Re: java8 up to 6x slower than java7
On 16.02.2014 20:36, Jan Burse wrote:
Jan Burse schrieb:
So the requirement was really to have very light weighted hash
maps for this data structure. Even if there is a small time overhead.
Problem was that application crashed without compaction, since
memory consumption was too high.
The requirement is that the following code should
eat up O(m) space and not O(m*n) space:
HashMap[] maps = new HashMap[m];
for (int i=0; i<m; i++) {
maps = new HashMap();
}
for (int i=0; i<m; i++) {
for (int j=0; j<n; i++) {
maps[i].put(j,j)
}
for (int j=0; j<n; i++) {
maps[i].remove(j);
}
}
What is n here? Is that some arbitrary input figure otherwise unrelated
to the shown code?
A small change which would help this code and avoid too much overhead is
to set the table to null once the Map is empty. Since all your Maps are
empty at the end this would help dramatically.
Cheers
robert