1 files changed, 151 insertions, 0 deletions
diff --git a/weed/shell/command_remote_cache.go b/weed/shell/command_remote_cache.go
new file mode 100644
index 000000000..a9386ac76
--- /dev/null
+++ b/weed/shell/command_remote_cache.go
@@ -0,0 +1,151 @@
+package shell
+
+import (
+	"flag"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"io"
+	"strings"
+)
+
+func init() {
+	Commands = append(Commands, &commandRemoteCache{})
+}
+
+type commandRemoteCache struct {
+}
+
+func (c *commandRemoteCache) Name() string {
+	return "remote.cache"
+}
+
+func (c *commandRemoteCache) Help() string {
+	return `cache the file content for mounted directories or files
+
+	# assume a remote storage is configured to name "s3_1"
+	remote.configure -name=s3_1 -type=s3 -access_key=xxx -secret_key=yyy
+	# mount and pull one bucket
+	remote.mount -dir=xxx -remote=s3_1/bucket
+
+	# after mount, run one of these command to cache the content of the files
+	remote.cache -dir=xxx
+	remote.cache -dir=xxx/some/sub/dir
+
+`
+}
+
+func (c *commandRemoteCache) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+
+	remoteMountCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
+
+	dir := remoteMountCommand.String("dir", "", "a directory in filer")
+
+	if err = remoteMountCommand.Parse(args); err != nil {
+		return nil
+	}
+
+	mappings, listErr := filer.ReadMountMappings(commandEnv.option.GrpcDialOption, commandEnv.option.FilerAddress)
+	if listErr != nil {
+		return listErr
+	}
+	if *dir == "" {
+		jsonPrintln(writer, mappings)
+		fmt.Fprintln(writer, "need to specify '-dir' option")
+		return nil
+	}
+
+	var localMountedDir string
+	var remoteStorageMountedLocation *filer_pb.RemoteStorageLocation
+	for k, loc := range mappings.Mappings {
+		if strings.HasPrefix(*dir, k) {
+			localMountedDir, remoteStorageMountedLocation = k, loc
+		}
+	}
+	if localMountedDir == "" {
+		jsonPrintln(writer, mappings)
+		fmt.Fprintf(writer, "%s is not mounted\n", *dir)
+		return nil
+	}
+
+	// find remote storage configuration
+	remoteStorageConf, err := filer.ReadRemoteStorageConf(commandEnv.option.GrpcDialOption, commandEnv.option.FilerAddress, remoteStorageMountedLocation.Name)
+	if err != nil {
+		return err
+	}
+
+	// pull content from remote
+	if err = c.cacheContentData(commandEnv, writer, util.FullPath(localMountedDir), remoteStorageMountedLocation, util.FullPath(*dir), remoteStorageConf); err != nil {
+		return fmt.Errorf("cache content data: %v", err)
+	}
+
+	return nil
+}
+
+func recursivelyTraverseDirectory(filerClient filer_pb.FilerClient, dirPath util.FullPath, visitEntry func(dir util.FullPath, entry *filer_pb.Entry) bool) (err error) {
+
+	err = filer_pb.ReadDirAllEntries(filerClient, dirPath, "", func(entry *filer_pb.Entry, isLast bool) error {
+		if entry.IsDirectory {
+			if !visitEntry(dirPath, entry) {
+				return nil
+			}
+			subDir := dirPath.Child(entry.Name)
+			if err := recursivelyTraverseDirectory(filerClient, subDir, visitEntry); err != nil {
+				return err
+			}
+		}else {
+			if !visitEntry(dirPath, entry) {
+				return nil
+			}
+		}
+		return nil
+	})
+	return
+}
+
+func shouldCacheToLocal(entry *filer_pb.Entry) bool {
+	if entry.IsDirectory {
+		return false
+	}
+	if entry.RemoteEntry == nil {
+		return false
+	}
+	if entry.RemoteEntry.LocalMtime == 0 && entry.RemoteEntry.RemoteSize > 0 {
+		return true
+	}
+	return false
+}
+
+func mayHaveCachedToLocal(entry *filer_pb.Entry) bool {
+	if entry.IsDirectory {
+		return false
+	}
+	if entry.RemoteEntry == nil {
+		return false
+	}
+	if entry.RemoteEntry.LocalMtime > 0 && len(entry.Chunks) > 0 {
+		return true
+	}
+	return false
+}
+
+func (c *commandRemoteCache) cacheContentData(commandEnv *CommandEnv, writer io.Writer, localMountedDir util.FullPath, remoteMountedLocation *filer_pb.RemoteStorageLocation, dirToCache util.FullPath, remoteConf *filer_pb.RemoteConf) error {
+
+	return recursivelyTraverseDirectory(commandEnv, dirToCache, func(dir util.FullPath, entry *filer_pb.Entry) bool {
+		if !shouldCacheToLocal(entry) {
+			return true // true means recursive traversal should continue
+		}
+
+		println(dir, entry.Name)
+
+		remoteLocation := filer.MapFullPathToRemoteStorageLocation(localMountedDir, remoteMountedLocation, dir.Child(entry.Name))
+
+		if err := filer.DownloadToLocal(commandEnv, remoteConf, remoteLocation, dir, entry); err != nil {
+			fmt.Fprintf(writer, "DownloadToLocal %+v: %v\n", remoteLocation, err)
+			return false
+		}
+
+		return true
+	})
+}