76 lines
3.1 KiB
Kotlin

package net.sergeych.bipack
import kotlinx.serialization.DeserializationStrategy
import kotlinx.serialization.ExperimentalSerializationApi
import kotlinx.serialization.descriptors.SerialDescriptor
import kotlinx.serialization.encoding.AbstractDecoder
import kotlinx.serialization.encoding.CompositeDecoder
import kotlinx.serialization.modules.EmptySerializersModule
import kotlinx.serialization.modules.SerializersModule
import kotlinx.serialization.serializer
import net.sergeych.bintools.CRC
import net.sergeych.bintools.DataSource
import net.sergeych.bintools.readNumber
import net.sergeych.bintools.toDataSource
class BipackDecoder(val input: DataSource, var elementsCount: Int = 0) : AbstractDecoder() {
private var elementIndex = 0
override val serializersModule: SerializersModule = EmptySerializersModule
override fun decodeBoolean(): Boolean = input.readByte().toInt() != 0
override fun decodeByte(): Byte = input.readByte()
override fun decodeShort(): Short = input.readNumber()
override fun decodeInt(): Int = input.readNumber()
override fun decodeLong(): Long = input.readNumber()
override fun decodeFloat(): Float = input.readFloat()
override fun decodeDouble(): Double = input.readDouble()
override fun decodeChar(): Char = Char(input.readNumber<UInt>().toInt())
fun readBytes(): ByteArray {
val length = input.readNumber<UInt>()
return input.readBytes(length.toInt())
}
override fun decodeString(): String = readBytes().decodeToString()
override fun decodeEnum(enumDescriptor: SerialDescriptor): Int = input.readNumber<UInt>().toInt()
override fun decodeElementIndex(descriptor: SerialDescriptor): Int {
if (elementIndex >= elementsCount) return CompositeDecoder.DECODE_DONE
return elementIndex++
}
override fun beginStructure(descriptor: SerialDescriptor): CompositeDecoder {
var count = descriptor.elementsCount
for( a in descriptor.annotations ) {
if( a is ExtendableFormat )
count = input.readNumber<UInt>().toInt()
else if( a is Framed ) {
val code = CRC.crc32(descriptor.serialName.encodeToByteArray())
val actual = input.readU32()
if( code != actual )
throw InvalidFrameException()
}
}
return BipackDecoder(input, count)
}
override fun decodeCollectionSize(descriptor: SerialDescriptor): Int =
input.readNumber<UInt>().toInt().also {
elementsCount = it
}
override fun decodeNotNullMark(): Boolean = decodeBoolean()
@ExperimentalSerializationApi
override fun decodeNull(): Nothing? = null
companion object {
fun <T> decode(source: DataSource, deserializer: DeserializationStrategy<T>): T =
BipackDecoder(source).decodeSerializableValue(deserializer)
inline fun <reified T> decode(source: DataSource): T = decode(source, serializer())
inline fun <reified T> decode(source: ByteArray): T =
decode(source.toDataSource(), serializer())
}
}