os0file.c

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	return(TRUE);
#endif
}

/***************************************************************************
Gets a file size. */

ibool
os_file_get_size(
/*=============*/
				/* out: TRUE if success */
	os_file_t	file,	/* in: handle to a file */
	ulint*		size,	/* out: least significant 32 bits of file
				size */
	ulint*		size_high)/* out: most significant 32 bits of size */
{
#ifdef __WIN__
	DWORD	high;
	DWORD	low;

	low = GetFileSize(file, &high);

	if ((low == 0xFFFFFFFF) && (GetLastError() != NO_ERROR)) {
		return(FALSE);
	}

	*size = low;
	*size_high = high;

	return(TRUE);
#else
	off_t	offs;

	offs = lseek(file, 0, SEEK_END);

	if (offs == ((off_t)-1)) {

		return(FALSE);
	}
	
	if (sizeof(off_t) > 4) {
	        *size = (ulint)(offs & 0xFFFFFFFFUL);
		*size_high = (ulint)(offs >> 32);
	} else {
		*size = (ulint) offs;
		*size_high = 0;
	}
	
	return(TRUE);	
#endif
}

/***************************************************************************
Gets file size as a 64-bit integer ib_longlong. */

ib_longlong
os_file_get_size_as_iblonglong(
/*===========================*/
				/* out: size in bytes, -1 if error */
	os_file_t	file)	/* in: handle to a file */
{
	ulint	size;
	ulint	size_high;
	ibool	success;

	success = os_file_get_size(file, &size, &size_high);

	if (!success) {

		return(-1);
	}

	return((((ib_longlong)size_high) << 32) + (ib_longlong)size);
}

/***************************************************************************
Write the specified number of zeros to a newly created file. */

ibool
os_file_set_size(
/*=============*/
				/* out: TRUE if success */
	const char*	name,	/* in: name of the file or path as a
				null-terminated string */
	os_file_t	file,	/* in: handle to a file */
	ulint		size,	/* in: least significant 32 bits of file
				size */
	ulint		size_high)/* in: most significant 32 bits of size */
{
	ib_longlong	current_size;
	ib_longlong	desired_size;
	ibool		ret;
	byte*   	buf;
	byte*   	buf2;
	ulint		buf_size;

	ut_a(size == (size & 0xFFFFFFFF));

	current_size = 0;
	desired_size = (ib_longlong)size + (((ib_longlong)size_high) << 32);

	/* Write up to 1 megabyte at a time. */
	buf_size = ut_min(64, (ulint) (desired_size / UNIV_PAGE_SIZE))
							* UNIV_PAGE_SIZE;
	buf2 = ut_malloc(buf_size + UNIV_PAGE_SIZE);

	/* Align the buffer for possible raw i/o */
	buf = ut_align(buf2, UNIV_PAGE_SIZE);

	/* Write buffer full of zeros */
	memset(buf, 0, buf_size);

	if (desired_size >= (ib_longlong)(100 * 1024 * 1024)) {
				
		fprintf(stderr, "InnoDB: Progress in MB:");
	}

	while (current_size < desired_size) {
		ulint	n_bytes;

		if (desired_size - current_size < (ib_longlong) buf_size) {
			n_bytes = (ulint) (desired_size - current_size);
		} else {
			n_bytes = buf_size;
		}

	        ret = os_file_write(name, file, buf,
				(ulint)(current_size & 0xFFFFFFFF),
				    (ulint)(current_size >> 32),
				n_bytes);
	        if (!ret) {
			ut_free(buf2);
	         	goto error_handling;
	        }
				
		/* Print about progress for each 100 MB written */
		if ((current_size + n_bytes) / (ib_longlong)(100 * 1024 * 1024)
		    != current_size / (ib_longlong)(100 * 1024 * 1024)) {

		        fprintf(stderr, " %lu00",
				(ulong) ((current_size + n_bytes)
					/ (ib_longlong)(100 * 1024 * 1024)));
		}
		
	        current_size += n_bytes;
	}

	if (desired_size >= (ib_longlong)(100 * 1024 * 1024)) {
				
		fprintf(stderr, "\n");
	}

	ut_free(buf2);

	ret = os_file_flush(file);

	if (ret) {
	        return(TRUE);
	}

error_handling:
	return(FALSE);
}

/***************************************************************************
Truncates a file at its current position. */

ibool
os_file_set_eof(
/*============*/
				/* out: TRUE if success */
	FILE*		file)	/* in: file to be truncated */
{
#ifdef __WIN__
	HANDLE h = (HANDLE) _get_osfhandle(fileno(file));
	return(SetEndOfFile(h));
#else /* __WIN__ */
	return(!ftruncate(fileno(file), ftell(file)));
#endif /* __WIN__ */
}

/***************************************************************************
Flushes the write buffers of a given file to the disk. */

ibool
os_file_flush(
/*==========*/
				/* out: TRUE if success */
	os_file_t	file)	/* in, own: handle to a file */
{
#ifdef __WIN__
	BOOL	ret;

	ut_a(file);

	os_n_fsyncs++;

	ret = FlushFileBuffers(file);

	if (ret) {
		return(TRUE);
	}

	/* Since Windows returns ERROR_INVALID_FUNCTION if the 'file' is
	actually a raw device, we choose to ignore that error if we are using
	raw disks */

	if (srv_start_raw_disk_in_use && GetLastError()
						== ERROR_INVALID_FUNCTION) {
	        return(TRUE);
	}

	os_file_handle_error(NULL, "flush");

	/* It is a fatal error if a file flush does not succeed, because then
	the database can get corrupt on disk */
	ut_error;

	return(FALSE);
#else
	int	ret;

#if defined(HAVE_DARWIN_THREADS)
# ifndef F_FULLFSYNC
	/* The following definition is from the Mac OS X 10.3 <sys/fcntl.h> */
#  define F_FULLFSYNC 51 /* fsync + ask the drive to flush to the media */
# elif F_FULLFSYNC != 51
#  error "F_FULLFSYNC != 51: ABI incompatibility with Mac OS X 10.3"
# endif
	/* Apple has disabled fsync() for internal disk drives in OS X. That
	caused corruption for a user when he tested a power outage. Let us in
	OS X use a nonstandard flush method recommended by an Apple
	engineer. */

	if (!srv_have_fullfsync) {
		/* If we are not on an operating system that supports this,
		then fall back to a plain fsync. */ 

		ret = fsync(file);
	} else {
		ret = fcntl(file, F_FULLFSYNC, NULL);

		if (ret) {
			/* If we are not on a file system that supports this,
			then fall back to a plain fsync. */ 
			ret = fsync(file);
		}
	}
#elif HAVE_FDATASYNC
	ret = fdatasync(file);
#else
/*	fprintf(stderr, "Flushing to file %p\n", file); */
	ret = fsync(file);
#endif
	os_n_fsyncs++;

	if (ret == 0) {
		return(TRUE);
	}
	
	/* Since Linux returns EINVAL if the 'file' is actually a raw device,
	we choose to ignore that error if we are using raw disks */

	if (srv_start_raw_disk_in_use && errno == EINVAL) {

	        return(TRUE);
	}

	ut_print_timestamp(stderr);
	
	fprintf(stderr,
		"  InnoDB: Error: the OS said file flush did not succeed\n");

	os_file_handle_error(NULL, "flush");

	/* It is a fatal error if a file flush does not succeed, because then
	the database can get corrupt on disk */
	ut_error;

	return(FALSE);
#endif
}

#ifndef __WIN__
/***********************************************************************
Does a synchronous read operation in Posix. */
static
ssize_t
os_file_pread(
/*==========*/
				/* out: number of bytes read, -1 if error */
	os_file_t	file,	/* in: handle to a file */
	void*		buf,	/* in: buffer where to read */
	ulint		n,	/* in: number of bytes to read */	
	ulint		offset,	/* in: least significant 32 bits of file
				offset from where to read */
	ulint		offset_high) /* in: most significant 32 bits of
				offset */
{
        off_t	offs;
	ssize_t	n_bytes;

	ut_a((offset & 0xFFFFFFFFUL) == offset);
        
        /* If off_t is > 4 bytes in size, then we assume we can pass a
	64-bit address */

        if (sizeof(off_t) > 4) {
	        offs = (off_t)offset + (((off_t)offset_high) << 32);
        				
        } else {
        	offs = (off_t)offset;

        	if (offset_high > 0) {
        		fprintf(stderr,
			"InnoDB: Error: file read at offset > 4 GB\n");
		}
        }

	os_n_file_reads++;

#if defined(HAVE_PREAD) && !defined(HAVE_BROKEN_PREAD)
        os_mutex_enter(os_file_count_mutex);
	os_file_n_pending_preads++;
	os_n_pending_reads++;
        os_mutex_exit(os_file_count_mutex);

        n_bytes = pread(file, buf, (ssize_t)n, offs);

        os_mutex_enter(os_file_count_mutex);
	os_file_n_pending_preads--;
	os_n_pending_reads--;
        os_mutex_exit(os_file_count_mutex);

	return(n_bytes);
#else
	{
	off_t	ret_offset;
	ssize_t	ret;
	ulint	i;

        os_mutex_enter(os_file_count_mutex);
	os_n_pending_reads++;
        os_mutex_exit(os_file_count_mutex);

	/* Protect the seek / read operation with a mutex */
	i = ((ulint) file) % OS_FILE_N_SEEK_MUTEXES;
	
	os_mutex_enter(os_file_seek_mutexes[i]);

	ret_offset = lseek(file, offs, SEEK_SET);

	if (ret_offset < 0) {
		ret = -1;
	} else {
		ret = read(file, buf, (ssize_t)n);
	}

	os_mutex_exit(os_file_seek_mutexes[i]);

        os_mutex_enter(os_file_count_mutex);
	os_n_pending_reads--;
        os_mutex_exit(os_file_count_mutex);

	return(ret);
	}
#endif
}

/***********************************************************************
Does a synchronous write operation in Posix. */
static
ssize_t
os_file_pwrite(
/*===========*/
				/* out: number of bytes written, -1 if error */
	os_file_t	file,	/* in: handle to a file */
	const void*	buf,	/* in: buffer from where to write */
	ulint		n,	/* in: number of bytes to write */	
	ulint		offset,	/* in: least significant 32 bits of file
				offset where to write */
	ulint		offset_high) /* in: most significant 32 bits of
				offset */
{
	ssize_t	ret;
        off_t	offs;

	ut_a((offset & 0xFFFFFFFFUL) == offset);

        /* If off_t is > 4 bytes in size, then we assume we can pass a
	64-bit address */

        if (sizeof(off_t) > 4) {
	  	offs = (off_t)offset + (((off_t)offset_high) << 32);
        } else {
        	offs = (off_t)offset;

        	if (offset_high > 0) {
        		fprintf(stderr,
			"InnoDB: Error: file write at offset > 4 GB\n");
		}
        }

	os_n_file_writes++;

#if defined(HAVE_PWRITE) && !defined(HAVE_BROKEN_PREAD)
        os_mutex_enter(os_file_count_mutex);
	os_file_n_pending_pwrites++;
	os_n_pending_writes++;
        os_mutex_exit(os_file_count_mutex);

	ret = pwrite(file, buf, (ssize_t)n, offs);

        os_mutex_enter(os_file_count_mutex);
	os_file_n_pending_pwrites--;
	os_n_pending_writes--;
        os_mutex_exit(os_file_count_mutex);

# ifdef UNIV_DO_FLUSH
	if (srv_unix_file_flush_method != SRV_UNIX_LITTLESYNC
	    && srv_unix_file_flush_method != SRV_UNIX_NOSYNC
	    && !os_do_not_call_flush_at_each_write) {
	    	
	        /* Always do fsync to reduce the probability that when
                the OS crashes, a database page is only partially
                physically written to disk. */

	        ut_a(TRUE == os_file_flush(file));
	}
# endif /* UNIV_DO_FLUSH */

        return(ret);
#else
	{
	off_t	ret_offset;
	ulint	i;

	os_mutex_enter(os_file_count_mutex);
	os_n_pending_writes++;
	os_mutex_exit(os_file_count_mutex);

	/* Protect the seek / write operation with a mutex */
	i = ((ulint) file) % OS_FILE_N_SEEK_MUTEXES;
	
	os_mutex_enter(os_file_seek_mutexes[i]);

	ret_offset = lseek(file, offs, SEEK_SET);

	if (ret_offset < 0) {
		ret = -1;

		goto func_exit;
	}
	
	ret = write(file, buf, (ssize_t)n);

# ifdef UNIV_DO_FLUSH
	if (srv_unix_file_flush_method != SRV_UNIX_LITTLESYNC
	    && srv_unix_file_flush_method != SRV_UNIX_NOSYNC
	    && !os_do_not_call_flush_at_each_write) {

	        /* Always do fsync to reduce the probability that when
                the OS crashes, a database page is only partially
                physically written to disk. */

	        ut_a(TRUE == os_file_flush(file));
	}
# endif /* UNIV_DO_FLUSH */

func_exit:
	os_mutex_exit(os_file_seek_mutexes[i]);

	os_mutex_enter(os_file_count_mutex);
	os_n_pending_writes--;
	os_mutex_exit(os_file_count_mutex);

	return(ret);
	}
#endif
}
#endif

/***********************************************************************
Requests a synchronous positioned read operation. */

ibool
os_file_read(
/*=========*/
				/* out: TRUE if request was
				successful, FALSE if fail */
	os_file_t	file,	/* in: handle to a file */
	void*		buf,	/* in: buffer where to read */
	ulint		offset,	/* in: least significant 32 bits of file
				offset where to read */
	ulint		offset_high, /* in: most significant 32 bits of
				offset */
	ulint		n)	/* in: number of bytes to read */	
{
#ifdef __WIN__
	BOOL		ret;
	DWORD		len;
	DWORD		ret2;
	DWORD		low;
	DWORD		high;
	ibool		retry;
	ulint		i;
	
	ut_a((offset & 0xFFFFFFFFUL) == offset);

	os_n_file_reads++;
	os_bytes_read_since_printout += n;

try_again:	
	ut_ad(file);
	ut_ad(buf);
	ut_ad(n > 0);

	low = (DWORD) offset;
	high = (DWORD) offset_high;

	os_mutex_enter(os_file_count_mutex);
	os_n_pending_reads++;
	os_mutex_exit(os_file_count_mutex);

	/* Protect the seek / read operation with a mutex */
	i = ((ulint) file) % OS_FILE_N_SEEK_MUTEXES;

	os_mutex_enter(os_file_seek_mutexes[i]);