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/*
* Authored by Alex Hultman, 2018-2019.
* Intellectual property of third-party.
* 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.
*/
#ifndef UWS_HTTPRESPONSE_H
#define UWS_HTTPRESPONSE_H
/* An HttpResponse is the channel on which you send back a response */
#include "AsyncSocket.h"
#include "HttpResponseData.h"
#include "HttpContextData.h"
#include "Utilities.h"
#include "f2/function2.hpp"
/* todo: tryWrite is missing currently, only send smaller segments with write */
namespace uWS {
/* Some pre-defined status constants to use with writeStatus */
static const char *HTTP_200_OK = "200 OK";
/* The general timeout for HTTP sockets */
static const int HTTP_TIMEOUT_S = 10;
template <bool SSL>
struct HttpResponse : public AsyncSocket<SSL> {
/* Solely used for getHttpResponseData() */
template <bool> friend struct TemplatedApp;
typedef AsyncSocket<SSL> Super;
private:
HttpResponseData<SSL> *getHttpResponseData() {
return (HttpResponseData<SSL> *) Super::getAsyncSocketData();
}
/* Write an unsigned 32-bit integer in hex */
void writeUnsignedHex(unsigned int value) {
char buf[10];
int length = utils::u32toaHex(value, buf);
/* For now we do this copy */
Super::write(buf, length);
}
/* Write an unsigned 32-bit integer */
void writeUnsigned(unsigned int value) {
char buf[10];
int length = utils::u32toa(value, buf);
/* For now we do this copy */
Super::write(buf, length);
}
/* When we are done with a response we mark it like so */
void markDone(HttpResponseData<SSL> *httpResponseData) {
httpResponseData->onAborted = nullptr;
/* Also remove onWritable so that we do not emit when draining behind the scenes. */
httpResponseData->onWritable = nullptr;
/* We are done with this request */
httpResponseData->state &= ~HttpResponseData<SSL>::HTTP_RESPONSE_PENDING;
}
/* Called only once per request */
void writeMark() {
writeHeader("uWebSockets", "v0.17");
}
/* Returns true on success, indicating that it might be feasible to write more data.
* Will start timeout if stream reaches totalSize or write failure. */
bool internalEnd(std::string_view data, int totalSize, bool optional, bool allowContentLength = true) {
/* Write status if not already done */
writeStatus(HTTP_200_OK);
/* If no total size given then assume this chunk is everything */
if (!totalSize) {
totalSize = (int) data.length();
}
HttpResponseData<SSL> *httpResponseData = getHttpResponseData();
if (httpResponseData->state & HttpResponseData<SSL>::HTTP_WRITE_CALLED) {
/* We do not have tryWrite-like functionalities, so ignore optional in this path */
/* Do not allow sending 0 chunk here */
if (data.length()) {
Super::write("\r\n", 2);
writeUnsignedHex((unsigned int) data.length());
Super::write("\r\n", 2);
/* Ignoring optional for now */
Super::write(data.data(), (int) data.length());
}
/* Terminating 0 chunk */
Super::write("\r\n0\r\n\r\n", 7);
markDone(httpResponseData);
/* tryEnd can never fail when in chunked mode, since we do not have tryWrite (yet), only write */
Super::timeout(HTTP_TIMEOUT_S);
return true;
} else {
/* Write content-length on first call */
if (!(httpResponseData->state & HttpResponseData<SSL>::HTTP_END_CALLED)) {
/* Write mark, this propagates to WebSockets too */
writeMark();
/* WebSocket upgrades does not allow content-length */
if (allowContentLength) {
/* Even zero is a valid content-length */
Super::write("Content-Length: ", 16);
writeUnsigned(totalSize);
Super::write("\r\n\r\n", 4);
} else {
Super::write("\r\n", 2);
}
/* Mark end called */
httpResponseData->state |= HttpResponseData<SSL>::HTTP_END_CALLED;
}
/* Even if we supply no new data to write, its failed boolean is useful to know
* if it failed to drain any prior failed header writes */
/* Write as much as possible without causing backpressure */
auto [written, failed] = Super::write(data.data(), (int) data.length(), optional);
httpResponseData->offset += written;
/* Success is when we wrote the entire thing without any failures */
bool success = (unsigned int) written == data.length() && !failed;
/* If we are now at the end, start a timeout. Also start a timeout if we failed. */
if (!success || httpResponseData->offset == totalSize) {
Super::timeout(HTTP_TIMEOUT_S);
}
/* Remove onAborted function if we reach the end */
if (httpResponseData->offset == totalSize) {
markDone(httpResponseData);
}
return success;
}
}
/* This call is identical to end, but will never write content-length and is thus suitable for upgrades */
void upgrade() {
internalEnd({nullptr, 0}, 0, false, false);
}
public:
/* Immediately terminate this Http response */
using Super::close;
using Super::getRemoteAddress;
/* Note: Headers are not checked in regards to timeout.
* We only check when you actively push data or end the request */
/* Write the HTTP status */
HttpResponse *writeStatus(std::string_view status) {
HttpResponseData<SSL> *httpResponseData = getHttpResponseData();
/* Do not allow writing more than one status */
if (httpResponseData->state & HttpResponseData<SSL>::HTTP_STATUS_CALLED) {
return this;
}
/* Update status */
httpResponseData->state |= HttpResponseData<SSL>::HTTP_STATUS_CALLED;
Super::write("HTTP/1.1 ", 9);
Super::write(status.data(), (int) status.length());
Super::write("\r\n", 2);
return this;
}
/* Write an HTTP header with string value */
HttpResponse *writeHeader(std::string_view key, std::string_view value) {
writeStatus(HTTP_200_OK);
Super::write(key.data(), (int) key.length());
Super::write(": ", 2);
Super::write(value.data(), (int) value.length());
Super::write("\r\n", 2);
return this;
}
/* Write an HTTP header with unsigned int value */
HttpResponse *writeHeader(std::string_view key, unsigned int value) {
Super::write(key.data(), (int) key.length());
Super::write(": ", 2);
writeUnsigned(value);
Super::write("\r\n", 2);
return this;
}
/* End the response with an optional data chunk. Always starts a timeout. */
void end(std::string_view data = {}) {
internalEnd(data, (int) data.length(), false);
}
/* Try and end the response. Returns [true, true] on success.
* Starts a timeout in some cases. Returns [ok, hasResponded] */
std::pair<bool, bool> tryEnd(std::string_view data, int totalSize = 0) {
return {internalEnd(data, totalSize, true), hasResponded()};
}
/* Write parts of the response in chunking fashion. Starts timeout if failed. */
bool write(std::string_view data) {
writeStatus(HTTP_200_OK);
/* Do not allow sending 0 chunks, they mark end of response */
if (!data.length()) {
/* If you called us, then according to you it was fine to call us so it's fine to still call us */
return true;
}
HttpResponseData<SSL> *httpResponseData = getHttpResponseData();
if (!(httpResponseData->state & HttpResponseData<SSL>::HTTP_WRITE_CALLED)) {
/* Write mark on first call to write */
writeMark();
writeHeader("Transfer-Encoding", "chunked");
httpResponseData->state |= HttpResponseData<SSL>::HTTP_WRITE_CALLED;
}
Super::write("\r\n", 2);
writeUnsignedHex((unsigned int) data.length());
Super::write("\r\n", 2);
auto [written, failed] = Super::write(data.data(), (int) data.length());
if (failed) {
Super::timeout(HTTP_TIMEOUT_S);
}
/* If we did not fail the write, accept more */
return !failed;
}
/* Get the current byte write offset for this Http response */
int getWriteOffset() {
HttpResponseData<SSL> *httpResponseData = getHttpResponseData();
return httpResponseData->offset;
}
/* Checking if we have fully responded and are ready for another request */
bool hasResponded() {
HttpResponseData<SSL> *httpResponseData = getHttpResponseData();
return !(httpResponseData->state & HttpResponseData<SSL>::HTTP_RESPONSE_PENDING);
}
/* Corks the response if possible. Leaves already corked socket be. */
HttpResponse *cork(fu2::unique_function<void()> &&handler) {
if (!Super::isCorked() && Super::canCork()) {
Super::cork();
handler();
/* Timeout on uncork failure, since most writes will succeed while corked */
auto [written, failed] = Super::uncork();
if (failed) {
/* For now we only have one single timeout so let's use it */
/* This behavior should equal the behavior in HttpContext when uncorking fails */
Super::timeout(HTTP_TIMEOUT_S);
}
} else {
/* We are already corked, or can't cork so let's just call the handler */
handler();
}
return this;
}
/* Attach handler for writable HTTP response */
HttpResponse *onWritable(fu2::unique_function<bool(int)> &&handler) {
HttpResponseData<SSL> *httpResponseData = getHttpResponseData();
httpResponseData->onWritable = std::move(handler);
return this;
}
/* Attach handler for aborted HTTP request */
HttpResponse *onAborted(fu2::unique_function<void()> &&handler) {
HttpResponseData<SSL> *httpResponseData = getHttpResponseData();
httpResponseData->onAborted = std::move(handler);
return this;
}
/* Attach a read handler for data sent. Will be called with FIN set true if last segment. */
void onData(fu2::unique_function<void(std::string_view, bool)> &&handler) {
HttpResponseData<SSL> *data = getHttpResponseData();
data->inStream = std::move(handler);
}
};
}
#endif // UWS_HTTPRESPONSE_H