static int memfile_ftruncate(
rtems_libio_t *iop,
off_t length
)
{
IMFS_memfile_t *memfile = IMFS_iop_to_memfile( iop );
/*
* POSIX 1003.1b does not specify what happens if you truncate a file
* and the new length is greater than the current size. We treat this
* as an extend operation.
*/
if ( length > memfile->File.size )
return IMFS_memfile_extend( memfile, true, length );
/*
* The in-memory files do not currently reclaim memory until the file is
* deleted. So we leave the previously allocated blocks in place for
* future use and just set the length.
*/
memfile->File.size = length;
IMFS_mtime_ctime_update( &memfile->File.Node );
return 0;
}
int memfile_ftruncate(
rtems_libio_t *iop,
off_t length
)
{
IMFS_jnode_t *the_jnode;
the_jnode = iop->pathinfo.node_access;
/*
* POSIX 1003.1b does not specify what happens if you truncate a file
* and the new length is greater than the current size. We treat this
* as an extend operation.
*/
if ( length > the_jnode->info.file.size )
return IMFS_memfile_extend( the_jnode, true, length );
/*
* The in-memory files do not currently reclaim memory until the file is
* deleted. So we leave the previously allocated blocks in place for
* future use and just set the length.
*/
the_jnode->info.file.size = length;
IMFS_mtime_ctime_update(the_jnode);
return 0;
}
/*
* memfile_lseek
*
* This routine processes the lseek() system call.
*/
off_t memfile_lseek(
rtems_libio_t *iop,
off_t offset,
int whence
)
{
IMFS_jnode_t *the_jnode;
the_jnode = iop->pathinfo.node_access;
if (IMFS_type( the_jnode ) == IMFS_LINEAR_FILE) {
if (iop->offset > the_jnode->info.linearfile.size)
iop->offset = the_jnode->info.linearfile.size;
}
else { /* Must be a block file (IMFS_MEMORY_FILE). */
if (IMFS_memfile_extend( the_jnode, iop->offset ))
rtems_set_errno_and_return_minus_one( ENOSPC );
iop->size = the_jnode->info.file.size;
}
return iop->offset;
}
/*
* IMFS_memfile_write
*
* This routine writes the specified data buffer into the in memory
* file pointed to by memfile. The file is extended as needed.
*/
ssize_t IMFS_memfile_write(
IMFS_memfile_t *memfile,
off_t start,
const unsigned char *source,
unsigned int length
)
{
block_p *block_ptr;
unsigned int block;
int status;
unsigned int my_length;
unsigned int to_copy = 0;
unsigned int last_byte;
unsigned int start_offset;
int copied;
const unsigned char *src;
src = source;
/*
* Perform internal consistency checks
*/
IMFS_assert( source );
IMFS_assert( memfile );
my_length = length;
/*
* If the last byte we are supposed to write is past the end of this
* in memory file, then extend the length.
*/
last_byte = start + my_length;
if ( last_byte > memfile->File.size ) {
bool zero_fill = start > memfile->File.size;
status = IMFS_memfile_extend( memfile, zero_fill, last_byte );
if ( status )
return status;
}
copied = 0;
/*
* Three phases to the write:
* + possibly the last part of one block
* + all of zero of more blocks
* + possibly the first part of one block
*/
/*
* Phase 1: possibly the last part of one block
*/
start_offset = start % IMFS_MEMFILE_BYTES_PER_BLOCK;
block = start / IMFS_MEMFILE_BYTES_PER_BLOCK;
if ( start_offset ) {
to_copy = IMFS_MEMFILE_BYTES_PER_BLOCK - start_offset;
if ( to_copy > my_length )
to_copy = my_length;
block_ptr = IMFS_memfile_get_block_pointer( memfile, block, 0 );
if ( !block_ptr )
return copied;
#if 0
fprintf(
stderr,
"write %d at %d in %d: %*s\n",
to_copy,
start_offset,
block,
to_copy,
src
);
#endif
memcpy( &(*block_ptr)[ start_offset ], src, to_copy );
src += to_copy;
block++;
my_length -= to_copy;
copied += to_copy;
}
/*
* Phase 2: all of zero of more blocks
*/
to_copy = IMFS_MEMFILE_BYTES_PER_BLOCK;
while ( my_length >= IMFS_MEMFILE_BYTES_PER_BLOCK ) {
block_ptr = IMFS_memfile_get_block_pointer( memfile, block, 0 );
if ( !block_ptr )
return copied;
#if 0
fprintf(stdout, "write %d in %d: %*s\n", to_copy, block, to_copy, src );
#endif
memcpy( &(*block_ptr)[ 0 ], src, to_copy );
src += to_copy;
block++;
my_length -= to_copy;
copied += to_copy;
}
/*
* Phase 3: possibly the first part of one block
*/
IMFS_assert( my_length < IMFS_MEMFILE_BYTES_PER_BLOCK );
to_copy = my_length;
if ( my_length ) {
block_ptr = IMFS_memfile_get_block_pointer( memfile, block, 0 );
if ( !block_ptr )
return copied;
#if 0
fprintf(stdout, "write %d in %d: %*s\n", to_copy, block, to_copy, src );
#endif
memcpy( &(*block_ptr)[ 0 ], src, my_length );
my_length = 0;
copied += to_copy;
}
IMFS_mtime_ctime_update( &memfile->File.Node );
return copied;
}
MEMFILE_STATIC ssize_t IMFS_memfile_write(
IMFS_jnode_t *the_jnode,
off_t start,
const unsigned char *source,
unsigned int length
)
{
block_p *block_ptr;
unsigned int block;
int status;
unsigned int my_length;
unsigned int to_copy = 0;
unsigned int last_byte;
unsigned int start_offset;
int copied;
const unsigned char *src;
src = source;
/*
* Perform internal consistency checks
*/
assert( the_jnode );
if ( !the_jnode )
rtems_set_errno_and_return_minus_one( EIO );
assert( the_jnode->type == IMFS_MEMORY_FILE );
if ( the_jnode->type != IMFS_MEMORY_FILE )
rtems_set_errno_and_return_minus_one( EIO );
/*
* Error check arguments
*/
assert( source );
if ( !source )
rtems_set_errno_and_return_minus_one( EINVAL );
/*
* If there is nothing to write, then quick exit.
*/
my_length = length;
if ( !my_length )
rtems_set_errno_and_return_minus_one( EINVAL );
/*
* If the last byte we are supposed to write is past the end of this
* in memory file, then extend the length.
*/
last_byte = start + length;
if ( last_byte > the_jnode->info.file.size ) {
status = IMFS_memfile_extend( the_jnode, last_byte );
if ( status )
rtems_set_errno_and_return_minus_one( ENOSPC );
}
copied = 0;
/*
* Three phases to the write:
* + possibly the last part of one block
* + all of zero of more blocks
* + possibly the first part of one block
*/
/*
* Phase 1: possibly the last part of one block
*/
start_offset = start % IMFS_MEMFILE_BYTES_PER_BLOCK;
block = start / IMFS_MEMFILE_BYTES_PER_BLOCK;
if ( start_offset ) {
to_copy = IMFS_MEMFILE_BYTES_PER_BLOCK - start_offset;
if ( to_copy > my_length )
to_copy = my_length;
block_ptr = IMFS_memfile_get_block_pointer( the_jnode, block, 0 );
assert( block_ptr );
if ( !block_ptr )
return copied;
#if 0
fprintf(stdout, "write %d at %d in %d: %*s\n", to_copy, start_offset, block, to_copy, src );
#endif
memcpy( &(*block_ptr)[ start_offset ], src, to_copy );
src += to_copy;
block++;
my_length -= to_copy;
copied += to_copy;
}
/*
* Phase 2: all of zero of more blocks
*/
to_copy = IMFS_MEMFILE_BYTES_PER_BLOCK;
while ( my_length >= IMFS_MEMFILE_BYTES_PER_BLOCK ) {
block_ptr = IMFS_memfile_get_block_pointer( the_jnode, block, 0 );
assert( block_ptr );
if ( !block_ptr )
return copied;
#if 0
fprintf(stdout, "write %d in %d: %*s\n", to_copy, block, to_copy, src );
#endif
memcpy( &(*block_ptr)[ 0 ], src, to_copy );
src += to_copy;
block++;
my_length -= to_copy;
copied += to_copy;
}
/*
* Phase 3: possibly the first part of one block
*/
assert( my_length < IMFS_MEMFILE_BYTES_PER_BLOCK );
to_copy = my_length;
if ( my_length ) {
block_ptr = IMFS_memfile_get_block_pointer( the_jnode, block, 0 );
assert( block_ptr );
if ( !block_ptr )
return copied;
#if 0
fprintf(stdout, "write %d in %d: %*s\n", to_copy, block, to_copy, src );
#endif
memcpy( &(*block_ptr)[ 0 ], src, my_length );
my_length = 0;
copied += to_copy;
}
IMFS_mtime_ctime_update( the_jnode );
return copied;
}
