deps/outs: get rid of self.info (#4502)

By itself `self.info` is quite confusing, as it is not clear what it is
about. Using `hash_info` makes much more sense and is required to
support alternative hash types.

Related to #4144, #3069, #1676

dvc/cache/base.py

@@ -620,17 +620,16 @@ def merge(self, ancestor_info, our_info, their_info):
         assert their_info
 
         if ancestor_info:
-            ancestor_hash = ancestor_info[self.tree.PARAM_CHECKSUM]
+            ancestor_hash = ancestor_info.value
             ancestor = self.get_dir_cache(ancestor_hash)
         else:
             ancestor = []
 
-        our_hash = our_info[self.tree.PARAM_CHECKSUM]
+        our_hash = our_info.value
         our = self.get_dir_cache(our_hash)
 
-        their_hash = their_info[self.tree.PARAM_CHECKSUM]
+        their_hash = their_info.value
         their = self.get_dir_cache(their_hash)
 
         merged = self._merge_dirs(ancestor, our, their)
-        hash_info = self.tree.save_dir_info(merged)
-        return {hash_info.name: hash_info.value}
+        return self.tree.save_dir_info(merged)

dvc/dependency/param.py

@@ -6,6 +6,7 @@
 
 from dvc.dependency.local import LocalDependency
 from dvc.exceptions import DvcException
+from dvc.hash_info import HashInfo
 from dvc.utils.serialize import LOADERS, ParseError
 
 
@@ -31,7 +32,7 @@ def __init__(self, stage, path, params):
             else:
                 assert isinstance(params, dict)
                 self.params = list(params.keys())
-                info = params
+                info = {self.PARAM_PARAMS: params}
 
         super().__init__(
             stage,
@@ -40,46 +41,48 @@ def __init__(self, stage, path, params):
             info=info,
         )
 
+    def dumpd(self):
+        ret = super().dumpd()
+        if not self.hash_info:
+            ret[self.PARAM_PARAMS] = self.params
+        return ret
+
     def fill_values(self, values=None):
         """Load params values dynamically."""
         if not values:
             return
+        info = {}
         for param in self.params:
             if param in values:
-                self.info[param] = values[param]
+                info[param] = values[param]
+        self.hash_info = HashInfo(self.PARAM_PARAMS, info)
 
-    def save(self):
-        super().save()
-        self.info = self.save_info()
+    def workspace_status(self):
+        status = super().workspace_status()
 
-    def status(self):
-        status = super().status()
-
-        if status[str(self)] == "deleted":
+        if status.get(str(self)) == "deleted":
             return status
 
         status = defaultdict(dict)
-        info = self.read_params()
+        info = self.hash_info.value if self.hash_info else {}
+        actual = self.read_params()
         for param in self.params:
-            if param not in info.keys():
+            if param not in actual.keys():
                 st = "deleted"
-            elif param not in self.info:
+            elif param not in info:
                 st = "new"
-            elif info[param] != self.info[param]:
+            elif actual[param] != info[param]:
                 st = "modified"
             else:
-                assert info[param] == self.info[param]
+                assert actual[param] == info[param]
                 continue
 
             status[str(self)][param] = st
 
         return status
 
-    def dumpd(self):
-        return {
-            self.PARAM_PATH: self.def_path,
-            self.PARAM_PARAMS: self.info or self.params,
-        }
+    def status(self):
+        return self.workspace_status()
 
     def read_params(self):
         if not self.exists:
@@ -102,7 +105,7 @@ def read_params(self):
                 pass
         return ret
 
-    def save_info(self):
+    def get_hash(self):
         info = self.read_params()
 
         missing_params = set(self.params) - set(info.keys())
@@ -113,4 +116,4 @@ def save_info(self):
                 )
             )
 
-        return info
+        return HashInfo(self.PARAM_PARAMS, info)

dvc/dependency/repo.py

@@ -49,12 +49,12 @@ def _make_repo(self, *, locked=True):
         rev = (d.get("rev_lock") if locked else None) or d.get("rev")
         return external_repo(d["url"], rev=rev)
 
-    def _get_checksum(self, locked=True):
+    def _get_hash(self, locked=True):
         from dvc.tree.repo import RepoTree
 
         with self._make_repo(locked=locked) as repo:
             try:
-                return repo.find_out_by_relpath(self.def_path).info["md5"]
+                return repo.find_out_by_relpath(self.def_path).hash_info
             except OutputNotFoundError:
                 path = PathInfo(os.path.join(repo.root_dir, self.def_path))
 
@@ -64,16 +64,14 @@ def _get_checksum(self, locked=True):
 
                 # We are polluting our repo cache with some dir listing here
                 if tree.isdir(path):
-                    return self.repo.cache.local.tree.get_hash(
-                        path, tree=tree
-                    ).value
+                    return self.repo.cache.local.tree.get_hash(path, tree=tree)
                 return tree.get_file_hash(path)
 
     def workspace_status(self):
-        current_checksum = self._get_checksum(locked=True)
-        updated_checksum = self._get_checksum(locked=False)
+        current = self._get_hash(locked=True)
+        updated = self._get_hash(locked=False)
 
-        if current_checksum != updated_checksum:
+        if current != updated:
             return {str(self): "update available"}
 
         return {}

dvc/external_repo.py

@@ -138,23 +138,23 @@ def fetch_external(self, paths: Iterable, **kwargs):
         def download_update(result):
             download_results.append(result)
 
-        save_infos = []
+        hash_infos = []
         for path in paths:
             if not self.repo_tree.exists(path):
                 raise PathMissingError(path, self.url)
-            hash_info = self.repo_tree.save_info(
+            hash_info = self.repo_tree.get_hash(
                 path, download_callback=download_update
-            )
+            ).to_dict()
             self.local_cache.save(
                 path,
                 self.repo_tree,
                 hash_info,
                 save_link=False,
                 download_callback=download_update,
             )
-            save_infos.append(hash_info)
+            hash_infos.append(hash_info)
 
-        return sum(download_results), failed, save_infos
+        return sum(download_results), failed, hash_infos
 
     def get_external(self, path, dest):
         """Convenience wrapper for fetch_external and checkout."""

dvc/hash_info.py

@@ -8,3 +8,13 @@ class HashInfo:
 
     def __bool__(self):
         return bool(self.value)
+
+    @classmethod
+    def from_dict(cls, d):
+        if not d:
+            return cls(None, None)
+        ((name, value),) = d.items()
+        return cls(name, value)
+
+    def to_dict(self):
+        return {self.name: self.value} if self else {}

dvc/output/base.py

@@ -13,6 +13,7 @@
     MergeError,
     RemoteCacheRequiredError,
 )
+from dvc.hash_info import HashInfo
 
 from ..tree.base import BaseTree
 
@@ -113,7 +114,7 @@ def __init__(
         self.stage = stage
         self.repo = stage.repo if stage else None
         self.def_path = path
-        self.info = info
+        self.hash_info = HashInfo.from_dict(info)
         if tree:
             self.tree = tree
         else:
@@ -174,10 +175,13 @@ def cache_path(self):
 
     @property
     def checksum(self):
-        return self.info.get(self.tree.PARAM_CHECKSUM)
+        return self.hash_info.value
 
     def get_checksum(self):
-        return self.tree.get_hash(self.path_info).value
+        return self.get_hash().value
+
+    def get_hash(self):
+        return self.tree.get_hash(self.path_info)
 
     @property
     def is_dir_checksum(self):
@@ -187,9 +191,6 @@ def is_dir_checksum(self):
     def exists(self):
         return self.tree.exists(self.path_info)
 
-    def save_info(self):
-        return self.tree.save_info(self.path_info)
-
     def changed_checksum(self):
         return self.checksum != self.get_checksum()
 
@@ -267,7 +268,7 @@ def save(self):
             self.verify_metric()
 
         if not self.use_cache:
-            self.info = self.save_info()
+            self.hash_info = self.get_hash()
             if not self.IS_DEPENDENCY:
                 logger.debug(
                     "Output '%s' doesn't use cache. Skipping saving.", self
@@ -280,15 +281,17 @@ def save(self):
             logger.debug("Output '%s' didn't change. Skipping saving.", self)
             return
 
-        self.info = self.save_info()
+        self.hash_info = self.get_hash()
 
     def commit(self):
-        assert self.info
+        assert self.hash_info
         if self.use_cache:
-            self.cache.save(self.path_info, self.cache.tree, self.info)
+            self.cache.save(
+                self.path_info, self.cache.tree, self.hash_info.to_dict()
+            )
 
     def dumpd(self):
-        ret = copy(self.info)
+        ret = copy(self.hash_info.to_dict())
         ret[self.PARAM_PATH] = self.def_path
 
         if self.IS_DEPENDENCY:
@@ -337,7 +340,7 @@ def checkout(
 
         return self.cache.checkout(
             self.path_info,
-            self.info,
+            self.hash_info.to_dict(),
             force=force,
             progress_callback=progress_callback,
             relink=relink,
@@ -535,11 +538,13 @@ def merge(self, ancestor, other):
 
         if ancestor:
             self._check_can_merge(ancestor)
-            ancestor_info = ancestor.info
+            ancestor_info = ancestor.hash_info
         else:
             ancestor_info = None
 
         self._check_can_merge(self)
         self._check_can_merge(other)
 
-        self.info = self.cache.merge(ancestor_info, self.info, other.info)
+        self.hash_info = self.cache.merge(
+            ancestor_info, self.hash_info, other.hash_info
+        )

dvc/stage/loader.py

@@ -6,6 +6,7 @@
 from funcy import get_in, lcat, project
 
 from dvc import dependency, output
+from dvc.hash_info import HashInfo
 
 from . import PipelineStage, Stage, loads_from
 from .exceptions import StageNameUnspecified, StageNotFound
@@ -42,9 +43,10 @@ def fill_from_lock(stage, lock_data=None):
             if isinstance(item, dependency.ParamsDependency):
                 item.fill_values(get_in(lock_data, [stage.PARAM_PARAMS, path]))
                 continue
-            item.info = get_in(checksums, [key, path], {})
-            item.info = item.info.copy()
-            item.info.pop("path", None)
+            info = get_in(checksums, [key, path], {})
+            info = info.copy()
+            info.pop("path", None)
+            item.hash_info = HashInfo.from_dict(info)
 
     @classmethod
     def load_stage(cls, dvcfile, name, stage_data, lock_data=None):

dvc/stage/serialize.py

@@ -138,7 +138,12 @@ def to_single_stage_lockfile(stage: "Stage") -> dict:
     params, deps = split_params_deps(stage)
     deps, outs = [
         [
-            OrderedDict([(PARAM_PATH, item.def_path), *item.info.items()])
+            OrderedDict(
+                [
+                    (PARAM_PATH, item.def_path),
+                    *item.hash_info.to_dict().items(),
+                ]
+            )
             for item in sort_by_path(items)
         ]
         for items in [deps, stage.outs]

dvc/tree/base.py

@@ -294,10 +294,6 @@ def path_to_hash(self, path):
 
         return "".join(parts)
 
-    def save_info(self, path_info, **kwargs):
-        hash_info = self.get_hash(path_info, **kwargs)
-        return {hash_info.name: hash_info.value}
-
     def _calculate_hashes(self, file_infos):
         file_infos = list(file_infos)
         with Tqdm(

tests/func/test_add.py

@@ -18,6 +18,7 @@
     OverlappingOutputPathsError,
     RecursiveAddingWhileUsingFilename,
 )
+from dvc.hash_info import HashInfo
 from dvc.main import main
 from dvc.output.base import OutputAlreadyTrackedError, OutputIsStageFileError
 from dvc.repo import Repo as DvcRepo
@@ -42,7 +43,7 @@ def test_add(tmp_dir, dvc):
     assert len(stage.outs) == 1
     assert len(stage.deps) == 0
     assert stage.cmd is None
-    assert stage.outs[0].info["md5"] == md5
+    assert stage.outs[0].hash_info == HashInfo("md5", md5)
     assert stage.md5 is None
 
     assert load_yaml("foo.dvc") == {
@@ -71,7 +72,7 @@ def test_add_directory(tmp_dir, dvc):
     assert len(stage.deps) == 0
     assert len(stage.outs) == 1
 
-    md5 = stage.outs[0].info["md5"]
+    md5 = stage.outs[0].hash_info.value
 
     dir_info = dvc.cache.local.load_dir_cache(md5)
     for info in dir_info:

tests/func/test_run_cache.py

@@ -76,7 +76,7 @@ def test_uncached_outs_are_cached(tmp_dir, dvc, run_copy):
         name="copy-foo-bar",
     )
     with dvc.state:
-        stage.outs[0].info = stage.outs[0].save_info()
+        stage.outs[0].hash_info = stage.outs[0].get_hash()
     assert os.path.exists(relpath(stage.outs[0].cache_path))
 
 

tests/func/test_tree.py

@@ -226,7 +226,7 @@ def test_repotree_cache_save(tmp_dir, dvc, scm, erepo_dir, local_cloud):
         cache = dvc.cache.local
         with cache.tree.state:
             path_info = PathInfo(erepo_dir / "dir")
-            hash_info = cache.tree.save_info(path_info)
+            hash_info = cache.tree.get_hash(path_info).to_dict()
             cache.save(path_info, tree, hash_info)
 
     for hash_ in expected: