cache: cache, limit: limit}
+}
+
+func (c *CacheBackendBlobReader) Open(ctx context.Context, owner, repo, commit, path string) (io.ReadCloser, error) {
+	key := fmt.Sprintf("%s/%s/%s/%s", owner, repo, commit, path)
+	lastCache, err := c.cache.Get(ctx, key)
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return nil, err
+	} else if lastCache == nil && err == nil {
+		// 边界缓存
+		return nil, os.ErrNotExist
+	} else if lastCache != nil {
+		return lastCache, nil
+	}
+	open, err := c.base.Open(ctx, c.client, owner, repo, commit, path, http.Header{})
+	if err != nil || open == nil {
+		if open != nil {
+			_ = open.Body.Close()
+		}
+		return nil, err
+	}
+	if open.StatusCode == http.StatusNotFound {
+		// 缓存 404 路由
+		_ = c.cache.Put(ctx, key, nil, time.Hour)
+		_ = open.Body.Close()
+		return nil, os.ErrNotExist
+	}
+
+	lastMod, err := time.Parse(http.TimeFormat, open.Header.Get("Last-Modified"))
+	if err != nil {
+		// 无时间，跳过
+		return open.Body, nil
+	}
+	length, err := strconv.ParseUint(open.Header.Get("Content-Length"), 10, 64)
+	// 无法计算大小，跳过
+	if err != nil {
+		return open.Body, nil
+	}
+	if length > c.limit {
+		// 超过最大大小，跳过
+		return &utils.SizeReadCloser{
+			ReadCloser: open.Body,
+			Size:       length,
+		}, nil
+	}
+
+	defer open.Body.Close()
+	allBytes, err := io.ReadAll(open.Body)
+	if err != nil {
+		return nil, err
+	}
+	if err = c.cache.Put(ctx, key, bytes.NewBuffer(allBytes), time.Hour); err != nil {
+		zap.L().Warn("缓存归档失败", zap.Error(err), zap.Int("Size", len(allBytes)), zap.Uint64("MaxSize", c.limit))
+	}
+	return &cache.Content{
+		ReadSeekCloser: utils.NopCloser{
+			ReadSeeker: bytes.NewReader(allBytes),
+		},
+		LastModified: lastMod,
+		Length:       length,
+	}, nil
+}