From f321fa5ad312e67e71e5eaf3b9b6b86256a82d96 Mon Sep 17 00:00:00 2001
From: Viktor Lofgren <vlofgren@marginalia.nu>
Date: Thu, 31 Aug 2023 13:52:29 +0200
Subject: [PATCH] (array) Override to Paging...Array$range()

This is a big performance boost in array.range().get().

Without an override, each access will go through pages[page].get(...) for each get()-operation.  This adds up very quickly.  BTreeReader does a bunch of get():s on a range()'d array during traversal in the queryData... methods.
---
 .../nu/marginalia/array/page/PagingIntArray.java   | 14 ++++++++++++++
 .../nu/marginalia/array/page/PagingLongArray.java  | 13 +++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/code/libraries/array/src/main/java/nu/marginalia/array/page/PagingIntArray.java b/code/libraries/array/src/main/java/nu/marginalia/array/page/PagingIntArray.java
index 0be2801c..88c7dcb1 100644
--- a/code/libraries/array/src/main/java/nu/marginalia/array/page/PagingIntArray.java
+++ b/code/libraries/array/src/main/java/nu/marginalia/array/page/PagingIntArray.java
@@ -6,6 +6,7 @@ import nu.marginalia.array.IntArray;
 import nu.marginalia.array.algo.SortingContext;
 import nu.marginalia.array.buffer.IntQueryBuffer;
 import nu.marginalia.array.delegate.ReferenceImplIntArrayDelegate;
+import nu.marginalia.array.delegate.ShiftedIntArray;
 import nu.marginalia.array.functional.*;
 import nu.marginalia.array.functor.IntFolder;
 import nu.marginalia.array.functor.IntIOFolder;
@@ -369,6 +370,19 @@ public class PagingIntArray extends AbstractPagingArray<IntArrayPage, IntBuffer>
         return size;
     }
 
+    public ShiftedIntArray range(long start, long end) {
+        if (partitioningScheme.isSamePage(start, end)) {
+            return pages[partitioningScheme.getPage(start)]
+                    .range(partitioningScheme.getOffset(start),
+                            partitioningScheme.getEndOffset(start, end)
+                    );
+        }
+        else {
+            return new ShiftedIntArray(start, end, this);
+        }
+    }
+
+
     @Override
     public ArrayRangeReference<IntArray> directRangeIfPossible(long start, long end) {
         if (partitioningScheme.isSamePage(start, end)) {
diff --git a/code/libraries/array/src/main/java/nu/marginalia/array/page/PagingLongArray.java b/code/libraries/array/src/main/java/nu/marginalia/array/page/PagingLongArray.java
index 0e01f1f3..57961273 100644
--- a/code/libraries/array/src/main/java/nu/marginalia/array/page/PagingLongArray.java
+++ b/code/libraries/array/src/main/java/nu/marginalia/array/page/PagingLongArray.java
@@ -6,6 +6,7 @@ import nu.marginalia.array.LongArray;
 import nu.marginalia.array.algo.SortingContext;
 import nu.marginalia.array.buffer.LongQueryBuffer;
 import nu.marginalia.array.delegate.ReferenceImplLongArrayDelegate;
+import nu.marginalia.array.delegate.ShiftedLongArray;
 import nu.marginalia.array.functional.LongBinaryIOOperation;
 import nu.marginalia.array.functional.LongIOTransformer;
 import nu.marginalia.array.functional.LongLongConsumer;
@@ -565,6 +566,18 @@ public class PagingLongArray extends AbstractPagingArray<LongArrayPage, LongBuff
         return pages[partitioningScheme.getPage(forOffset)];
     }
 
+    public ShiftedLongArray range(long start, long end) {
+        if (partitioningScheme.isSamePage(start, end)) {
+            return pages[partitioningScheme.getPage(start)]
+                    .range(partitioningScheme.getOffset(start),
+                           partitioningScheme.getEndOffset(start, end)
+                    );
+        }
+        else {
+            return new ShiftedLongArray(start, end, this);
+        }
+    }
+
     public ArrayRangeReference<LongArray> directRangeIfPossible(long start, long end) {
         if (partitioningScheme.isSamePage(start, end)) {
             return new ArrayRangeReference<>(