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/*
* Copyright (C) 2014 Square, Inc.
*
* 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 okio
import java.io.IOException
import java.util.zip.CRC32
import kotlin.text.Charsets.UTF_8
import okio.ByteString.Companion.decodeHex
import okio.ByteString.Companion.of
import okio.TestUtil.reverseBytes
import org.junit.Assert.assertEquals
import org.junit.Assert.assertFalse
import org.junit.Assert.assertTrue
import org.junit.Assert.fail
import org.junit.Test
class GzipSourceTest {
@Test
fun gunzip() {
val gzipped = Buffer()
gzipped.write(gzipHeader)
gzipped.write(deflated)
gzipped.write(gzipTrailer)
assertGzipped(gzipped)
}
@Test
fun gunzip_withHCRC() {
val hcrc = CRC32()
val gzipHeader = gzipHeaderWithFlags(0x02.toByte())
hcrc.update(gzipHeader.toByteArray())
val gzipped = Buffer()
gzipped.write(gzipHeader)
gzipped.writeShort(hcrc.value.toShort().reverseBytes().toInt()) // little endian
gzipped.write(deflated)
gzipped.write(gzipTrailer)
assertGzipped(gzipped)
}
@Test
fun gunzip_withExtra() {
val gzipped = Buffer()
gzipped.write(gzipHeaderWithFlags(0x04.toByte()))
gzipped.writeShort(7.toShort().reverseBytes().toInt()) // little endian extra length
gzipped.write("blubber".toByteArray(UTF_8), 0, 7)
gzipped.write(deflated)
gzipped.write(gzipTrailer)
assertGzipped(gzipped)
}
@Test
fun gunzip_withName() {
val gzipped = Buffer()
gzipped.write(gzipHeaderWithFlags(0x08.toByte()))
gzipped.write("foo.txt".toByteArray(UTF_8), 0, 7)
gzipped.writeByte(0) // zero-terminated
gzipped.write(deflated)
gzipped.write(gzipTrailer)
assertGzipped(gzipped)
}
@Test
fun gunzip_withComment() {
val gzipped = Buffer()
gzipped.write(gzipHeaderWithFlags(0x10.toByte()))
gzipped.write("rubbish".toByteArray(UTF_8), 0, 7)
gzipped.writeByte(0) // zero-terminated
gzipped.write(deflated)
gzipped.write(gzipTrailer)
assertGzipped(gzipped)
}
/**
* For portability, it is a good idea to export the gzipped bytes and try running gzip. Ex.
* `echo gzipped | base64 --decode | gzip -l -v`
*/
@Test
fun gunzip_withAll() {
val gzipped = Buffer()
gzipped.write(gzipHeaderWithFlags(0x1c.toByte()))
gzipped.writeShort(7.toShort().reverseBytes().toInt()) // little endian extra length
gzipped.write("blubber".toByteArray(UTF_8), 0, 7)
gzipped.write("foo.txt".toByteArray(UTF_8), 0, 7)
gzipped.writeByte(0) // zero-terminated
gzipped.write("rubbish".toByteArray(UTF_8), 0, 7)
gzipped.writeByte(0) // zero-terminated
gzipped.write(deflated)
gzipped.write(gzipTrailer)
assertGzipped(gzipped)
}
private fun assertGzipped(gzipped: Buffer) {
val gunzipped = gunzip(gzipped)
assertEquals("It's a UNIX system! I know this!", gunzipped.readUtf8())
}
/**
* Note that you cannot test this with old versions of gzip, as they interpret flag bit 1 as
* CONTINUATION, not HCRC. For example, this is the case with the default gzip on osx.
*/
@Test
fun gunzipWhenHeaderCRCIncorrect() {
val gzipped = Buffer()
gzipped.write(gzipHeaderWithFlags(0x02.toByte()))
gzipped.writeShort(0.toShort().toInt()) // wrong HCRC!
gzipped.write(deflated)
gzipped.write(gzipTrailer)
try {
gunzip(gzipped)
fail()
} catch (e: IOException) {
assertEquals("FHCRC: actual 0x0000261d != expected 0x00000000", e.message)
}
}
@Test
fun gunzipWhenCRCIncorrect() {
val gzipped = Buffer()
gzipped.write(gzipHeader)
gzipped.write(deflated)
gzipped.writeInt(0x1234567.reverseBytes()) // wrong CRC
gzipped.write(gzipTrailer.toByteArray(), 3, 4)
try {
gunzip(gzipped)
fail()
} catch (e: IOException) {
assertEquals("CRC: actual 0x37ad8f8d != expected 0x01234567", e.message)
}
}
@Test
fun gunzipWhenLengthIncorrect() {
val gzipped = Buffer()
gzipped.write(gzipHeader)
gzipped.write(deflated)
gzipped.write(gzipTrailer.toByteArray(), 0, 4)
gzipped.writeInt(0x123456.reverseBytes()) // wrong length
try {
gunzip(gzipped)
fail()
} catch (e: IOException) {
assertEquals("ISIZE: actual 0x00000020 != expected 0x00123456", e.message)
}
}
@Test
fun gunzipExhaustsSource() {
val gzippedSource = Buffer()
.write("1f8b08000000000000004b4c4a0600c241243503000000".decodeHex()) // 'abc'
val exhaustableSource = ExhaustableSource(gzippedSource)
val gunzippedSource = GzipSource(exhaustableSource).buffer()
assertEquals('a'.code.toLong(), gunzippedSource.readByte().toLong())
assertEquals('b'.code.toLong(), gunzippedSource.readByte().toLong())
assertEquals('c'.code.toLong(), gunzippedSource.readByte().toLong())
assertFalse(exhaustableSource.exhausted)
assertEquals(-1, gunzippedSource.read(Buffer(), 1))
assertTrue(exhaustableSource.exhausted)
}
@Test
fun gunzipThrowsIfSourceIsNotExhausted() {
val gzippedSource = Buffer()
.write("1f8b08000000000000004b4c4a0600c241243503000000".decodeHex()) // 'abc'
gzippedSource.writeByte('d'.code) // This byte shouldn't be here!
val gunzippedSource = GzipSource(gzippedSource).buffer()
assertEquals('a'.code.toLong(), gunzippedSource.readByte().toLong())
assertEquals('b'.code.toLong(), gunzippedSource.readByte().toLong())
assertEquals('c'.code.toLong(), gunzippedSource.readByte().toLong())
try {
gunzippedSource.readByte()
fail()
} catch (expected: IOException) {
}
}
private fun gzipHeaderWithFlags(flags: Byte): ByteString {
val result = gzipHeader.toByteArray()
result[3] = flags
return of(*result)
}
private val gzipHeader = "1f8b0800000000000000".decodeHex()
// Deflated "It's a UNIX system! I know this!"
private val deflated = "f32c512f56485408f5f38c5028ae2c2e49cd5554f054c8cecb2f5728c9c82c560400".decodeHex()
private val gzipTrailer = (
"" +
"8d8fad37" + // Checksum of deflated.
"20000000"
) // 32 in little endian.
.decodeHex()
private fun gunzip(gzipped: Buffer): Buffer {
val result = Buffer()
val source = GzipSource(gzipped)
while (source.read(result, Int.MAX_VALUE.toLong()) != -1L) {
}
return result
}
/** This source keeps track of whether its read has returned -1. */
internal class ExhaustableSource(private val source: Source) : Source {
var exhausted = false
override fun read(sink: Buffer, byteCount: Long): Long {
val result = source.read(sink, byteCount)
if (result == -1L) exhausted = true
return result
}
override fun timeout(): Timeout {
return source.timeout()
}
override fun close() {
source.close()
}
}
}
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