introduce onBody callback function in CurlClient

Summary:
introduce a onBody callback function in CurlClient so the response value can be checked.

Also re-type httpPaths and requestGaps in HQToolClientParams from std::vector<folly::StringPiece> to std::vector<std::string> because
1. there was a bug with a vector of StringPiece.
    HQToolParamsBuilderFromCmdline takes a list of gflags from the caller to override gflags. It works only in the scope of gflags::FlagSaver. https://fburl.com/code/5bg24j7v. After the constructor function is finished, gflag value will be changed back and so does requestGaps/httpPaths because StringPieces are just pointers to some other allocation not owned by themselves
 2. To create a client wrapper to send massive requests to multiple vips and check the return values,  we need to create separate and different params for each HQClient instance so we need requestGaps and httpPaths to be a vector of strings.

Reviewed By: kvtsoy

Differential Revision: D59966312

fbshipit-source-id: 00c0a50691d566d3ffa59a0a7253979e86e63cec

proxygen/httpclient/samples/curl/CurlClient.cpp

@@ -251,6 +251,9 @@ void CurlClient::onHeadersComplete(unique_ptr<HTTPMessage> msg) noexcept {
 }
 
 void CurlClient::onBody(std::unique_ptr<folly::IOBuf> chain) noexcept {
+ if (onBodyFunc_ && chain) {
+ onBodyFunc_.value()(request_, chain.get());
+ }
  if (!loggingEnabled_) {
  return;
  }

proxygen/httpclient/samples/curl/CurlClient.h

@@ -136,6 +136,12 @@ class CurlClient
  eomFunc_ = eomFunc;
  }
 
+ void setOnBodyFunc(
+ const std::function<void(const proxygen::HTTPMessage& request,
+ const folly::IOBuf* chainBuf)>& onBodyFunc) {
+ onBodyFunc_ = onBodyFunc;
+ }
+
  protected:
  void sendBodyFromFile();
 
@@ -169,6 +175,10 @@ class CurlClient
 
  folly::Optional<std::function<void()>> eomFunc_;
 
+ folly::Optional<std::function<void(const proxygen::HTTPMessage& request,
+ const folly::IOBuf* chainBuf)>>
+ onBodyFunc_;
+
  friend class CurlPushHandler;
 };
 

proxygen/httpserver/samples/hq/HQClient.cpp

@@ -143,6 +143,10 @@ HQClient::sendRequest(const proxygen::URL& requestUrl) {
  }
  }
  client->sendRequest(txn);
+
+ if (onBodyFunc_) {
+ client->setOnBodyFunc(onBodyFunc_.value());
+ }
  curls_.emplace_back(std::move(client));
  return txn;
 }

proxygen/httpserver/samples/hq/HQClient.h

@@ -8,11 +8,13 @@
 
 #pragma once
 
+#include <folly/io/IOBuf.h>
 #include <list>
 #include <memory>
 #include <proxygen/httpclient/samples/curl/CurlClient.h>
 #include <proxygen/httpserver/samples/hq/H1QUpstreamSession.h>
 #include <proxygen/httpserver/samples/hq/HQCommandLine.h>
+#include <proxygen/lib/http/HTTPMessage.h>
 #include <proxygen/lib/http/session/HQUpstreamSession.h>
 #include <quic/common/events/HighResQuicTimer.h>
 
@@ -31,6 +33,12 @@ class HQClient : private quic::QuicSocket::ConnectionSetupCallback {
 
  int start();
 
+ void setOnBodyFunc(
+ const std::function<void(const proxygen::HTTPMessage& request,
+ const folly::IOBuf* chainBuf)>& onBodyFunc) {
+ onBodyFunc_ = onBodyFunc;
+ }
+
  private:
  // Conn setup callback
  void onConnectionSetupError(quic::QuicError code) noexcept override;
@@ -99,6 +107,10 @@ class HQClient : private quic::QuicSocket::ConnectionSetupCallback {
 
  std::deque<std::chrono::milliseconds> requestGaps_;
 
+ folly::Optional<std::function<void(const proxygen::HTTPMessage& request,
+ const folly::IOBuf* chainBuf)>>
+ onBodyFunc_;
+
  bool failed_{false};
 
  bool replaySafe_{false};

proxygen/httpserver/samples/hq/HQCommandLine.cpp

@@ -439,6 +439,7 @@ HQToolParamsBuilderFromCmdline::HQToolParamsBuilderFromCmdline(
  gflags::FlagSaver saver;
 
  for (auto& kv : initial) {
+ LOG(INFO) << "Overriding HQToolParams " << kv.first << " to " << kv.second;
  gflags::SetCommandLineOptionWithMode(
  kv.first.c_str(),
  kv.second.c_str(),

proxygen/httpserver/samples/hq/HQCommandLine.h

@@ -29,10 +29,10 @@ struct HQToolClientParams : public HQBaseParams {
  proxygen::HTTPHeaders httpHeaders;
  std::string httpBody;
  proxygen::HTTPMethod httpMethod;
- std::vector<folly::StringPiece> httpPaths;
+ std::vector<std::string> httpPaths;
  bool migrateClient{false};
  bool sendRequestsSequentially;
- std::vector<folly::StringPiece> requestGaps;
+ std::vector<std::string> requestGaps;
 };
 
 struct HQToolServerParams : public HQServerParams {