/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 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 */ /* When this header is included from a private HDF5 header, don't make calls to H5open() */ #undef H5OPEN #ifndef H5private_H #define H5OPEN H5open(), #else /* H5private_H */ #define H5OPEN #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. */ #define H5F_ACC_RDONLY (H5CHECK H5OPEN 0x0000u) /**< Absence of RDWR: read-only */ #define H5F_ACC_RDWR (H5CHECK H5OPEN 0x0001u) /**< Open for read and write */ #define H5F_ACC_TRUNC (H5CHECK H5OPEN 0x0002u) /**< Overwrite existing files */ #define H5F_ACC_EXCL (H5CHECK H5OPEN 0x0004u) /**< Fail if file already exists*/ /* NOTE: 0x0008u was H5F_ACC_DEBUG, now deprecated */ #define H5F_ACC_CREAT (H5CHECK H5OPEN 0x0010u) /**< Create non-existing files */ #define H5F_ACC_SWMR_WRITE \ (H5CHECK 0x0020u) /**< Indicate that this file is open for writing in a \ * single-writer/multi-reader (SWMR) scenario. \ * Note that the process(es) opening the file for reading \ * must open the file with #H5F_ACC_RDONLY and use the \ * #H5F_ACC_SWMR_READ access flag. */ #define H5F_ACC_SWMR_READ \ (H5CHECK 0x0040u) /**< Indicate that this file is open for reading in a \ * single-writer/multi-reader (SWMR) scenario. Note that \ * the process(es) opening the file for SWMR reading must \ * also open the file with the #H5F_ACC_RDONLY flag. */ /** * 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 H5OPEN 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 */ //! typedef struct H5F_info2_t { struct { unsigned version; /**< Superblock version # */ hsize_t super_size; /**< Superblock size */ hsize_t super_ext_size; /**< Superblock extension size */ } super; struct { unsigned version; /**< Version # of file free space management */ hsize_t meta_size; /**< Free space manager metadata size */ hsize_t tot_space; /**< Amount of free space in the file */ } free; struct { unsigned version; /**< Version # of shared object header info */ 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_info2_t; //! /** * 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; /** * Free space section information */ //! typedef struct H5F_sect_info_t { haddr_t addr; /**< Address of free space section */ hsize_t size; /**< Size of free space section */ } H5F_sect_info_t; //! /** * Library's format versions */ typedef enum H5F_libver_t { H5F_LIBVER_ERROR = -1, H5F_LIBVER_EARLIEST = 0, /**< Use the earliest possible format for storing objects */ H5F_LIBVER_V18 = 1, /**< Use the latest v18 format for storing objects */ H5F_LIBVER_V110 = 2, /**< Use the latest v110 format for storing objects */ H5F_LIBVER_V112 = 3, /**< Use the latest v112 format for storing objects */ H5F_LIBVER_NBOUNDS } H5F_libver_t; #define H5F_LIBVER_LATEST H5F_LIBVER_V112 /** * File space handling strategy */ //! typedef enum H5F_fspace_strategy_t { H5F_FSPACE_STRATEGY_FSM_AGGR = 0, /**< Mechanisms: free-space managers, aggregators, and virtual file drivers This is the library default when not set */ H5F_FSPACE_STRATEGY_PAGE = 1, /**< Mechanisms: free-space managers with embedded paged aggregation and virtual file drivers */ H5F_FSPACE_STRATEGY_AGGR = 2, /**< Mechanisms: aggregators and virtual file drivers */ H5F_FSPACE_STRATEGY_NONE = 3, /**< Mechanisms: virtual file drivers */ H5F_FSPACE_STRATEGY_NTYPES /**< Sentinel */ } H5F_fspace_strategy_t; //! /** * File space handling strategy for release 1.10.0 * * \deprecated 1.10.1 */ typedef enum H5F_file_space_type_t { H5F_FILE_SPACE_DEFAULT = 0, /**< Default (or current) free space strategy setting */ H5F_FILE_SPACE_ALL_PERSIST = 1, /**< Persistent free space managers, aggregators, virtual file driver */ H5F_FILE_SPACE_ALL = 2, /**< Non-persistent free space managers, aggregators, virtual file driver This is the library default */ H5F_FILE_SPACE_AGGR_VFD = 3, /**< Aggregators, Virtual file driver */ H5F_FILE_SPACE_VFD = 4, /**< Virtual file driver */ H5F_FILE_SPACE_NTYPES /**< Sentinel */ } H5F_file_space_type_t; //! #define H5F_NUM_METADATA_READ_RETRY_TYPES 21 /** * Data structure to report the collection of read retries for metadata items with checksum as * used by H5Fget_metadata_read_retry_info() */ typedef struct H5F_retry_info_t { unsigned nbins; uint32_t *retries[H5F_NUM_METADATA_READ_RETRY_TYPES]; } H5F_retry_info_t; //! /** * Callback for H5Pset_object_flush_cb() in a file access property list */ typedef herr_t (*H5F_flush_cb_t)(hid_t object_id, void *udata); /*********************/ /* Public Prototypes */ /*********************/ #ifdef __cplusplus extern "C" { #endif /** * \ingroup H5F * * \brief Checks if a file can be opened with a given file access property * list * * \param[in] container_name Name of a file * \fapl_id * * \return \htri_t * * \details H5Fis_accessible() checks if the file specified by \p * container_name can be opened with the file access property list * \p fapl_id. * * \note The H5Fis_accessible() function enables files to be checked with a * given file access property list, unlike H5Fis_hdf5(), which only uses * the default file driver when opening a file. * * \since 1.12.0 * */ H5_DLL htri_t H5Fis_accessible(const char *container_name, hid_t fapl_id); /** * \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 Deletes an HDF5 file * * \param[in] filename Name of the file to delete * \fapl_id * * \return \herr_t * * \details H5Fdelete() deletes an HDF5 file \p filename with a file access * property list \p fapl_id. The \p fapl_id should be configured with * the same VOL connector or VFD that was used to open the file. * * This API was introduced for use with the Virtual Object Layer * (VOL). With the VOL, HDF5 "files" can map to arbitrary storage * schemes such as object stores and relational database tables. The * data created by these implementations may be inconvenient for a * user to remove without a detailed knowledge of the storage scheme. * H5Fdelete() gives VOL connector authors the ability to add * connector-specific delete code to their connectors so that users * can remove these "files" without detailed knowledge of the storage * scheme. * * For a VOL connector, H5Fdelete() deletes the file in a way that * makes sense for the specified VOL connector. * * For the native HDF5 connector, HDF5 files will be deleted via the * VFDs, each of which will have to be modified to delete the files it * creates. * * For all implementations, H5Fdelete() will first check if the file * is an HDF5 file via H5Fis_accessible(). This is done to ensure that * H5Fdelete() cannot be used as an arbitrary file deletion call. * * \since 1.12.0 * */ H5_DLL herr_t H5Fdelete(const char *filename, hid_t fapl_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 Retrieves a file's file number that uniquely identifies an open file * * \file_id * \param[out] fileno A buffer to hold the file number * * \return \herr_t * * \details H5Fget_fileno() retrieves a file number for a file specified by the * file identifier \p file_id and the pointer \p fnumber to the file * number. * * \since 1.12.0 * */ H5_DLL herr_t H5Fget_fileno(hid_t file_id, unsigned long *fileno); /** * \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 the file's end-of-allocation (EOA) * * \file_id * \param[out] eoa The file's EOA * * \return \herr_t * * \details H5Fget_eoa() retrieves the file's EOA and returns it in the * parameter eoa. * * \since 1.10.2 * */ H5_DLL herr_t H5Fget_eoa(hid_t file_id, haddr_t *eoa); /** * \ingroup H5F * * \brief Sets the file' EOA to the maximum of (EOA, EOF) + increment * * \file_id * \param[in] increment The number of bytes to be added to the maximum of * (EOA, EOF) * * \return \herr_t * * \details H5Fincrement_filesize() sets the file's EOA to the maximum of (EOA, * EOF) + \p increment. The EOA is the end-of-file address stored in * the file's superblock while EOF is the file's actual end-of-file. * * \since 1.10.2 * */ H5_DLL herr_t H5Fincrement_filesize(hid_t file_id, hsize_t increment); /** * \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_info2() returns global information for the file associated * with the object identifier \p obj_id in the H5F_info2_t \c struct * named \p file_info. * * \p obj_id is an identifier for any object in the file of interest. * * H5F_info2_t struct is defined in H5Fpublic.h as follows: * \snippet this H5F_info2_t_snip * * The \c super sub-struct contains the following information: * \li \c vers is the version number of the superblock. * \li \c super_size is the size of the superblock. * \li \c super_ext_size is the size of the superblock extension. * * The \c free sub-struct contains the following information: * \li vers is the version number of the free-space manager. * \li \c hdr_size is the size of the free-space manager header. * \li \c tot_space is the total amount of free space in the file. * * The \c sohm sub-struct contains shared object header message * information as follows: * \li \c vers is the version number of the shared object header information. * \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. * \li \p heap_size is the size of the heap. * * * \since 1.10.0 * */ H5_DLL herr_t H5Fget_info2(hid_t obj_id, H5F_info2_t *file_info); /** * \ingroup SWMR * * \brief Retrieves the collection of read retries for metadata entries with checksum * * \file_id * \param[out] info Struct containing the collection of read retries for metadata * entries with checksum * \return \herr_t\n * * \details \Bold{Failure Modes:} * \li When the input identifier is not a file identifier. * \li When the pointer to the output structure is NULL. * \li When the memory allocation for \p retries failed. * * \details H5Fget_metadata_read_retry_info() retrieves information regarding the number * of read retries for metadata entries with checksum for the file \p file_id. * This information is reported in the H5F_retry_info_t struct defined in * H5Fpublic.h as follows: * \snippet this H5F_retry_info_t_snip * \c nbins is the number of bins for each \c retries[i] of metadata entry \c i. * It is calculated based on the current number of read attempts used in the * library and logarithmic base 10. * * If read retries are incurred for a metadata entry \c i, the library will * allocate memory for \Code{retries[i] (nbins * sizeof(uint32_t)} and store * the collection of retries there. If there are no retries for a metadata entry * \c i, \Code{retries[i]} will be NULL. After a call to this routine, users should * free each \Code{retries[i]} that is non-NULL, otherwise resource leak will occur. * * For the library default read attempts of 100 for SWMR access, nbins will be 2 * as depicted below: * \li \Code{retries[i][0]} is the number of 1 to 9 read retries. * \li \Code{retries[i][1]} is the number of 10 to 99 read retries. * For the library default read attempts of 1 for non-SWMR access, \c nbins will * be 0 and each \Code{retries[i]} will be NULL. * * The following table lists the 21 metadata entries of \Code{retries[]}: * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Index for \Code{retries[]}Metadata entries*
0Object header (version 2)
1Object header chunk (version 2)
2B-tree header (version 2)
3B-tree internal node (version 2)
4B-tree leaf node (version 2)
5Fractal heap header
6Fractal heap direct block (optional checksum)
7Fractal heap indirect block
8Free-space header
9Free-space sections
10Shared object header message table
11Shared message record list
12Extensive array header
13Extensive array index block
14Extensive array super block
15Extensive array data block
16Extensive array data block page
17Fixed array super block
18Fixed array data block
19Fixed array data block page
20File's superblock (version 2)
* All entries are of version 0 (zero) unless indicated * otherwise.
* * \note On a system that is not atomic, the library might possibly read inconsistent * metadata with checksum when performing single-writer/multiple-reader (SWMR) * operations for an HDF5 file. Upon encountering such situations, the library * will try reading the metadata again for a set number of times to attempt to * obtain consistent data. The maximum number of read attempts used by the library * will be either the value set via H5Pset_metadata_read_attempts() or the library * default value when a value is not set.\n * When the current number of metadata read attempts used in the library is unable * to remedy the reading of inconsistent metadata on a system, the user can assess * the information obtained via this routine to derive a different maximum value. * The information can also be helpful for debugging purposes to identify potential * issues with metadata flush dependencies and SWMR implementation in general. * * \since 1.10.0 * */ H5_DLL herr_t H5Fget_metadata_read_retry_info(hid_t file_id, H5F_retry_info_t *info); /** * \ingroup SWMR * * \brief Retrieves free-space section information for a file * * \file_id * * \return \herr_t * * \details H5Fstart_swmr_write() will activate SWMR writing mode for a file * associated with \p file_id. This routine will prepare and ensure * the file is safe for SWMR writing as follows: * \li Check that the file is opened with write access (#H5F_ACC_RDWR). * \li Check that the file is opened with the latest library format to * ensure data structures with check-summed metadata are used. * \li Check that the file is not already marked in SWMR writing mode. * \li Enable reading retries for check-summed metadata to remedy * possible checksum failures from reading inconsistent metadata * on a system that is not atomic. * \li Turn off usage of the library's accumulator to avoid possible * ordering problem on a system that is not atomic. * \li Perform a flush of the file’s data buffers and metadata to set * a consistent state for starting SWMR write operations. * * Library objects are groups, datasets, and committed datatypes. For * the current implementation, groups and datasets can remain open when * activating SWMR writing mode, but not committed datatypes. Attributes * attached to objects cannot remain open either. * * \since 1.10.0 * */ H5_DLL herr_t H5Fstart_swmr_write(hid_t file_id); /** * \ingroup H5F * * \brief Retrieves free-space section information for a file * * \file_id * \param[in] type The file memory allocation type * \param[in] nsects The number of free-space sections * \param[out] sect_info Array of instances of H5F_sect_info_t in which * the free-space section information is to be returned * * \return Returns the number of free-space sections for the specified * free-space manager in the file; otherwise returns a negative value. * * \details H5Fget_free_sections() retrieves free-space section information for * the free-space manager with type that is associated with file * \p file_id. If type is #H5FD_MEM_DEFAULT, this routine retrieves * free-space section information for all the free-space managers in * the file. * * Valid values for \p type are the following: * \mem_types * * H5F_sect_info_t is defined as follows (in H5Fpublic.h): * \snippet this H5F_sect_info_t_snip * * This routine retrieves free-space section information for \p nsects * sections or at most the maximum number of sections in the specified * free-space manager. If the number of sections is not known, a * preliminary H5Fget_free_sections() call can be made by setting \p * sect_info to NULL and the total number of free-space sections for * the specified free-space manager will be returned. Users can then * allocate space for entries in \p sect_info, each of which is * defined as an H5F_sect_info_t \c struct. * * \attention \Bold{Failure Modes:} This routine will fail when the following * is true: * \li The library fails to retrieve the file creation property list * associated with \p file_id. * \li If the parameter \p sect_info is non-null, but the parameter * \p nsects is equal to 0. * \li The library fails to retrieve free-space section information * for the file. * * \since 1.10.0 * */ H5_DLL ssize_t H5Fget_free_sections(hid_t file_id, H5F_mem_t type, size_t nsects, H5F_sect_info_t *sect_info /*out*/); /** * \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); /** * \ingroup H5F * * \brief Enables the switch of version bounds setting for a file * * \file_id * \param[in] low The earliest version of the library that will be used for * writing objects * \param[in] high The latest version of the library that will be used for * writing objects * * \return \herr_t * * \details H5Fset_libver_bounds() enables the switch of version bounds setting * for an open file associated with \p file_id. * * For the parameters \p low and \p high, see the description for * H5Pset_libver_bounds(). * * \par Example * \snippet H5F_examples.c libver_bounds * * \since 1.10.2 * */ H5_DLL herr_t H5Fset_libver_bounds(hid_t file_id, H5F_libver_t low, H5F_libver_t high); /** * \ingroup MDC * * \brief Starts logging metadata cache events if logging was previously enabled * * \file_id * * \return \herr_t * * \details The metadata cache is a central part of the HDF5 library through * which all \Emph{file metadata} reads and writes take place. File * metadata is normally invisible to the user and is used by the * library for purposes such as locating and indexing data. File * metadata should not be confused with user metadata, which consists * of attributes created by users and attached to HDF5 objects such * as datasets via H5A API calls. * * Due to the complexity of the cache, a trace/logging feature has been * created that can be used by HDF5 developers for debugging and performance * analysis. The functions that control this functionality will normally be * of use to a very limited number of developers outside of The HDF Group. * The functions have been documented to help users create logs that can * be sent with bug reports. * * Control of the log functionality is straightforward. Logging is enabled * via the H5Pset_mdc_log_options() function, which will modify the file * access property list used to open or create a file. This function has * a flag that determines whether logging begins at file open or starts * in a paused state. Log messages can then be controlled via the * H5Fstart_mdc_logging() and H5Fstop_mdc_logging() functions. * H5Pget_mdc_log_options() can be used to examine a file access property * list, and H5Fget_mdc_logging_status() will return the current state of * the logging flags. * * The log format is described in the \ref_mdc_logging document. * * \note Logging can only be started or stopped if metadata cache logging was enabled * via H5Pset_mdc_log_options().\n * When enabled and currently logging, the overhead of the logging feature will * almost certainly be significant.\n * The log file is opened when the HDF5 file is opened or created and not when * this function is called for the first time.\n * This function opens the log file and starts logging metadata cache operations * for a particular file. Calling this function when logging has already been * enabled will be considered an error. * * \since 1.10.0 * */ H5_DLL herr_t H5Fstart_mdc_logging(hid_t file_id); /** * \ingroup MDC * * \brief Stops logging metadata cache events if logging was previously enabled and is currently ongoing * * \file_id * * \return \herr_t * * \details The metadata cache is a central part of the HDF5 library through * which all \Emph{file metadata} reads and writes take place. File * metadata is normally invisible to the user and is used by the * library for purposes such as locating and indexing data. File * metadata should not be confused with user metadata, which consists * of attributes created by users and attached to HDF5 objects such * as datasets via H5A API calls. * * Due to the complexity of the cache, a trace/logging feature has been * created that can be used by HDF5 developers for debugging and performance * analysis. The functions that control this functionality will normally be * of use to a very limited number of developers outside of The HDF Group. * The functions have been documented to help users create logs that can * be sent with bug reports. * * Control of the log functionality is straightforward. Logging is enabled * via the H5Pset_mdc_log_options() function, which will modify the file * access property list used to open or create a file. This function has * a flag that determines whether logging begins at file open or starts * in a paused state. Log messages can then be controlled via the * H5Fstart_mdc_logging() and H5Fstop_mdc_logging() functions. * H5Pget_mdc_log_options() can be used to examine a file access property * list, and H5Fget_mdc_logging_status() will return the current state of * the logging flags. * * The log format is described in the \ref_mdc_logging document. * * \note Logging can only be started or stopped if metadata cache logging was enabled * via H5Pset_mdc_log_options().\n * This function only suspends the logging operations. The log file will remain * open and will not be closed until the HDF5 file is closed. * * \since 1.10.0 * */ H5_DLL herr_t H5Fstop_mdc_logging(hid_t file_id); /** * \ingroup MDC * * \brief Gets the current metadata cache logging status * * \file_id * \param[out] is_enabled Whether logging is enabled * \param[out] is_currently_logging Whether events are currently being logged * \return \herr_t * * \details The metadata cache is a central part of the HDF5 library through * which all \Emph{file metadata} reads and writes take place. File * metadata is normally invisible to the user and is used by the * library for purposes such as locating and indexing data. File * metadata should not be confused with user metadata, which consists * of attributes created by users and attached to HDF5 objects such * as datasets via H5A API calls. * * Due to the complexity of the cache, a trace/logging feature has been * created that can be used by HDF5 developers for debugging and performance * analysis. The functions that control this functionality will normally be * of use to a very limited number of developers outside of The HDF Group. * The functions have been documented to help users create logs that can * be sent with bug reports. * * Control of the log functionality is straightforward. Logging is enabled * via the H5Pset_mdc_log_options() function, which will modify the file * access property list used to open or create a file. This function has * a flag that determines whether logging begins at file open or starts * in a paused state. Log messages can then be controlled via the * H5Fstart_mdc_logging() and H5Fstop_mdc_logging() functions. * H5Pget_mdc_log_options() can be used to examine a file access property * list, and H5Fget_mdc_logging_status() will return the current state of * the logging flags. * * The log format is described in the \ref_mdc_logging document. * * \note Unlike H5Fstart_mdc_logging() and H5Fstop_mdc_logging(), this function can * be called on any open file identifier. * * \since 1.10.0 */ H5_DLL herr_t H5Fget_mdc_logging_status(hid_t file_id, hbool_t *is_enabled, hbool_t *is_currently_logging); /** * \ingroup SWMR * * \todo UFO? */ H5_DLL herr_t H5Fformat_convert(hid_t fid); /** * \ingroup H5F * * \brief Resets the page buffer statistics * * \file_id * * \return \herr_t * * \details H5Freset_page_buffering_stats() resets the page buffer statistics * for a specified file identifier \p file_id. * * \since 1.10.1 * */ H5_DLL herr_t H5Freset_page_buffering_stats(hid_t file_id); /** * \ingroup H5F * * \brief Retrieves statistics about page access when it is enabled * * \file_id * \param[out] accesses Two integer array for the number of metadata and raw * data accesses to the page buffer * \param[out] hits Two integer array for the number of metadata and raw data * hits in the page buffer * \param[out] misses Two integer array for the number of metadata and raw data * misses in the page buffer * \param[out] evictions Two integer array for the number of metadata and raw * data evictions from the page buffer * \param[out] bypasses Two integer array for the number of metadata and raw * data accesses that bypass the page buffer * * \return \herr_t * * \details H5Fget_page_buffering_stats() retrieves page buffering statistics * such as the number of metadata and raw data accesses (\p accesses), * hits (\p hits), misses (\p misses), evictions (\p evictions), and * accesses that bypass the page buffer (\p bypasses). * * \since 1.10.1 * */ H5_DLL herr_t H5Fget_page_buffering_stats(hid_t file_id, unsigned accesses[2], unsigned hits[2], unsigned misses[2], unsigned evictions[2], unsigned bypasses[2]); /** * \ingroup MDC * * \brief Obtains information about a cache image if it exists * * \file_id * \param[out] image_addr Offset of the cache image if it exists, or \c HADDR_UNDEF if it does not * \param[out] image_size Length of the cache image if it exists, or 0 if it does not * \returns \herr_t * * \details * \parblock * H5Fget_mdc_image_info() returns information about a cache image if it exists. * * When an HDF5 file is opened in Read/Write mode, any metadata cache image will * be read and deleted from the file on the first metadata cache access (or, if * persistent free space managers are enabled, on the first file space * allocation / deallocation, or read of free space manager status, whichever * comes first). * * Thus, if the file is opened Read/Write, H5Fget_mdc_image_info() should be called * immediately after file open and before any other operation. If H5Fget_mdc_image_info() * is called after the cache image is loaded, it will correctly report that no cache image * exists, as the image will have already been read and deleted from the file. In the Read Only * case, the function may be called at any time, as any cache image will not be deleted * from the file. * \endparblock * * \since 1.10.1 */ H5_DLL herr_t H5Fget_mdc_image_info(hid_t file_id, haddr_t *image_addr, hsize_t *image_size); /** * \ingroup H5F * * \brief Retrieves the setting for whether or not a file will create minimized * dataset object headers * * \file_id * \param[out] minimize Flag indicating whether the library will or will not * create minimized dataset object headers * * \return \herr_t * * \details H5Fget_dset_no_attrs_hint() retrieves the no dataset attributes * hint setting for the file specified by the file identifier \p * file_id. This setting is used to inform the library to create * minimized dataset object headers when \c TRUE. * * The setting's value is returned in the boolean pointer minimize. * * \since 1.10.5 * */ H5_DLL herr_t H5Fget_dset_no_attrs_hint(hid_t file_id, hbool_t *minimize); /** * \ingroup H5F * * \brief Sets the flag to create minimized dataset object headers * * \file_id * \param[in] minimize Flag indicating whether the library will or will not * create minimized dataset object headers * * \return \herr_t * * \details H5Fset_dset_no_attrs_hint() sets the no dataset attributes hint * setting for the file specified by the file identifier \p file_id. * If the boolean flag \p minimize is set to \c TRUE, then the library * will create minimized dataset object headers in the file. * \Bold{All} files that refer to the same file-on-disk will be * affected by the most recent setting, regardless of the file * identifier/handle (e.g., as returned by H5Fopen()). By setting the * \p minimize flag to \c TRUE, the library expects that no attributes * will be added to the dataset - attributes can be added, but they * are appended with a continuation message, which can reduce * performance. * * \attention This setting interacts with H5Pset_dset_no_attrs_hint(): if * either is set to \c TRUE, then the created dataset's object header * will be minimized. * * \since 1.10.5 * */ H5_DLL herr_t H5Fset_dset_no_attrs_hint(hid_t file_id, hbool_t minimize); #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 */ /* Symbols defined for compatibility with previous versions of the HDF5 API. * * Use of these symbols is deprecated. */ #ifndef H5_NO_DEPRECATED_SYMBOLS /* Macros */ #define H5F_ACC_DEBUG (H5CHECK H5OPEN 0x0000u) /**< Print debug info \deprecated In which version? */ /* Typedefs */ /** * Current "global" information about file */ //! typedef struct H5F_info1_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_info1_t; //! /* Function prototypes */ /** * \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 * * \deprecated This function has been renamed from H5Fget_info() and is * deprecated in favor of the macro #H5Fget_info or the function * H5Fget_info2(). * * \details H5Fget_info1() returns global information for the file associated * with the object identifier \p obj_id in the H5F_info1_t \c struct * named \p file_info. * * \p obj_id is an identifier for any object in the file of interest. * * H5F_info1_t struct is defined in H5Fpublic.h as follows: * \snippet this H5F_info1_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. * * \version 1.10.0 Function H5Fget_info() renamed to H5Fget_info1() and * deprecated in this release. * * \since 1.8.0 * */ H5_DLL herr_t H5Fget_info1(hid_t obj_id, H5F_info1_t *file_info); /** * \ingroup H5F * * \brief Sets thelatest version of the library to be used for writing objects * * \file_id * \param[in] latest_format Latest format flag * * \return \herr_t * * \deprecated When? * * \todo In which version was this function deprecated? * */ H5_DLL herr_t H5Fset_latest_format(hid_t file_id, hbool_t latest_format); /** * \ingroup H5F * * \brief Determines whether a file is in the HDF5 format * * \param[in] file_name File name * * \return \htri_t * * \deprecated When? * * \details H5Fis_hdf5() determines whether a file is in the HDF5 format. * * \todo In which version was this function deprecated? * */ H5_DLL htri_t H5Fis_hdf5(const char *file_name); #endif /* H5_NO_DEPRECATED_SYMBOLS */ #ifdef __cplusplus } #endif #endif /* H5Fpublic_H */