com.squareup.okhttp.internal.spdy.Settings 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 com.squareup.okhttp.internal.spdy;
final class Settings {
/**
* From the spdy/3 spec, the default initial window size for all streams is
* 64 KiB. (Chrome 25 uses 10 MiB).
*/
static final int DEFAULT_INITIAL_WINDOW_SIZE = 64 * 1024;
/** Peer request to clear durable settings. */
static final int FLAG_CLEAR_PREVIOUSLY_PERSISTED_SETTINGS = 0x1;
/** Sent by servers only. The peer requests this setting persisted for future connections. */
static final int PERSIST_VALUE = 0x1;
/** Sent by clients only. The client is reminding the server of a persisted value. */
static final int PERSISTED = 0x2;
/** Sender's estimate of max incoming kbps. */
static final int UPLOAD_BANDWIDTH = 0x1;
/** Sender's estimate of max outgoing kbps. */
static final int DOWNLOAD_BANDWIDTH = 0x2;
/** Sender's estimate of milliseconds between sending a request and receiving a response. */
static final int ROUND_TRIP_TIME = 0x3;
/** Sender's maximum number of concurrent streams. */
static final int MAX_CONCURRENT_STREAMS = 0x4;
/** Current CWND in Packets. */
static final int CURRENT_CWND = 0x5;
/** Retransmission rate. Percentage */
static final int DOWNLOAD_RETRANS_RATE = 0x6;
/** Window size in bytes. */
static final int INITIAL_WINDOW_SIZE = 0x7;
/** Window size in bytes. */
static final int CLIENT_CERTIFICATE_VECTOR_SIZE = 0x8;
/** Total number of settings. */
static final int COUNT = 0x9;
/** Bitfield of which flags that values. */
private int set;
/** Bitfield of flags that have {@link #PERSIST_VALUE}. */
private int persistValue;
/** Bitfield of flags that have {@link #PERSISTED}. */
private int persisted;
/** Flag values. */
private final int[] values = new int[COUNT];
void set(int id, int idFlags, int value) {
if (id >= values.length) {
return; // Discard unknown settings.
}
int bit = 1 << id;
set |= bit;
if ((idFlags & PERSIST_VALUE) != 0) {
persistValue |= bit;
} else {
persistValue &= ~bit;
}
if ((idFlags & PERSISTED) != 0) {
persisted |= bit;
} else {
persisted &= ~bit;
}
values[id] = value;
}
/** Returns true if a value has been assigned for the setting {@code id}. */
boolean isSet(int id) {
int bit = 1 << id;
return (set & bit) != 0;
}
/** Returns the value for the setting {@code id}, or 0 if unset. */
int get(int id) {
return values[id];
}
/** Returns the flags for the setting {@code id}, or 0 if unset. */
int flags(int id) {
int result = 0;
if (isPersisted(id)) result |= Settings.PERSISTED;
if (persistValue(id)) result |= Settings.PERSIST_VALUE;
return result;
}
/** Returns the number of settings that have values assigned. */
int size() {
return Integer.bitCount(set);
}
int getUploadBandwidth(int defaultValue) {
int bit = 1 << UPLOAD_BANDWIDTH;
return (bit & set) != 0 ? values[UPLOAD_BANDWIDTH] : defaultValue;
}
int getDownloadBandwidth(int defaultValue) {
int bit = 1 << DOWNLOAD_BANDWIDTH;
return (bit & set) != 0 ? values[DOWNLOAD_BANDWIDTH] : defaultValue;
}
int getRoundTripTime(int defaultValue) {
int bit = 1 << ROUND_TRIP_TIME;
return (bit & set) != 0 ? values[ROUND_TRIP_TIME] : defaultValue;
}
int getMaxConcurrentStreams(int defaultValue) {
int bit = 1 << MAX_CONCURRENT_STREAMS;
return (bit & set) != 0 ? values[MAX_CONCURRENT_STREAMS] : defaultValue;
}
int getCurrentCwnd(int defaultValue) {
int bit = 1 << CURRENT_CWND;
return (bit & set) != 0 ? values[CURRENT_CWND] : defaultValue;
}
int getDownloadRetransRate(int defaultValue) {
int bit = 1 << DOWNLOAD_RETRANS_RATE;
return (bit & set) != 0 ? values[DOWNLOAD_RETRANS_RATE] : defaultValue;
}
int getInitialWindowSize(int defaultValue) {
int bit = 1 << INITIAL_WINDOW_SIZE;
return (bit & set) != 0 ? values[INITIAL_WINDOW_SIZE] : defaultValue;
}
int getClientCertificateVectorSize(int defaultValue) {
int bit = 1 << CLIENT_CERTIFICATE_VECTOR_SIZE;
return (bit & set) != 0 ? values[CLIENT_CERTIFICATE_VECTOR_SIZE] : defaultValue;
}
/**
* Returns true if this user agent should use this setting in future SPDY
* connections to the same host.
*/
boolean persistValue(int id) {
int bit = 1 << id;
return (persistValue & bit) != 0;
}
/** Returns true if this setting was persisted. */
boolean isPersisted(int id) {
int bit = 1 << id;
return (persisted & bit) != 0;
}
/**
* Writes {@code other} into this. If any setting is populated by this and
* {@code other}, the value and flags from {@code other} will be kept.
*/
void merge(Settings other) {
for (int i = 0; i < COUNT; i++) {
if (!other.isSet(i)) continue;
set(i, other.flags(i), other.get(i));
}
}
}