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gfarm

NAME

gfarm - Gfarm native API library

SYNOPSIS

 #include <gfarm/gfarm.h>
 

DESCRIPTION

The Gfarm library provides an interface layer to the gfarm filesystem. This manual only gives an overview of the library, please use manual pages of each functions to see the detail of the functions.

INITIALIZE / FINALIZE

gfarm_initialize(3) function is used for the initilization of the Gfarm library, and gfarm_terminate(3) function is used for the termination of the library.

FILE INPUT/OUTPUT OPERATIONS

gfs_pio_set_local(3) function specifies current node number and total number of nodes as an initialization step of a parallel process. To open an existing file as a stream, gfs_pio_open(3) function is used. To create an file and open the file as a stream, gfs_pio_create(3) function is used. gfs_pio_close(3) function is used to close such streams. gfs_pio_set_view_index(3) function and gfs_pio_set_view_local(3) function specifies an access method of a parallel file.

gfs_pio_error(3) function is used to see whether an error happens or not about a stream. gfs_pio_eof(3) function is used to see whether a stream, which is opened for read, already reaches end-of-file or not. gfs_pio_seek(3) function changes the current position of the stream.

gfs_pio_getc(3) functions reads a character from a stream, and gfs_pio_ungetc(3) functions puts back a character to a stream. gfs_pio_getline(3) function, gfs_pio_gets(3) function, and gfs_pio_readline(3) function read one line from a stream, and gfs_pio_readdelim(3) function reads from stream until delimiter character, specified by the function argument, appears. gfs_pio_read(3) functions reads specified bytes from a stream.

gfs_pio_putc(3) function writes one character to a stream, and gfs_pio_putline(3) function and gfs_pio_puts(3) function write one line to a stream. gfs_pio_write(3) function writes specified bytes to a stream. gfs_pio_flush(3) function, gfs_pio_sync(3) function and gfs_pio_datasync(3) function moves buffered data to a storage device. gfs_pio_truncate(3) function truncates a file.

DIRECTORY ACCESS

gfs_chdir(3) function changes current working directory. gfs_realpath(3) function returns full pathname of the argument.

gfs_opendir(3) function opens a directory, and gfs_readdir(3) function retrieves entries of the directory. gfs_closedir(3) function closes the directory.

A gfs_glob_t data, which is initilized by gfs_glob_init(3) function, can be passed to gfs_glob(3) function, and the gfs_glob function returns list of matched file/directory names in the gfs_glob_t. The gfs_glob_t must be released by gfs_glob_free(3) function. gfs_glob_add(3) function is used add an entry to gfs_glob_t.

FILE / DIRECTORY MANIPULATION

gfs_chmod(3) function changes the mode of a file, and gfs_utimes(3) function changes file's modified time and access time.

gfs_mkdir(3) function creates a directory, and gfs_rmdir(3) function removes a directory. gfs_unlink(3) function removes a file, and gfs_unlink_section(3) function removes a fragment which is a member of a parallel file. gfs_rename(3) function renames a file or a directory.

gfs_stat(3) function returns information like size, modified/access time, etc. The struct gfs_stat returned by gfs_stat function must be released by gfs_stat_free(3) function.

UTILITY FUNCTIONS

gfarm_hostlist_read(3) function, gfarm_import_fragment_config_read(3) function, and gfarm_import_fragment_size_alloc(3) function are utility functions used to register a file as a fragmented parallel file. Please see the source code of gfimport_text(1) command and gfimport_fixed(1) command as an example how to use these functions.

STRING ARRAY MANIPULATION UTILITIES

A gfarm_stringlist type variable represents an array of strings, and this type is initialized by gfarm_stringlist_init(3) function. gfarm_stringlist_add(3) function is used to add a string to a gfarm_stringlist. gfarm_stringlist_cat(3) function is used to add strings to a gfarm_stringlist. gfarm_stringlist_free(3) function releases gfarm_stringlist. gfarm_stringlist_elem(3) function or GFARM_STRINGLIST_ELEM() macro can be used to access each string of an array. gfarm_stringlist_length(3) function can be used to see number of strings in an array.

gfarm_strings_free_deeply(3) function releases a string array and each element of the array by calling standard library function free().

STRING ARRAY MANIPULATION MACROS

GFARM_STRINGLIST_ELEM(list, i)

represents i-th element of the list argument which type is gfarm_stringlist. This macro can be used as a L-value. If this macro is used as a value, it returns same result with gfarm_stringlist_elem(3) function.

GFARM_STRINGLIST_STRARRAY(list)

returns pointer to first element of the list argument which type is gfarm_stringlist. The type of the return value is a pointer to pointer to a character.

INTERNAL FUNCTIONS

gfarm_url_program_register(3) function, gfarm_url_hosts_schedule(3) function, gfarm_url_fragments_replicate(3) function, gfarm_url_program_deliver(3) function, gfarm_url_section_replicate_from_to(3) function, and gfarm_url_section_replicate_to(3) functions are internal functions of Gfarm. These manual are provided by historical reasons, but these specification may be changed later.