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| author | Dominik Stadler <centic@apache.org> | 2024-07-15 05:41:14 +0000 |
|---|---|---|
| committer | Dominik Stadler <centic@apache.org> | 2024-07-15 05:41:14 +0000 |
| commit | 719e7154a19c00e1c2464e5f93a1567d8ca5ed72 (patch) | |
| tree | 7770905ba7f96075670ac8f354bfe11b671584fa | |
| parent | a9717512382201ee290a4d1e52c6f195db16e8ab (diff) | |
| download | poi-719e7154a19c00e1c2464e5f93a1567d8ca5ed72.tar.gz poi-719e7154a19c00e1c2464e5f93a1567d8ca5ed72.zip | |
Optimize generating numbers for bullets in Word
Using char[] instead of String improves performance of this
operation considerably, especially in JDK 11+ where StringBuilder
was switched to work on bytes instead of chars.
This is likely only relevant for very large documents, it was visible
in a synthetic test-file from fuzzing.
git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1919239 13f79535-47bb-0310-9956-ffa450edef68
| -rw-r--r-- | poi-scratchpad/src/main/java/org/apache/poi/hwpf/converter/NumberFormatter.java | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/poi-scratchpad/src/main/java/org/apache/poi/hwpf/converter/NumberFormatter.java b/poi-scratchpad/src/main/java/org/apache/poi/hwpf/converter/NumberFormatter.java index 087add5cbf..483c227c23 100644 --- a/poi-scratchpad/src/main/java/org/apache/poi/hwpf/converter/NumberFormatter.java +++ b/poi-scratchpad/src/main/java/org/apache/poi/hwpf/converter/NumberFormatter.java @@ -19,6 +19,7 @@ package org.apache.poi.hwpf.converter; +import java.util.Arrays; import java.util.Locale; import org.apache.poi.util.Beta; @@ -28,8 +29,12 @@ import org.apache.poi.util.Beta; */ @Beta public final class NumberFormatter { - private static final String[] ROMAN_LETTERS = { "m", "cm", "d", "cd", "c", - "xc", "l", "xl", "x", "ix", "v", "iv", "i" }; + // use char[] instead of String to speed up StringBuilder.append(), especially in JDK 11+ + // where StringBuilder internally switched from char[] to byte[] + private static final char[][] ROMAN_LETTERS = Arrays.stream( + new String[] { "m", "cm", "d", "cd", "c", "xc", "l", "xl", "x", "ix", "v", "iv", "i" }). + map(String::toCharArray). + toArray(char[][]::new); private static final int[] ROMAN_VALUES = { 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 }; @@ -86,7 +91,7 @@ public final class NumberFormatter { StringBuilder result = new StringBuilder(); for ( int i = 0; i < ROMAN_LETTERS.length; i++ ) { - String letter = ROMAN_LETTERS[i]; + char[] letter = ROMAN_LETTERS[i]; int value = ROMAN_VALUES[i]; while ( number >= value ) { number -= value; |