Skip to content

Cache hash code of StringArrayDeviceID #453

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
jt2594838 merged 1 commit into from
Apr 22, 2025
Merged

Cache hash code of StringArrayDeviceID #453

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 19 additions & 1 deletion java/tsfile/src/main/java/org/apache/tsfile/file/metadata/StringArrayDeviceID.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -76,6 +76,15 @@ public IDeviceID create(String[] segments) {
// or we can just use a tuple like Relational DB.
private final String[] segments;

/** Cache the hash code */
private int hash; // Default to 0

/**
* Cache if the hash has been calculated as actually being zero, enabling us to avoid
* recalculating this.
*/
private boolean hashIsZero; // Default to false;

public StringArrayDeviceID(String... deviceIdSegments) {
this.segments = formalize(deviceIdSegments);
}
Expand Down Expand Up @@ -306,7 +315,16 @@ public boolean equals(Object o) {

@Override
public int hashCode() {
return Arrays.hashCode(segments);
int h = hash;
if (h == 0 && !hashIsZero) {
h = Arrays.hashCode(segments);
if (h == 0) {
hashIsZero = true;
} else {
hash = h;
}
}
return h;
}

@Override
Expand Down
Loading