Add readVarInt and writeVarInt extension methods

Signed-off-by: Graham <gpe@openrs2.org>
bzip2
Graham 4 years ago
parent 29fecec34e
commit 6f13a0a737
  1. 34
      buffer/src/main/kotlin/org/openrs2/buffer/ByteBufExtensions.kt
  2. 102
      buffer/src/test/kotlin/org/openrs2/buffer/ByteBufExtensionsTest.kt

@ -128,6 +128,40 @@ public fun ByteBuf.writeVersionedString(s: CharSequence): ByteBuf {
return this
}
public fun ByteBuf.readVarInt(): Int {
var value = 0
var byte: Int
do {
byte = readUnsignedByte().toInt()
value = (value shl 7) or (byte and 0x7F)
} while ((byte and 0x80) != 0)
return value
}
public fun ByteBuf.writeVarInt(v: Int): ByteBuf {
if ((v and 0x7F.inv()) != 0) {
if ((v and 0x3FFF.inv()) != 0) {
if ((v and 0x1FFFFF.inv()) != 0) {
if ((v and 0xFFFFFFF.inv()) != 0) {
writeByte(((v ushr 28) and 0x7F) or 0x80)
}
writeByte(((v ushr 21) and 0x7F) or 0x80)
}
writeByte(((v ushr 14) and 0x7F) or 0x80)
}
writeByte(((v ushr 7) and 0x7F) or 0x80)
}
writeByte(v and 0x7F)
return this
}
public fun ByteBuf.crc32(): Int {
return crc32(readerIndex(), readableBytes())
}

@ -586,6 +586,108 @@ class ByteBufExtensionsTest {
}
}
@Test
fun testReadVarInt() {
wrappedBuffer(0x7F).use { buf ->
assertEquals(0x7F, buf.readVarInt())
}
wrappedBuffer(0x81.toByte(), 0x00).use { buf ->
assertEquals(0x80, buf.readVarInt())
}
wrappedBuffer(0xFF.toByte(), 0x7F).use { buf ->
assertEquals(0x3FFF, buf.readVarInt())
}
wrappedBuffer(0x81.toByte(), 0x80.toByte(), 0x00).use { buf ->
assertEquals(0x4000, buf.readVarInt())
}
wrappedBuffer(0xFF.toByte(), 0xFF.toByte(), 0x7F.toByte()).use { buf ->
assertEquals(0x1FFFFF, buf.readVarInt())
}
wrappedBuffer(0x81.toByte(), 0x80.toByte(), 0x80.toByte(), 0x00).use { buf ->
assertEquals(0x200000, buf.readVarInt())
}
wrappedBuffer(0xFF.toByte(), 0xFF.toByte(), 0xFF.toByte(), 0x7F).use { buf ->
assertEquals(0xFFFFFFF, buf.readVarInt())
}
wrappedBuffer(0x81.toByte(), 0x80.toByte(), 0x80.toByte(), 0x80.toByte(), 0x00).use { buf ->
assertEquals(0x10000000, buf.readVarInt())
}
}
@Test
fun testWriteVarInt() {
ByteBufAllocator.DEFAULT.buffer().use { actual ->
actual.writeVarInt(0x7F)
wrappedBuffer(0x7F).use { expected ->
assertEquals(expected, actual)
}
}
ByteBufAllocator.DEFAULT.buffer().use { actual ->
actual.writeVarInt(0x80)
wrappedBuffer(0x81.toByte(), 0x00).use { expected ->
assertEquals(expected, actual)
}
}
ByteBufAllocator.DEFAULT.buffer().use { actual ->
actual.writeVarInt(0x3FFF)
wrappedBuffer(0xFF.toByte(), 0x7F).use { expected ->
assertEquals(expected, actual)
}
}
ByteBufAllocator.DEFAULT.buffer().use { actual ->
actual.writeVarInt(0x4000)
wrappedBuffer(0x81.toByte(), 0x80.toByte(), 0x00).use { expected ->
assertEquals(expected, actual)
}
}
ByteBufAllocator.DEFAULT.buffer().use { actual ->
actual.writeVarInt(0x1FFFFF)
wrappedBuffer(0xFF.toByte(), 0xFF.toByte(), 0x7F).use { expected ->
assertEquals(expected, actual)
}
}
ByteBufAllocator.DEFAULT.buffer().use { actual ->
actual.writeVarInt(0x200000)
wrappedBuffer(0x81.toByte(), 0x80.toByte(), 0x80.toByte(), 0x00).use { expected ->
assertEquals(expected, actual)
}
}
ByteBufAllocator.DEFAULT.buffer().use { actual ->
actual.writeVarInt(0xFFFFFFF)
wrappedBuffer(0xFF.toByte(), 0xFF.toByte(), 0xFF.toByte(), 0x7F).use { expected ->
assertEquals(expected, actual)
}
}
ByteBufAllocator.DEFAULT.buffer().use { actual ->
actual.writeVarInt(0x10000000)
wrappedBuffer(0x81.toByte(), 0x80.toByte(), 0x80.toByte(), 0x80.toByte(), 0x00).use { expected ->
assertEquals(expected, actual)
}
}
}
@Test
fun testCrc32() {
val s = "AAThe quick brown fox jumps over the lazy dogA"

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