Summary:
The Python `ExceptionInfo` data has the potential to extend lifetime of Python
objects that were on the Python frame while the execution was thrown. This
lifetime extension is very dangerous when executing Python procedures because
we use a custom internal memory allocator that is destroyed immediately when
the procedure is done with its execution.
This diff only keeps the formatted Python traceback (as a string) to avoid any
lifetime extension for the Python objects so that the memory allocator can
safely be destroyed after the procedure has finished its execution.
Reviewers: llugovic
Reviewed By: llugovic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2739
Summary:
`PyObject_Init` shouldn't be used in conjunction with `PyObject_New`.
The official Python documentation doesn't say this explicitly and many examples
on the web suggest that they must be used together. When they are used together
everything works when Memgraph is built against the release Python binary, but
doesn't work when built against the debug Python binary.
An implicit example that `PyObject_Init` shouldn't be used with `PyObject_New`
can be found in the Python source, in the file `Include/objimpl.h`:
```
This example code implements an object constructor with a custom
allocator, where PyObject_New is inlined, and shows the important
distinction between two steps (at least):
1) the actual allocation of the object storage;
2) the initialization of the Python specific fields
in this storage with PyObject_{Init, InitVar}.
PyObject *
YourObject_New(...)
{
PyObject *op;
op = (PyObject *) Your_Allocator(_PyObject_SIZE(YourTypeStruct));
if (op == NULL)
return PyErr_NoMemory();
PyObject_Init(op, &YourTypeStruct);
op->ob_field = value;
...
return op;
}
Note that in C++, the use of the new operator usually implies that
the 1st step is performed automatically for you, so in a C++ class
constructor you would start directly with PyObject_Init/InitVar
```
It explains that `PyObject_New` is actually equal to `malloc` +
`PyObject_Init`.
Reviewers: llugovic
Reviewed By: llugovic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2737
Summary:
This fixes an issue in Py(Vertex|Edge)GetProperty and prevents any
further issues of that type at the cost of additional typing effort.
Reviewers: ipaljak, llugovic
Reviewed By: ipaljak, llugovic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2735
Summary:
Currently, when starting Memgraph with the production package (DEB/RPM),
Memgraph always outputs an error for not being able to replace an existing
query module (`example.so` with `example.c`). This diff introduces a precheck
so that the error message is correct - so that Memgraph doesn't try to replace
an `.so` file with a `.c` file before verifying that the `.c` file is a valid
query module (which it obviously isn't). Also, I have moved the source of the
example into a subdirectory so that it isn't even considered while loading
modules.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2724
Summary:
You should now be able to invoke query procedures written in Python. To
test the example you can run memgraph with PYTHONPATH set to `include`.
For example, assuming you are in the root of the repo, run this command.
PYTHONPATH=$PWD/include ./build/memgraph --query-modules-directory=./query_modules/
Alternatively, you can set a symlink inside the ./query_modules to point
to `include/mgp.py`, so there's no need to set PYTHONPATH. For example,
assuming you are in the root of the repo, run the following.
cd ./query_modules
ln -s ../include/mgp.py
cd ..
./build/memgraph --query-modules-directory=./query_modules/
Depends on D207
Reviewers: mferencevic, ipaljak, dsantl
Reviewed By: ipaljak
Subscribers: buda, tlastre, pullbot
Differential Revision: https://phabricator.memgraph.io/D2708
Summary:
When invoking a Python registered procedures we want to convert
`mgp_value` types to user facing 'mgp' types.
Depends on D2706
Reviewers: mferencevic, ipaljak
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2707
Summary:
Now that unique constraint feature is added to Memgraph database,
we should update `DUMP DATABASE` with list of existing unique constraints.
Reviewers: mferencevic
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2698
Summary:
With this diff you should now be able to register `example.py` and read
procedures found there. The procedures will be listed through `CALL
mg.procedures() YIELD *` query, but invoking them will raise
`NotYetImplemented`.
If you wish to test this, you will need to run the Memgraph executable
with PYTHONPATH set to the `include` directory where `mgp.py` is found.
Additionally, you need to pass `--query-modules-directory` flag to
Memgraph, such that it points to where it will find the `example.py`.
For example, when running from the root directory of Memgraph repo, the
shell invocation below should do the trick (assuming `./build/memgraph`
is where is the executable). Make sure that `./query_modules/` does not
have `example.so` built, as that may interfere with loading
`example.py`.
PYTHONPATH=$PWD/include ./build/memgraph --query-modules-directory=./query_modules/
Reviewers: mferencevic, ipaljak, llugovic
Reviewed By: mferencevic, ipaljak, llugovic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2678
Summary:
Before this change, unique constraints supported only pairs of label
and a single property. With this change, unique constraints can be
created for label and set of properties.
Better tests for unique constraints in general are also included in
this diff.
Reviewers: mferencevic, teon.banek
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2653
Summary:
`query::procedure::Module` is now an interface class through which
users interact with loaded modules. At the moment, the interface is implemented
by three concrete classes: `query::procedure::BuiltinModule`,
`query::procedure::SharedLibraryModule` and `query::procedure::PythonModule`.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2664
Summary:
This diff contains a basic implementation of unique constraints consistent with
the MVCC storage.
Stale records in the unique constraints are collected by the garbage collector.
Tests for checking correctness of unique constraints and violations are included.
Note: currently we only support a pair of label and a single property. Support for
multiple properties will be added later.
Reviewers: mferencevic, teon.banek
Reviewed By: mferencevic, teon.banek
Subscribers: buda, ipaljak, pullbot
Differential Revision: https://phabricator.memgraph.io/D2608
Summary:
This only imports the `.py` files into the global interpreter. These
modules are not exposed to query execution. A later diff will add that
support.
Reviewers: mferencevic, ipaljak
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2660
Summary:
The antlr openCypher parser generation is moved to query. Also, header files
have been added to the list of generated files so that if any header file is
deleted CMake will know that it has to regenerate it.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2652
