Use a static table of tokens for agi::Path

The set of possible tokens is fixed, so using std::map is a bunch of
pointless overhead (that turns out to not even really simplify the
code).

libaegisub/common/path.cpp

@@ -14,10 +14,6 @@
 //
 // Aegisub Project http://www.aegisub.org/
 
-/// @file path.cpp
-/// @brief Platform-independent path code
-/// @ingroup libaegisub
-
 #include "libaegisub/path.h"
 
 #include "libaegisub/fs.h"
@@ -26,44 +22,56 @@
 #include <boost/range/distance.hpp>
 
 namespace {
-	template<class T, class U>
+static const char *tokens[] = {
-	typename T::const_iterator last_less_than(T const& cont, U const& value) {
+	"?audio",
-		auto it = cont.upper_bound(value);
+	"?data",
-		if (it != cont.begin())
+	"?dictionary",
-			--it;
+	"?local",
-		return it;
+	"?script",
+	"?temp",
+	"?user",
+	"?video"
+};
+
+int find_token(const char *str, size_t len) {
+	if (len < 5 || str[0] != '?') return -1;
+	int idx;
+	switch (str[1] + str[4]) {
+	case 'a' + 'i': idx = 0; break;
+	case 'd' + 'a': idx = 1; break;
+	case 'd' + 't': idx = 2; break;
+	case 'l' + 'a': idx = 3; break;
+	case 's' + 'i': idx = 4; break;
+	case 't' + 'p': idx = 5; break;
+	case 'u' + 'r': idx = 6; break;
+	case 'v' + 'e': idx = 7; break;
+	default: return -1;
 	}
+
+	return strncmp(str, tokens[idx], strlen(tokens[idx])) == 0 ? idx : -1;
+}
 }
 
 namespace agi {
 
 Path::Path() {
-	tokens["?user"];
+	static_assert(sizeof(paths) / sizeof(paths[0]) == sizeof(tokens) / sizeof(tokens[0]),
-	tokens["?local"];
+		"Token and path arrays need to be the same size");
-	tokens["?data"];
-	tokens["?temp"];
-	tokens["?dictionary"];
-
 	FillPlatformSpecificPaths();
-
-	tokens["?audio"];
-	tokens["?script"];
-	tokens["?video"];
 }
 
 fs::path Path::Decode(std::string const& path) const {
-	const auto it = last_less_than(tokens, path);
+	int idx = find_token(path.c_str(), path.size());
-
+	if (idx == -1 || paths[idx].empty())
-	if (!it->second.empty() && boost::starts_with(path, it->first))
-		return (it->second/path.substr(it->first.size())).make_preferred();
 		return fs::path(path).make_preferred();
+	return (paths[idx]/path.substr(strlen(tokens[idx]))).make_preferred();
 }
 
 fs::path Path::MakeRelative(fs::path const& path, std::string const& token) const {
-	const auto it = tokens.find(token);
+	int idx = find_token(token.c_str(), token.size());
-	if (it == tokens.end()) throw agi::InternalError("Bad token: " + token);
+	if (idx == -1) throw agi::InternalError("Bad token: " + token);
 
-	return MakeRelative(path, it->second);
+	return MakeRelative(path, paths[idx]);
 }
 
 fs::path Path::MakeRelative(fs::path const& path, fs::path const& base) const {
@@ -92,53 +100,47 @@ fs::path Path::MakeRelative(fs::path const& path, fs::path const& base) const {
 
 fs::path Path::MakeAbsolute(fs::path path, std::string const& token) const {
 	if (path.empty()) return path;
-	const auto it = tokens.find(token);
+	int idx = find_token(token.c_str(), token.size());
-	if (it == tokens.end()) throw agi::InternalError("Bad token: " + token);
+	if (idx == -1) throw agi::InternalError("Bad token: " + token);
 
 	path.make_preferred();
 	const auto str = path.string();
 	if (boost::starts_with(str, "?dummy") || boost::starts_with(str, "dummy-audio:"))
 		return path;
-	return (it->second.empty() || path.is_absolute()) ? path : it->second/path;
+	return (paths[idx].empty() || path.is_absolute()) ? path : paths[idx]/path;
 }
 
 std::string Path::Encode(fs::path const& path) const {
 	// Find the shortest encoding of path made relative to each token
 	std::string shortest = path.string();
 	size_t length = boost::distance(path);
-	for (auto const& tok : tokens) {
+	for (size_t i = 0; i < paths.size(); ++i) {
-		if (tok.second.empty()) continue;
+		if (paths[i].empty()) continue;
 
-		const auto p = MakeRelative(path, tok.first);
+		const auto p = MakeRelative(path, tokens[i]);
 		const size_t d = boost::distance(p);
 		if (d < length) {
 			length = d;
-			shortest = (tok.first/p).string();
+			shortest = (tokens[i]/p).string();
 		}
 	}
 
 	return shortest;
 }
 
-void Path::SetToken(std::string const& token_name, fs::path const& token_value) {
+void Path::SetToken(const char *token_name, fs::path const& token_value) {
-	const auto it = tokens.find(token_name);
+	int idx = find_token(token_name, strlen(token_name));
-	if (it == tokens.end()) throw agi::InternalError("Bad token: " + token_name);
+	if (idx == -1) throw agi::InternalError("Bad token: " + std::string(token_name));
 
 	if (token_value.empty())
-		it->second = token_value;
+		paths[idx] = token_value;
 	else if (!token_value.is_absolute())
-		it->second.clear();
+		paths[idx].clear();
 	else {
-		it->second = token_value;
+		paths[idx] = token_value;
-		it->second.make_preferred();
+		paths[idx].make_preferred();
-		if (fs::FileExists(it->second))
+		if (fs::FileExists(paths[idx]))
-			it->second = it->second.parent_path();
+			paths[idx] = paths[idx].parent_path();
-	}
-
-	paths.clear();
-	for (auto const& tok : tokens) {
-		if (!tok.second.empty())
-			paths[tok.second] = tok.first;
 	}
 }
 

libaegisub/include/libaegisub/path.h

@@ -14,23 +14,16 @@
 //
 // Aegisub Project http://www.aegisub.org/
 
-/// @file path.h
-/// @brief Common paths.
-/// @ingroup libaegisub
-
 #include <libaegisub/fs_fwd.h>
 
+#include <array>
 #include <boost/filesystem/path.hpp>
-#include <map>
 
 namespace agi {
 /// Class for handling everything path-related in Aegisub
 class Path {
 	/// Token -> Path map
-	std::map<std::string, fs::path> tokens;
+	std::array<fs::path, 8> paths;
-
-	/// Path -> Token map
-	std::map<fs::path, std::string> paths;
 
 	/// Platform-specific code to fill in the default paths, called in the constructor
 	void FillPlatformSpecificPaths();
@@ -74,7 +67,7 @@ public:
 	/// @param token_name A single word token beginning with '?'
 	/// @param token_value An absolute path to a directory or file
 	/// @throws InternalError if `token` is not a valid token name
-	void SetToken(std::string const& token_name, fs::path const& token_value);
+	void SetToken(const char *token_name, fs::path const& token_value);
 };
 
 }

libaegisub/windows/path_win.cpp

@@ -40,7 +40,7 @@ agi::fs::path WinGetFolderPath(int folder) {
 namespace agi {
 
 void Path::FillPlatformSpecificPaths() {
-	tokens["?temp"] = boost::filesystem::temp_directory_path();
+	SetToken("?temp", boost::filesystem::temp_directory_path());
 
 	SetToken("?user", WinGetFolderPath(CSIDL_APPDATA)/"Aegisub");
 	SetToken("?local", WinGetFolderPath(CSIDL_LOCAL_APPDATA)/"Aegisub");