コード例 #1
0
ファイル: bitmap_index.c プロジェクト: swistak/skarbnik
/*
 * Attaches BitMap to memory mapped file that is created in indices/ directory.
 * file name is based on nmap name, so bit map name should be valid linux file
 * name.
 *
 * File is created immidietly and space is allocated to match requested bit map
 * size. Previously allocated bit map space is freed without copying it!
 */
BitMap bm_attach_to_file(BitMap self) {
    int fname_length = strlen(self->name) + 8 + 4 + 1; // length of 'indices/' + length of '.idx' + 1 for 0
    char* fname = malloc(fname_length);
    struct stat buffer;
    int fsize = self->part_length * sizeof (BitMapPart);
    sprintf(fname, "indices/%s.idx", self->name);
    
    if (self->parts) free(self->parts);

    try_io(self->fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0600));
    try_io(fstat(self->fd, &buffer));
    if (buffer.st_size < fsize) {
        try_io(lseek(self->fd, fsize - 1, SEEK_SET));
        try_io(write(self->fd, "\0", 1));
    }
    try_io(self->parts = mmap(NULL, fsize, PROT_WRITE | PROT_READ, MAP_SHARED, self->fd, 0));

    free(fname);
    return (self);
}
コード例 #2
0
ファイル: bitmap_index.c プロジェクト: swistak/skarbnik
/*
 * Resizes bitmap to new bit length. If bit length falls into same part length,
 * then nothing is changed besides bit_length.
 *
 * realloc and mremap are used - both claim to copy data, but they might change
 * address of parts pointer. Becouse of that, client should not store pointers
 * to arbitrary parts, instead store index of part relative to first part.
 * 
 */
BitMap bm_resize(BitMap self, int new_bit_length) {
    int new_part_length = bm_part_length(new_bit_length);
    int new_byte_size = new_part_length * sizeof (BitMapPart);

    if (new_part_length != self->part_length) {
        if (self->persisted) {
            try_io(lseek(self->fd, new_byte_size - 1, SEEK_SET));
            try_io(write(self->fd, "\0", 1));
            self->parts = mremap(
                    self->parts,
                    self->part_length * sizeof (BitMapPart),
                    new_byte_size,
                    MREMAP_MAYMOVE
                    );
        } else {
            self->parts = realloc(self->parts, new_byte_size);
        }
    }

    self->bit_length = new_bit_length;
    self->part_length = new_part_length;

    return (self);
}
コード例 #3
0
ファイル: priv_vfs_read_write.c プロジェクト: coyizumi/cs111
void
priv_vfs_readwrite_fother(int asroot, int injail, struct test *test)
{

	try_io("priv_vfs_readwrite_fother(none, O_RDONLY)", fpath_none,
	    asroot, injail, O_RDONLY, asroot ? 0 : -1, EACCES);
	try_io("priv_vfs_readwrite_fother(none, O_WRONLY)", fpath_none,
	    asroot, injail, O_WRONLY, asroot ? 0 : -1, EACCES);
	try_io("priv_vfs_readwrite_fother(none, O_RDWR)", fpath_none,
	    asroot, injail, O_RDWR, asroot ? 0 : -1, EACCES);

	try_io("priv_vfs_readwrite_fother(read, O_RDONLY)", fpath_read,
	    asroot, injail, O_RDONLY, 0, 0);
	try_io("priv_vfs_readwrite_fother(read, O_WRONLY)", fpath_read,
	    asroot, injail, O_WRONLY, asroot ? 0 : -1, EACCES);
	try_io("priv_vfs_readwrite_fother(read, O_RDWR)", fpath_read,
	    asroot, injail, O_RDWR, asroot ? 0 : -1, EACCES);

	try_io("priv_vfs_readwrite_fother(write, O_RDONLY)", fpath_write,
	    asroot, injail, O_RDONLY, asroot ? 0 : -1, EACCES);
	try_io("priv_vfs_readwrite_fother(write, O_WRONLY)", fpath_write,
	    asroot, injail, O_WRONLY, 0, 0);
	try_io("priv_vfs_readwrite_fother(write, O_RDWR)", fpath_write,
	    asroot, injail, O_RDWR, asroot ? 0 : -1, EACCES);

	try_io("priv_vfs_readwrite_fother(write, O_RDONLY)", fpath_readwrite,
	    asroot, injail, O_RDONLY, 0, 0);
	try_io("priv_vfs_readwrite_fother(write, O_WRONLY)", fpath_readwrite,
	    asroot, injail, O_WRONLY, 0, 0);
	try_io("priv_vfs_readwrite_fother(write, O_RDWR)", fpath_readwrite,
	    asroot, injail, O_RDWR, 0, 0);
}