okhttp3.internal.http2.Settings.kt Maven / Gradle / Ivy
/*
* Copyright (C) 2012 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 okhttp3.internal.http2
/**
* Settings describe characteristics of the sending peer, which are used by the receiving peer.
* Settings are [connection][Http2Connection] scoped.
*/
class Settings {
/** Bitfield of which flags that values. */
private var set: Int = 0
/** Flag values. */
private val values = IntArray(COUNT)
/** Returns -1 if unset. */
val headerTableSize: Int
get() {
val bit = 1 shl HEADER_TABLE_SIZE
return if (bit and set != 0) values[HEADER_TABLE_SIZE] else -1
}
val initialWindowSize: Int
get() {
val bit = 1 shl INITIAL_WINDOW_SIZE
return if (bit and set != 0) values[INITIAL_WINDOW_SIZE] else DEFAULT_INITIAL_WINDOW_SIZE
}
fun clear() {
set = 0
values.fill(0)
}
operator fun set(id: Int, value: Int): Settings {
if (id < 0 || id >= values.size) {
return this // Discard unknown settings.
}
val bit = 1 shl id
set = set or bit
values[id] = value
return this
}
/** Returns true if a value has been assigned for the setting `id`. */
fun isSet(id: Int): Boolean {
val bit = 1 shl id
return set and bit != 0
}
/** Returns the value for the setting `id`, or 0 if unset. */
operator fun get(id: Int): Int = values[id]
/** Returns the number of settings that have values assigned. */
fun size(): Int = Integer.bitCount(set)
// TODO: honor this setting.
fun getEnablePush(defaultValue: Boolean): Boolean {
val bit = 1 shl ENABLE_PUSH
return if (bit and set != 0) values[ENABLE_PUSH] == 1 else defaultValue
}
fun getMaxConcurrentStreams(): Int {
val bit = 1 shl MAX_CONCURRENT_STREAMS
return if (bit and set != 0) values[MAX_CONCURRENT_STREAMS] else Int.MAX_VALUE
}
fun getMaxFrameSize(defaultValue: Int): Int {
val bit = 1 shl MAX_FRAME_SIZE
return if (bit and set != 0) values[MAX_FRAME_SIZE] else defaultValue
}
fun getMaxHeaderListSize(defaultValue: Int): Int {
val bit = 1 shl MAX_HEADER_LIST_SIZE
return if (bit and set != 0) values[MAX_HEADER_LIST_SIZE] else defaultValue
}
/**
* Writes `other` into this. If any setting is populated by this and `other`, the
* value and flags from `other` will be kept.
*/
fun merge(other: Settings) {
for (i in 0 until COUNT) {
if (!other.isSet(i)) continue
set(i, other[i])
}
}
companion object {
/**
* From the HTTP/2 specs, the default initial window size for all streams is 64 KiB. (Chrome 25
* uses 10 MiB).
*/
const val DEFAULT_INITIAL_WINDOW_SIZE = 65535
/** HTTP/2: Size in bytes of the table used to decode the sender's header blocks. */
const val HEADER_TABLE_SIZE = 1
/** HTTP/2: The peer must not send a PUSH_PROMISE frame when this is 0. */
const val ENABLE_PUSH = 2
/** Sender's maximum number of concurrent streams. */
const val MAX_CONCURRENT_STREAMS = 4
/** HTTP/2: Size in bytes of the largest frame payload the sender will accept. */
const val MAX_FRAME_SIZE = 5
/** HTTP/2: Advisory only. Size in bytes of the largest header list the sender will accept. */
const val MAX_HEADER_LIST_SIZE = 6
/** Window size in bytes. */
const val INITIAL_WINDOW_SIZE = 7
/** Total number of settings. */
const val COUNT = 10
}
}