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|
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Copyright by The HDF Group. *
* Copyright by the Board of Trustees of the University of Illinois. *
* 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. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* This file contains public declarations for the H5F module.
*/
#ifndef H5Fpublic_H
#define H5Fpublic_H
/* Public header files needed by this file */
#include "H5public.h"
#include "H5ACpublic.h"
#include "H5Ipublic.h"
/* When this header is included from a private header, don't make calls to H5check() */
#undef H5CHECK
#ifndef H5private_H
#define H5CHECK H5check(),
#else /* H5private_H */
#define H5CHECK
#endif /* H5private_H */
/*
* These are the bits that can be passed to the `flags' argument of
* H5Fcreate() and H5Fopen(). Use the bit-wise OR operator (|) to combine
* them as needed. As a side effect, they call H5check_version() to make sure
* that the application is compiled with a version of the hdf5 header files
* which are compatible with the library to which the application is linked.
* We're assuming that these constants are used rather early in the hdf5
* session.
*
* H5F_ACC_DEBUG no longer has any prints any special debug info. The symbol is
* being retained and will be listed as deprecated in HDF5 1.10.0.
*/
#define H5F_ACC_RDONLY (H5CHECK 0x0000u) /**< Absence of RDWR: read-only */
#define H5F_ACC_RDWR (H5CHECK 0x0001u) /**< Open for read and write */
#define H5F_ACC_TRUNC (H5CHECK 0x0002u) /**< Overwrite existing files */
#define H5F_ACC_EXCL (H5CHECK 0x0004u) /**< Fail if file already exists*/
#define H5F_ACC_DEBUG (H5CHECK 0x0000u) /**< print debug info (no longer used) */
#define H5F_ACC_CREAT (H5CHECK 0x0010u) /**< create non-existing files */
/**
* Default property list identifier
*
* \internal Value passed to H5Pset_elink_acc_flags to cause flags to be taken from the parent file.
* \internal ignore setting on lapl
*/
#define H5F_ACC_DEFAULT (H5CHECK 0xffffu)
/* Flags for H5Fget_obj_count() & H5Fget_obj_ids() calls */
#define H5F_OBJ_FILE (0x0001u) /**< File objects */
#define H5F_OBJ_DATASET (0x0002u) /**< Dataset objects */
#define H5F_OBJ_GROUP (0x0004u) /**< Group objects */
#define H5F_OBJ_DATATYPE (0x0008u) /**< Named datatype objects */
#define H5F_OBJ_ATTR (0x0010u) /**< Attribute objects */
#define H5F_OBJ_ALL (H5F_OBJ_FILE | H5F_OBJ_DATASET | H5F_OBJ_GROUP | H5F_OBJ_DATATYPE | H5F_OBJ_ATTR)
#define H5F_OBJ_LOCAL \
(0x0020u) /**< Restrict search to objects opened through current file ID \
(as opposed to objects opened through any file ID accessing this file) */
#define H5F_FAMILY_DEFAULT (hsize_t)0
#ifdef H5_HAVE_PARALLEL
/**
* Use this constant string as the MPI_Info key to set H5Fmpio debug flags.
* To turn on H5Fmpio debug flags, set the MPI_Info value with this key to
* have the value of a string consisting of the characters that turn on the
* desired flags.
*/
#define H5F_MPIO_DEBUG_KEY "H5F_mpio_debug_key"
#endif /* H5_HAVE_PARALLEL */
/**
* The scope of an operation such as H5Fflush(), e.g.,
* a single file vs. a set of mounted files
*/
typedef enum H5F_scope_t {
H5F_SCOPE_LOCAL = 0, /**< The specified file handle only */
H5F_SCOPE_GLOBAL = 1 /**< The entire virtual file */
} H5F_scope_t;
/**
* Unlimited file size for H5Pset_external()
*/
#define H5F_UNLIMITED ((hsize_t)(-1L))
/**
* How does file close behave?
*/
typedef enum H5F_close_degree_t {
H5F_CLOSE_DEFAULT = 0, /**< Use the degree pre-defined by underlying VFD */
H5F_CLOSE_WEAK = 1, /**< File closes only after all opened objects are closed */
H5F_CLOSE_SEMI = 2, /**< If no opened objects, file is closed; otherwise, file close fails */
H5F_CLOSE_STRONG = 3 /**< If there are opened objects, close them first, then close file */
} H5F_close_degree_t;
/**
* Current "global" information about file
*/
//! <!-- [H5F_info_t_snip] -->
typedef struct H5F_info_t {
hsize_t super_ext_size; /**< Superblock extension size */
struct {
hsize_t hdr_size; /**< Shared object header message header size */
H5_ih_info_t msgs_info; /**< Shared object header message index & heap size */
} sohm;
} H5F_info_t;
//! <!-- [H5F_info_t_snip] -->
/**
* Types of allocation requests. The values larger than #H5FD_MEM_DEFAULT
* should not change other than adding new types to the end. These numbers
* might appear in files.
*
* \internal Please change the log VFD flavors array if you change this
* enumeration.
*/
typedef enum H5F_mem_t {
H5FD_MEM_NOLIST = -1, /**< Data should not appear in the free list.
* Must be negative.
*/
H5FD_MEM_DEFAULT = 0, /**< Value not yet set. Can also be the
* datatype set in a larger allocation
* that will be suballocated by the library.
* Must be zero.
*/
H5FD_MEM_SUPER = 1, /**< Superblock data */
H5FD_MEM_BTREE = 2, /**< B-tree data */
H5FD_MEM_DRAW = 3, /**< Raw data (content of datasets, etc.) */
H5FD_MEM_GHEAP = 4, /**< Global heap data */
H5FD_MEM_LHEAP = 5, /**< Local heap data */
H5FD_MEM_OHDR = 6, /**< Object header data */
H5FD_MEM_NTYPES /**< Sentinel value - must be last */
} H5F_mem_t;
/**
* Library's format versions
*/
typedef enum H5F_libver_t {
H5F_LIBVER_EARLIEST, /**< Use the earliest possible format for storing objects */
H5F_LIBVER_LATEST /**< Use the latest possible format available for storing objects*/
} H5F_libver_t;
/* Define file format version for 1.8 to prepare for 1.10 release.
* (Not used anywhere now)*/
#define H5F_LIBVER_18 H5F_LIBVER_LATEST
#ifdef __cplusplus
extern "C" {
#endif
/**
* \ingroup H5F
*
* \brief Checks if a file can be opened with a given file access property
* list
*
* \param[in] filename Name of a file
*
* \return \htri_t
*
* \details H5F__is_hdf5() checks if the file specified by \p
* filename can be opened.
*
* \note The H5Fis_hdf5(), only uses
* the default file driver when opening a file.
*
*/
H5_DLL htri_t H5Fis_hdf5(const char *filename);
/**
* \ingroup H5F
*
* \brief Creates an HDF5 file
*
* \param[in] filename Name of the file to create
* \param[in] flags File access flags. Allowable values are:
* - #H5F_ACC_TRUNC: Truncate file, if it already exists,
* erasing all data previously stored in the file
* - #H5F_ACC_EXCL: Fail if file already exists
* \fcpl_id
* \fapl_id
* \return \hid_t{file}
*
* \details H5Fcreate() is the primary function for creating HDF5 files; it
* creates a new HDF5 file with the specified name and property lists.
*
* The \p filename parameter specifies the name of the new file.
*
* The \p flags parameter specifies whether an existing file is to be
* overwritten. It should be set to either #H5F_ACC_TRUNC to overwrite
* an existing file or #H5F_ACC_EXCL, instructing the function to fail
* if the file already exists.
*
* New files are always created in read-write mode, so the read-write
* and read-only flags, #H5F_ACC_RDWR and #H5F_ACC_RDONLY,
* respectively, are not relevant in this function. Further note that
* a specification of #H5F_ACC_RDONLY will be ignored; the file will
* be created in read-write mode, regardless.
*
* More complex behaviors of file creation and access are controlled
* through the file creation and file access property lists,
* \p fcpl_id and \p fapl_id, respectively. The value of #H5P_DEFAULT
* for any property list value indicates that the library should use
* the default values for that appropriate property list.
*
* The return value is a file identifier for the newly-created file;
* this file identifier should be closed by calling H5Fclose() when
* it is no longer needed.
*
* \par Example
* \snippet H5F_examples.c minimal
*
* \note #H5F_ACC_TRUNC and #H5F_ACC_EXCL are mutually exclusive; use
* exactly one.
*
* \note An additional flag, #H5F_ACC_DEBUG, prints debug information. This
* flag can be combined with one of the above values using the bit-wise
* OR operator (\c |), but it is used only by HDF5 library developers;
* \Emph{it is neither tested nor supported for use in applications}.
*
* \attention \Bold{Special case — File creation in the case of an already-open file:}
* If a file being created is already opened, by either a previous
* H5Fopen() or H5Fcreate() call, the HDF5 library may or may not
* detect that the open file and the new file are the same physical
* file. (See H5Fopen() regarding the limitations in detecting the
* re-opening of an already-open file.)\n
* If the library detects that the file is already opened,
* H5Fcreate() will return a failure, regardless of the use of
* #H5F_ACC_TRUNC.\n
* If the library does not detect that the file is already opened
* and #H5F_ACC_TRUNC is not used, H5Fcreate() will return a failure
* because the file already exists. Note that this is correct
* behavior.\n
* But if the library does not detect that the file is already
* opened and #H5F_ACC_TRUNC is used, H5Fcreate() will truncate the
* existing file and return a valid file identifier. Such a
* truncation of a currently-opened file will almost certainly
* result in errors. While unlikely, the HDF5 library may not be
* able to detect, and thus report, such errors.\n
* Applications should avoid calling H5Fcreate() with an already
* opened file.
*
* \since 1.0.0
*
* \see H5Fopen(), H5Fclose()
*
*/
H5_DLL hid_t H5Fcreate(const char *filename, unsigned flags, hid_t fcpl_id, hid_t fapl_id);
/**
* \ingroup H5F
*
* \brief Opens an existing HDF5 file
*
* \param[in] filename Name of the file to be opened
* \param[in] flags File access flags. Allowable values are:
* - #H5F_ACC_RDWR: Allows read and write access to file
* - #H5F_ACC_RDONLY: Allows read-only access to file
* - #H5F_ACC_RDWR \c | #H5F_ACC_SWMR_WRITE: Indicates that
* the file is open for writing in a
* single-writer/multi-writer (SWMR) scenario.
* - #H5F_ACC_RDONLY \c | #H5F_ACC_SWMR_READ: Indicates
* that the file is open for reading in a
* single-writer/multi-reader (SWMR) scenario.
* - An additional flag, #H5F_ACC_DEBUG, prints debug
* information. This flag can be combined with one of the
* above values using the bit-wise OR operator (\c |), but
* it is used only by HDF5 library developers;
* \Emph{it is neither tested nor supported} for use in
* applications.
* \fapl_id
* \return \hid_t{file}
*
* \details H5Fopen() is the primary function for accessing existing HDF5 files.
* This function opens the named file in the specified access mode and
* with the specified access property list.
*
* Note that H5Fopen() does not create a file if it does not already
* exist; see H5Fcreate().
*
* The \p filename parameter specifies the name of the file to be
* opened.
*
* The \p fapl_id parameter specifies the file access property list.
* Use of #H5P_DEFAULT specifies that default I/O access properties
* are to be used.
*
* The \p flags parameter specifies whether the file will be opened in
* read-write or read-only mode, #H5F_ACC_RDWR or #H5F_ACC_RDONLY,
* respectively. More complex behaviors of file access are controlled
* through the file-access property list.
*
* The return value is a file identifier for the open file; this file
* identifier should be closed by calling H5Fclose() when it is no
* longer needed.
*
* \par Example
* \snippet H5F_examples.c open
*
* \note #H5F_ACC_RDWR and #H5F_ACC_RDONLY are mutually exclusive; use
* exactly one.
*
* \attention \Bold{Special cases — Multiple opens:} A file can often be opened
* with a new H5Fopen() call without closing an already-open
* identifier established in a previous H5Fopen() or H5Fcreate()
* call. Each such H5Fopen() call will return a unique identifier
* and the file can be accessed through any of these identifiers as
* long as the identifier remains valid. In such multiply-opened
* cases, the open calls must use the same flags argument and the
* file access property lists must use the same file close degree
* property setting (see the external link discussion below and
* H5Pset_fclose_degree()).\n
* In some cases, such as files on a local Unix file system, the
* HDF5 library can detect that a file is multiply opened and will
* maintain coherent access among the file identifiers.\n
* But in many other cases, such as parallel file systems or
* networked file systems, it is not always possible to detect
* multiple opens of the same physical file. In such cases, HDF5
* will treat the file identifiers as though they are accessing
* different files and will be unable to maintain coherent access.
* Errors are likely to result in these cases. While unlikely, the
* HDF5 library may not be able to detect, and thus report,
* such errors.\n
* It is generally recommended that applications avoid multiple
* opens of the same file.
*
* \attention \Bold{Special restriction on multiple opens of a file first
* opened by means of an external link:} When an external link is
* followed, the external file is always opened with the weak file
* close degree property setting, #H5F_CLOSE_WEAK (see
* H5Lcreate_external() and H5Pset_fclose_degree()). If the file is
* reopened with H5Fopen while it remains held open from such an
* external link call, the file access property list used in the
* open call must include the file close degree setting
* #H5F_CLOSE_WEAK or the open will fail.
*
* \version 1.10.0 The #H5F_ACC_SWMR_WRITE and #H5F_ACC_SWMR_READ flags were added.
*
* \see H5Fclose()
*
*/
H5_DLL hid_t H5Fopen(const char *filename, unsigned flags, hid_t fapl_id);
/**
* \ingroup H5F
*
* \brief Returns a new identifier for a previously-opened HDF5 file
*
* \param[in] file_id Identifier of a file for which an additional identifier
* is required
*
* \return \hid_t{file}
*
* \details H5Freopen() returns a new file identifier for an already-open HDF5
* file, as specified by \p file_id. Both identifiers share caches and
* other information. The only difference between the identifiers is
* that the new identifier is not mounted anywhere and no files are
* mounted on it.
*
* The new file identifier should be closed by calling H5Fclose() when
* it is no longer needed.
*
* \note Note that there is no circumstance under which H5Freopen() can
* actually open a closed file; the file must already be open and have an
* active \p file_id. E.g., one cannot close a file with H5Fclose() on
* \p file_id then use H5Freopen() on \p file_id to reopen it.
*
*/
H5_DLL hid_t H5Freopen(hid_t file_id);
/**
* \ingroup H5F
*
* \brief Flushes all buffers associated with a file to storage
*
* \loc_id{object_id}
* \param[in] scope The scope of the flush action
*
* \return \herr_t
*
* \details H5Fflush() causes all buffers associated with a file to be
* immediately flushed to storage without removing the data from the
* cache.
*
* \p object_id can be any object associated with the file, including
* the file itself, a dataset, a group, an attribute, or a named
* datatype.
*
* \p scope specifies whether the scope of the flush action is
* global or local. Valid values are as follows:
* \scopes
*
* \par Example
* \snippet H5F_examples.c flush
*
* \attention HDF5 does not possess full control over buffering. H5Fflush()
* flushes the internal HDF5 buffers then asks the operating system
* (the OS) to flush the system buffers for the open files. After
* that, the OS is responsible for ensuring that the data is
* actually flushed to disk.
*
*/
H5_DLL herr_t H5Fflush(hid_t object_id, H5F_scope_t scope);
/**
* \ingroup H5F
*
* \brief Terminates access to an HDF5 file
*
* \file_id
* \return \herr_t
*
* \details H5Fclose() terminates access to an HDF5 file (specified by
* \p file_id) by flushing all data to storage.
*
* If this is the last file identifier open for the file and no other
* access identifier is open (e.g., a dataset identifier, group
* identifier, or shared datatype identifier), the file will be fully
* closed and access will end.
*
* \par Example
* \snippet H5F_examples.c minimal
*
* \note \Bold{Delayed close:} Note the following deviation from the
* above-described behavior. If H5Fclose() is called for a file but one
* or more objects within the file remain open, those objects will remain
* accessible until they are individually closed. Thus, if the dataset
* \c data_sample is open when H5Fclose() is called for the file
* containing it, \c data_sample will remain open and accessible
* (including writable) until it is explicitly closed. The file will be
* automatically closed once all objects in the file have been closed.\n
* Be warned, however, that there are circumstances where it is not
* possible to delay closing a file. For example, an MPI-IO file close is
* a collective call; all of the processes that opened the file must
* close it collectively. The file cannot be closed at some time in the
* future by each process in an independent fashion. Another example is
* that an application using an AFS token-based file access privilege may
* destroy its AFS token after H5Fclose() has returned successfully. This
* would make any future access to the file, or any object within it,
* illegal.\n
* In such situations, applications must close all open objects in a file
* before calling H5Fclose. It is generally recommended to do so in all
* cases.
*
* \see H5Fopen()
*
*/
H5_DLL herr_t H5Fclose(hid_t file_id);
/**
* \ingroup H5F
*
* \brief Returns a file creation property list identifier
*
* \file_id
* \return \hid_t{file creation property list}
*
* \details H5Fget_create_plist() returns the file creation property list
* identifier identifying the creation properties used to create this
* file. This function is useful for duplicating properties when
* creating another file.
*
* The creation property list identifier should be released with
* H5Pclose().
*
*/
H5_DLL hid_t H5Fget_create_plist(hid_t file_id);
/**
* \ingroup H5F
*
* \brief Returns a file access property list identifier
*
* \file_id
* \return \hid_t{file access property list}
*
* \details H5Fget_access_plist() returns the file access property list
* identifier of the specified file.
*
*/
H5_DLL hid_t H5Fget_access_plist(hid_t file_id);
/**
* \ingroup H5F
*
* \brief Determines the read/write or read-only status of a file
*
* \file_id
* \param[out] intent Access mode flag as originally passed with H5Fopen()
*
* \return \herr_t
*
* \details Given the identifier of an open file, \p file_id, H5Fget_intent()
* retrieves the intended access mode" flag passed with H5Fopen() when
* the file was opened.
*
* The value of the flag is returned in \p intent. Valid values are as
* follows:
* \file_access
*
* \note The function will not return an error if intent is NULL; it will
* simply do nothing.
*
* \version 1.10.0 Function enhanced to work with SWMR functionality.
*
* \since 1.8.0
*
*/
H5_DLL herr_t H5Fget_intent(hid_t file_id, unsigned *intent);
/**
* \ingroup H5F
*
* \brief Returns the number of open object identifiers for an open file
*
* \file_id or #H5F_OBJ_ALL for all currently-open HDF5 files
* \param[in] types Type of object for which identifiers are to be returned
*
* \return Returns the number of open objects if successful; otherwise returns
* a negative value.
*
* \details Given the identifier of an open file, file_id, and the desired
* object types, types, H5Fget_obj_count() returns the number of open
* object identifiers for the file.
*
* To retrieve a count of open identifiers for open objects in all
* HDF5 application files that are currently open, pass the value
* #H5F_OBJ_ALL in \p file_id.
*
* The types of objects to be counted are specified in types as
* follows:
* \obj_types
*
* Multiple object types can be combined with the
* logical \c OR operator (|). For example, the expression
* \c (#H5F_OBJ_DATASET|#H5F_OBJ_GROUP) would call for datasets and
* groups.
*
* \version 1.6.8, 1.8.2 Function return type changed to \c ssize_t.
* \version 1.6.5 #H5F_OBJ_LOCAL has been added as a qualifier on the types
* of objects to be counted. #H5F_OBJ_LOCAL restricts the
* search to objects opened through current file identifier.
*
*/
H5_DLL ssize_t H5Fget_obj_count(hid_t file_id, unsigned types);
/**
*-------------------------------------------------------------------------
* \ingroup H5F
*
* \brief Returns a list of open object identifiers
*
* \file_id or #H5F_OBJ_ALL for all currently-open HDF5 files
* \param[in] types Type of object for which identifiers are to be returned
* \param[in] max_objs Maximum number of object identifiers to place into
* \p obj_id_list
* \param[out] obj_id_list Pointer to the returned buffer of open object
* identifiers
*
* \return Returns number of objects placed into \p obj_id_list if successful;
* otherwise returns a negative value.
*
* \details Given the file identifier \p file_id and the type of objects to be
* identified, types, H5Fget_obj_ids() returns the list of identifiers
* for all open HDF5 objects fitting the specified criteria.
*
* To retrieve identifiers for open objects in all HDF5 application
* files that are currently open, pass the value #H5F_OBJ_ALL in
* \p file_id.
*
* The types of object identifiers to be retrieved are specified in
* types using the codes listed for the same parameter in
* H5Fget_obj_count().
*
* To retrieve a count of open objects, use the H5Fget_obj_count()
* function. This count can be used to set the \p max_objs parameter.
*
* \version 1.8.2 Function return type changed to \c ssize_t and \p
* max_objs parameter datatype changed to \c size_t.
* \version 1.6.8 Function return type changed to \c ssize_t and \p
* max_objs parameter datatype changed to \c size_t.
* \since 1.6.0
*
*/
H5_DLL ssize_t H5Fget_obj_ids(hid_t file_id, unsigned types, size_t max_objs, hid_t *obj_id_list);
/**
* \ingroup H5F
*
* \brief Returns pointer to the file handle from the virtual file driver
*
* \file_id
* \fapl_id{fapl}
* \param[out] file_handle Pointer to the file handle being used by the
* low-level virtual file driver
*
* \return \herr_t
*
* \details Given the file identifier \p file_id and the file access property
* list \p fapl_id, H5Fget_vfd_handle() returns a pointer to the file
* handle from the low-level file driver currently being used by the
* HDF5 library for file I/O.
*
* \note For most drivers, the value of \p fapl_id will be #H5P_DEFAULT. For
* the \c FAMILY or \c MULTI drivers, this value should be defined
* through the property list functions: H5Pset_family_offset() for the
* \c FAMILY driver and H5Pset_multi_type() for the \c MULTI driver
*
* \since 1.6.0
*
*/
H5_DLL herr_t H5Fget_vfd_handle(hid_t file_id, hid_t fapl, void **file_handle);
/**
* \ingroup H5F
*
* \brief Mounts an HDF5 file
*
* \loc_id{loc}
* \param[in] name Name of the group onto which the file specified by \p child
* is to be mounted
* \file_id{child}
* \param[in] plist File mount property list identifier. Pass #H5P_DEFAULT!
*
* \return \herr_t
*
* \details H5Fmount() mounts the file specified by \p child onto the object
* specified by \p loc and \p name using the mount properties \p plist
* If the object specified by \p loc is a dataset, named datatype or
* attribute, then the file will be mounted at the location where the
* attribute, dataset, or named datatype is attached.
*
* \par Example
* \snippet H5F_examples.c mount
*
* \note To date, no file mount properties have been defined in HDF5. The
* proper value to pass for \p plist is #H5P_DEFAULT, indicating the
* default file mount property list.
*
*/
H5_DLL herr_t H5Fmount(hid_t loc, const char *name, hid_t child, hid_t plist);
/**
* \ingroup H5F
*
* \brief Unounts an HDF5 file
*
* \loc_id{loc}
* \param[in] name Name of the mount point
*
* \return \herr_t
*
* \details Given a mount point, H5Funmount() dissociates the mount point's
* file from the file mounted there. This function does not close
* either file.
*
* The mount point can be either the group in the parent or the root
* group of the mounted file (both groups have the same name). If the
* mount point was opened before the mount then it is the group in the
* parent; if it was opened after the mount then it is the root group
* of the child.
*
*/
H5_DLL herr_t H5Funmount(hid_t loc, const char *name);
/**
* \ingroup H5F
*
* \brief Returns the amount of free space in a file (in bytes)
*
* \file_id
*
* \return Returns the amount of free space in the file if successful;
* otherwise returns a negative value.
*
* \details Given the identifier of an open file, \p file_id,
* H5Fget_freespace() returns the amount of space that is unused by
* any objects in the file.
*
* The interpretation of this number depends on the configured free space
* management strategy. For example, if the HDF5 library only tracks free
* space in a file from a file open or create until that file is closed,
* then this routine will report the free space that has been created
* during that interval.
*
* \since 1.6.1
*
*/
H5_DLL hssize_t H5Fget_freespace(hid_t file_id);
/**
* \ingroup H5F
*
* \brief Returns the size of an HDF5 file (in bytes)
*
* \file_id
* \param[out] size Size of the file, in bytes
*
* \return \herr_t
*
* \details H5Fget_filesize() returns the size of the HDF5 file specified by
* \p file_id.
*
* The returned size is that of the entire file, as opposed to only
* the HDF5 portion of the file. I.e., size includes the user block,
* if any, the HDF5 portion of the file, and any data that may have
* been appended beyond the data written through the HDF5 library.
*
* \since 1.6.3
*
*/
H5_DLL herr_t H5Fget_filesize(hid_t file_id, hsize_t *size);
/**
* \ingroup H5F
*
* \brief Retrieves a copy of the image of an existing, open file
*
* \file_id
* \param[out] buf_ptr Pointer to the buffer into which the image of the
* HDF5 file is to be copied. If \p buf_ptr is NULL,
* no data will be copied but the function’s return value
* will still indicate the buffer size required (or a
* negative value on error).
* \param[out] buf_len Size of the supplied buffer
*
* \return ssize_t
*
* \details H5Fget_file_image() retrieves a copy of the image of an existing,
* open file. This routine can be used with files opened using the
* SEC2 (or POSIX), STDIO, and Core (or Memory) virtual file drivers
* (VFDs).
*
* If the return value of H5Fget_file_image() is a positive value, it
* will be the length in bytes of the buffer required to store the
* file image. So if the file size is unknown, it can be safely
* determined with an initial H5Fget_file_image() call with buf_ptr
* set to NULL. The file image can then be retrieved with a second
* H5Fget_file_image() call with \p buf_len set to the initial call’s
* return value.
*
* While the current file size can also be retrieved with
* H5Fget_filesize(), that call may produce a larger value than is
* needed. The value returned by H5Fget_filesize() includes the user
* block, if it exists, and any unallocated space at the end of the
* file. It is safe in all situations to get the file size with
* H5Fget_file_image() and it often produces a value that is more
* appropriate for the size of a file image buffer.
*
* \note \Bold{Recommended Reading:} This function is part of the file image
* operations feature set. It is highly recommended to study the guide
* \ref_file_image_ops before using this feature set.
*
* \attention H5Pget_file_image() will fail, returning a negative value, if the
* file is too large for the supplied buffer.
*
* \see H5LTopen_file_image(), H5Pset_file_image(), H5Pget_file_image(),
* H5Pset_file_image_callbacks(), H5Pget_file_image_callbacks()
*
* \since 1.8.0
*
*/
H5_DLL ssize_t H5Fget_file_image(hid_t file_id, void *buf_ptr, size_t buf_len);
/**
* \ingroup MDC
*
* \brief Obtains current metadata cache configuration for target file
*
* \file_id
* \param[in,out] config_ptr Pointer to the H5AC_cache_config_t instance in which
* the current metadata cache configuration is to be
* reported. The fields of this structure are discussed
* \ref H5AC-cache-config-t "here".
* \return \herr_t
*
* \note The \c in direction applies only to the H5AC_cache_config_t::version
* field. All other fields are out parameters.
*
* \details H5Fget_mdc_config() loads the current metadata cache configuration
* into the instance of H5AC_cache_config_t pointed to by the \p config_ptr
* parameter.\n
* The fields of the H5AC_cache_config_t structure are shown below:
* \snippet H5ACpublic.h H5AC_cache_config_t_snip
* \click4more
*
* \since 1.8.0
*
*/
H5_DLL herr_t H5Fget_mdc_config(hid_t file_id, H5AC_cache_config_t *config_ptr);
/**
* \ingroup MDC
*
* \brief Attempts to configure metadata cache of target file
*
* \file_id
* \param[in,out] config_ptr Pointer to the H5AC_cache_config_t instance
* containing the desired configuration.
* The fields of this structure are discussed
* \ref H5AC-cache-config-t "here".
* \return \herr_t
*
* \details H5Fset_mdc_config() attempts to configure the file's metadata cache
* according configuration supplied in \p config_ptr.
* \snippet H5ACpublic.h H5AC_cache_config_t_snip
* \click4more
*
* \since 1.8.0
*
*/
H5_DLL herr_t H5Fset_mdc_config(hid_t file_id, H5AC_cache_config_t *config_ptr);
/**
* \ingroup MDC
*
* \brief Obtains target file's metadata cache hit rate
*
* \file_id
* \param[out] hit_rate_ptr Pointer to the double in which the hit rate is returned. Note that
* \p hit_rate_ptr is undefined if the API call fails
* \return \herr_t
*
* \details H5Fget_mdc_hit_rate() queries the metadata cache of the target file to obtain its hit rate
* \Code{(cache hits / (cache hits + cache misses))} since the last time hit rate statistics
* were reset. If the cache has not been accessed since the last time the hit rate stats were
* reset, the hit rate is defined to be 0.0.
*
* The hit rate stats can be reset either manually (via H5Freset_mdc_hit_rate_stats()), or
* automatically. If the cache's adaptive resize code is enabled, the hit rate stats will be
* reset once per epoch. If they are reset manually as well, the cache may behave oddly.
*
* See the overview of the metadata cache in the special topics section of the user manual for
* details on the metadata cache and its adaptive resize algorithms.
*
*/
H5_DLL herr_t H5Fget_mdc_hit_rate(hid_t file_id, double *hit_rate_ptr);
/**
* \ingroup MDC
*
* \brief Obtains current metadata cache size data for specified file
*
* \file_id
* \param[out] max_size_ptr Pointer to the location in which the current cache maximum size is to be
* returned, or NULL if this datum is not desired
* \param[out] min_clean_size_ptr Pointer to the location in which the current cache minimum clean
* size is to be returned, or NULL if that datum is not desired
* \param[out] cur_size_ptr Pointer to the location in which the current cache size is to be returned,
* or NULL if that datum is not desired
* \param[out] cur_num_entries_ptr Pointer to the location in which the current number of entries in
* the cache is to be returned, or NULL if that datum is not desired
* \returns \herr_t
*
* \details H5Fget_mdc_size() queries the metadata cache of the target file for the desired size
* information, and returns this information in the locations indicated by the pointer
* parameters. If any pointer parameter is NULL, the associated data is not returned.
*
* If the API call fails, the values returned via the pointer parameters are undefined.
*
* If adaptive cache resizing is enabled, the cache maximum size and minimum clean size
* may change at the end of each epoch. Current size and current number of entries can
* change on each cache access.
*
* Current size can exceed maximum size under certain conditions. See the overview of the
* metadata cache in the special topics section of the user manual for a discussion of this.
*
*/
H5_DLL herr_t H5Fget_mdc_size(hid_t file_id, size_t *max_size_ptr, size_t *min_clean_size_ptr,
size_t *cur_size_ptr, int *cur_num_entries_ptr);
/**
* \ingroup MDC
*
* \brief Resets hit rate statistics counters for the target file
*
* \file_id
* \returns \herr_t
*
* \details
* \parblock
* H5Freset_mdc_hit_rate_stats() resets the hit rate statistics counters in the metadata cache
* associated with the specified file.
*
* If the adaptive cache resizing code is enabled, the hit rate statistics are reset at the beginning
* of each epoch. This API call allows you to do the same thing from your program.
*
* The adaptive cache resizing code may behave oddly if you use this call when adaptive cache resizing
* is enabled. However, the call should be useful if you choose to control metadata cache size from your
* program.
*
* See \ref_mdc_in_hdf5 for details about the metadata cache and the adaptive cache resizing
* algorithms. If you have not read, understood, and thought about the material covered in that
* documentation,
* you should not be using this API call.
* \endparblock
*
*/
H5_DLL herr_t H5Freset_mdc_hit_rate_stats(hid_t file_id);
/**
* \ingroup H5F
*
* \brief Retrieves name of file to which object belongs
*
* \obj_id
* \param[out] name Buffer for the file name
* \param[in] size Size, in bytes, of the \p name buffer
*
* \return Returns the length of the file name if successful; otherwise returns
* a negative value.
*
* \details H5Fget_name() retrieves the name of the file to which the object \p
* obj_id belongs. The object can be a file, group, dataset,
* attribute, or named datatype.
*
* Up to \p size characters of the file name are returned in \p name;
* additional characters, if any, are not returned to the user
* application.
*
* If the length of the name, which determines the required value of
* size, is unknown, a preliminary H5Fget_name() call can be made by
* setting \p name to NULL. The return value of this call will be the
* size of the file name; that value plus one (1) can then be assigned
* to size for a second H5Fget_name() call, which will retrieve the
* actual name. (The value passed in with the parameter \p size must
* be one greater than size in bytes of the actual name in order to
* accommodate the null terminator; if \p size is set to the exact
* size of the name, the last byte passed back will contain the null
* terminator and the last character will be missing from the name
* passed back to the calling application.)
*
* If an error occurs, the buffer pointed to by \p name is unchanged
* and the function returns a negative value.
*
* \since 1.6.3
*
*/
H5_DLL ssize_t H5Fget_name(hid_t obj_id, char *name, size_t size);
/**
* \ingroup H5F
*
* \brief Retrieves name of file to which object belongs
*
* \fgdta_obj_id
* \param[out] file_info Buffer for global file information
*
* \return \herr_t
*
* \details H5Fget_info() returns global information for the file associated
* with the object identifier \p obj_id in the H5F_info_t \c struct
* named \p file_info.
*
* \p obj_id is an identifier for any object in the file of interest.
*
* H5F_info_t struct is defined in H5Fpublic.h as follows:
* \snippet this H5F_info_t_snip
*
* \c super_ext_size is the size of the superblock extension.
*
* The \c sohm sub-struct contains shared object header message
* information as follows:
* \li \c hdr_size is the size of the shared object header message.
* \li \c msgs_info is an H5_ih_info_t struct defined in H5public.h as
* follows: \snippet H5public.h H5_ih_info_t_snip
*
* \li \p index_size is the summed size of all the shared object
* header indexes. Each index might be either a B-tree or
* a list.
*
* \since 1.8.0
*
*/
H5_DLL herr_t H5Fget_info(hid_t obj_id, H5F_info_t *file_info);
/**
* \ingroup H5F
*
* \brief Clears the external link open file cache
*
* \file_id
* \return \herr_t
*
* \details H5Fclear_elink_file_cache() evicts all the cached child files in
* the specified file’s external file cache, causing them to be closed
* if there is nothing else holding them open.
*
* H5Fclear_elink_file_cache() does not close the cache itself;
* subsequent external link traversals from the parent file will again
* cache the target file. See H5Pset_elink_file_cache_size() for
* information on closing the file cache.
*
* \see H5Pset_elink_file_cache_size(), H5Pget_elink_file_cache_size()
*
* \since 1.8.7
*
*/
H5_DLL herr_t H5Fclear_elink_file_cache(hid_t file_id);
#ifdef H5_HAVE_PARALLEL
/**
* \ingroup PH5F
*
* \brief Sets the MPI atomicity mode
*
* \file_id
* \param[in] flag Logical flag for atomicity setting. Valid values are:
* \li \c 1 -- Sets MPI file access to atomic mode.
* \li \c 0 -- Sets MPI file access to nonatomic mode.
* \returns \herr_t
*
* \par Motivation
* H5Fset_mpi_atomicity() is applicable only in parallel environments using MPI I/O.
* The function is one of the tools used to ensure sequential consistency. This means
* that a set of operations will behave as though they were performed in a serial
* order consistent with the program order.
*
* \details
* \parblock
* H5Fset_mpi_atomicity() sets MPI consistency semantics for data access to the file,
* \p file_id.
*
* If \p flag is set to \c 1, all file access operations will appear atomic, guaranteeing
* sequential consistency. If \p flag is set to \c 0, enforcement of atomic file access
* will be turned off.
*
* H5Fset_mpi_atomicity() is a collective function and all participating processes must
* pass the same values for \p file_id and \p flag.
*
* This function is available only when the HDF5 library is configured with parallel support
* (\Code{--enable-parallel}). It is useful only when used with the #H5FD_MPIO driver
* (see H5Pset_fapl_mpio()).
* \endparblock
*
* \attention
* \parblock
* H5Fset_mpi_atomicity() calls \Code{MPI_File_set_atomicity} underneath and is not supported
* if the execution platform does not support \Code{MPI_File_set_atomicity}. When it is
* supported and used, the performance of data access operations may drop significantly.
*
* In certain scenarios, even when \Code{MPI_File_set_atomicity} is supported, setting
* atomicity with H5Fset_mpi_atomicity() and \p flag set to 1 does not always yield
* strictly atomic updates. For example, some H5Dwrite() calls translate to multiple
* \Code{MPI_File_write_at} calls. This happens in all cases where the high-level file
* access routine translates to multiple lower level file access routines.
* The following scenarios will raise this issue:
* \li Non-contiguous file access using independent I/O
* \li Partial collective I/O using chunked access
* \li Collective I/O using filters or when data conversion is required
*
* This issue arises because MPI atomicity is a matter of MPI file access operations rather
* than HDF5 access operations. But the user is normally seeking atomicity at the HDF5 level.
* To accomplish this, the application must set a barrier after a write, H5Dwrite(), but before
* the next read, H5Dread(), in addition to calling H5Fset_mpi_atomicity().The barrier will
* guarantee that all underlying write operations execute atomically before the read
* operations starts. This ensures additional ordering semantics and will normally produce
* the desired behavior.
* \endparblock
*
* \see \ref_cons_semantics
*
* \since 1.8.9
*
*/
H5_DLL herr_t H5Fset_mpi_atomicity(hid_t file_id, hbool_t flag);
/**
* \ingroup PH5F
*
* \brief Retrieves the atomicity mode in use
*
* \file_id
* \param[out] flag Logical flag for atomicity setting. Valid values are:
* \li 1 -- MPI file access is set to atomic mode.
* \li 0 -- MPI file access is set to nonatomic mode.
* \returns \herr_t
*
* \details H5Fget_mpi_atomicity() retrieves the current consistency semantics mode for
* data access for the file \p file_id.
*
* Upon successful return, \p flag will be set to \c 1 if file access is set
* to atomic mode and \c 0 if file access is set to nonatomic mode.
*
* \see \ref_cons_semantics
*
* \since 1.8.9
*
*/
H5_DLL herr_t H5Fget_mpi_atomicity(hid_t file_id, hbool_t *flag);
#endif /* H5_HAVE_PARALLEL */
#ifdef __cplusplus
}
#endif
#endif /* H5Fpublic_H */
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