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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.
*/
@file:JvmName("-DeflaterSinkExtensions")
@file:Suppress("NOTHING_TO_INLINE") // Aliases to public API.
package okio
import org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
import java.io.IOException
import java.util.zip.Deflater
/**
* A sink that uses [DEFLATE](http://tools.ietf.org/html/rfc1951) to
* compress data written to another source.
*
* ### Sync flush
*
* Aggressive flushing of this stream may result in reduced compression. Each
* call to [flush] immediately compresses all currently-buffered data;
* this early compression may be less effective than compression performed
* without flushing.
*
* This is equivalent to using [Deflater] with the sync flush option.
* This class does not offer any partial flush mechanism. For best performance,
* only call [flush] when application behavior requires it.
*/
class DeflaterSink
/**
* This internal constructor shares a buffer with its trusted caller.
* In general we can't share a BufferedSource because the deflater holds input
* bytes until they are inflated.
*/
internal constructor(private val sink: BufferedSink, private val deflater: Deflater) : Sink {
constructor(sink: Sink, deflater: Deflater) : this(sink.buffer(), deflater)
private var closed = false
@Throws(IOException::class)
override fun write(source: Buffer, byteCount: Long) {
checkOffsetAndCount(source.size, 0, byteCount)
var remaining = byteCount
while (remaining > 0) {
// Share bytes from the head segment of 'source' with the deflater.
val head = source.head!!
val toDeflate = minOf(remaining, head.limit - head.pos).toInt()
deflater.setInput(head.data, head.pos, toDeflate)
// Deflate those bytes into sink.
deflate(false)
// Mark those bytes as read.
source.size -= toDeflate
head.pos += toDeflate
if (head.pos == head.limit) {
source.head = head.pop()
SegmentPool.recycle(head)
}
remaining -= toDeflate
}
}
@IgnoreJRERequirement
private fun deflate(syncFlush: Boolean) {
val buffer = sink.buffer
while (true) {
val s = buffer.writableSegment(1)
// The 4-parameter overload of deflate() doesn't exist in the RI until
// Java 1.7, and is public (although with @hide) on Android since 2.3.
// The @hide tag means that this code won't compile against the Android
// 2.3 SDK, but it will run fine there.
val deflated = if (syncFlush) {
deflater.deflate(s.data, s.limit, Segment.SIZE - s.limit, Deflater.SYNC_FLUSH)
} else {
deflater.deflate(s.data, s.limit, Segment.SIZE - s.limit)
}
if (deflated > 0) {
s.limit += deflated
buffer.size += deflated
sink.emitCompleteSegments()
} else if (deflater.needsInput()) {
if (s.pos == s.limit) {
// We allocated a tail segment, but didn't end up needing it. Recycle!
buffer.head = s.pop()
SegmentPool.recycle(s)
}
return
}
}
}
@Throws(IOException::class)
override fun flush() {
deflate(true)
sink.flush()
}
internal fun finishDeflate() {
deflater.finish()
deflate(false)
}
@Throws(IOException::class)
override fun close() {
if (closed) return
// Emit deflated data to the underlying sink. If this fails, we still need
// to close the deflater and the sink; otherwise we risk leaking resources.
var thrown: Throwable? = null
try {
finishDeflate()
} catch (e: Throwable) {
thrown = e
}
try {
deflater.end()
} catch (e: Throwable) {
if (thrown == null) thrown = e
}
try {
sink.close()
} catch (e: Throwable) {
if (thrown == null) thrown = e
}
closed = true
if (thrown != null) throw thrown
}
override fun timeout(): Timeout = sink.timeout()
override fun toString() = "DeflaterSink($sink)"
}
/**
* Returns an [DeflaterSink] that DEFLATE-compresses data to this [Sink] while writing.
*
* @see DeflaterSink
*/
inline fun Sink.deflate(deflater: Deflater = Deflater()): DeflaterSink =
DeflaterSink(this, deflater)
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