pyUtils.h

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//
// Copyright 2016 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
//    names, trademarks, service marks, or product names of the Licensor
//    and its affiliates, except as required to comply with Section 4(c) of
//    the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
#ifndef PXR_BASE_TF_PY_UTILS_H
#define PXR_BASE_TF_PY_UTILS_H


#include "pxr/pxr.h"

#include "pxr/base/tf/refPtr.h"
#include "pxr/base/tf/weakPtr.h"
#include "pxr/base/tf/diagnosticLite.h"
#include "pxr/base/tf/preprocessorUtilsLite.h"
#include "pxr/base/tf/py3Compat.h"
#include "pxr/base/tf/pyInterpreter.h"
#include "pxr/base/tf/pyLock.h"
#include "pxr/base/tf/api.h"

#include <functional>
#include <typeinfo>
#include <string>
#include <vector>

#include <boost/python/dict.hpp>
#include <boost/python/extract.hpp>
#include <boost/python/handle.hpp>
#include <boost/python/object.hpp>
#include <boost/python/type_id.hpp>

PXR_NAMESPACE_OPEN_SCOPE

#define TF_PY_REPR_PREFIX \
    std::string(TF_PP_STRINGIZE(MFB_PACKAGE_MODULE) ".")

TF_API bool TfPyIsInitialized();

TF_API void TfPyThrowIndexError(std::string const &msg);

TF_API void TfPyThrowRuntimeError(std::string const &msg);

TF_API void TfPyThrowStopIteration(std::string const &msg);

TF_API void TfPyThrowKeyError(std::string const &msg);

TF_API void TfPyThrowValueError(std::string const &msg);

TF_API void TfPyThrowTypeError(std::string const &msg);

TF_API bool TfPyIsNone(boost::python::object const &obj);

TF_API bool TfPyIsNone(boost::python::handle<> const &obj);

// Helper for \c TfPyObject().
TF_API void Tf_PyObjectError(bool printError);

template <typename T>
boost::python::object TfPyObject(T const &t, bool complainOnFailure = true) {
    // initialize python if it isn't already, so at least we can try to return
    // an object
    if (!TfPyIsInitialized()) {
        TF_CODING_ERROR("Called TfPyObject without python being initialized!");
        TfPyInitialize();
    }

    TfPyLock pyLock;

    // Will only be able to return objects which have been wrapped.
    // Returns None otherwise
    try {
        return boost::python::object(t);
    } catch (boost::python::error_already_set const &) {
        Tf_PyObjectError(complainOnFailure);
        return boost::python::object();
   }
}

inline
boost::python::object TfPyObject(PyObject* t, bool complainOnFailure = true) {
    TfPyLock pyLock;
    return boost::python::object(boost::python::handle<>(t));
}

TF_API std::string TfPyObjectRepr(boost::python::object const &t);

template <typename T>
std::string TfPyRepr(T const &t) {
    if (!TfPyIsInitialized())
        return "<python not initialized>";
    TfPyLock lock;
    return TfPyObjectRepr(TfPyObject(t));
}

template <typename T>
std::string TfPyRepr(const std::vector<T> &v) {
    std::string result("[");
    typename std::vector<T>::const_iterator i = v.begin();
    if (i != v.end()) {
        result += TfPyRepr(*i);
        ++i;
    }
    while (i != v.end()) {
        result += ", " + TfPyRepr(*i);
        ++i;
    }
    result += "]";
    return result;
}

TF_API
boost::python::object
TfPyEvaluate(
    std::string const &expr,
    boost::python::dict const &extraGlobals = boost::python::dict());

TF_API 
int64_t
TfPyNormalizeIndex(int64_t index, uint64_t size, bool throwError = false);

TF_API std::string TfPyGetClassName(boost::python::object const &obj);


TF_API boost::python::object
TfPyGetClassObject(std::type_info const &type);

template <typename T>
boost::python::object
TfPyGetClassObject() {
    return TfPyGetClassObject(typeid(T));
}

TF_API
void
Tf_PyWrapOnceImpl(boost::python::type_info const &,
                  std::function<void()> const&,
                  bool *);

template <typename T>
void
TfPyWrapOnce(std::function<void()> const &wrapFunc)
{
    // Don't try to wrap if python isn't initialized.
    if (!TfPyIsInitialized()) {
        return;
    }

    static bool isTypeWrapped = false;
    if (isTypeWrapped) {
        return;
    }

    Tf_PyWrapOnceImpl(boost::python::type_id<T>(), wrapFunc, &isTypeWrapped);
}

TF_API
void Tf_PyLoadScriptModule(std::string const &name);

template <class Map>
boost::python::dict TfPyCopyMapToDictionary(Map const &map) {
    TfPyLock lock;
    boost::python::dict d;
    for (typename Map::const_iterator i = map.begin(); i != map.end(); ++i)
        d[i->first] = i->second;
    return d;
}

template<class Seq>
boost::python::list TfPyCopySequenceToList(Seq const &seq) {
    TfPyLock lock;
    boost::python::list l;
    for (typename Seq::const_iterator i = seq.begin();
         i != seq.end(); ++i)
        l.append(*i);
    return l; 
}

template <class Seq>
boost::python::object TfPyCopySequenceToSet(Seq const &seq) {
    TfPyLock lock;
    boost::python::handle<> set{boost::python::allow_null(PySet_New(nullptr))};
    if (!set) {
        boost::python::throw_error_already_set();
    }
    for (auto const& item : seq) {
        boost::python::object obj(item);
        if (PySet_Add(set.get(), obj.ptr()) == -1) {
            boost::python::throw_error_already_set();
        }
    }
    return boost::python::object(set);
}

template<class Seq>
boost::python::tuple TfPyCopySequenceToTuple(Seq const &seq) {
    return boost::python::tuple(TfPyCopySequenceToList(seq));
}

TF_API
boost::python::object TfPyCopyBufferToByteArray(const char* buffer, size_t size);

TF_API
std::vector<std::string> TfPyGetTraceback();

TF_API
void TfPyGetStackFrames(std::vector<uintptr_t> *frames);

TF_API
void TfPyDumpTraceback();

TF_API
bool TfPySetenv(const std::string & name, const std::string & value);

TF_API
bool TfPyUnsetenv(const std::string & name);

// Private helper method to TfPyEvaluateAndExtract.
//
TF_API bool Tf_PyEvaluateWithErrorCheck(
    const std::string & expr, boost::python::object * obj);

template <typename T>
bool TfPyEvaluateAndExtract(const std::string & expr, T * t)
{
    if (expr.empty())
        return false;

    // Take the lock before doing anything with boost::python.
    TfPyLock lock;

    // Though TfPyEvaluate (called by Tf_PyEvaluateWithErroCheck) takes the
    // python lock, it is important that we lock before we initialize the 
    // boost::python::object, since it will increment and decrement ref counts 
    // outside of the call to TfPyEvaluate.
    boost::python::object obj;
    if (!Tf_PyEvaluateWithErrorCheck(expr, &obj))
        return false;

    boost::python::extract<T> extractor(obj);

    if (!extractor.check())
        return false;

    *t = extractor();

    return true;
}

TF_API
void TfPyPrintError();

PXR_NAMESPACE_CLOSE_SCOPE

#endif // PXR_BASE_TF_PY_UTILS_H