path: root/c++/src/H5IdComponent.cpp

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * All rights reserved.                                                      *
 *                                                                           *
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 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include <string>

#include "H5Include.h"
#include "H5Exception.h"
#include "H5Library.h"
#include "H5IdComponent.h"
#include "H5DataSpace.h"

namespace H5 {

#ifndef DOXYGEN_SHOULD_SKIP_THIS
// This flag indicates whether H5Library::initH5cpp has been called to register
// the terminating functions with atexit()
bool IdComponent::H5cppinit = false;

// This flag is used to decide whether H5dont_atexit should be called.
// Subclasses that have global constants use it.  This is a temporary
// work-around in 1.8.16.  It will be removed after HDFFV-9540 is fixed.
bool IdComponent::H5dontAtexit_called = false;
#endif // DOXYGEN_SHOULD_SKIP_THIS

//--------------------------------------------------------------------------
// Function:    IdComponent::incRefCount
///\brief       Increment reference counter for a given id.
//--------------------------------------------------------------------------
void
IdComponent::incRefCount(const hid_t obj_id) const
{
    if (p_valid_id(obj_id))
        if (H5Iinc_ref(obj_id) < 0)
            throw IdComponentException(inMemFunc("incRefCount"), "incrementing object ref count failed");
}

//--------------------------------------------------------------------------
// Function:    IdComponent::incRefCount
///\brief       Increment reference counter for the id of this object.
//--------------------------------------------------------------------------
void
IdComponent::incRefCount() const
{
    incRefCount(getId());
}

//--------------------------------------------------------------------------
// Function:    IdComponent::decRefCount
///\brief       Decrement reference counter for a given id.
// Modification:
//              Added the check for ref counter to give a little more info
//              on why H5Idec_ref fails in some cases - BMR 5/19/2005
//--------------------------------------------------------------------------
void
IdComponent::decRefCount(const hid_t obj_id) const
{
    if (p_valid_id(obj_id))
        if (H5Idec_ref(obj_id) < 0) {
            if (H5Iget_ref(obj_id) <= 0)
                throw IdComponentException(inMemFunc("decRefCount"), "object ref count is 0 or negative");
            else
                throw IdComponentException(inMemFunc("decRefCount"), "decrementing object ref count failed");
        }
}

//--------------------------------------------------------------------------
// Function:    IdComponent::decRefCount
///\brief       Decrement reference counter for the id of this object.
//--------------------------------------------------------------------------
void
IdComponent::decRefCount() const
{
    decRefCount(getId());
}

//--------------------------------------------------------------------------
// Function:    IdComponent::getCounter
///\brief       Returns the reference counter for a given id.
///\return      Reference count
//--------------------------------------------------------------------------
int
IdComponent::getCounter(const hid_t obj_id) const
{
    int counter = 0;
    if (p_valid_id(obj_id)) {
        counter = H5Iget_ref(obj_id);
        if (counter < 0)
            throw IdComponentException(inMemFunc("incRefCount"),
                                       "getting object ref count failed - negative");
    }
    return (counter);
}

//--------------------------------------------------------------------------
// Function:    IdComponent::getCounter
///\brief       Returns the reference counter for the id of this object.
///\return      Reference count
//--------------------------------------------------------------------------
int
IdComponent::getCounter() const
{
    return (getCounter(getId()));
}

//--------------------------------------------------------------------------
// Function:    getHDFObjType (static)
///\brief       Given an id, returns the type of the object.
///\return      a valid HDF object type, which may be one of the following:
///             \li \c H5I_FILE
///             \li \c H5I_GROUP
///             \li \c H5I_DATATYPE
///             \li \c H5I_DATASPACE
///             \li \c H5I_DATASET
///             \li \c H5I_ATTR
///             \li or \c H5I_BADID, if no valid type can be determined or the
///                         input object id is invalid.
//--------------------------------------------------------------------------
H5I_type_t
IdComponent::getHDFObjType(const hid_t obj_id)
{
    if (obj_id <= 0)
        return H5I_BADID; // invalid
    H5I_type_t id_type = H5Iget_type(obj_id);
    if (id_type <= H5I_BADID || id_type >= H5I_NTYPES)
        return H5I_BADID; // invalid
    else
        return id_type; // valid type
}

//--------------------------------------------------------------------------
// Function:    getHDFObjType
///\brief       Returns the type of the object.  It is an overloaded function
///             of the above function.
///\return      a valid HDF object type, which may be one of the following:
///             \li \c H5I_FILE
///             \li \c H5I_GROUP
///             \li \c H5I_DATATYPE
///             \li \c H5I_DATASPACE
///             \li \c H5I_DATASET
///             \li \c H5I_ATTR
///             \li or \c H5I_BADID, if no valid type can be determined or the
///                         input object id is invalid.
//--------------------------------------------------------------------------
H5I_type_t
IdComponent::getHDFObjType() const
{
    return (getHDFObjType(getId()));
}

//--------------------------------------------------------------------------
// Function:    getNumMembers (static)
///\brief       Returns the number of members of the given type.
///\return      Number of members
///\par Description
///             If there is no member of the given type, getNumMembers will
///             return 0.  Valid types are:
///             \li \c H5I_FILE (= 1)
///             \li \c H5I_GROUP
///             \li \c H5I_DATATYPE
///             \li \c H5I_DATASPACE
///             \li \c H5I_DATASET
///             \li \c H5I_ATTR
///             \li \c H5I_VFL
///             \li \c H5I_VOL
///             \li \c H5I_GENPROP_CLS
///             \li \c H5I_GENPROP_LST
///             \li \c H5I_ERROR_CLASS
///             \li \c H5I_ERROR_MSG
///             \li \c H5I_ERROR_STACK
//--------------------------------------------------------------------------
hsize_t
IdComponent::getNumMembers(H5I_type_t type)
{
    hsize_t nmembers  = 0;
    herr_t  ret_value = H5Inmembers(type, &nmembers);
    if (ret_value < 0)
        throw IdComponentException("getNumMembers", "H5Inmembers failed");
    else
        return (nmembers);
}

//--------------------------------------------------------------------------
// Function:    isValid (static)
///\brief       Checks if the given ID is valid.
///\return      true if the given identifier is valid, and false, otherwise.
///\par Description
///             A valid ID is one that is in use and has an application
///             reference count of at least 1.
//--------------------------------------------------------------------------
bool
IdComponent::isValid(hid_t an_id)
{
    // Call C function
    htri_t ret_value = H5Iis_valid(an_id);
    if (ret_value > 0)
        return true;
    else if (ret_value == 0)
        return false;
    else // Raise exception when H5Iis_valid returns a negative value
        throw IdComponentException("isValid", "H5Iis_valid failed");
}

//--------------------------------------------------------------------------
// Function:    typeExists (static)
///\brief       Queries if a given type is currently registered with the
///             library.
///\return      true if the given type exists, and false, otherwise.
///\par Description
///             Valid types are:
///             \li \c H5I_FILE (= 1)
///             \li \c H5I_GROUP
///             \li \c H5I_DATATYPE
///             \li \c H5I_DATASPACE
///             \li \c H5I_DATASET
///             \li \c H5I_ATTR
///             \li \c H5I_VFL
///             \li \c H5I_VOL
///             \li \c H5I_GENPROP_CLS
///             \li \c H5I_GENPROP_LST
///             \li \c H5I_ERROR_CLASS
///             \li \c H5I_ERROR_MSG
///             \li \c H5I_ERROR_STACK
//--------------------------------------------------------------------------
bool
IdComponent::typeExists(H5I_type_t type)
{
    // Call C function
    htri_t ret_value = H5Itype_exists(type);
    if (ret_value > 0)
        return true;
    else if (ret_value == 0)
        return false;
    else // Raise exception when H5Itype_exists returns a negative value
        throw IdComponentException("typeExists", "H5Itype_exists failed");
}

//--------------------------------------------------------------------------
// Function:    IdComponent::operator=
///\brief       Assignment operator.
///\param       rhs - IN: Reference to the existing object
///\return      Reference to IdComponent instance
///\exception   H5::IdComponentException when attempt to close the HDF5
///             object fails
// Description
//              First, close the current valid id of this object.  Then
//              copy the id from rhs to this object, and increment the
//              reference counter of the id to indicate that another object
//              is referencing that id.
// Modification
//        2010/5/9 - BMR
//              Removed close() and incRefCount() because setId/p_setId takes
//              care of close() and setId takes care incRefCount().
//--------------------------------------------------------------------------
IdComponent &
IdComponent::operator=(const IdComponent &rhs)
{
    if (this != &rhs) {
        // handling references to this id
        try {
            setId(rhs.getId());
            // Note: a = b, so there are two objects with the same hdf5 id
            // that's why incRefCount is needed, and it is called by setId
        }
        catch (Exception &close_error) {
            throw FileIException(inMemFunc("operator="), close_error.getDetailMsg());
        }
    }
    return *this;
}

//--------------------------------------------------------------------------
// Function:    IdComponent::setId
///\brief       Sets the identifier of this object to a new value.
///\param       new_id - IN: New identifier to be set to
///\exception   H5::IdComponentException when the attempt to close the HDF5
///             object fails
// Description:
//              p_setId ensures that the current valid id of this object is
//              properly closed before resetting the object's id to the new id.
// Modification
//        2008/7/23 - BMR
//              Changed all subclasses' setId to p_setId and put back setId
//              here.  p_setId is used in the library where the id provided
//              by a C API passed on to user's application in the form of a
//              C++ API object, which will be destroyed properly, and so
//              p_setId does not call incRefCount.  On the other hand, the
//              public version setId is used by other applications, in which
//              the id passed to setId is that of another C++ API object, so
//              setId must call incRefCount.
//--------------------------------------------------------------------------
void
IdComponent::setId(const hid_t new_id)
{
    // set to new_id
    p_setId(new_id);

    // increment the reference counter of the new id
    incRefCount();
}

//--------------------------------------------------------------------------
// Function:    IdComponent destructor
///\brief       Noop destructor.
//--------------------------------------------------------------------------
IdComponent::~IdComponent()
{
}

//
// Implementation of protected functions for HDF5 Reference Interface
// and miscellaneous helpers.
//

#ifndef DOXYGEN_SHOULD_SKIP_THIS
//--------------------------------------------------------------------------
// Function:    IdComponent::inMemFunc
///\brief       Makes and returns string "<class-name>::<func_name>"
///\param       func_name - Name of the function where failure occurs
// Description
///             Concatenates the class name of this object with the
///             passed-in function name to create a string that indicates
///             where the failure occurs.  The class-name is provided by
///             fromClass().  This string will be used by a base class when
///             an exception is thrown.
//--------------------------------------------------------------------------
H5std_string
IdComponent::inMemFunc(const char *func_name) const
{
    H5std_string full_name = func_name;
    full_name.insert(0, "::");
    full_name.insert(0, fromClass());
    return (full_name);
}

//--------------------------------------------------------------------------
// Function:    IdComponent default constructor - private
///\brief       Default constructor.
//--------------------------------------------------------------------------
IdComponent::IdComponent()
{
    // initH5cpp will register the terminating functions with atexit().
    // This should only be done once.
    if (!H5cppinit) {
        H5Library::initH5cpp();
        H5cppinit = true;
    }
}

//--------------------------------------------------------------------------
// Function:    IdComponent::p_get_file_name (protected)
// Purpose      Gets the name of the file, in which this object belongs.
// Exception:   H5::IdComponentException
// Description:
//              This function is protected so that the user applications can
//              only have access to its code via H5Location subclasses.
//      September 2017
//              This function should be moved to H5Location now that Attribute
//              inherits from H5Location.
//--------------------------------------------------------------------------
H5std_string
IdComponent::p_get_file_name() const
{
    hid_t temp_id = getId();

    // Preliminary call to H5Fget_name to get the length of the file name
    ssize_t name_size = H5Fget_name(temp_id, NULL, 0);

    // If H5Aget_name returns a negative value, raise an exception,
    if (name_size < 0) {
        throw IdComponentException("", "H5Fget_name failed");
    }

    // The actual message size is the cast value + 1 for the terminal ASCII NUL
    // (unfortunate in/out type sign mismatch)
    size_t actual_name_size = static_cast<size_t>(name_size) + 1;

    // Call H5Fget_name again to get the actual file name
    char *name_C = new char[actual_name_size]();

    name_size = H5Fget_name(temp_id, name_C, actual_name_size);

    // Check for failure again
    if (name_size < 0) {
        delete[] name_C;
        throw IdComponentException("", "H5Fget_name failed");
    }

    // Convert the C file name and return
    H5std_string file_name(name_C);
    delete[] name_C;

    return file_name;
}

//
// Local functions used in this class
//

//--------------------------------------------------------------------------
// Function:    p_valid_id
// Purpose      Verifies that the given id is a valid id so it can be passed
//              into an H5I C function.
// Return       true if id is valid, false, otherwise
//--------------------------------------------------------------------------
bool
IdComponent::p_valid_id(const hid_t obj_id)
{
    if (obj_id <= 0)
        return false;

    H5I_type_t id_type = H5Iget_type(obj_id);
    return (id_type > H5I_BADID && id_type < H5I_NTYPES);
}

// Notes about IdComponent::id
//      May 2008 - BMR
//              Class hierarchy is revised to address bugzilla 1068...
//              ...member IdComponent::id is moved into subclasses, and
//              IdComponent::getId now becomes pure virtual function.
//              (reasons: 1. encountered problems when adding H5Location;
//                        2. Scott Meyers, item 33)

#endif // DOXYGEN_SHOULD_SKIP_THIS

} // namespace H5