DM-31251: Allow butler.ingest to work with execution butler

doc/changes/DM-31251.misc.rst

@@ -0,0 +1,2 @@
+Add ``split`` transfer mode that can be used when some files are inside the datastore and some files are outside the datastore.
+This is equivalent to using `None` and ``direct`` mode dynamically.

python/lsst/daf/butler/_butler.py

@@ -1516,8 +1516,8 @@ def ingest(self, *datasets: FileDataset, transfer: Optional[str] = "auto", run:
             standardized form.
         transfer : `str`, optional
             If not `None`, must be one of 'auto', 'move', 'copy', 'direct',
-            'hardlink', 'relsymlink' or 'symlink', indicating how to transfer
-            the file.
+            'split', 'hardlink', 'relsymlink' or 'symlink', indicating how to
+            transfer the file.
         run : `str`, optional
             The name of the run ingested datasets should be added to,
             overriding ``self.run``.
@@ -1568,16 +1568,49 @@ def ingest(self, *datasets: FileDataset, transfer: Optional[str] = "auto", run:
             # This list intentionally shared across the inner loop, since it's
             # associated with `dataset`.
             resolvedRefs: List[DatasetRef] = []
+
+            # Somewhere to store pre-existing refs if we have an
+            # execution butler.
+            existingRefs: List[DatasetRef] = []
+
             for ref in dataset.refs:
                 if ref.dataId in groupedData[ref.datasetType]:
                     raise ConflictingDefinitionError(f"Ingest conflict. Dataset {dataset.path} has same"
                                                      " DataId as other ingest dataset"
                                                      f" {groupedData[ref.datasetType][ref.dataId][0].path} "
                                                      f" ({ref.dataId})")
+                if self._allow_put_of_predefined_dataset:
+                    existing_ref = self.registry.findDataset(ref.datasetType,
+                                                             dataId=ref.dataId,
+                                                             collections=run)
+                    if existing_ref:
+                        if self.datastore.knows(existing_ref):
+                            raise ConflictingDefinitionError(f"Dataset associated with path {dataset.path}"
+                                                             f" already exists as {existing_ref}.")
+                        # Store this ref elsewhere since it already exists
+                        # and we do not want to remake it but we do want
+                        # to store it in the datastore.
+                        existingRefs.append(existing_ref)
+
+                        # Nothing else to do until we have finished
+                        # iterating.
+                        continue
+
                 groupedData[ref.datasetType][ref.dataId] = (dataset, resolvedRefs)
 
+            if existingRefs:
+
+                if len(dataset.refs) != len(existingRefs):
+                    # Keeping track of partially pre-existing datasets is hard
+                    # and should generally never happen. For now don't allow
+                    # it.
+                    raise ConflictingDefinitionError(f"For dataset {dataset.path} some dataIds already exist"
+                                                     " in registry but others do not. This is not supported.")
+
+                # Attach the resolved refs if we found them.
+                dataset.refs = existingRefs
+
         # Now we can bulk-insert into Registry for each DatasetType.
-        allResolvedRefs: List[DatasetRef] = []
         for datasetType, groupForType in progress.iter_item_chunks(groupedData.items(),
                                                                    desc="Bulk-inserting datasets by type"):
             refs = self.registry.insertDatasets(
@@ -1593,13 +1626,11 @@ def ingest(self, *datasets: FileDataset, transfer: Optional[str] = "auto", run:
                 resolvedRefs.append(ref)
 
         # Go back to the original FileDatasets to replace their refs with the
-        # new resolved ones, and also build a big list of all refs.
-        allResolvedRefs = []
+        # new resolved ones.
         for groupForType in progress.iter_chunks(groupedData.values(),
                                                  desc="Reassociating resolved dataset refs with files"):
             for dataset, resolvedRefs in groupForType.values():
                 dataset.refs = resolvedRefs
-                allResolvedRefs.extend(resolvedRefs)
 
         # Bulk-insert everything into Datastore.
         self.datastore.ingest(*datasets, transfer=transfer)

python/lsst/daf/butler/datastores/fileDatastore.py

@@ -723,8 +723,16 @@ def _overrideTransferMode(self, *datasets: FileDataset, transfer: Optional[str]
             # Allow ButlerURI to use its own knowledge
             transfer = "auto"
         else:
-            raise ValueError("Some datasets are inside the datastore and some are outside."
-                             " Please use an explicit transfer mode and not 'auto'.")
+            # This can happen when importing from a datastore that
+            # has had some datasets ingested using "direct" mode.
+            # Also allow ButlerURI to sort it out but warn about it.
+            # This can happen if you are importing from a datastore
+            # that had some direct transfer datasets.
+            log.warning("Some datasets are inside the datastore and some are outside. Using 'split' "
+                        "transfer mode. This assumes that the files outside the datastore are "
+                        "still accessible to the new butler since they will not be copied into "
+                        "the target datastore.")
+            transfer = "split"
 
         return transfer
 
@@ -783,7 +791,7 @@ def _standardizeIngestPath(self, path: Union[str, ButlerURI], *,
         FileNotFoundError
             Raised if one of the given files does not exist.
         """
-        if transfer not in (None, "direct") + self.root.transferModes:
+        if transfer not in (None, "direct", "split") + self.root.transferModes:
             raise NotImplementedError(f"Transfer mode {transfer} not supported.")
 
         # A relative URI indicates relative to datastore root
@@ -852,7 +860,7 @@ def _extractIngestInfo(self, path: Union[str, ButlerURI], ref: DatasetRef, *,
         have_sized = False
 
         tgtLocation: Optional[Location]
-        if transfer is None:
+        if transfer is None or transfer == "split":
             # A relative path is assumed to be relative to the datastore
             # in this context
             if not srcUri.isabs():
@@ -861,10 +869,18 @@ def _extractIngestInfo(self, path: Union[str, ButlerURI], ref: DatasetRef, *,
                 # Work out the path in the datastore from an absolute URI
                 # This is required to be within the datastore.
                 pathInStore = srcUri.relative_to(self.root)
-                if pathInStore is None:
+                if pathInStore is None and transfer is None:
                     raise RuntimeError(f"Unexpectedly learned that {srcUri} is "
                                        f"not within datastore {self.root}")
-                tgtLocation = self.locationFactory.fromPath(pathInStore)
+                if pathInStore:
+                    tgtLocation = self.locationFactory.fromPath(pathInStore)
+                elif transfer == "split":
+                    # Outside the datastore but treat that as a direct ingest
+                    # instead.
+                    tgtLocation = None
+                else:
+                    raise RuntimeError(f"Unexpected transfer mode encountered: {transfer} for"
+                                       f" URI {srcUri}")
         elif transfer == "direct":
             # Want to store the full URI to the resource directly in
             # datastore. This is useful for referring to permanent archive
@@ -1292,6 +1308,11 @@ def getURIs(self, ref: DatasetRef,
                     raise RuntimeError(f"Unexpectedly got no component name for a component at {location}")
                 uri = location.uri
                 if guessing and not uri.exists():
+                    # If we are trusting then it is entirely possible for
+                    # some components to be missing. In that case we skip
+                    # to the next component.
+                    if self.trustGetRequest:
+                        continue
                     raise FileNotFoundError(f"Expected URI ({uri}) does not exist")
                 components[storedFileInfo.component] = uri
 
@@ -1810,7 +1831,7 @@ def transfer_from(self, source_datastore: Datastore, refs: Iterable[DatasetRef],
         # require that the URI inside the source datastore should be stored
         # directly in the target datastore, which seems unlikely to be useful
         # since at any moment the source datastore could delete the file.
-        if transfer == "direct":
+        if transfer in ("direct", "split"):
             raise ValueError("Can not transfer from a source datastore using direct mode since"
                              " those files are controlled by the other datastore.")