input/curl: move code to class CurlRequest

The CurlRequest gives us a more low-level API to CURL without the
InputStream interface, integrated into our IOThread.

src/lib/curl/Request.cxx

@@ -0,0 +1,231 @@
+/*
+ * Copyright (C) 2008-2017 Max Kellermann <max@duempel.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "Request.hxx"
+#include "Global.hxx"
+#include "Version.hxx"
+#include "Handler.hxx"
+#include "util/RuntimeError.hxx"
+#include "util/StringUtil.hxx"
+#include "util/StringView.hxx"
+#include "util/CharUtil.hxx"
+
+#include <curl/curl.h>
+
+#include <algorithm>
+
+#include <assert.h>
+#include <string.h>
+
+CurlRequest::CurlRequest(CurlGlobal &_global, const char *url,
+			 CurlResponseHandler &_handler)
+	:global(_global), handler(_handler)
+{
+	error_buffer[0] = 0;
+
+	easy.SetOption(CURLOPT_PRIVATE, (void *)this);
+	easy.SetOption(CURLOPT_USERAGENT, "Music Player Daemon " VERSION);
+	easy.SetOption(CURLOPT_HEADERFUNCTION, _HeaderFunction);
+	easy.SetOption(CURLOPT_WRITEHEADER, this);
+	easy.SetOption(CURLOPT_WRITEFUNCTION, WriteFunction);
+	easy.SetOption(CURLOPT_WRITEDATA, this);
+	easy.SetOption(CURLOPT_NETRC, 1l);
+	easy.SetOption(CURLOPT_ERRORBUFFER, error_buffer);
+	easy.SetOption(CURLOPT_NOPROGRESS, 1l);
+	easy.SetOption(CURLOPT_NOSIGNAL, 1l);
+	easy.SetOption(CURLOPT_CONNECTTIMEOUT, 10l);
+	easy.SetOption(CURLOPT_URL, url);
+
+	global.Add(easy.Get(), *this);
+}
+
+CurlRequest::~CurlRequest()
+{
+	FreeEasy();
+}
+
+void
+CurlRequest::FreeEasy()
+{
+	if (!easy)
+		return;
+
+	global.Remove(easy.Get());
+	easy = nullptr;
+}
+
+void
+CurlRequest::Resume()
+{
+	curl_easy_pause(easy.Get(), CURLPAUSE_CONT);
+
+	if (IsCurlOlderThan(0x072000))
+		/* libcurl older than 7.32.0 does not update
+		   its sockets after curl_easy_pause(); force
+		   libcurl to do it now */
+		global.ResumeSockets();
+
+	global.InvalidateSockets();
+}
+
+bool
+CurlRequest::FinishHeaders()
+{
+	if (state != State::HEADERS)
+		return true;
+
+	state = State::BODY;
+
+	long status = 0;
+	curl_easy_getinfo(easy.Get(), CURLINFO_RESPONSE_CODE, &status);
+
+	try {
+		handler.OnHeaders(status, std::move(headers));
+		return true;
+	} catch (...) {
+		state = State::CLOSED;
+		handler.OnError(std::current_exception());
+		return false;
+	}
+}
+
+void
+CurlRequest::FinishBody()
+{
+	if (!FinishHeaders())
+		return;
+
+	if (state != State::BODY)
+		return;
+
+	state = State::CLOSED;
+	handler.OnEnd();
+}
+
+void
+CurlRequest::Done(CURLcode result)
+{
+	FreeEasy();
+
+	try {
+		if (result != CURLE_OK) {
+			StripRight(error_buffer);
+			const char *msg = error_buffer;
+			if (*msg == 0)
+				msg = curl_easy_strerror(result);
+			throw FormatRuntimeError("CURL failed: %s", msg);
+		}
+	} catch (...) {
+		state = State::CLOSED;
+		handler.OnError(std::current_exception());
+		return;
+	}
+
+	FinishBody();
+}
+
+inline void
+CurlRequest::HeaderFunction(StringView s)
+{
+	if (state > State::HEADERS)
+		return;
+
+	if (s.size > 5 && memcmp(s.data, "HTTP/", 5) == 0) {
+		/* this is the boundary to a new response, for example
+		   after a redirect */
+		headers.clear();
+		return;
+	}
+
+	const char *header = s.data;
+	const char *end = StripRight(header, header + s.size);
+
+	const char *value = s.Find(':');
+	if (value == nullptr)
+		return;
+
+	std::string name(header, value);
+	std::transform(name.begin(), name.end(), name.begin(), ToLowerASCII);
+
+	/* skip the colon */
+
+	++value;
+
+	/* strip the value */
+
+	value = StripLeft(value, end);
+	end = StripRight(value, end);
+
+	headers.emplace(std::move(name), std::string(value, end));
+}
+
+size_t
+CurlRequest::_HeaderFunction(void *ptr, size_t size, size_t nmemb, void *stream)
+{
+	CurlRequest &c = *(CurlRequest *)stream;
+
+	size *= nmemb;
+
+	c.HeaderFunction({(const char *)ptr, size});
+	return size;
+}
+
+inline size_t
+CurlRequest::DataReceived(const void *ptr, size_t received_size)
+{
+	assert(received_size > 0);
+
+	if (!FinishHeaders())
+		return 0;
+
+	try {
+		handler.OnData({ptr, received_size});
+		return received_size;
+	} catch (Pause) {
+		return CURL_WRITEFUNC_PAUSE;
+	} catch (...) {
+		state = State::CLOSED;
+		handler.OnError(std::current_exception());
+		return 0;
+	}
+
+}
+
+size_t
+CurlRequest::WriteFunction(void *ptr, size_t size, size_t nmemb, void *stream)
+{
+	CurlRequest &c = *(CurlRequest *)stream;
+
+	size *= nmemb;
+	if (size == 0)
+		return 0;
+
+	return c.DataReceived(ptr, size);
+}