Path: new class "Path" wraps filesystem path stringspath

1 files changed, 125 insertions, 0 deletions

diff --git a/src/Path.hxx b/src/Path.hxx
index db3f95961..ad40fa551 100644
--- a/src/Path.hxx
+++ b/src/Path.hxx
@@ -21,7 +21,14 @@
 #define MPD_PATH_HXX
 
 #include "check.h"
+#include "gcc.h"
 
+#include <glib.h>
+
+#include <algorithm>
+
+#include <assert.h>
+#include <string.h>
 #include <limits.h>
 
 #if !defined(MPD_PATH_MAX)
@@ -54,4 +61,122 @@ utf8_to_fs_charset(const char *path_utf8);
 
 const char *path_get_fs_charset();
 
+/**
+ * A path name in the native file system character set.
+ */
+class Path {
+	char *value;
+
+	struct Donate {};
+
+	Path(Donate, char *_value):value(_value) {}
+
+public:
+	Path(Path &&other):value(other.value) {
+		other.value = nullptr;
+	}
+
+	Path(const Path &other) = delete;
+
+#if 0
+	/* this is the correct implementation, but unfortunately it
+	   disables compiler optimizations */
+	Path(const Path &other)
+		:value(g_strdup(other.value)) {}
+#endif
+
+
+	~Path() {
+		/* free() can be optimized by gcc, while g_free() can
+		   not: when the compiler knows that the value is
+		   nullptr, it will not emit a free() call in the
+		   inlined destructor; however on Windows, we need to
+		   call g_free(), because the value has been allocated
+		   by GLib, and on Windows, this matters */
+#ifdef WIN32
+		g_free(value);
+#else
+		free(value);
+#endif
+	}
+
+	gcc_const
+	static Path Null() {
+		return Path(Donate(), nullptr);
+	}
+
+	gcc_pure
+	static Path Build(const char *a, const char *b) {
+		return Path(Donate(), g_build_filename(a, b, nullptr));
+	}
+
+	static Path Build(const char *a, const Path &b) {
+		return Build(a, b.c_str());
+	}
+
+	static Path Build(const Path &a, const Path &b) {
+		return Build(a.c_str(), b.c_str());
+	}
+
+	gcc_pure
+	static Path FromFS(const char *fs) {
+		return Path(Donate(), g_strdup(fs));
+	}
+
+	gcc_pure
+	static Path FromUTF8(const char *utf8) {
+		return Path(Donate(), utf8_to_fs_charset(utf8));
+	}
+
+	Path &operator=(const Path &other) {
+		value = g_strdup(other.value);
+		return *this;
+	}
+
+	Path &operator=(Path &&other) {
+		std::swap(value, other.value);
+		return *this;
+	}
+
+	char *Steal() {
+		char *result = value;
+		value = nullptr;
+		return result;
+	}
+
+	bool IsNull() const {
+		return value == nullptr;
+	}
+
+	void SetNull() {
+		g_free(value);
+		value = nullptr;
+	}
+
+	gcc_pure
+	size_t length() const {
+		assert(value != nullptr);
+
+		return strlen(value);
+	}
+
+	gcc_pure
+	const char *c_str() const {
+		assert(value != nullptr);
+
+		return value;
+	}
+
+	/**
+	 * Convert the path to UTF-8.  The caller is responsible for
+	 * freeing the return value with g_free().  Returns nullptr on
+	 * error.
+	 */
+	char *ToUTF8() const {
+		return value != nullptr
+			? fs_charset_to_utf8(value)
+			: nullptr;
+	}
+};
+
 #endif