Init V4 community edition (#2265)

* Init V4 community edition

* Init V4 community edition

pkg/filemanager/driver/handler.go

@@ -0,0 +1,122 @@
+package driver
+
+import (
+	"context"
+	"os"
+	"time"
+
+	"github.com/cloudreve/Cloudreve/v4/pkg/boolset"
+	"github.com/cloudreve/Cloudreve/v4/pkg/filemanager/fs"
+)
+
+const (
+	// HandlerCapabilityProxyRequired this handler requires Cloudreve's proxy to get file content
+	HandlerCapabilityProxyRequired HandlerCapability = iota
+	// HandlerCapabilityInboundGet this handler supports directly get file's RSCloser, usually
+	// indicates that the file is stored in the same machine as Cloudreve
+	HandlerCapabilityInboundGet
+	// HandlerCapabilityUploadSentinelRequired this handler does not support compliance callback mechanism,
+	// thus it requires Cloudreve's sentinel to guarantee the upload is under control. Cloudreve will try
+	// to delete the placeholder file and cancel the upload session if upload callback is not made after upload
+	// session expire.
+	HandlerCapabilityUploadSentinelRequired
+)
+
+type (
+	MetaType  string
+	MediaMeta struct {
+		Key   string   `json:"key"`
+		Value string   `json:"value"`
+		Type  MetaType `json:"type"`
+	}
+
+	HandlerCapability int
+
+	GetSourceArgs struct {
+		Expire      *time.Time
+		IsDownload  bool
+		Speed       int64
+		DisplayName string
+	}
+
+	// Handler 存储策略适配器
+	Handler interface {
+		// 上传文件, dst为文件存储路径，size 为文件大小。上下文关闭
+		// 时，应取消上传并清理临时文件
+		Put(ctx context.Context, file *fs.UploadRequest) error
+
+		// 删除一个或多个给定路径的文件，返回删除失败的文件路径列表及错误
+		Delete(ctx context.Context, files ...string) ([]string, error)
+
+		// Open physical files. Only implemented if HandlerCapabilityInboundGet capability is set.
+		// Returns file path and an os.File object.
+		Open(ctx context.Context, path string) (*os.File, error)
+
+		// LocalPath returns the local path of a file.
+		// Only implemented if HandlerCapabilityInboundGet capability is set.
+		LocalPath(ctx context.Context, path string) string
+
+		// Thumb returns the URL for a thumbnail of given entity.
+		Thumb(ctx context.Context, expire *time.Time, ext string, e fs.Entity) (string, error)
+
+		// 获取外链/下载地址，
+		// url - 站点本身地址,
+		// isDownload - 是否直接下载
+		Source(ctx context.Context, e fs.Entity, args *GetSourceArgs) (string, error)
+
+		// Token 获取有效期为ttl的上传凭证和签名
+		Token(ctx context.Context, uploadSession *fs.UploadSession, file *fs.UploadRequest) (*fs.UploadCredential, error)
+
+		// CancelToken 取消已经创建的有状态上传凭证
+		CancelToken(ctx context.Context, uploadSession *fs.UploadSession) error
+
+		// CompleteUpload completes a previously created upload session.
+		CompleteUpload(ctx context.Context, session *fs.UploadSession) error
+
+		// List 递归列取远程端path路径下文件、目录，不包含path本身，
+		// 返回的对象路径以path作为起始根目录.
+		// recursive - 是否递归列出
+		// List(ctx context.Context, path string, recursive bool) ([]response.Object, error)
+
+		// Capabilities returns the capabilities of this handler
+		Capabilities() *Capabilities
+
+		// MediaMeta extracts media metadata from the given file.
+		MediaMeta(ctx context.Context, path, ext string) ([]MediaMeta, error)
+	}
+
+	Capabilities struct {
+		StaticFeatures *boolset.BooleanSet
+		// MaxSourceExpire indicates the maximum allowed expiration duration of a source URL
+		MaxSourceExpire time.Duration
+		// MinSourceExpire indicates the minimum allowed expiration duration of a source URL
+		MinSourceExpire time.Duration
+		// MediaMetaSupportedExts indicates the extensions of files that support media metadata. Empty list
+		// indicates that no file supports extracting media metadata.
+		MediaMetaSupportedExts []string
+		// GenerateMediaMeta indicates whether to generate media metadata using local generators.
+		MediaMetaProxy bool
+		// ThumbSupportedExts indicates the extensions of files that support thumbnail generation. Empty list
+		// indicates that no file supports thumbnail generation.
+		ThumbSupportedExts []string
+		// ThumbSupportAllExts indicates whether to generate thumbnails for all files, regardless of their extensions.
+		ThumbSupportAllExts bool
+		// ThumbMaxSize indicates the maximum allowed size of a thumbnail. 0 indicates that no limit is set.
+		ThumbMaxSize int64
+		// ThumbProxy indicates whether to generate thumbnails using local generators.
+		ThumbProxy bool
+	}
+)
+
+const (
+	MetaTypeExif        MetaType = "exif"
+	MediaTypeMusic      MetaType = "music"
+	MetaTypeStreamMedia MetaType = "stream"
+)
+
+type ForceUsePublicEndpointCtx struct{}
+
+// WithForcePublicEndpoint sets the context to force using public endpoint for supported storage policies.
+func WithForcePublicEndpoint(ctx context.Context, value bool) context.Context {
+	return context.WithValue(ctx, ForceUsePublicEndpointCtx{}, value)
+}