feedc0de/boost_intrusive
1
0
Fork 0
forked from boostorg/intrusive
Code Pull Requests Activity

no message

Browse Source 
[SVN r37976]
This commit is contained in:
Ion Gaztañaga
2007-06-12 17:13:44 +00:00
parent a574da08ed
commit ad5dcdf8b3
8 changed files with 94 additions and 87 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
include/boost/intrusive/hashtable.hpp
View File

@@ -648,30 +648,43 @@ class hashtable
try{
size_type n = 0;
bool same_buffer = old_buckets == new_buckets;
//If we are shrinking the bucket array, just rehash the last nodes
if(same_buffer && (old_buckets_len > new_buckets_len)){
const bool same_buffer = old_buckets == new_buckets;
//If the new bucket length is a common factor
//of the old one we can avoid hash calculations.
const bool fast_shrink = (old_buckets_len > new_buckets_len) &&
(old_buckets_len % new_buckets_len) == 0;
//If we are shrinking the same bucket array and it's
//is a fast shrink, just rehash the last nodes
if(same_buffer && fast_shrink){
n = new_buckets_len;
}
//Iterate through nodes
for(; n < old_buckets_len; ++n){
bucket_type &old_bucket = old_buckets[n];
local_iterator before_i(old_bucket.before_begin());
local_iterator end(old_bucket.end());
local_iterator i(old_bucket.begin());
for(;i != end; ++i){
size_type new_n = this->priv_hasher()(*i) % new_buckets_len;
//If this is a buffer expansion don't move if it's not necessary
if(same_buffer && new_n == n){
++before_i;
}
else{
bucket_type &new_b = new_buckets[new_n];
new_b.splice_after(new_b.before_begin(), old_bucket, before_i);
i = before_i;
if(!fast_shrink){
local_iterator before_i(old_bucket.before_begin());
local_iterator end(old_bucket.end());
local_iterator i(old_bucket.begin());
for(;i != end; ++i){
const size_type new_n = (this->priv_hasher()(*i) % new_buckets_len);
//If this is a buffer expansion don't move if it's not necessary
if(same_buffer && new_n == n){
++before_i;
}
else{
bucket_type &new_b = new_buckets[new_n];
new_b.splice_after(new_b.before_begin(), old_bucket, before_i);
i = before_i;
}
}
}
else{
const size_type new_n = n % new_buckets_len;
bucket_type &new_b = new_buckets[new_n];
new_b.splice_after(new_b.before_begin(), old_bucket);
}
}
this->priv_buckets() = new_buckets;