Rewrote test/blank.c to new API practice, inflated explanation comments

This commit is contained in:
Thomas Schmitt 2006-08-27 22:26:09 +00:00
parent 6ff1a35c65
commit 3d012e70b9

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@ -1,63 +1,251 @@
/* -*- indent-tabs-mode: t; tab-width: 8; c-basic-offset: 8; -*- */ /* -*- indent-tabs-mode: t; tab-width: 8; c-basic-offset: 8; -*- */
/** See this for the decisive API specs . libburn.h is The Original */
#include <libburn/libburn.h> #include <libburn/libburn.h>
/* test/blank.c , API illustration of blanking a used CD-RW
Copyright (C) ???? - 2006 Derek Foreman
Copyright (C) 2006 - 2006 Thomas Schmitt
This is provided under GPL only. Don't ask for anything else for now.
Read. Try. Think. Play. Write yourself some code. Be free of our copyright.
*/
#include <unistd.h> #include <unistd.h>
#include <stdio.h> #include <stdio.h>
#include <assert.h> #include <assert.h>
#include <ctype.h>
#include <string.h> #include <string.h>
#include <stdlib.h> #include <stdlib.h>
/* Some in-advance definitions to allow a more comprehensive ordering
of the functions and their explanations in here */
int burn_app_aquire_by_adr(char *drive_adr);
int burn_app_aquire_by_driveno(int drive_no);
/** This is a rough example. For simplicity it uses global variables.
Drives are systemwide global, so we do not give away much of good style.
*/
/** This list will hold the drives known to libburn. This might be all CD
drives of the system and thus might impose severe impact on the system.
*/
static struct burn_drive_info *drives; static struct burn_drive_info *drives;
/** If you start a long lasting operation with n_drives > 1 then you are not
friendly to the users of other drives on those systems. Beware. */
static unsigned int n_drives; static unsigned int n_drives;
static void blank_disc(struct burn_drive *drive)
/** You need to aquire a drive before burning. The API offers this as one
compact call and alternatively as application controllable gestures of
whitelisting, scanning for drives and finally grabbing one of them.
If you have a persistent address of the drive, then the compact call is
to prefer. See test/burniso.c for a more detailed explanation.
*/
int burn_app_aquire_drive(char *drive_adr, int driveno)
{
int ret;
if(drive_adr != NULL && drive_adr[0] != 0)
ret = burn_app_aquire_by_adr(drive_adr);
else
ret = burn_app_aquire_by_driveno(driveno);
return ret;
}
/** If the persistent drive address is known, then this approach is much
more un-obtrusive to the systemwide livestock of drives. Only the
given drive device will be opened during this procedure.
*/
int burn_app_aquire_by_adr(char *drive_adr)
{
int ret;
printf("Aquiring drive '%s' ...\n",drive_adr);
ret = burn_drive_scan_and_grab(&drives,drive_adr,1);
if (ret <= 0)
printf("Failed\n");
else
printf("done\n");
return ret;
}
/** This method demonstrates how to use libburn without knowing a persistent
drive address in advance. It has to make sure that after assessing the
list of available drives, all drives get closed again. Only then it is
sysadmin-acceptable to aquire the desired drive for a prolonged time.
This drive closing is enforced here by shutting down libburn and
restarting it again with the much more un-obtrusive approach to use
a persistent address and thus to only touch the one desired drive.
*/
int burn_app_aquire_by_driveno(int driveno)
{
char adr[BURN_DRIVE_ADR_LEN];
int ret;
printf("Scanning for devices ...\n");
while (!burn_drive_scan(&drives, &n_drives)) ;
if (n_drives <= 0) {
printf("Failed (no drives found)\n");
return 0;
}
printf("done\n");
if (n_drives <= driveno) {
fprintf(stderr,
"Found only %d drives. Number %d not available.\n",
n_drives,driveno);
return 0;
}
/* Interactive programs may choose the drive number at this moment.
drive[0] to drive[n_drives-1] are struct burn_drive_info
as defined in libburn/libburn.h . This structure is part of API
and thus will strive for future compatibility on source level.
Have a look at the info offered. Have a look at test/devices.c .
Caution: do not take .location for drive address. Always use
burn_drive_get_adr() or you might become incompatible
in future.
Note: bugs with struct burn_drive_info - if any - will not be
easy to fix. Please report them but also strive for
workarounds on application level.
*/
/* Now save yourself from sysadmins' revenge */
/* If n_drives == 1 this would be not really necessary, though.
You could now call burn_drive_grab() and avoid libburn restart.
We don't try to be smart here and follow the API's strong urge. */
if (burn_drive_get_adr(&(drives[driveno]), adr) <=0) {
fprintf(stderr,
"Cannot inquire persistent drive address of drive number %d\n",
driveno);
return 0;
}
printf("Detected '%s' as persistent address of drive number %d\n",
adr,driveno);
/* In cdrskin this causes a delayed sigsegv. I understand we risk only
a small memory leak by not doing:
burn_drive_info_free(drives);
*/
burn_finish();
printf(
"Re-Initializing library to release any unintended drives ...\n");
if (burn_initialize())
printf("done\n");
else {
printf("Failed\n");
fprintf(stderr,"\nFailed to re-initialize libburn.\n");
return 0;
}
ret = burn_app_aquire_by_adr(adr);
return ret;
}
/** Makes a previously used CD-RW ready for thorough re-usal.
To our knowledge it is hardly possible to abort an ongoing blank operation
because after start it is entirely handled by the drive.
So expect a blank run to survive the end of the blanking process and be
patient for the usual timespan of a normal blank run. Only after that
time has surely elapsed, only then you should start any rescue attempts
with the drive. If necessary at all.
*/
static void blank_disc(struct burn_drive *drive, int blank_fast)
{ {
enum burn_disc_status s; enum burn_disc_status s;
struct burn_progress p; struct burn_progress p;
int do_blank = 0;
#ifdef Blank_late_grab_obsoletion_revoke_and_faiL
/* This is obsoleted now by the burn_app_aquire* functions.
There is no real benefit in grabbing late.
Beneficial is to scan only one drive.
*/
if (!burn_drive_grab(drive, 1)) { if (!burn_drive_grab(drive, 1)) {
fprintf(stderr, "Unable to open the drive!\n"); fprintf(stderr, "Unable to open the drive!\n");
return; return;
} }
#endif /* Blank_late_grab_obsoletion_revoke_and_faiL */
while (burn_drive_get_status(drive, NULL)) { while (burn_drive_get_status(drive, NULL))
usleep(1000); usleep(1000);
}
while ((s = burn_disc_get_status(drive)) == BURN_DISC_UNREADY) while ((s = burn_disc_get_status(drive)) == BURN_DISC_UNREADY)
usleep(1000); usleep(1000);
printf("%d\n", s); printf(
if (s != BURN_DISC_FULL) { "Drive media status: %d (see libburn/libburn.h BURN_DISC_*)\n", s);
do_blank = 0;
if (s == BURN_DISC_BLANK) {
fprintf(stderr,
"IDLE: Blank CD media detected. Will leave it untouched\n");
} else if (s == BURN_DISC_FULL || s == BURN_DISC_APPENDABLE) {
do_blank = 1;
} else if (s == BURN_DISC_EMPTY) {
fprintf(stderr,"FATAL: No media detected in drive\n");
} else {
fprintf(stderr,
"FATAL: Cannot recognize drive and media state\n");
}
if(do_blank && !burn_disc_erasable(drive)) {
fprintf(stderr,
"FATAL : Media is not of erasable type\n");
do_blank = 0;
}
if (!do_blank) {
burn_drive_release(drive, 0); burn_drive_release(drive, 0);
fprintf(stderr, "No disc found!\n");
return; return;
} }
fprintf(stderr, "Blanking disc..."); printf(
burn_disc_erase(drive, 1); "Beginning to %s-blank CD media. Will display sector numbers.\n",
(blank_fast?"fast":"full"));
burn_disc_erase(drive, blank_fast);
while (burn_drive_get_status(drive, &p)) { while (burn_drive_get_status(drive, &p)) {
printf("%d\n", p.sector); printf("%d\n", p.sector);
sleep(2); sleep(2);
} }
fprintf(stderr, "Done\n"); printf("Done\n");
burn_drive_release(drive, 0); burn_drive_release(drive, 0);
} }
void parse_args(int argc, char **argv, int *drive) void parse_args(int argc, char **argv, char **drive_adr, int *driveno,
int *blank_fast)
{ {
int i; int i;
int help = 0; int help = 0;
static char no_drive_adr[]= {""};
*drive_adr = no_drive_adr;
for (i = 1; i < argc; ++i) { for (i = 1; i < argc; ++i) {
if (!strcmp(argv[i], "--drive")) { if (!strcmp(argv[i], "--blank_fast")) {
*blank_fast= 1;
} else if (!strcmp(argv[i], "--blank_full")) {
*blank_fast= 0;
} else if (!strcmp(argv[i], "--drive")) {
++i; ++i;
if (i >= argc) if (i >= argc) {
printf("--drive requires an argument\n"); printf("--drive requires an argument\n");
else exit(3);
*drive = atoi(argv[i]); } else if (isdigit(argv[i][0])) {
*drive_adr = no_drive_adr;
*driveno = atoi(argv[i]);
} else
*drive_adr = argv[i];
} else if (!strcmp(argv[i], "--verbose")) { } else if (!strcmp(argv[i], "--verbose")) {
++i; ++i;
if (i >= argc) if (i >= argc)
@ -69,31 +257,37 @@ void parse_args(int argc, char **argv, int *drive)
} }
} }
if (help) { if (help) {
printf("Usage: %s [--drive <num>] [--verbose <level>]\n", printf("Usage: %s\n", argv[0]);
argv[0]); printf(" [--blank_fast|--blank_full] [--drive <address>|<num>]\n");
exit(EXIT_FAILURE); printf(" [--verbose <level>]\n");
exit(3);
} }
} }
int main(int argc, char **argv) int main(int argc, char **argv)
{ {
int drive = 0; int driveno = 0, blank_fast= 1;
char *drive_adr= NULL;
parse_args(argc, argv, &drive);
fprintf(stderr, "Initializing library..."); parse_args(argc, argv, &drive_adr, &driveno, &blank_fast);
printf("Initializing library ...\n");
if (burn_initialize()) if (burn_initialize())
fprintf(stderr, "Success\n"); printf("done\n");
else { else {
printf("Failed\n"); printf("Failed\n");
fprintf(stderr,"\nFATAL: Failed to initialize libburn.\n");
return 1; return 1;
} }
fprintf(stderr, "Scanning for devices..."); if (burn_app_aquire_drive(drive_adr,driveno)<=0) {
while (!burn_drive_scan(&drives, &n_drives)) ; fprintf(stderr,"\nFATAL: Failed to aquire drive.\n");
fprintf(stderr, "Done\n"); return 2;
}
blank_disc(drives[driveno].drive, blank_fast);
blank_disc(drives[drive].drive);
burn_drive_info_free(drives); burn_drive_info_free(drives);
burn_finish(); burn_finish();
return 0; return 0;