20083: Track both loadedPDH and savedPDH for checking local changes.

[arvados.git] / sdk / go / arvados / fs_collection.go

diff --git a/sdk/go/arvados/fs_collection.go b/sdk/go/arvados/fs_collection.go
index 354658a257dba00d54f9d98f9f7c1328e84b7ae2..8e0537730052672d778e12cbbc13edb267e9cb61 100644 (file)
--- a/sdk/go/arvados/fs_collection.go
+++ b/sdk/go/arvados/fs_collection.go
@@ -44,9 +44,17 @@ type CollectionFileSystem interface {
 type collectionFileSystem struct {
        fileSystem
        uuid           string
-       savedPDH       atomic.Value
        replicas       int
        storageClasses []string
+
+       // PDH returned by the server as of last sync/load.
+       loadedPDH atomic.Value
+       // PDH of the locally generated manifest as of last
+       // sync/load. This can differ from loadedPDH after loading a
+       // version that was generated with different code and sorts
+       // filenames differently than we do, for example.
+       savedPDH atomic.Value
+
        // guessSignatureTTL tracks a lower bound for the server's
        // configured BlobSigningTTL. The guess is initially zero, and
        // increases when we come across a signature with an expiry
@@ -74,7 +82,7 @@ func (c *Collection) FileSystem(client apiClient, kc keepClient) (CollectionFile
                        thr:       newThrottle(concurrentWriters),
                },
        }
-       fs.savedPDH.Store(c.PortableDataHash)
+       fs.loadedPDH.Store(c.PortableDataHash)
        if r := c.ReplicationDesired; r != nil {
                fs.replicas = *r
        }
@@ -94,6 +102,13 @@ func (c *Collection) FileSystem(client apiClient, kc keepClient) (CollectionFile
        if err := root.loadManifest(c.ManifestText); err != nil {
                return nil, err
        }
+
+       txt, err := root.marshalManifest(context.Background(), ".")
+       if err != nil {
+               return nil, err
+       }
+       fs.savedPDH.Store(PortableDataHash(txt))
+
        backdateTree(root, modTime)
        fs.root = root
        return fs, nil
@@ -296,7 +311,7 @@ func (fs *collectionFileSystem) Truncate(int64) error {
 // Return value is true if new content was loaded from upstream and
 // any unsaved local changes have been discarded.
 func (fs *collectionFileSystem) checkChangesOnServer(force bool) (bool, error) {
-       if fs.uuid == "" && fs.savedPDH.Load() == "" {
+       if fs.uuid == "" && fs.loadedPDH.Load() == "" {
                return false, nil
        }
 
@@ -316,6 +331,7 @@ func (fs *collectionFileSystem) checkChangesOnServer(force bool) (bool, error) {
                return false, nil
        }
 
+       loadedPDH, _ := fs.loadedPDH.Load().(string)
        getparams := map[string]interface{}{"select": []string{"portable_data_hash", "manifest_text"}}
        if fs.uuid != "" {
                var coll Collection
@@ -323,7 +339,7 @@ func (fs *collectionFileSystem) checkChangesOnServer(force bool) (bool, error) {
                if err != nil {
                        return false, err
                }
-               if coll.PortableDataHash != fs.savedPDH.Load().(string) {
+               if coll.PortableDataHash != loadedPDH {
                        // collection has changed upstream since we
                        // last loaded or saved. Refresh local data,
                        // losing any unsaved local changes.
@@ -339,15 +355,16 @@ func (fs *collectionFileSystem) checkChangesOnServer(force bool) (bool, error) {
                        if err != nil {
                                return false, err
                        }
-                       fs.savedPDH.Store(coll.PortableDataHash)
+                       fs.loadedPDH.Store(coll.PortableDataHash)
+                       fs.savedPDH.Store(newfs.(*collectionFileSystem).savedPDH.Load())
                        return true, nil
                }
                fs.updateSignatures(coll.ManifestText)
                return false, nil
        }
-       if pdh := fs.savedPDH.Load().(string); pdh != "" {
+       if loadedPDH != "" {
                var coll Collection
-               err := fs.RequestAndDecode(&coll, "GET", "arvados/v1/collections/"+pdh, nil, getparams)
+               err := fs.RequestAndDecode(&coll, "GET", "arvados/v1/collections/"+loadedPDH, nil, getparams)
                if err != nil {
                        return false, err
                }
@@ -368,8 +385,9 @@ func (fs *collectionFileSystem) refreshSignature(locator string) string {
                go fs.checkChangesOnServer(false)
                return locator
        }
+       loadedPDH, _ := fs.loadedPDH.Load().(string)
        var manifests string
-       for _, id := range []string{fs.uuid, fs.savedPDH.Load().(string)} {
+       for _, id := range []string{fs.uuid, loadedPDH} {
                if id == "" {
                        continue
                }
@@ -405,7 +423,8 @@ func (fs *collectionFileSystem) Sync() error {
        if err != nil {
                return fmt.Errorf("sync failed: %s", err)
        }
-       if PortableDataHash(txt) == fs.savedPDH.Load() {
+       savingPDH := PortableDataHash(txt)
+       if savingPDH == fs.savedPDH.Load() {
                // No local changes since last save or initial load.
                return nil
        }
@@ -432,7 +451,8 @@ func (fs *collectionFileSystem) Sync() error {
                return fmt.Errorf("sync failed: update %s: %w", fs.uuid, err)
        }
        fs.updateSignatures(coll.ManifestText)
-       fs.savedPDH.Store(coll.PortableDataHash)
+       fs.loadedPDH.Store(coll.PortableDataHash)
+       fs.savedPDH.Store(savingPDH)
        return nil
 }