SubwayTooter-Android-App/exif/src/main/java/it/sephiroth/android/library/exif2/utils/CountedDataInputStream.kt

149 lines
3.6 KiB
Kotlin

/*
* Copyright (C) 2012 The Android Open Source Project
*
* 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.
*/
package it.sephiroth.android.library.exif2.utils
import java.io.EOFException
import java.io.FilterInputStream
import java.io.IOException
import java.io.InputStream
import java.nio.ByteBuffer
import java.nio.ByteOrder
import java.nio.charset.Charset
import java.nio.charset.StandardCharsets
@Suppress("unused")
internal class CountedDataInputStream constructor(`in` : InputStream) :
FilterInputStream(`in`) {
// allocate a byte buffer for a long value;
private val mByteArray = ByteArray(8)
private val mByteBuffer = ByteBuffer.wrap(mByteArray)
var readByteCount = 0
private set
var end = 0
var byteOrder : ByteOrder
get() = mByteBuffer.order()
set(order) {
mByteBuffer.order(order)
}
@Throws(IOException::class)
override fun read(b : ByteArray) : Int {
val r = `in`.read(b)
readByteCount += if(r >= 0) r else 0
return r
}
@Throws(IOException::class)
override fun read() : Int {
val r = `in`.read()
readByteCount += if(r >= 0) 1 else 0
return r
}
@Throws(IOException::class)
override fun read(b : ByteArray, off : Int, len : Int) : Int {
val r = `in`.read(b, off, len)
readByteCount += if(r >= 0) r else 0
return r
}
@Throws(IOException::class)
override fun skip(length : Long) : Long {
val skip = `in`.skip(length)
readByteCount += skip.toInt()
return skip
}
@Throws(IOException::class)
fun skipTo(target : Long) {
val cur = readByteCount.toLong()
val diff = target - cur
if(diff < 0) throw IndexOutOfBoundsException("skipTo: negative move")
skipOrThrow(diff)
}
@Throws(IOException::class)
fun skipOrThrow(length : Long) {
if(skip(length) != length) throw EOFException()
}
@Throws(IOException::class)
fun readUnsignedShort() : Int = readShort().toInt() and 0xffff
@Throws(IOException::class)
fun readShort() : Short {
readOrThrow(mByteArray, 0, 2)
mByteBuffer.rewind()
return mByteBuffer.short
}
@Throws(IOException::class)
fun readByte() : Byte {
readOrThrow(mByteArray, 0, 1)
mByteBuffer.rewind()
return mByteBuffer.get()
}
@Throws(IOException::class)
fun readUnsignedByte() : Int {
readOrThrow(mByteArray, 0, 1)
mByteBuffer.rewind()
return mByteBuffer.get().toInt() and 0xff
}
@Throws(IOException::class)
@JvmOverloads
fun readOrThrow(b : ByteArray, off : Int = 0, len : Int = b.size) {
val r = read(b, off, len)
if(r != len) throw EOFException()
}
@Throws(IOException::class)
fun readUnsignedInt() : Long {
return readInt().toLong() and 0xffffffffL
}
@Throws(IOException::class)
fun readInt() : Int {
readOrThrow(mByteArray, 0, 4)
mByteBuffer.rewind()
return mByteBuffer.int
}
@Throws(IOException::class)
fun readLong() : Long {
readOrThrow(mByteArray, 0, 8)
mByteBuffer.rewind()
return mByteBuffer.long
}
@Throws(IOException::class)
fun readString(n : Int) : String {
val buf = ByteArray(n)
readOrThrow(buf)
return String(buf, StandardCharsets.UTF_8)
}
@Throws(IOException::class)
fun readString(n : Int, charset : Charset) : String {
val buf = ByteArray(n)
readOrThrow(buf)
return String(buf, charset)
}
}