Skip to content
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

Jump to bottom

[SPARK-8301][SQL] Improve UTF8String substring/startsWith/endsWith/contains performance #6804

Closed
wants to merge 11 commits into from
Closed

[SPARK-8301][SQL] Improve UTF8String substring/startsWith/endsWith/contains performance #6804

Changes from 1 commit
Commits
Show all changes
11 commits
Select commit Hold shift + click to select a range
b17909e
[SPARK-8301] removed unnecessary copying of UTF8String. Added a priva…
tarekbecker Jun 13, 2015
79cb55b
[SPARK-8301] null check. Added test cases for null check.
tarekbecker Jun 14, 2015
d2fb05f
[SPARK-8301] added additional null checks
tarekbecker Jun 15, 2015
a5f853a
[SPARK-8301] changed visibility of set to protected. Changed annotati…
tarekbecker Jun 15, 2015
e4530d2
[SPARK-8301] changed call of UTF8String.set to UTF8String.from
tarekbecker Jun 15, 2015
3a0040f
[SPARK-8301] changed call of UTF8String.set to UTF8String.from
tarekbecker Jun 15, 2015
9f17cc8
[SPARK-8301] fixed conversion byte to string in codegen
tarekbecker Jun 15, 2015
1c327eb
[SPARK-8301] removed new
tarekbecker Jun 16, 2015
9ca0473
[SPARK-8301] removed null checks
tarekbecker Jun 18, 2015
6d7b068
[SPARK-8301] removed null checks
tarekbecker Jun 18, 2015
f5d6b9a
fixed parentheses and annotation
tarekbecker Jun 18, 2015
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
23 changes: 15 additions & 8 deletions unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -131,24 +131,31 @@ public boolean contains(final UTF8String substring) {
}

for (int i = 0; i <= bytes.length - b.length; i++) {
// TODO: Avoid copying.
if (bytes[i] == b[0] && Arrays.equals(Arrays.copyOfRange(bytes, i, i + b.length), b)) {
if (bytes[i] == b[0] && startsWith(substring, i)) {
return true;
}
}
return false;
}

private boolean startsWith(final UTF8String prefix, int offset) {
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Nit: If we use startsWith(final byte[] prefix, int offset), it will may save some calls of s.getBytes(). (not sure how is the difference).

byte[] b = prefix.getBytes();
if (b.length + offset > bytes.length || offset < 0) {
return false;
}
int i = 0;
while (i < b.length && b[i] == bytes[i + offset]) {
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

As @rxin suggested, we could use unsafe API to compare 8 bytes at once. But I think in most cases the suffix will be short and this while loop will terminate very fast, it may not worth that complication.

The while loop is good to me.

i++;
}
return i == b.length;
}

public boolean startsWith(final UTF8String prefix) {
final byte[] b = prefix.getBytes();
// TODO: Avoid copying.
return b.length <= bytes.length && Arrays.equals(Arrays.copyOfRange(bytes, 0, b.length), b);
return startsWith(prefix, 0);
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Right now, UTF8String is only used by catalyst, can it will check prefix is null or not. Since this is a public method, it's still good to check prefix is null or not.

}

public boolean endsWith(final UTF8String suffix) {
final byte[] b = suffix.getBytes();
return b.length <= bytes.length &&
Arrays.equals(Arrays.copyOfRange(bytes, bytes.length - b.length, bytes.length), b);
return startsWith(suffix, bytes.length - suffix.getBytes().length);
}

public UTF8String toUpperCase() {
Expand Down