struct cigar_t * merge_cigar_t( const struct cigar_t * c )
{
struct cigar_t * res = NULL;
if ( c != NULL && c -> length > 0 )
{
res = malloc( sizeof * res );
if ( res != NULL )
{
init_cigar_t( res, c->size );
if ( res->size == c->size )
{
int i, last;
append_to_cigar_t( res, c->op[ 0 ], c->count[ 0 ] );
for ( i = 1; i < c->length; ++i )
{
last = res->length - 1;
if ( can_merge( c->op[ i ], res->op[ last ] ) )
{
res->count[ last ] += c->count[ i ];
res->op[ last ] = 'M';
}
else
append_to_cigar_t( res, c->op[ i ], c->count[ i ] );
}
}
}
}
return res;
}
inline bool
try_merge(Run& run, Iterator iter, Range const& range)
{
// if *iter intersects with, or is adjacent to, 'range'...
if (can_merge(*iter, range))
{
typedef typename Range::value_type value_type;
typedef integer_traits<value_type> integer_traits;
// merge range and *iter
merge(*iter, range);
// collapse all subsequent ranges that can merge with *iter:
Iterator i = iter+1;
// 1. skip subsequent ranges completely included in *iter
while (i != run.end() && i->last <= iter->last)
++i;
// 2. collapse next range if adjacent or overlapping with *iter
if (i != run.end() && i->first-1 <= iter->last)
{
iter->last = i->last;
++i;
}
// erase all ranges that were collapsed
run.erase(iter+1, i);
return true;
}
return false;
}
void Header::merge_header(const Header& to_merge_with)
{
// should have already verified that could merge before performing merge.
//// DEBUG
if (! can_merge(to_merge_with))
assert(false);
//// END DEBUG
// do not currently handle differently-sized headers.
if (to_merge_with._header_str.size() != _header_str.size())
assert(false);
for (int i = 0; i < _header_str.size(); ++i)
{
char my_char = _header_str[i];
// keep match any char
if (my_char == MATCH_ANY_CHAR)
continue;
char their_char = to_merge_with._header_str[i];
if (my_char != their_char)
_header_str[i] = MATCH_ANY_CHAR;
}
}
/*
* Mark a range of blocks as belonging to the "system zone" --- that
* is, filesystem metadata blocks which should never be used by
* inodes.
*/
static int add_system_zone(struct ext4_sb_info *sbi,
ext4_fsblk_t start_blk,
unsigned int count)
{
struct ext4_system_zone *new_entry = NULL, *entry;
struct rb_node **n = &sbi->system_blks.rb_node, *node;
struct rb_node *parent = NULL, *new_node = NULL;
while (*n) {
parent = *n;
entry = rb_entry(parent, struct ext4_system_zone, node);
if (start_blk < entry->start_blk)
n = &(*n)->rb_left;
else if (start_blk >= (entry->start_blk + entry->count))
n = &(*n)->rb_right;
else {
if (start_blk + count > (entry->start_blk +
entry->count))
entry->count = (start_blk + count -
entry->start_blk);
new_node = *n;
new_entry = rb_entry(new_node, struct ext4_system_zone,
node);
break;
}
}
if (!new_entry) {
new_entry = kmem_cache_alloc(ext4_system_zone_cachep,
GFP_KERNEL);
if (!new_entry)
return -ENOMEM;
new_entry->start_blk = start_blk;
new_entry->count = count;
new_node = &new_entry->node;
rb_link_node(new_node, parent, n);
rb_insert_color(new_node, &sbi->system_blks);
}
/* Can we merge to the left? */
node = rb_prev(new_node);
if (node) {
entry = rb_entry(node, struct ext4_system_zone, node);
if (can_merge(entry, new_entry)) {
new_entry->start_blk = entry->start_blk;
new_entry->count += entry->count;
rb_erase(node, &sbi->system_blks);
kmem_cache_free(ext4_system_zone_cachep, entry);
}
}
/* Can we merge to the right? */
node = rb_next(new_node);
if (node) {
entry = rb_entry(node, struct ext4_system_zone, node);
if (can_merge(new_entry, entry)) {
new_entry->count += entry->count;
rb_erase(node, &sbi->system_blks);
kmem_cache_free(ext4_system_zone_cachep, entry);
}
}
return 0;
}