node/lib/_http_outgoing.js

650 строки
17 KiB
JavaScript

'use strict';
const assert = require('assert').ok;
const Stream = require('stream');
const timers = require('timers');
const util = require('util');
const Buffer = require('buffer').Buffer;
const common = require('_http_common');
const CRLF = common.CRLF;
const chunkExpression = common.chunkExpression;
const debug = common.debug;
const connectionExpression = /^Connection$/i;
const transferEncodingExpression = /^Transfer-Encoding$/i;
const closeExpression = /close/i;
const contentLengthExpression = /^Content-Length$/i;
const dateExpression = /^Date$/i;
const expectExpression = /^Expect$/i;
const trailerExpression = /^Trailer$/i;
const automaticHeaders = {
connection: true,
'content-length': true,
'transfer-encoding': true,
date: true
};
var dateCache;
function utcDate() {
if (!dateCache) {
var d = new Date();
dateCache = d.toUTCString();
timers.enroll(utcDate, 1000 - d.getMilliseconds());
timers._unrefActive(utcDate);
}
return dateCache;
}
utcDate._onTimeout = function() {
dateCache = undefined;
};
function OutgoingMessage() {
Stream.call(this);
this.output = [];
this.outputEncodings = [];
this.outputCallbacks = [];
this.writable = true;
this._last = false;
this.chunkedEncoding = false;
this.shouldKeepAlive = true;
this.useChunkedEncodingByDefault = true;
this.sendDate = false;
this._removedHeader = {};
this._contentLength = null;
this._hasBody = true;
this._trailer = '';
this.finished = false;
this._headerSent = false;
this.socket = null;
this.connection = null;
this._header = null;
this._headers = null;
this._headerNames = {};
}
util.inherits(OutgoingMessage, Stream);
exports.OutgoingMessage = OutgoingMessage;
OutgoingMessage.prototype.setTimeout = function(msecs, callback) {
if (callback)
this.on('timeout', callback);
if (!this.socket) {
this.once('socket', function(socket) {
socket.setTimeout(msecs);
});
} else {
this.socket.setTimeout(msecs);
}
return this;
};
// It's possible that the socket will be destroyed, and removed from
// any messages, before ever calling this. In that case, just skip
// it, since something else is destroying this connection anyway.
OutgoingMessage.prototype.destroy = function(error) {
if (this.socket)
this.socket.destroy(error);
else
this.once('socket', function(socket) {
socket.destroy(error);
});
};
// This abstract either writing directly to the socket or buffering it.
OutgoingMessage.prototype._send = function(data, encoding, callback) {
// This is a shameful hack to get the headers and first body chunk onto
// the same packet. Future versions of Node are going to take care of
// this at a lower level and in a more general way.
if (!this._headerSent) {
if (typeof data === 'string' &&
encoding !== 'hex' &&
encoding !== 'base64') {
data = this._header + data;
} else {
this.output.unshift(this._header);
this.outputEncodings.unshift('binary');
this.outputCallbacks.unshift(null);
}
this._headerSent = true;
}
return this._writeRaw(data, encoding, callback);
};
OutgoingMessage.prototype._writeRaw = function(data, encoding, callback) {
if (typeof encoding === 'function') {
callback = encoding;
encoding = null;
}
if (data.length === 0) {
if (typeof callback === 'function')
process.nextTick(callback);
return true;
}
var connection = this.connection;
if (connection &&
connection._httpMessage === this &&
connection.writable &&
!connection.destroyed) {
// There might be pending data in the this.output buffer.
var outputLength = this.output.length;
if (outputLength > 0) {
var output = this.output;
var outputEncodings = this.outputEncodings;
var outputCallbacks = this.outputCallbacks;
for (var i = 0; i < outputLength; i++) {
connection.write(output[i], outputEncodings[i],
outputCallbacks[i]);
}
this.output = [];
this.outputEncodings = [];
this.outputCallbacks = [];
}
// Directly write to socket.
return connection.write(data, encoding, callback);
} else if (connection && connection.destroyed) {
// The socket was destroyed. If we're still trying to write to it,
// then we haven't gotten the 'close' event yet.
return false;
} else {
// buffer, as long as we're not destroyed.
return this._buffer(data, encoding, callback);
}
};
OutgoingMessage.prototype._buffer = function(data, encoding, callback) {
this.output.push(data);
this.outputEncodings.push(encoding);
this.outputCallbacks.push(callback);
return false;
};
OutgoingMessage.prototype._storeHeader = function(firstLine, headers) {
// firstLine in the case of request is: 'GET /index.html HTTP/1.1\r\n'
// in the case of response it is: 'HTTP/1.1 200 OK\r\n'
var state = {
sentConnectionHeader: false,
sentContentLengthHeader: false,
sentTransferEncodingHeader: false,
sentDateHeader: false,
sentExpect: false,
sentTrailer: false,
messageHeader: firstLine
};
if (headers) {
var keys = Object.keys(headers);
var isArray = Array.isArray(headers);
var field, value;
for (var i = 0, l = keys.length; i < l; i++) {
var key = keys[i];
if (isArray) {
field = headers[key][0];
value = headers[key][1];
} else {
field = key;
value = headers[key];
}
if (Array.isArray(value)) {
for (var j = 0; j < value.length; j++) {
storeHeader(this, state, field, value[j]);
}
} else {
storeHeader(this, state, field, value);
}
}
}
// Date header
if (this.sendDate === true && state.sentDateHeader === false) {
state.messageHeader += 'Date: ' + utcDate() + CRLF;
}
// Force the connection to close when the response is a 204 No Content or
// a 304 Not Modified and the user has set a "Transfer-Encoding: chunked"
// header.
//
// RFC 2616 mandates that 204 and 304 responses MUST NOT have a body but
// node.js used to send out a zero chunk anyway to accommodate clients
// that don't have special handling for those responses.
//
// It was pointed out that this might confuse reverse proxies to the point
// of creating security liabilities, so suppress the zero chunk and force
// the connection to close.
var statusCode = this.statusCode;
if ((statusCode === 204 || statusCode === 304) &&
this.chunkedEncoding === true) {
debug(statusCode + ' response should not use chunked encoding,' +
' closing connection.');
this.chunkedEncoding = false;
this.shouldKeepAlive = false;
}
// keep-alive logic
if (this._removedHeader.connection) {
this._last = true;
this.shouldKeepAlive = false;
} else if (state.sentConnectionHeader === false) {
var shouldSendKeepAlive = this.shouldKeepAlive &&
(state.sentContentLengthHeader ||
this.useChunkedEncodingByDefault ||
this.agent);
if (shouldSendKeepAlive) {
state.messageHeader += 'Connection: keep-alive\r\n';
} else {
this._last = true;
state.messageHeader += 'Connection: close\r\n';
}
}
if (state.sentContentLengthHeader === false &&
state.sentTransferEncodingHeader === false) {
if (!this._hasBody) {
// Make sure we don't end the 0\r\n\r\n at the end of the message.
this.chunkedEncoding = false;
} else if (!this.useChunkedEncodingByDefault) {
this._last = true;
} else {
if (!state.sentTrailer &&
!this._removedHeader['content-length'] &&
typeof this._contentLength === 'number') {
state.messageHeader += 'Content-Length: ' + this._contentLength +
'\r\n';
} else if (!this._removedHeader['transfer-encoding']) {
state.messageHeader += 'Transfer-Encoding: chunked\r\n';
this.chunkedEncoding = true;
} else {
// We should only be able to get here if both Content-Length and
// Transfer-Encoding are removed by the user.
// See: test/parallel/test-http-remove-header-stays-removed.js
debug('Both Content-Length and Transfer-Encoding are removed');
}
}
}
this._header = state.messageHeader + CRLF;
this._headerSent = false;
// wait until the first body chunk, or close(), is sent to flush,
// UNLESS we're sending Expect: 100-continue.
if (state.sentExpect) this._send('');
};
function storeHeader(self, state, field, value) {
// Protect against response splitting. The if statement is there to
// minimize the performance impact in the common case.
if (/[\r\n]/.test(value))
value = value.replace(/[\r\n]+[ \t]*/g, '');
state.messageHeader += field + ': ' + value + CRLF;
if (connectionExpression.test(field)) {
state.sentConnectionHeader = true;
if (closeExpression.test(value)) {
self._last = true;
} else {
self.shouldKeepAlive = true;
}
} else if (transferEncodingExpression.test(field)) {
state.sentTransferEncodingHeader = true;
if (chunkExpression.test(value)) self.chunkedEncoding = true;
} else if (contentLengthExpression.test(field)) {
state.sentContentLengthHeader = true;
} else if (dateExpression.test(field)) {
state.sentDateHeader = true;
} else if (expectExpression.test(field)) {
state.sentExpect = true;
} else if (trailerExpression.test(field)) {
state.sentTrailer = true;
}
}
OutgoingMessage.prototype.setHeader = function(name, value) {
if (typeof name !== 'string')
throw new TypeError('`name` should be a string in setHeader(name, value).');
if (value === undefined)
throw new Error('`value` required in setHeader("' + name + '", value).');
if (this._header)
throw new Error('Can\'t set headers after they are sent.');
if (this._headers === null)
this._headers = {};
var key = name.toLowerCase();
this._headers[key] = value;
this._headerNames[key] = name;
if (automaticHeaders[key])
this._removedHeader[key] = false;
};
OutgoingMessage.prototype.getHeader = function(name) {
if (arguments.length < 1) {
throw new Error('`name` is required for getHeader(name).');
}
if (!this._headers) return;
var key = name.toLowerCase();
return this._headers[key];
};
OutgoingMessage.prototype.removeHeader = function(name) {
if (arguments.length < 1) {
throw new Error('`name` is required for removeHeader(name).');
}
if (this._header) {
throw new Error('Can\'t remove headers after they are sent.');
}
var key = name.toLowerCase();
if (key === 'date')
this.sendDate = false;
else if (automaticHeaders[key])
this._removedHeader[key] = true;
if (this._headers) {
delete this._headers[key];
delete this._headerNames[key];
}
};
OutgoingMessage.prototype._renderHeaders = function() {
if (this._header) {
throw new Error('Can\'t render headers after they are sent to the client.');
}
var headersMap = this._headers;
if (!headersMap) return {};
var headers = {};
var keys = Object.keys(headersMap);
var headerNames = this._headerNames;
for (var i = 0, l = keys.length; i < l; i++) {
var key = keys[i];
headers[headerNames[key]] = headersMap[key];
}
return headers;
};
Object.defineProperty(OutgoingMessage.prototype, 'headersSent', {
configurable: true,
enumerable: true,
get: function() { return !!this._header; }
});
OutgoingMessage.prototype.write = function(chunk, encoding, callback) {
if (this.finished) {
var err = new Error('write after end');
process.nextTick(writeAfterEndNT, this, err, callback);
return true;
}
if (!this._header) {
this._implicitHeader();
}
if (!this._hasBody) {
debug('This type of response MUST NOT have a body. ' +
'Ignoring write() calls.');
return true;
}
if (typeof chunk !== 'string' && !(chunk instanceof Buffer)) {
throw new TypeError('first argument must be a string or Buffer');
}
// If we get an empty string or buffer, then just do nothing, and
// signal the user to keep writing.
if (chunk.length === 0) return true;
var len, ret;
if (this.chunkedEncoding) {
if (typeof chunk === 'string' &&
encoding !== 'hex' &&
encoding !== 'base64' &&
encoding !== 'binary') {
len = Buffer.byteLength(chunk, encoding);
chunk = len.toString(16) + CRLF + chunk + CRLF;
ret = this._send(chunk, encoding, callback);
} else {
// buffer, or a non-toString-friendly encoding
if (typeof chunk === 'string')
len = Buffer.byteLength(chunk, encoding);
else
len = chunk.length;
if (this.connection && !this.connection.corked) {
this.connection.cork();
process.nextTick(connectionCorkNT, this.connection);
}
this._send(len.toString(16), 'binary', null);
this._send(crlf_buf, null, null);
this._send(chunk, encoding, null);
ret = this._send(crlf_buf, null, callback);
}
} else {
ret = this._send(chunk, encoding, callback);
}
debug('write ret = ' + ret);
return ret;
};
function writeAfterEndNT(self, err, callback) {
self.emit('error', err);
if (callback) callback(err);
}
function connectionCorkNT(conn) {
if (conn)
conn.uncork();
}
OutgoingMessage.prototype.addTrailers = function(headers) {
this._trailer = '';
var keys = Object.keys(headers);
var isArray = Array.isArray(headers);
var field, value;
for (var i = 0, l = keys.length; i < l; i++) {
var key = keys[i];
if (isArray) {
field = headers[key][0];
value = headers[key][1];
} else {
field = key;
value = headers[key];
}
this._trailer += field + ': ' + value + CRLF;
}
};
const crlf_buf = new Buffer('\r\n');
OutgoingMessage.prototype.end = function(data, encoding, callback) {
if (typeof data === 'function') {
callback = data;
data = null;
} else if (typeof encoding === 'function') {
callback = encoding;
encoding = null;
}
if (data && typeof data !== 'string' && !(data instanceof Buffer)) {
throw new TypeError('first argument must be a string or Buffer');
}
if (this.finished) {
return false;
}
var self = this;
function finish() {
self.emit('finish');
}
if (typeof callback === 'function')
this.once('finish', callback);
if (!this._header) {
if (data) {
if (typeof data === 'string')
this._contentLength = Buffer.byteLength(data, encoding);
else
this._contentLength = data.length;
} else {
this._contentLength = 0;
}
this._implicitHeader();
}
if (data && !this._hasBody) {
debug('This type of response MUST NOT have a body. ' +
'Ignoring data passed to end().');
data = null;
}
if (this.connection && data)
this.connection.cork();
var ret;
if (data) {
// Normal body write.
ret = this.write(data, encoding);
}
if (this._hasBody && this.chunkedEncoding) {
ret = this._send('0\r\n' + this._trailer + '\r\n', 'binary', finish);
} else {
// Force a flush, HACK.
ret = this._send('', 'binary', finish);
}
if (this.connection && data)
this.connection.uncork();
this.finished = true;
// There is the first message on the outgoing queue, and we've sent
// everything to the socket.
debug('outgoing message end.');
if (this.output.length === 0 && this.connection._httpMessage === this) {
this._finish();
}
return ret;
};
OutgoingMessage.prototype._finish = function() {
assert(this.connection);
this.emit('prefinish');
};
// This logic is probably a bit confusing. Let me explain a bit:
//
// In both HTTP servers and clients it is possible to queue up several
// outgoing messages. This is easiest to imagine in the case of a client.
// Take the following situation:
//
// req1 = client.request('GET', '/');
// req2 = client.request('POST', '/');
//
// When the user does
//
// req2.write('hello world\n');
//
// it's possible that the first request has not been completely flushed to
// the socket yet. Thus the outgoing messages need to be prepared to queue
// up data internally before sending it on further to the socket's queue.
//
// This function, outgoingFlush(), is called by both the Server and Client
// to attempt to flush any pending messages out to the socket.
OutgoingMessage.prototype._flush = function() {
var socket = this.socket;
var outputLength, ret;
if (socket && socket.writable) {
// There might be remaining data in this.output; write it out
outputLength = this.output.length;
if (outputLength > 0) {
var output = this.output;
var outputEncodings = this.outputEncodings;
var outputCallbacks = this.outputCallbacks;
for (var i = 0; i < outputLength; i++) {
ret = socket.write(output[i], outputEncodings[i],
outputCallbacks[i]);
}
this.output = [];
this.outputEncodings = [];
this.outputCallbacks = [];
}
if (this.finished) {
// This is a queue to the server or client to bring in the next this.
this._finish();
} else if (ret) {
// This is necessary to prevent https from breaking
this.emit('drain');
}
}
};
OutgoingMessage.prototype.flushHeaders = function() {
if (!this._header) {
this._implicitHeader();
}
// Force-flush the headers.
this._send('');
};
OutgoingMessage.prototype.flush = util.deprecate(function() {
this.flushHeaders();
}, 'flush is deprecated. Use flushHeaders instead.');