Entry into the contest, calculate_average_mtopolnik.sh (#246)

* calculate_average_mtopolnik

* short hash (just first 8 bytes of name)

* Remove unneeded checks

* Remove archiving classes

* 2x larger hashtable

* Add "set" to setters

* Simplify parsing temperature, remove newline search

* Reduce the size of the name slot

* Store name length and use to detect collision

* Reduce memory loads in parseTemperature

* Use short for min/max

* Extract constant for semicolon

* Fix script header

* Explicit bash shell in shebang

* Inline usage of broadcast semicolon

* Try vectorization

* Remove vectorization

* Go Unsafe

* Use SWAR temperature parsing by merykitty

* Inline some things

* Remove commented-out MemorySegment usage

* Inline namesMem.asSlice() invocation

* Try out JVM JIT flags

* Implement strcmp

* Remove unused instance variables

* Optimize hashing

* Put station name into hashtable

* Reorder method

* Remove usage of MemorySegment.getUtf8String

Replace with UNSAFE.copyMemory() and new String()

* Fix hashing bug

* Remove outdated comments

* Fix informative constants

* Use broadcastByte() more

* Improve method naming

* More hashing

* Revert more hashing

* Add commented-out code to hash 16 bytes

* Slight cleanup

* Align hashtable at cacheline boundary

* Add Graal Native image

* Revert Graal Native image

This reverts commit d916a42326d89bd1a841bbbecfae185adb8679d7.

* Simplify shell script (no SDK selection)

* Move a constant, zero out hashtable on start

* Better name comparison

* Add prepare_mtopolnik.sh

* Cleaner idiom in name comparison

* AND instead of MOD for hashtable indexing

* Improve word masking code

* Fix formatting

* Reduce memory loads

* Remove endianness checks

* Avoid hash == 0 problem

* Fix subtle bug

* MergeSort of parellel results

* Touch up perf

* Touch up perf

* Remove -Xmx256m

* Extract result printing method

* Print allocation details on OOME

* Single mmap

* Use global allocation arena

1 files changed, 21 insertions, 0 deletions

diff --git a/calculate_average_mtopolnik.sh b/calculate_average_mtopolnik.sh
new file mode 100755
index 0000000..e48711a
--- /dev/null
+++ b/calculate_average_mtopolnik.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+#
+#  Copyright 2023 The original authors
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+# -XX:+UnlockDiagnosticVMOptions -XX:PrintAssemblyOptions=intel -XX:CompileCommand=print,*.CalculateAverage_mtopolnik::recordMeasurementAndAdvanceCursor"
+# -XX:InlineSmallCode=10000 -XX:-TieredCompilation -XX:CICompilerCount=2 -XX:CompileThreshold=1000\
+java --enable-preview \
+  --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_mtopolnik