com.facebook.presto.jdbc.internal.okhttp3.internal.http2.Http2 Maven / Gradle / Ivy
/*
* Copyright (C) 2013 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.facebook.presto.jdbc.internal.okhttp3.internal.http2;
import java.io.IOException;
import com.facebook.presto.jdbc.internal.okio.ByteString;
import static com.facebook.presto.jdbc.internal.okhttp3.internal.Util.format;
public final class Http2 {
static final ByteString CONNECTION_PREFACE
= ByteString.encodeUtf8("PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n");
/** The initial max frame size, applied independently writing to, or reading from the peer. */
static final int INITIAL_MAX_FRAME_SIZE = 0x4000; // 16384
static final byte TYPE_DATA = 0x0;
static final byte TYPE_HEADERS = 0x1;
static final byte TYPE_PRIORITY = 0x2;
static final byte TYPE_RST_STREAM = 0x3;
static final byte TYPE_SETTINGS = 0x4;
static final byte TYPE_PUSH_PROMISE = 0x5;
static final byte TYPE_PING = 0x6;
static final byte TYPE_GOAWAY = 0x7;
static final byte TYPE_WINDOW_UPDATE = 0x8;
static final byte TYPE_CONTINUATION = 0x9;
static final byte FLAG_NONE = 0x0;
static final byte FLAG_ACK = 0x1; // Used for settings and ping.
static final byte FLAG_END_STREAM = 0x1; // Used for headers and data.
static final byte FLAG_END_HEADERS = 0x4; // Used for headers and continuation.
static final byte FLAG_END_PUSH_PROMISE = 0x4;
static final byte FLAG_PADDED = 0x8; // Used for headers and data.
static final byte FLAG_PRIORITY = 0x20; // Used for headers.
static final byte FLAG_COMPRESSED = 0x20; // Used for data.
/** Lookup table for valid frame types. */
private static final String[] FRAME_NAMES = new String[] {
"DATA",
"HEADERS",
"PRIORITY",
"RST_STREAM",
"SETTINGS",
"PUSH_PROMISE",
"PING",
"GOAWAY",
"WINDOW_UPDATE",
"CONTINUATION"
};
/**
* Lookup table for valid flags for DATA, HEADERS, CONTINUATION. Invalid combinations are
* represented in binary.
*/
static final String[] FLAGS = new String[0x40]; // Highest bit flag is 0x20.
static final String[] BINARY = new String[256];
static {
for (int i = 0; i < BINARY.length; i++) {
BINARY[i] = format("%8s", Integer.toBinaryString(i)).replace(' ', '0');
}
FLAGS[FLAG_NONE] = "";
FLAGS[FLAG_END_STREAM] = "END_STREAM";
int[] prefixFlags = new int[] {FLAG_END_STREAM};
FLAGS[FLAG_PADDED] = "PADDED";
for (int prefixFlag : prefixFlags) {
FLAGS[prefixFlag | FLAG_PADDED] = FLAGS[prefixFlag] + "|PADDED";
}
FLAGS[FLAG_END_HEADERS] = "END_HEADERS"; // Same as END_PUSH_PROMISE.
FLAGS[FLAG_PRIORITY] = "PRIORITY"; // Same as FLAG_COMPRESSED.
FLAGS[FLAG_END_HEADERS | FLAG_PRIORITY] = "END_HEADERS|PRIORITY"; // Only valid on HEADERS.
int[] frameFlags = new int[] {
FLAG_END_HEADERS, FLAG_PRIORITY, FLAG_END_HEADERS | FLAG_PRIORITY
};
for (int frameFlag : frameFlags) {
for (int prefixFlag : prefixFlags) {
FLAGS[prefixFlag | frameFlag] = FLAGS[prefixFlag] + '|' + FLAGS[frameFlag];
FLAGS[prefixFlag | frameFlag | FLAG_PADDED]
= FLAGS[prefixFlag] + '|' + FLAGS[frameFlag] + "|PADDED";
}
}
for (int i = 0; i < FLAGS.length; i++) { // Fill in holes with binary representation.
if (FLAGS[i] == null) FLAGS[i] = BINARY[i];
}
}
private Http2() {
}
static IllegalArgumentException illegalArgument(String message, Object... args) {
throw new IllegalArgumentException(format(message, args));
}
static IOException ioException(String message, Object... args) throws IOException {
throw new IOException(format(message, args));
}
/**
* Returns human-readable representation of HTTP/2 frame headers.
*
* The format is:
*
*
* direction streamID length type flags
*
*
* Where direction is {@code <<} for inbound and {@code >>} for outbound.
*
* For example, the following would indicate a HEAD request sent from the client.
*
* {@code
* << 0x0000000f 12 HEADERS END_HEADERS|END_STREAM
* }
*
*/
static String frameLog(boolean inbound, int streamId, int length, byte type, byte flags) {
String formattedType = type < FRAME_NAMES.length ? FRAME_NAMES[type] : format("0x%02x", type);
String formattedFlags = formatFlags(type, flags);
return format("%s 0x%08x %5d %-13s %s", inbound ? "<<" : ">>", streamId, length,
formattedType, formattedFlags);
}
/**
* Looks up valid string representing flags from the table. Invalid combinations are represented
* in binary.
*/
// Visible for testing.
static String formatFlags(byte type, byte flags) {
if (flags == 0) return "";
switch (type) { // Special case types that have 0 or 1 flag.
case TYPE_SETTINGS:
case TYPE_PING:
return flags == FLAG_ACK ? "ACK" : BINARY[flags];
case TYPE_PRIORITY:
case TYPE_RST_STREAM:
case TYPE_GOAWAY:
case TYPE_WINDOW_UPDATE:
return BINARY[flags];
}
String result = flags < FLAGS.length ? FLAGS[flags] : BINARY[flags];
// Special case types that have overlap flag values.
if (type == TYPE_PUSH_PROMISE && (flags & FLAG_END_PUSH_PROMISE) != 0) {
return result.replace("HEADERS", "PUSH_PROMISE"); // TODO: Avoid allocation.
} else if (type == TYPE_DATA && (flags & FLAG_COMPRESSED) != 0) {
return result.replace("PRIORITY", "COMPRESSED"); // TODO: Avoid allocation.
}
return result;
}
}