Implementation of database server

src/ansys/mapdl/core/check_version.py

@@ -14,6 +14,8 @@
     (0, 3, 0): "2021R1",
     (0, 4, 0): "2021R2",
     (0, 4, 1): "2021R2",
+    (0, 5, 0): "2022R1",
+    (0, 5, 1): "2022R2",  # as of 21 Mar 2022 unreleased
 }
 
 

src/ansys/mapdl/core/database/__init__.py

@@ -0,0 +1 @@
+from .database import MapdlDb

src/ansys/mapdl/core/database/database.py

@@ -0,0 +1,311 @@
+"""Contains the MapdlDb classes, allowing the access to MAPDL DB from Python."""
+from enum import Enum
+import time
+from warnings import warn
+import weakref
+
+from ansys.api.mapdl.v0 import mapdl_db_pb2_grpc
+import grpc
+
+from ..mapdl_grpc import MapdlGrpc
+
+
+class WithinBeginLevel:
+    """Context manager to run MAPDL within the being level."""
+
+    def __init__(self, mapdl):
+        self._mapdl = mapdl
+
+    def __enter__(self):
+        self._mapdl._cache_routine()
+        if "BEGIN" not in self._mapdl._cached_routine.upper():
+            self._mapdl.finish()
+
+    def __exit__(self, type, value, traceback):
+        if "BEGIN" not in self._mapdl._cached_routine.upper():
+            self._mapdl._resume_routine
+
+
+class DBDef(Enum):  # From MAPDL ansysdef.inc include file
+    DB_SELECTED = 1
+    DB_NUMDEFINED = 12
+    DB_NUMSELECTED = 13
+    DB_MAXDEFINED = 14
+    DB_MAXRECLENG = 15
+    DB_GETNEXTRECD = 16
+    DB_MAXALLOC = 17
+    DB_OBJFLAG = -777
+    DB_NEXT = -888
+    DB_NEXT_ALLOC = -889
+    DB_MODIFIED = -999
+    DB_INTERNAL = -9999
+
+
+class MapdlDb:
+    """Abstract mapdl db class.  Created from a ``Mapdl`` instance.
+
+    Examples
+    --------
+    Create an instance.
+
+    >>> from ansys.mapdl.core import launch_mapdl
+    >>> mapdl = launch_mapdl()
+    >>> db = mapdl.db
+
+    Get the number of nodes
+
+    Get a given node
+
+    Set a new node into MAPDL DB
+
+    """
+
+    def __init__(self, mapdl):
+        if not isinstance(mapdl, MapdlGrpc):
+            raise TypeError("``mapdl`` must be a MapdlGrpc instance")
+        self._mapdl_weakref = weakref.ref(mapdl)
+        self._stub = None
+        self._channel = None
+        # self._itele = -1
+        self._ip = None
+        self._server = {}
+        self._channel_str = None
+        self._state = None
+        self._nodes = None
+        self._elems = None
+
+    def __str__(self):
+        if self.active:
+            return f"MAPDL database server active at {self._channel_str}"
+        else:
+            return f"MAPDL database server not active"
+
+    @property
+    def _mapdl(self):
+        """Return the weakly referenced instance of mapdl"""
+        return self._mapdl_weakref()
+
+    @property
+    def _server_version(self):
+        """Return the version of MAPDL"""
+        return self._mapdl._server_version
+
+    def _start(self) -> int:
+        """Start the database server.
+
+        Returns
+        -------
+        int
+            Port of the database server.
+
+        """
+        self._mapdl._log.debug("Starting MAPDL server")
+
+        # database server must be run from the "BEGIN" level
+        self._mapdl._cache_routine()
+        with WithinBeginLevel(self._mapdl):
+            self._mapdl.run("/DBS,SERVER,START")
+
+        # Scan the DBServer.info file to get the Port Number
+
+        # Default is 50055
+        status = self._mapdl._download_as_raw("DBServer.info").decode()
+
+        try:
+            # expected of the form 'Port : 50055'
+            port = int(status.split(":")[1])
+        except Exception as e:  # pragma: no cover
+            self._mapdl._log.error(
+                "Unable to read port number from '%s' due to\n%s", status, str(e)
+            )
+            port = 50055
+
+        self._mapdl._log.debug("MAPDL database server started on port %d", port)
+        return port
+
+    @property
+    def active(self) -> bool:
+        """Return if the database server is active."""
+        return "NOT" not in self._status()
+
+    def start(self, timeout=10):
+        """Start the gRPC MAPDL database server.
+
+        Parameters
+        ----------
+        timeout : float, optional
+            Timeout to start the service.
+
+        Examples
+        --------
+        >>> db.start()
+        """
+
+        # only start if not already running
+        is_running = self.active
+        self._mapdl._log.debug("MAPDL DB server running: %s", str(is_running))
+        if is_running:
+            return
+        db_port = self._start()
+
+        self._ip = self._mapdl._ip
+        self._server = {"ip": self._ip, "port": db_port}
+        self._channel_str = f"{self._ip}:{db_port}"
+
+        self._channel = grpc.insecure_channel(self._channel_str)
+        self._state = grpc.channel_ready_future(self._channel)
+        self._stub = mapdl_db_pb2_grpc.MapdlDbServiceStub(self._channel)
+
+        # wait until the channel matures
+        tstart = time.time()
+        while ((time.time() - tstart) < timeout) and not self._state._matured:
+            time.sleep(0.01)
+
+        if not self._state._matured:  # pragma: no cover
+            raise RuntimeError(
+                "Unable to establish connection to MAPDL database server"
+            )
+        self._mapdl._log.debug("Established connection to MAPDL database server")
+
+    def _stop(self):
+        """Stop the MAPDL database service."""
+        with WithinBeginLevel(self._mapdl):
+            return self._mapdl.run("/DBS,SERVER,STOP")
+
+    def stop(self):
+        """Shutdown the MAPDL database service and close the connection.
+
+        Examples
+        --------
+        Stop the database service.
+
+        >>> mapdl.db.stop()
+        """
+        if not self.active:
+            warn("Server is already shutdown")
+            return
+
+        self._mapdl._log.debug("Closing the connection with the MAPDL DB Server")
+        self._stop()
+        self._channel.close()
+        self._channel = None
+        self._stub = None
+        self._state = None
+
+    def _status(self):
+        """Return the status of the MADPL DB Server.
+
+        Examples
+        --------
+        >>> output = mapdl.db._status()
+        >>> print(output)
+        >ENTERING THE SERVER MODE: STATUS
+
+         DB Server is NOT currently running ..
+        """
+        # Need to use the health check here
+        with WithinBeginLevel(self._mapdl):
+            return self._mapdl.run("/DBS,SERVER,STATUS")
+
+    def load(self, fname, progress_bar=False):
+        """Load a MAPDL database file in memory.
+
+        Parameters
+        ----------
+        fname : str
+            The file name of the database to load.
+
+        Examples
+        --------
+        >>> mapdl.db.load('file.db')
+        """
+        self._mapdl._get_file_path(fname, progress_bar=progress_bar)
+        return self._mapdl.resume(fname)
+
+    def save(self, fname, option="ALL"):
+        """Save a MAPDL database to disk.
+
+        Parameters
+        ----------
+        fname : str
+            Filename to save the database to.
+
+        option : str
+            The mode for saving the database, either:
+
+            * "ALL" - Both the model and the solution
+            * "MODEL" - Just the model
+            * "SOLU" - Just the solution
+
+        Examples
+        --------
+        >>> mapdl.db.save('model.db', option=)
+        """
+        allowed = ["ALL", "MODEL", "SOLU"]
+        if option.upper() not in allowed:
+            raise ValueError(f"Option must be one of the following: {allowed}")
+
+        return self._mapdl.run(f"SAVE,{fname},,,{option}")
+
+    def clear(self, **kwargs):
+        """Delete everything in the MAPDL DB.
+
+        Examples
+        --------
+        >>> mapdl.db.clear()
+        """
+        return self._mapdl.run("/CLEAR,ALL")
+
+    @property
+    def nodes(self):
+        """MAPDL database nodes interface.
+
+        Returns
+        -------
+        :class:`DbNodes <ansys.mapdl.core.DbNodes>`
+
+        Examples
+        --------
+        Get the number of nodes in the MAPDL DB
+
+        >>> db = mapdl.db
+        >>> nodes = db.nodes
+        >>> nodes.num()
+
+        Push a new node into MAPDL
+
+        >>> nodes.set(...)
+        >>>
+        """
+        if self._nodes is None:
+            from .nodes import DbNodes  # here to avoid circular import
+
+            self._nodes = DbNodes(self)
+        return self._nodes
+
+    @property
+    def elems(self):
+        """MAPDL database element interface.
+
+        Returns
+        -------
+        :class:`DbElems <ansys.mapdl.core.DbElems>`
+
+        Examples
+        --------
+        Get the number of elems in the MAPDL DB
+
+        >>> db = mapdl.db
+        >>> elems = db.elems
+        >>> elems.num()
+
+        Push a new elem into MAPDL
+
+        >>> elems.set(...)
+        >>>
+        """
+        if self._elems is None:
+            from .elems import DbElems  # here to avoid circular import
+
+            self._elems = DbElems(self)
+        return self._elems