input/qobuz: use class DelegateCurlResponseHandler to eliminate duplicate code

src/input/plugins/QobuzErrorParser.cxx

@@ -40,24 +40,18 @@ static constexpr yajl_callbacks qobuz_error_parser_callbacks = {
 
 QobuzErrorParser::QobuzErrorParser(unsigned _status,
 				   const std::multimap<std::string, std::string> &headers)
-	:status(_status),
-	 parser(&qobuz_error_parser_callbacks, nullptr, this)
+	:YajlResponseParser(&qobuz_error_parser_callbacks, nullptr, this),
+	 status(_status)
 {
 	auto i = headers.find("content-type");
 	if (i == headers.end() || i->second.find("/json") == i->second.npos)
 		throw FormatRuntimeError("Status %u from Qobuz", status);
 }
 
-void
-QobuzErrorParser::OnData(ConstBuffer<void> data)
-{
-	parser.Parse((const unsigned char *)data.data, data.size);
-}
-
 void
 QobuzErrorParser::OnEnd()
 {
-	parser.CompleteParse();
+	YajlResponseParser::OnEnd();
 
 	if (!message.empty())
 		throw FormatRuntimeError("Error from Qobuz: %s",

src/input/plugins/QobuzErrorParser.hxx

@@ -21,9 +21,8 @@
 #define QOBUZ_ERROR_PARSER_HXX
 
 #include "check.h"
-#include "lib/yajl/Handle.hxx"
+#include "lib/yajl/ResponseParser.hxx"
 
-#include <exception>
 #include <string>
 #include <map>
 
@@ -33,11 +32,9 @@ struct StringView;
 /**
  * Parse an error JSON response.
  */
-class QobuzErrorParser {
+class QobuzErrorParser final : public YajlResponseParser {
 	const unsigned status;
 
-	Yajl::Handle parser;
-
 	enum class State {
 		NONE,
 		MESSAGE,
@@ -53,16 +50,9 @@ public:
 	QobuzErrorParser(unsigned status,
 			 const std::multimap<std::string, std::string> &headers);
 
-	/**
-	 * Feed response body data into the JSON parser.
-	 */
-	void OnData(ConstBuffer<void> data);
-
-	/**
-	 * Throw an exception describing the error condition.  Call
-	 * this at the end of the response body.
-	 */
-	void OnEnd();
+protected:
+	/* virtual methods from CurlResponseParser */
+	void OnEnd() override;
 
 public:
 	/* yajl callbacks */

src/input/plugins/QobuzLoginRequest.cxx

@@ -20,11 +20,12 @@
 #include "config.h"
 #include "QobuzLoginRequest.hxx"
 #include "QobuzErrorParser.hxx"
+#include "QobuzSession.hxx"
 #include "lib/curl/Form.hxx"
 #include "lib/yajl/Callbacks.hxx"
 #include "util/RuntimeError.hxx"
 
-using Wrapper = Yajl::CallbacksWrapper<QobuzLoginRequest>;
+using Wrapper = Yajl::CallbacksWrapper<QobuzLoginRequest::ResponseParser>;
 static constexpr yajl_callbacks parse_callbacks = {
 	nullptr,
 	nullptr,
@@ -39,6 +40,43 @@ static constexpr yajl_callbacks parse_callbacks = {
 	nullptr,
 };
 
+class QobuzLoginRequest::ResponseParser final : public YajlResponseParser {
+	enum class State {
+		NONE,
+		DEVICE,
+		DEVICE_ID,
+		USER_AUTH_TOKEN,
+	} state = State::NONE;
+
+	unsigned map_depth = 0;
+
+	QobuzSession session;
+
+public:
+	explicit ResponseParser() noexcept
+		:YajlResponseParser(&parse_callbacks, nullptr, this) {}
+
+	QobuzSession &&GetSession();
+
+	/* yajl callbacks */
+	bool String(StringView value) noexcept;
+	bool StartMap() noexcept;
+	bool MapKey(StringView value) noexcept;
+	bool EndMap() noexcept;
+};
+
+inline QobuzSession &&
+QobuzLoginRequest::ResponseParser::GetSession()
+{
+	if (session.user_auth_token.empty())
+		throw std::runtime_error("No user_auth_token in login response");
+
+	if (session.device_id.empty())
+		throw std::runtime_error("No device id in login response");
+
+	return std::move(session);
+}
+
 static std::multimap<std::string, std::string>
 MakeLoginForm(const char *app_id,
 	      const char *username, const char *email,
@@ -95,50 +133,26 @@ QobuzLoginRequest::~QobuzLoginRequest() noexcept
 	request.StopIndirect();
 }
 
-void
-QobuzLoginRequest::OnHeaders(unsigned status,
-			     std::multimap<std::string, std::string> &&headers)
+std::unique_ptr<CurlResponseParser>
+QobuzLoginRequest::MakeParser(unsigned status,
+			      std::multimap<std::string, std::string> &&headers)
 {
-	if (status != 200) {
-		error_parser = std::make_unique<QobuzErrorParser>(status, headers);
-		return;
-	}
+	if (status != 200)
+		return std::make_unique<QobuzErrorParser>(status, headers);
 
 	auto i = headers.find("content-type");
 	if (i == headers.end() || i->second.find("/json") == i->second.npos)
 		throw std::runtime_error("Not a JSON response from Qobuz");
 
-	parser = {&parse_callbacks, nullptr, this};
+	return std::make_unique<ResponseParser>();
 }
 
 void
-QobuzLoginRequest::OnData(ConstBuffer<void> data)
+QobuzLoginRequest::FinishParser(std::unique_ptr<CurlResponseParser> p)
 {
-	if (error_parser) {
-		error_parser->OnData(data);
-		return;
-	}
-
-	parser.Parse((const unsigned char *)data.data, data.size);
-}
-
-void
-QobuzLoginRequest::OnEnd()
-{
-	if (error_parser) {
-		error_parser->OnEnd();
-		return;
-	}
-
-	parser.CompleteParse();
-
-	if (session.user_auth_token.empty())
-		throw std::runtime_error("No user_auth_token in login response");
-
-	if (session.device_id.empty())
-		throw std::runtime_error("No device id in login response");
-
-	handler.OnQobuzLoginSuccess(std::move(session));
+	assert(dynamic_cast<ResponseParser *>(p.get()) != nullptr);
+	auto &rp = (ResponseParser &)*p;
+	handler.OnQobuzLoginSuccess(rp.GetSession());
 }
 
 void
@@ -148,7 +162,7 @@ QobuzLoginRequest::OnError(std::exception_ptr e) noexcept
 }
 
 inline bool
-QobuzLoginRequest::String(StringView value) noexcept
+QobuzLoginRequest::ResponseParser::String(StringView value) noexcept
 {
 	switch (state) {
 	case State::NONE:
@@ -168,7 +182,7 @@ QobuzLoginRequest::String(StringView value) noexcept
 }
 
 inline bool
-QobuzLoginRequest::StartMap() noexcept
+QobuzLoginRequest::ResponseParser::StartMap() noexcept
 {
 	switch (state) {
 	case State::NONE:
@@ -187,7 +201,7 @@ QobuzLoginRequest::StartMap() noexcept
 }
 
 inline bool
-QobuzLoginRequest::MapKey(StringView value) noexcept
+QobuzLoginRequest::ResponseParser::MapKey(StringView value) noexcept
 {
 	switch (state) {
 	case State::NONE:
@@ -217,7 +231,7 @@ QobuzLoginRequest::MapKey(StringView value) noexcept
 }
 
 inline bool
-QobuzLoginRequest::EndMap() noexcept
+QobuzLoginRequest::ResponseParser::EndMap() noexcept
 {
 	switch (state) {
 	case State::NONE:

src/input/plugins/QobuzLoginRequest.hxx

@@ -21,17 +21,11 @@
 #define QOBUZ_LOGIN_REQUEST_HXX
 
 #include "check.h"
-#include "QobuzSession.hxx"
-#include "lib/curl/Handler.hxx"
+#include "lib/curl/Delegate.hxx"
 #include "lib/curl/Request.hxx"
-#include "lib/yajl/Handle.hxx"
-
-#include <exception>
-#include <memory>
-#include <string>
 
 class CurlRequest;
-class QobuzErrorParser;
+struct QobuzSession;
 
 class QobuzLoginHandler {
 public:
@@ -39,29 +33,14 @@ public:
 	virtual void OnQobuzLoginError(std::exception_ptr error) noexcept = 0;
 };
 
-class QobuzLoginRequest final : CurlResponseHandler {
+class QobuzLoginRequest final : DelegateCurlResponseHandler {
 	CurlRequest request;
 
-	std::unique_ptr<QobuzErrorParser> error_parser;
-
-	Yajl::Handle parser;
-
-	enum class State {
-		NONE,
-		DEVICE,
-		DEVICE_ID,
-		USER_AUTH_TOKEN,
-	} state = State::NONE;
-
-	unsigned map_depth = 0;
-
-	QobuzSession session;
-
-	std::exception_ptr error;
-
 	QobuzLoginHandler &handler;
 
 public:
+	class ResponseParser;
+
 	QobuzLoginRequest(CurlGlobal &curl,
 			  const char *base_url, const char *app_id,
 			  const char *username, const char *email,
@@ -76,19 +55,13 @@ public:
 	}
 
 private:
-	/* virtual methods from CurlResponseHandler */
-	void OnHeaders(unsigned status,
-		       std::multimap<std::string, std::string> &&headers) override;
-	void OnData(ConstBuffer<void> data) override;
-	void OnEnd() override;
-	void OnError(std::exception_ptr e) noexcept override;
+	/* virtual methods from DelegateCurlResponseHandler */
+	std::unique_ptr<CurlResponseParser> MakeParser(unsigned status,
+						       std::multimap<std::string, std::string> &&headers) override;
+	void FinishParser(std::unique_ptr<CurlResponseParser> p) override;
 
-public:
-	/* yajl callbacks */
-	bool String(StringView value) noexcept;
-	bool StartMap() noexcept;
-	bool MapKey(StringView value) noexcept;
-	bool EndMap() noexcept;
+	/* virtual methods from CurlResponseHandler */
+	void OnError(std::exception_ptr e) noexcept override;
 };
 
 #endif

src/input/plugins/QobuzTrackRequest.cxx

@@ -24,7 +24,7 @@
 #include "lib/yajl/Callbacks.hxx"
 #include "util/RuntimeError.hxx"
 
-using Wrapper = Yajl::CallbacksWrapper<QobuzTrackRequest>;
+using Wrapper = Yajl::CallbacksWrapper<QobuzTrackRequest::ResponseParser>;
 static constexpr yajl_callbacks parse_callbacks = {
 	nullptr,
 	nullptr,
@@ -39,6 +39,31 @@ static constexpr yajl_callbacks parse_callbacks = {
 	nullptr,
 };
 
+class QobuzTrackRequest::ResponseParser final : public YajlResponseParser {
+	enum class State {
+		NONE,
+		URL,
+	} state = State::NONE;
+
+	std::string url;
+
+public:
+	explicit ResponseParser() noexcept
+		:YajlResponseParser(&parse_callbacks, nullptr, this) {}
+
+	std::string &&GetUrl() {
+		if (url.empty())
+			throw std::runtime_error("No url in track response");
+
+		return std::move(url);
+	}
+
+	/* yajl callbacks */
+	bool String(StringView value) noexcept;
+	bool MapKey(StringView value) noexcept;
+	bool EndMap() noexcept;
+};
+
 static std::string
 MakeTrackUrl(QobuzClient &client, const char *track_id)
 {
@@ -68,47 +93,26 @@ QobuzTrackRequest::~QobuzTrackRequest() noexcept
 	request.StopIndirect();
 }
 
-void
-QobuzTrackRequest::OnHeaders(unsigned status,
-			     std::multimap<std::string, std::string> &&headers)
+std::unique_ptr<CurlResponseParser>
+QobuzTrackRequest::MakeParser(unsigned status,
+			      std::multimap<std::string, std::string> &&headers)
 {
-	if (status != 200) {
-		error_parser = std::make_unique<QobuzErrorParser>(status, headers);
-		return;
-	}
+	if (status != 200)
+		return std::make_unique<QobuzErrorParser>(status, headers);
 
 	auto i = headers.find("content-type");
 	if (i == headers.end() || i->second.find("/json") == i->second.npos)
 		throw std::runtime_error("Not a JSON response from Qobuz");
 
-	parser = {&parse_callbacks, nullptr, this};
+	return std::make_unique<ResponseParser>();
 }
 
 void
-QobuzTrackRequest::OnData(ConstBuffer<void> data)
+QobuzTrackRequest::FinishParser(std::unique_ptr<CurlResponseParser> p)
 {
-	if (error_parser) {
-		error_parser->OnData(data);
-		return;
-	}
-
-	parser.Parse((const unsigned char *)data.data, data.size);
-}
-
-void
-QobuzTrackRequest::OnEnd()
-{
-	if (error_parser) {
-		error_parser->OnEnd();
-		return;
-	}
-
-	parser.CompleteParse();
-
-	if (url.empty())
-		throw std::runtime_error("No url in track response");
-
-	handler.OnQobuzTrackSuccess(std::move(url));
+	assert(dynamic_cast<ResponseParser *>(p.get()) != nullptr);
+	auto &rp = (ResponseParser &)*p;
+	handler.OnQobuzTrackSuccess(rp.GetUrl());
 }
 
 void
@@ -118,7 +122,7 @@ QobuzTrackRequest::OnError(std::exception_ptr e) noexcept
 }
 
 inline bool
-QobuzTrackRequest::String(StringView value) noexcept
+QobuzTrackRequest::ResponseParser::String(StringView value) noexcept
 {
 	switch (state) {
 	case State::NONE:
@@ -133,7 +137,7 @@ QobuzTrackRequest::String(StringView value) noexcept
 }
 
 inline bool
-QobuzTrackRequest::MapKey(StringView value) noexcept
+QobuzTrackRequest::ResponseParser::MapKey(StringView value) noexcept
 {
 	if (value.Equals("url"))
 		state = State::URL;
@@ -144,7 +148,7 @@ QobuzTrackRequest::MapKey(StringView value) noexcept
 }
 
 inline bool
-QobuzTrackRequest::EndMap() noexcept
+QobuzTrackRequest::ResponseParser::EndMap() noexcept
 {
 	state = State::NONE;
 

src/input/plugins/QobuzTrackRequest.hxx

@@ -21,17 +21,11 @@
 #define QOBUZ_TRACK_REQUEST_HXX
 
 #include "check.h"
-#include "lib/curl/Handler.hxx"
+#include "lib/curl/Delegate.hxx"
 #include "lib/curl/Slist.hxx"
 #include "lib/curl/Request.hxx"
-#include "lib/yajl/Handle.hxx"
-
-#include <exception>
-#include <memory>
-#include <string>
 
 class QobuzClient;
-class QobuzErrorParser;
 struct QobuzSession;
 
 class QobuzTrackHandler
@@ -42,27 +36,16 @@ public:
 	virtual void OnQobuzTrackError(std::exception_ptr error) noexcept = 0;
 };
 
-class QobuzTrackRequest final : CurlResponseHandler {
+class QobuzTrackRequest final : DelegateCurlResponseHandler {
 	CurlSlist request_headers;
 
 	CurlRequest request;
 
-	std::unique_ptr<QobuzErrorParser> error_parser;
-
-	Yajl::Handle parser;
-
-	enum class State {
-		NONE,
-		URL,
-	} state = State::NONE;
-
-	std::string url;
-
-	std::exception_ptr error;
-
 	QobuzTrackHandler &handler;
 
 public:
+	class ResponseParser;
+
 	QobuzTrackRequest(QobuzClient &client, const QobuzSession &session,
 			  const char *track_id,
 			  QobuzTrackHandler &_handler) noexcept;
@@ -74,11 +57,12 @@ public:
 	}
 
 private:
+	/* virtual methods from DelegateCurlResponseHandler */
+	std::unique_ptr<CurlResponseParser> MakeParser(unsigned status,
+						       std::multimap<std::string, std::string> &&headers) override;
+	void FinishParser(std::unique_ptr<CurlResponseParser> p) override;
+
 	/* virtual methods from CurlResponseHandler */
-	void OnHeaders(unsigned status,
-		       std::multimap<std::string, std::string> &&headers) override;
-	void OnData(ConstBuffer<void> data) override;
-	void OnEnd() override;
 	void OnError(std::exception_ptr e) noexcept override;
 
 public: