typedef struct gfal_filestatus {
char *surl;
char *turl;
int status;
char *explanation;
int pinlifetime;
struct stat64 stat;
struct gfal_filestatus *subpaths;
int nbsubpaths;
} gfal_filestatus;
typedef struct gfal_request {
/* [optional]
* if set to 1, 'surls' to NULL, and endpoint specified,
* 'nbfiles' SURLs will be generated */
int generatesurls;
/* [optional]
* only used to generate SURLs, if specified */
char *relative_path;
/* [required]
* number of files in 'surls' */
int nbfiles;
/* [required]
* list of surls */
char **surls;
/* [optional]
* endpoint */
char *endpoint;
/* [required by gfal_turlsfromsurls]
* 0 for get request, 1 for put request */
int oflag;
/* [optional]
* list of file sizes
* can be useful for gfal_turlsfromsurls with put request */
GFAL_LONG64 *filesizes;
/* [optional]
* SE type to use *by default* */
enum se_type defaultsetype;
/* [optional]
* SE type to use - will fail if this type cannot be used */
enum se_type setype;
/* [optional]
* if set to 1, no bdii call will be done
* endpoint must be set up for SRM-compliant SE */
int no_bdii_check;
/* [optional]
* timeout */
int timeout;
/* [optional]
* list of protocols to use */
char **protocols;
/* [optional] only used with SRMv2 */
char *srmv2_spacetokendesc;
int srmv2_desiredpintime;
int srmv2_lslevels;
int srmv2_lsoffset;
int srmv2_lscount;
} *gfal_request;
/******************** Common functions ********************/
const char *gfal_version ();
int gfal_set_verbose (int);
int gfal_set_vo (const char *vo);
void gfal_set_nobdii (int);
void gfal_set_timeout_connect (int);
int gfal_get_timeout_connect ();
void gfal_set_timeout_sendreceive (int);
int gfal_get_timeout_sendreceive ();
void gfal_set_timeout_bdii (int);
int gfal_get_timeout_bdii ();
void gfal_set_timeout_srm (int);
int gfal_get_timeout_srm ();
/******************** POSIX functions ********************/
int gfal_access (const char *, int);
int gfal_chmod (const char *, mode_t);
int gfal_close (int);
int gfal_closedir (DIR *);
int gfal_creat (const char *, mode_t);
int gfal_creat64 (const char *, mode_t);
off_t gfal_lseek (int, off_t, int);
int gfal_mkdir (const char *, mode_t);
int gfal_open (const char *, int, mode_t);
int gfal_open64 (const char *, int, mode_t);
DIR *gfal_opendir (const char *);
ssize_t gfal_read (int, void *, size_t);
struct dirent *gfal_readdir (DIR *);
int gfal_rename (const char *, const char *);
int gfal_rmdir (const char *);
ssize_t gfal_setfilchg (int, const void *, size_t);
int gfal_unlink (const char *);
ssize_t gfal_write (int, const void *, size_t);
off64_t gfal_lseek64 (int, off64_t, int);
int gfal_lstat (const char *, struct stat *);
int gfal_lstat64 (const char *, struct stat64 *);
int gfal_stat (const char *, struct stat *);
int gfal_stat64 (const char *, struct stat64 *);
struct dirent64 *gfal_readdir64 (DIR *);
/******************** SRM functions ********************/
gfal_request gfal_request_new ();
int gfal_init (gfal_request, gfal_internal *, char *, int);
int gfal_deletesurls (gfal_internal, char *, int);
int gfal_removedir (gfal_internal, char *, int);
int gfal_turlsfromsurls (gfal_internal, char *, int);
int gfal_ls (gfal_internal, char *, int);
int gfal_ls_end (gfal_internal, char *, int);
int gfal_get (gfal_internal, char *, int);
int gfal_getstatus (gfal_internal, char *, int);
int gfal_prestage (gfal_internal, char *, int);
int gfal_prestagestatus (gfal_internal, char *, int);
int gfal_pin (gfal_internal, char *, int);
int gfal_release (gfal_internal, char *, int);
int gfal_set_xfer_done (gfal_internal, char *, int);
int gfal_set_xfer_running (gfal_internal, char *, int);
int gfal_abortrequest (gfal_internal, char *, int);
int gfal_abortfiles (gfal_internal, char *, int);
int gfal_get_results (gfal_internal, gfal_filestatus **);
int gfal_get_ids_setype (gfal_internal, enum se_type *, int *, int **, char **);
int gfal_get_ids (gfal_internal, int *, int **, char **);
int gfal_set_ids (gfal_internal, int, const int *, int, const char *, char *, int);
void gfal_internal_free (gfal_internal);
The GFAL library hides these interactions and presents a Posix interface for the I/O operations. The currently supported protocols are: file for local access, dcap, gsidcap and kdcap (dCache access protocol) and rfio (CASTOR/DPM access protocol).
The function names are obtained by prepending gfal_ to the Posix names, for example gfal_open, gfal_read, gfal_close ...
The argument lists and the values returned by the functions are identical.
an LFN starts with lfn:
a GUID starts with guid:
an SURL starts with srm://
a TURL starts with a protocol name
All these libraries are available as shared libraries as well as archive libraries.
setenv LCG_GFAL_INFOSYS lcg-bdii.cern.ch:2170
setenv LCG_GFAL_VO dteam
setenv RMC_ENDPOINT \
http://rlscert01.cern.ch:7777/dteam/edg-replica-metadata-catalog/services/edg-replica-metadata-catalog
setenv LRC_ENDPOINT \
http://rlscert01.cern.ch:7777/dteam/edg-local-replica-catalog/services/edg-local-replica-catalog
setenv LCG_CATALOG_TYPE lfc
and optionally
setenv LFC_HOST lfc-shared.cern.ch
setenv LCG_GFAL_FULL_SURLS_IN_FC 1
But, be CAREFUL, defining that when BDII can be used will prevent users from choosing the SRM version they want to use, and will create complexity when SRM version will change!
setenv LCG_RFIO_TYPE dpm
First of all, you have to create a 'gfal_request' object, in which you will be able to set your parameters :
gfal_request req;
...
if ((req = gfal_request_new ()) == NULL) {
// ERROR ...
}
req->surls = ...
req->nbfiles = ...
...
To see the meaning of each parameter, have a look to the documentation of gfal_init(). Once, you have set all the desired parameters in this request, you have to the internal gfal object like this :
gfal_internal gfal;
....
if (gfal_init (req, &gfal, errbuf, errbufsz) < 0) {
// ERROR ...
}
DO NOT MODIFY this object by hand. If you need other parameters, just make a new request and run gfal_init again on it. Moreover, do not free any members of req while you are using the internal object, because it uses them !
Then, you just have to pass this internal object gfal to gfal functions :
if (gfal_turlsfromsurls (gfal, errbuf, errbufsz) < 0) {
// ERROR ...
}
Finally, you have to call a specific function to get the results :
gfal_filestatus *filestatuses;
...
if (gfal_get_results (gfal, &filestatuses) < 0) {
// ERROR ...
}
It is recommended to keep the same 'gfal_internal' object (one per thread) for making requests on same SURLs.
Once the 'gfal_internal' object is not needed anymore, it must be freed:
gfal_internal_free (gfal);
But, it won't free the arguments which were in your initial request (eg. list of SURLs), you have to free them by hand if needed, in addition to the request ('gfal_request' object).
It is possible to get this information by setting environment variables.
For bash:
export CGSI_TRACE=1
export CGSI_TRACEFILE=/path/to/your/file
For csh:
setenv CGSI_TRACE 1
sentenv CGSI_TRACEFILE /path/to/your/file
Then just run your program, and information which is exchanged between GFAL and other components will be put into /path/to/your/file
#include <fcntl.h> #include <stdio.h> #include "gfal_api.h" #define BLKLEN 65536 main(int argc, char **argv) { int fd; int i; char ibuf[BLKLEN]; char obuf[BLKLEN]; int rc; if (argc != 2) { fprintf (stderr, "usage: %s filename\n", argv[0]); exit (1); } for (i = 0; i < BLKLEN; i++) obuf[i] = i; printf ("creating file %s\n", argv[1]); if ((fd = gfal_open (argv[1], O_WRONLY|O_CREAT, 0644)) < 0) { perror ("gfal_open"); exit (1); } printf ("open successful, fd = %d\n", fd); if ((rc = gfal_write (fd, obuf, BLKLEN)) != BLKLEN) { if (rc < 0) perror ("gfal_write"); else fprintf (stderr, "gfal_write returns %d\n", rc); (void) gfal_close (fd); exit (1); } printf ("write successful\n"); if ((rc = gfal_close (fd)) < 0) { perror ("gfal_close"); exit (1); } printf ("close successful\n"); printf ("reading back %s\n", argv[1]); if ((fd = gfal_open (argv[1], O_RDONLY, 0)) < 0) { perror ("gfal_open"); exit (1); } printf ("open successful, fd = %d\n", fd); if ((rc = gfal_read (fd, ibuf, BLKLEN)) != BLKLEN) { if (rc < 0) perror ("gfal_read"); else fprintf (stderr, "gfal_read returns %d\n", rc); (void) gfal_close (fd); exit (1); } printf ("read successful\n"); if ((rc = gfal_close (fd)) < 0) { perror ("gfal_close"); exit (1); } printf ("close successful\n"); for (i = 0; i < BLKLEN; i++) { if (ibuf[i] != obuf[i]) { fprintf (stderr, "compare failed at offset %d\n", i); exit (1); } } printf ("compare successful\n"); exit (0); }