From d4be1689e25d97a5cc136f547bf6c69976d1c832 Mon Sep 17 00:00:00 2001
From: Infendro <infendro@noreply.infendro.com>
Date: Sat, 13 Dec 2025 23:51:08 +0100
Subject: [PATCH] optimize `nextBytes()`

---
 .../kotlin/com/infendro/random/csprng/HMAC.kt |  1 -
 .../kotlin/com/infendro/random/prng/LCG.kt    |  1 -
 .../kotlin/com/infendro/random/prng/PRNG.kt   | 25 +++++++++++++++++--
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/commonMain/kotlin/com/infendro/random/csprng/HMAC.kt b/src/commonMain/kotlin/com/infendro/random/csprng/HMAC.kt
index 66cd4ec..58b496b 100644
--- a/src/commonMain/kotlin/com/infendro/random/csprng/HMAC.kt
+++ b/src/commonMain/kotlin/com/infendro/random/csprng/HMAC.kt
@@ -35,7 +35,6 @@ class HMAC internal constructor(
         val bytes = buildList {
             while (size < count) {
                 v = hmac.hash(k, v)
-
                 addAll(v.take(min(count - size, function.bytes)))
             }
         }.toUByteArray()
diff --git a/src/commonMain/kotlin/com/infendro/random/prng/LCG.kt b/src/commonMain/kotlin/com/infendro/random/prng/LCG.kt
index d3bbe82..9e72a73 100644
--- a/src/commonMain/kotlin/com/infendro/random/prng/LCG.kt
+++ b/src/commonMain/kotlin/com/infendro/random/prng/LCG.kt
@@ -26,7 +26,6 @@ class LCG internal constructor() : PRNG() {
         return buildList {
             while (size < count) {
                 x = (a * x + c) % m
-
                 addAll(x.toUByteArray().takeLast(min(count - size, 6)))
             }
         }.toUByteArray()
diff --git a/src/commonMain/kotlin/com/infendro/random/prng/PRNG.kt b/src/commonMain/kotlin/com/infendro/random/prng/PRNG.kt
index 751aa33..52547a7 100644
--- a/src/commonMain/kotlin/com/infendro/random/prng/PRNG.kt
+++ b/src/commonMain/kotlin/com/infendro/random/prng/PRNG.kt
@@ -15,12 +15,33 @@ abstract class PRNG : Random() {
     override fun nextBits(
         bitCount: Int,
     ): Int {
-        if (bitCount !in 0..32) throw Exception()
-        if (bitCount == 0) return 0
+        if (bitCount !in 0..32)
+            throw IllegalArgumentException()
+        if (bitCount == 0)
+            return 0
 
         return generate(4).toInt() ushr (32 - bitCount)
     }
 
+    override fun nextBytes(
+        array: ByteArray,
+        fromIndex: Int,
+        toIndex: Int,
+    ): ByteArray {
+        if (fromIndex !in 0..array.size || toIndex !in 0..array.size)
+            throw IllegalArgumentException()
+        if (fromIndex > toIndex)
+            throw IllegalArgumentException()
+
+        val size = toIndex - fromIndex
+        val bytes = generate(size).asByteArray()
+        for (i in 0..<size) {
+            array[i + fromIndex] = bytes[i]
+        }
+
+        return array
+    }
+
     companion object {
         fun LCG() = com.infendro.random.prng.LCG()
     }