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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Copyright by The HDF Group. *
* All rights reserved. *
* *
* This file is part of HDF5. The full HDF5 copyright notice, including *
* 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. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* Purpose: The public header file for the core virtual file driver (VFD)
*/
#ifndef H5FDcore_H
#define H5FDcore_H
/** Initializer for the core VFD */
#define H5FD_CORE (H5FDperform_init(H5FD_core_init))
/** Identifier for the core VFD */
#define H5FD_CORE_VALUE H5_VFD_CORE
#ifdef __cplusplus
extern "C" {
#endif
/** @private
*
* \brief Private initializer for the core VFD
*/
H5_DLL hid_t H5FD_core_init(void);
/**
* \ingroup FAPL
*
* \brief Modifies the file access property list to use the #H5FD_CORE driver
*
* \fapl_id
* \param[in] increment Size, in bytes, of memory increments
* \param[in] backing_store Boolean flag indicating whether to write the file
* contents to disk when the file is closed
* \returns \herr_t
*
* \details H5Pset_fapl_core() modifies the file access property list to use the
* #H5FD_CORE driver.
*
* The #H5FD_CORE driver enables an application to work with a file in
* memory, speeding reads and writes as no disk access is made. File
* contents are stored only in memory until the file is closed. The \p
* backing_store parameter determines whether file contents are ever
* written to disk.
*
* \p increment specifies the increment by which allocated memory is to
* be increased each time more memory is required.
*
* While using H5Fcreate() to create a core file, if the \p
* backing_store is set to 1 (true), the file contents are flushed to a
* file with the same name as this core file when the file is closed or
* access to the file is terminated in memory.
*
* The application is allowed to open an existing file with #H5FD_CORE
* driver. While using H5Fopen() to open an existing file, if the \p
* backing_store is set to 1 (true) and the \c flags for H5Fopen() is set to
* #H5F_ACC_RDWR, any change to the file contents are saved to the file
* when the file is closed. If \p backing_store is set to 0 (false) and the \c
* flags for H5Fopen() is set to #H5F_ACC_RDWR, any change to the file
* contents will be lost when the file is closed. If the flags for
* H5Fopen() is set to #H5F_ACC_RDONLY, no change to the file is
* allowed either in memory or on file.
*
* \note Currently this driver cannot create or open family or multi files.
*
* \since 1.4.0
*
*/
H5_DLL herr_t H5Pset_fapl_core(hid_t fapl_id, size_t increment, hbool_t backing_store);
/**
* \ingroup FAPL
*
* \brief Queries core file driver properties
*
* \fapl_id
* \param[out] increment Size, in bytes, of memory increments
* \param[out] backing_store Boolean flag indicating whether to write the file
* contents to disk when the file is closed
* \returns \herr_t
*
* \details H5Pget_fapl_core() queries the #H5FD_CORE driver properties as set
* by H5Pset_fapl_core().
*
* \since 1.4.0
*
*/
H5_DLL herr_t H5Pget_fapl_core(hid_t fapl_id, size_t *increment /*out*/, hbool_t *backing_store /*out*/);
#ifdef __cplusplus
}
#endif
#endif
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