aboutsummaryrefslogtreecommitdiff
path: root/src/main/java
diff options
context:
space:
mode:
Diffstat (limited to 'src/main/java')
-rw-r--r--src/main/java/dev/morling/onebrc/CalculateAverage_artsiomkorzun.java162
1 files changed, 94 insertions, 68 deletions
diff --git a/src/main/java/dev/morling/onebrc/CalculateAverage_artsiomkorzun.java b/src/main/java/dev/morling/onebrc/CalculateAverage_artsiomkorzun.java
index bb2198f..2a1a387 100644
--- a/src/main/java/dev/morling/onebrc/CalculateAverage_artsiomkorzun.java
+++ b/src/main/java/dev/morling/onebrc/CalculateAverage_artsiomkorzun.java
@@ -34,7 +34,6 @@ public class CalculateAverage_artsiomkorzun {
private static final Path FILE = Path.of("./measurements.txt");
private static final long SEGMENT_SIZE = 4 * 1024 * 1024;
- private static final long SEGMENT_OVERLAP = 128;
private static final long COMMA_PATTERN = 0x3B3B3B3B3B3B3B3BL;
private static final long DOT_BITS = 0x10101000;
private static final long MAGIC_MULTIPLIER = (100 * 0x1000000 + 10 * 0x10000 + 1);
@@ -363,15 +362,19 @@ public class CalculateAverage_artsiomkorzun {
for (int segment; (segment = counter.getAndIncrement()) < segmentCount;) {
long position = SEGMENT_SIZE * segment;
- long size = Math.min(SEGMENT_SIZE + SEGMENT_OVERLAP, fileSize - position);
- long address = fileAddress + position;
- long limit = address + Math.min(SEGMENT_SIZE, size - 1);
+ long size = Math.min(SEGMENT_SIZE, fileSize - position - 1);
+ long start = fileAddress + position;
+ long end = start + size;
if (segment > 0) {
- address = next(address);
+ start = next(start);
}
- aggregate(aggregates, address, limit);
+ long chunk = (end - start) / 3;
+ long left = next(start + chunk);
+ long right = next(start + chunk + chunk);
+
+ aggregate(aggregates, start, left - 1, left, right - 1, right, end);
}
while (!result.compareAndSet(null, aggregates)) {
@@ -390,94 +393,117 @@ public class CalculateAverage_artsiomkorzun {
return position;
}
- private static void aggregate(Aggregates aggregates, long position, long limit) {
- // this parsing can produce seg fault at page boundaries
- // e.g. file size is 4096 and the last entry is X=0.0, which is less than 8 bytes
- // as a result a read will be split across pages, where one of them is not mapped
- // but for some reason it works on my machine, leaving to investigate
+ private static void aggregate(Aggregates aggregates, long position1, long limit1, long position2, long limit2, long position3, long limit3) {
+ while (position1 <= limit1 && position2 <= limit2 && position3 <= limit3) {
+ long word1 = word(position1);
+ long word2 = word(position2);
+ long word3 = word(position3);
+
+ long separator1 = separator(word1);
+ long separator2 = separator(word2);
+ long separator3 = separator(word3);
+
+ position1 = process(aggregates, position1, word1, separator1);
+ position2 = process(aggregates, position2, word2, separator2);
+ position3 = process(aggregates, position3, word3, separator3);
+ }
+
+ while (position1 <= limit1) {
+ long word1 = word(position1);
+ long separator1 = separator(word1);
+ position1 = process(aggregates, position1, word1, separator1);
+ }
+
+ while (position2 <= limit2) {
+ long word2 = word(position2);
+ long separator2 = separator(word2);
+ position2 = process(aggregates, position2, word2, separator2);
+ }
+
+ while (position3 <= limit3) {
+ long word3 = word(position3);
+ long separator3 = separator(word3);
+ position3 = process(aggregates, position3, word3, separator3);
+ }
+ }
+
+ private static long process(Aggregates aggregates, long position, long word, long separator) {
+ long end = position;
+
+ int length;
+ int hash;
+ int value;
+
+ if (separator != 0) {
+ length = length(separator);
+ word = mask(word, separator);
+ hash = mix(word);
+ end += length;
- while (position <= limit) { // branchy version, credit: thomaswue
- int length;
- int hash;
- int value;
+ long num = word(end);
+ int dot = dot(num);
+ value = value(num, dot);
+ end += (dot >> 3) + 3;
+ long pointer = aggregates.find(word, hash);
- long word = word(position);
- long separator = separator(word);
- long end = position;
+ if (pointer != 0) {
+ Aggregates.update(pointer, value);
+ return end;
+ }
+ }
+ else {
+ long word0 = word;
+ word = word(end + 8);
+ separator = separator(word);
if (separator != 0) {
- length = length(separator);
+ length = length(separator) + 8;
word = mask(word, separator);
- hash = mix(word);
+ hash = mix(word ^ word0);
end += length;
long num = word(end);
int dot = dot(num);
value = value(num, dot);
end += (dot >> 3) + 3;
- long ptr = aggregates.find(word, hash);
+ long pointer = aggregates.find(word0, word, hash);
- if (ptr != 0) {
- Aggregates.update(ptr, value);
- position = end;
- continue;
+ if (pointer != 0) {
+ Aggregates.update(pointer, value);
+ return end;
}
}
else {
- long word0 = word;
- word = word(position + 8);
- separator = separator(word);
+ length = 16;
+ long h = word ^ word0;
- if (separator != 0) {
- length = length(separator) + 8;
+ while (true) {
+ word = word(end + length);
+ separator = separator(word);
+
+ if (separator == 0) {
+ length += 8;
+ h ^= word;
+ continue;
+ }
+
+ length += length(separator);
word = mask(word, separator);
- hash = mix(word ^ word0);
+ hash = mix(h ^ word);
end += length;
long num = word(end);
int dot = dot(num);
value = value(num, dot);
end += (dot >> 3) + 3;
- long ptr = aggregates.find(word0, word, hash);
-
- if (ptr != 0) {
- Aggregates.update(ptr, value);
- position = end;
- continue;
- }
- }
- else {
- length = 16;
- long h = word ^ word0;
-
- while (true) {
- word = word(position + length);
- separator = separator(word);
-
- if (separator == 0) {
- length += 8;
- h ^= word;
- continue;
- }
-
- length += length(separator);
- word = mask(word, separator);
- hash = mix(h ^ word);
- end += length;
-
- long num = word(end);
- int dot = dot(num);
- value = value(num, dot);
- end += (dot >> 3) + 3;
- break;
- }
+ break;
}
}
-
- long ptr = aggregates.put(position, word, length, hash);
- Aggregates.update(ptr, value);
- position = end;
}
+
+ long pointer = aggregates.put(position, word, length, hash);
+ Aggregates.update(pointer, value);
+ return end;
}
private static long separator(long word) {
generated by cgit v1.2.3 (git 2.25.1) at 2026-05-13 12:26:21 +0000