use string_view in create_torrent (#1120)

use string_view in create_torrent

include/libtorrent/create_torrent.hpp

@@ -38,7 +38,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/config.hpp"
 #include "libtorrent/storage.hpp"
 #include "libtorrent/hasher.hpp"
-#include "libtorrent/file.hpp" // for combine_path etc.
+#include "libtorrent/string_view.hpp"
 
 #include <vector>
 #include <string>
@@ -233,8 +233,8 @@ namespace libtorrent
 		// files of the torrent in it.
 		// 
 		// The second function, ``add_http_seed()`` adds an HTTP seed instead.
-		void add_url_seed(std::string const& url);
+		void add_url_seed(string_view url);
-		void add_http_seed(std::string const& url);
+		void add_http_seed(string_view url);
 
 		// This adds a DHT node to the torrent. This especially useful if you're creating a
 		// tracker less torrent. It can be used by clients to bootstrap their DHT node from.
@@ -248,16 +248,16 @@ namespace libtorrent
 		// info-hash. The tier is the fallback priority of the tracker. All trackers with tier 0 are
 		// tried first (in any order). If all fail, trackers with tier 1 are tried. If all of those
 		// fail, trackers with tier 2 are tried, and so on.
-		void add_tracker(std::string const& url, int tier = 0);
+		void add_tracker(string_view url, int tier = 0);
 
 		// This function sets an X.509 certificate in PEM format to the torrent. This makes the
 		// torrent an *SSL torrent*. An SSL torrent requires that each peer has a valid certificate
 		// signed by this root certificate. For SSL torrents, all peers are connecting over SSL
 		// connections. For more information, see the section on ssl-torrents_.
 		// 
-		// The string is not the path to the cert, it's the actual content of the certificate,
+		// The string is not the path to the cert, it's the actual content of the
-		// loaded into a std::string.
+		// certificate.
-		void set_root_cert(std::string const& pem);
+		void set_root_cert(string_view pem);
 
 		// Sets and queries the private flag of the torrent.
 		// Torrents with the private flag set ask clients to not use any other
@@ -292,7 +292,7 @@ namespace libtorrent
 		// 
 		// .. _`BEP 38`: http://www.bittorrent.org/beps/bep_0038.html
 		void add_similar_torrent(sha1_hash ih);
-		void add_collection(std::string c);
+		void add_collection(string_view c);
 
 	private:
 

src/create_torrent.cpp

@@ -41,6 +41,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/announce_entry.hpp"
 #include "libtorrent/performance_counters.hpp" // for counters
 #include "libtorrent/alert_manager.hpp"
+#include "libtorrent/file.hpp" // for combine_path etc.
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -59,15 +60,15 @@ namespace libtorrent
 		inline bool ignore_subdir(std::string const& leaf)
 		{ return leaf == ".." || leaf == "."; }
 
-		int get_file_attributes(std::string const& p)
+		int get_file_attributes(string_view p)
 		{
 #ifdef TORRENT_WINDOWS
 			WIN32_FILE_ATTRIBUTE_DATA attr;
 #if TORRENT_USE_WSTRING
-			std::wstring path = convert_to_wstring(p);
+			std::wstring path = convert_to_wstring(p.to_string());
 			GetFileAttributesExW(path.c_str(), GetFileExInfoStandard, &attr);
 #else
-			std::string path = convert_to_native(p);
+			std::string path = convert_to_native(p.to_string());
 			GetFileAttributesExA(path.c_str(), GetFileExInfoStandard, &attr);
 #endif // TORRENT_USE_WSTRING
 			if (attr.dwFileAttributes == INVALID_FILE_ATTRIBUTES) return 0;
@@ -75,7 +76,7 @@ namespace libtorrent
 			return 0;
 #else
 			struct stat s;
-			if (lstat(convert_to_native(p).c_str(), &s) < 0) return 0;
+			if (lstat(convert_to_native(p.to_string()).c_str(), &s) < 0) return 0;
 			int file_attr = 0;
 			if (s.st_mode & S_IXUSR)
 				file_attr += file_storage::attribute_executable;
@@ -665,18 +666,18 @@ namespace libtorrent
 		return dict;
 	}
 
-	void create_torrent::add_tracker(std::string const& url, int tier)
+	void create_torrent::add_tracker(string_view url, int const tier)
 	{
-		m_urls.push_back(announce_entry(url, tier));
+		m_urls.push_back(announce_entry(url.to_string(), tier));
 
 		std::sort(m_urls.begin(), m_urls.end()
 			, [] (announce_entry const& lhs, announce_entry const& rhs)
 			{ return lhs.second < rhs.second; } );
 	}
 
-	void create_torrent::set_root_cert(std::string const& cert)
+	void create_torrent::set_root_cert(string_view cert)
 	{
-		m_root_cert = cert;
+		m_root_cert.assign(cert.data(), cert.size());
 	}
 
 	void create_torrent::add_similar_torrent(sha1_hash ih)
@@ -684,9 +685,9 @@ namespace libtorrent
 		m_similar.push_back(ih);
 	}
 
-	void create_torrent::add_collection(std::string c)
+	void create_torrent::add_collection(string_view c)
 	{
-		m_collections.push_back(c);
+		m_collections.emplace_back(c);
 	}
 
 	void create_torrent::set_hash(int index, sha1_hash const& h)
@@ -709,14 +710,14 @@ namespace libtorrent
 		m_nodes.push_back(node);
 	}
 
-	void create_torrent::add_url_seed(std::string const& url)
+	void create_torrent::add_url_seed(string_view url)
 	{
-		m_url_seeds.push_back(url);
+		m_url_seeds.emplace_back(url);
 	}
 
-	void create_torrent::add_http_seed(std::string const& url)
+	void create_torrent::add_http_seed(string_view url)
 	{
-		m_http_seeds.push_back(url);
+		m_http_seeds.emplace_back(url);
 	}
 
 	void create_torrent::set_comment(char const* str)