Introduce Dataset inheritance from blosc2.Operand

caterva2/client.py

@@ -561,7 +561,7 @@ def remove(self):
         return self.client.remove(self.path)
 
 
-class Dataset(File):
+class Dataset(File, blosc2.Operand):
     def __init__(self, root, path):
         """
         Represents a dataset within a Blosc2 container.
@@ -1292,6 +1292,53 @@ def lazyexpr(self, name, expression, operands=None, compute=False):
         )
         return pathlib.PurePosixPath(dataset)
 
+    def upload_lazyexpr(self, remotepath, expression, compute=False):
+        """
+        Creates a lazy expression dataset.
+
+        A dataset at the specified path will be created or overwritten if already
+        exists.
+
+        Parameters
+        ----------
+        remotepath : str
+            Path to save the lazy expression to.
+        expression : blosc2.LazyExpr
+            Expression to be evaluated.
+        operands : dict
+            Mapping of variables in the expression to their corresponding dataset paths.
+        compute : bool, optional
+            If false, generate lazyexpr and do not compute anything.
+            If true, compute lazy expression on creation and save (full) result.
+            Default false.
+
+        Returns
+        -------
+        Path
+            Path of the created dataset.
+        """
+        urlbase, remotepath = _format_paths(self.urlbase, remotepath)
+        if not isinstance(expression, blosc2.LazyExpr):
+            raise ValueError("argument ``expression`` must be blosc2.LazyExpr instance.")
+        operands = expression.operands
+        if operands is not None:
+            operands = {k: str(v) for k, v in operands.items()}
+        else:
+            operands = {}
+        expr = {
+            "name": None,
+            "expression": expression.expression,
+            "operands": operands,
+            "compute": compute,
+        }
+        dataset = api_utils.post(
+            f"{self.urlbase}/api/upload_lazyexpr/{remotepath}",
+            expr,
+            auth_cookie=self.cookie,
+            timeout=self.timeout,
+        )
+        return pathlib.PurePosixPath(dataset)
+
     def adduser(self, newuser, password=None, superuser=False):
         """
         Adds a user to the server.

caterva2/models.py

@@ -74,8 +74,8 @@ class LazyArray(pydantic.BaseModel):
     mtime: datetime.datetime | None
 
 
-class NewLazyExpr(pydantic.BaseModel):
-    name: str
+class Cat2LazyExpr(pydantic.BaseModel):
+    name: str | None
     expression: str
     operands: dict[str, str]
     compute: bool

caterva2/services/server.py

@@ -654,7 +654,14 @@ async def get_chunk(
     return responses.StreamingResponse(downloader)
 
 
-def make_expr(name: str, expr: str, operands: dict[str, str], user: db.User, compute: bool = False) -> str:
+def make_expr(
+    name: str | None,
+    expr: str,
+    operands: dict[str, str],
+    user: db.User,
+    compute: bool = False,
+    remotepath: pathlib.Path | None = None,
+) -> str:
     """
     Create a lazy expression dataset in personal space.
 
@@ -665,12 +672,14 @@ def make_expr(name: str, expr: str, operands: dict[str, str], user: db.User, com
     Parameters
     ----------
     name : str
-        The name of the dataset to be created (without extension).
+        The name of the dataset to be created without extension.
     expr : str
         The expression to be evaluated.  It must result in a lazy expression.
     operands : dictionary of strings mapping to strings
         The variables used in the expression and which dataset paths they
         refer to.
+    remotepath: pathlib.Path
+        Where to save the lazy expression. Only valid if name is None.
 
     Returns
     -------
@@ -682,10 +691,9 @@ def make_expr(name: str, expr: str, operands: dict[str, str], user: db.User, com
         raise srv_utils.raise_unauthorized("Creating lazy expressions requires authentication")
 
     # Parse expression
-    name = name.strip()
     expr = expr.strip()
-    if not name or not expr:
-        raise ValueError("Name or expression should not be empty")
+    if not expr or (not remotepath and not name):
+        raise ValueError("Name/remotepath and expression should not be empty")
     vars = blosc2.get_expr_operands(expr)
 
     # Open expression datasets
@@ -699,27 +707,70 @@ def make_expr(name: str, expr: str, operands: dict[str, str], user: db.User, com
 
     # Create the lazy expression dataset
     arr = blosc2.lazyexpr(expr, var_dict)
-    if not isinstance(arr, blosc2.LazyExpr):
-        cname = type(arr).__name__
-        raise TypeError(f"Evaluates to {cname} instead of lazy expression")
 
-    # Save to filesystem
-    path = settings.personal / str(user.id)
-    path.mkdir(exist_ok=True, parents=True)
-    urlpath = f"{path / name}.b2nd"
+    # Handle name or path
+    if name is None:  # provided a path
+        # Get the absolute path for this user
+        urlpath = get_writable_path(remotepath, user)
+        abspath = urlpath.parent
+        if urlpath.suffix != ".b2nd":
+            raise ValueError('If path extension provided must be ".b2nd".')
+        path = str(remotepath)
+    else:  # just provided a name
+        name = name.strip()
+        abspath = settings.personal / str(user.id)
+        urlpath = f"{abspath / name}.b2nd"
+        path = f"@personal/{name}.b2nd"
+
+    abspath.mkdir(exist_ok=True, parents=True)
+
     if any(method in expr for method in linalg_funcs):
         compute = True
     if compute:
         arr.compute(urlpath=urlpath, mode="w")
     else:
         arr.save(urlpath=urlpath, mode="w")
 
-    return f"@personal/{name}.b2nd"
+    return path
+
+
+@app.post("/api/upload_lazyexpr/{path:path}")
+async def upload_lazyexpr(
+    path: pathlib.Path,
+    expr: models.Cat2LazyExpr,
+    user: db.User = Depends(current_active_user),
+) -> str:
+    """
+    Upload a lazy expression dataset (to any root).
+
+    The JSON request body must contain a "name"=None for the dataset to be created,
+    an "expression" to be evaluated, which must result in
+    a lazy expression, and an "operands" object which maps variable names used
+    in the expression to the dataset paths that they refer to.
+
+    Returns
+    -------
+    str
+        The path of the newly created (or overwritten) dataset.
+    """
+    if expr.name is not None:
+        raise ValueError("Cannot provide name and path.")
+    try:
+        result_path = make_expr(expr.name, expr.expression, expr.operands, user, expr.compute, path)
+    except (SyntaxError, ValueError, TypeError) as exc:
+        raise srv_utils.raise_bad_request(f"Invalid name or expression: {exc}") from exc
+    except KeyError as ke:
+        detail = f"Expression error: {ke.args[0]} is not in the list of available datasets"
+        raise srv_utils.raise_bad_request(detail) from ke
+    except RuntimeError as exc:
+        raise srv_utils.raise_bad_request(f"Runtime error: {exc}") from exc
+
+    return result_path
 
 
 @app.post("/api/lazyexpr/")
 async def lazyexpr(
-    expr: models.NewLazyExpr,
+    expr: models.Cat2LazyExpr,
     user: db.User = Depends(current_active_user),
 ) -> str:
     """

caterva2/tests/test_api.py

@@ -680,6 +680,16 @@ def test_lazyexpr(auth_client):
     b = auth_client.fetch(lxpath)
     np.testing.assert_array_equal(a[:], b[:])
 
+    # test streamlined API
+    a = auth_client.get(oppt)
+    ls = blosc2.lazyexpr(f"linspace(0, 1, {a.shape[0]})")
+    mylazyexpr = a + 0
+    mylazyexpr += 2 * ls
+    res = a[:] + 2 * ls[:]
+    lxpath = auth_client.upload_lazyexpr("@shared/newexpr.b2nd", mylazyexpr)
+    b = auth_client.fetch(lxpath)
+    np.testing.assert_array_equal(res, b[:])
+
 
 # More exercises for the expression evaluation with Blosc2 arrays
 @pytest.mark.parametrize(