Filesystem abstraction prototype - Partial path implementation

Initialisation, assignment, comparison, conversion to string, hashing

Makefile

@@ -43,6 +43,8 @@ COMMON = \
 	 c-sync.cc \
 	 c-syncedit.cc \
 	 c-syncoverrides.cc \
+	 \
+	 p-filesystem.cc \
 # END COMMON
 
 TOOL = \

p-filesystem.cc

@@ -0,0 +1,182 @@
+/******************************************************************************/
+/* FILESYSTEM ABSTRACTION *****************************************************/
+/******************************************************************************/
+
+#include <p-filesystem.hh>
+using namespace ebcl;
+
+#ifdef _WIN32
+# define M_PATHSEP_ '\\'
+#else
+# define M_PATHSEP_ '/'
+#endif
+
+
+/*= T_FSPath =================================================================*/
+
+bool T_FSPath::IsValidRoot(
+		T_String const& str ) noexcept
+{
+	if ( !str ) {
+		return true;
+	}
+
+#ifdef _WIN32
+	// TODO: support for network names (\\server\path)
+	if ( str.length( ) == 3 && ( str.endsWith( ":\\" )
+				|| str.endsWith( ":/" ) ) ) {
+		return str[ 0 ].isAlpha( );
+	} else {
+		return ( str == "/" || str == "\\" );
+	}
+#else
+	return ( str == "/" || str == "\\" );
+#endif
+}
+
+bool T_FSPath::IsValidComponent(
+		T_String const& str ) noexcept
+{
+	if ( !str ) {
+		return false;
+	}
+
+	T_StringIterator it{ str };
+	while ( !it.atEnd( ) ) {
+		const auto c{ it.character( ) };
+		it.next( );
+		if ( c.isControl( ) || c == '\\' || c == '/' || c == '"'
+				|| c == '<' || c == '>' || c == '|' || c == ':'
+				|| c == '*' || c == '?' ) {
+			return false;
+		}
+	}
+	return true;
+}
+
+/*----------------------------------------------------------------------------*/
+
+T_FSPath::T_FSPath(
+		T_String const& path ) noexcept
+{
+	if ( !path ) {
+		valid_ = true;
+		return;
+	}
+
+	// Find sequences of (back)slashes in the string. For each sequence
+	// we will store the positions of the first and last (back)slash.
+	T_AutoArray< uint32_t , 64 > slashPos;
+	T_StringIterator it{ path };
+	while ( !it.atEnd( ) ) {
+		const auto c{ it.character( ) };
+		const auto p{ it.index( ) };
+		it.next( );
+
+		if ( c != '/' && c != '\\' ) {
+			continue;
+		}
+
+		const auto ps{ slashPos.size( ) };
+		if ( ps == 0 || slashPos[ ps - 1 ] != p - 1 ) {
+			slashPos.add( p );
+			slashPos.add( p );
+		} else {
+			slashPos[ ps - 1 ] ++;
+		}
+	}
+
+	// No (back)slashes, this is a relative path
+	const auto sps{ slashPos.size( ) };
+	if ( sps == 0 ) {
+		components_.add( path );
+		valid_ = IsValidComponent( path );
+		return;
+	}
+
+	// Collect the first item, with the first (back)slash included,
+	// check if it's a root
+	const auto firstSlashPos{ slashPos[ 0 ] };
+	T_String firstItem{ path.substr( 0 , 1 + firstSlashPos ) };
+	valid_ = true;
+	if ( IsValidRoot( firstItem ) ) {
+		root_ = std::move( firstItem );
+	}
+
+	// Get and check the components
+	uint32_t pos{ root_ ? 2u : 0u };
+	while ( pos <= sps ) {
+		T_String item{ path.range(
+			pos ? ( 1 + slashPos[ pos - 1 ] ) : 0 ,
+			pos == sps ? path.length( ) : ( slashPos[ pos ] - 1 ) )
+		};
+		assert( item || pos == sps );
+		if ( item ) {
+			valid_ = valid_ && IsValidComponent( item );
+			components_.add( std::move( item ) );
+		}
+		pos += 2;
+	}
+}
+
+/*----------------------------------------------------------------------------*/
+
+uint32_t T_FSPath::computeHash( ) const noexcept
+{
+	uint32_t h{ ComputeHash( root_ ) };
+	const auto cs{ components_.size( ) };
+	h = ( ( h << 27 ) | ( h >> 5 ) ) ^ cs;
+	for ( auto i = 0u ; i < cs ; i ++ ) {
+		h = ( ( h << 27 ) | ( h >> 5 ) ) ^ ComputeHash( components_[ i ] );
+	}
+	return h;
+}
+
+void T_FSPath::appendTo(
+		T_StringBuilder& sb ) const noexcept
+{
+	const auto cs{ components_.size( ) };
+	if ( !( root_ || cs ) ) {
+		sb << '.';
+		return;
+	}
+
+	for ( auto i = 0u ; i < cs ; i ++ ) {
+		if ( i == 0 ) {
+			sb << root_;
+		} else {
+			sb << M_PATHSEP_;
+		}
+		sb << components_[ i ];
+	}
+}
+
+/*----------------------------------------------------------------------------*/
+
+#ifdef _WIN32
+# define M_CMPSTR_(A,B) (A).compareIgnoreCase( B )
+#else
+# define M_CMPSTR_(A,B) (A).compare( B )
+#endif
+
+int32_t T_FSPath::compareTo(
+		T_FSPath const& other ) const noexcept
+{
+	if ( &other == this ) {
+		return 0;
+	}
+
+	int32_t cmp{ M_CMPSTR_( root_ , other.root_ ) };
+	if ( cmp == 0 ) {
+		const auto nca{ components_.size( ) } ,
+			ncb{ other.components_.size( ) } ,
+			nc{ std::min( nca , ncb ) };
+		for ( auto i = 0u ; i < nc && cmp == 0 ; i ++ ) {
+			cmp = M_CMPSTR_( components_[ i ] , other.components_[ i ] );
+		}
+		if ( cmp == 0 ) {
+			cmp = T_Comparator< uint32_t >::compare( nca , ncb );
+		}
+	}
+	return cmp;
+}

p-filesystem.hh

@@ -54,7 +54,6 @@ class T_FSPath
 
 	T_String const& root( ) const noexcept;
 	T_Components const& components( ) const noexcept;
-	// FIXME: provide iterators for the components
 
 	bool isRelative( ) const noexcept;
 	bool isAbsolute( ) const noexcept;
@@ -68,10 +67,14 @@ class T_FSPath
 	// Append to a string builder
 	void appendTo( T_StringBuilder& sb ) const noexcept;
 
-	// Equality operators. On Windows the comparison will be
+	// Comparisons. On Windows the comparison will be case-insensitive.
-	// case-insensitive.
+	int32_t compareTo( T_FSPath const& other ) const noexcept;
 	bool operator ==( T_FSPath const& other ) const noexcept;
 	bool operator !=( T_FSPath const& other ) const noexcept;
+	bool operator <( T_FSPath const& other ) const noexcept;
+	bool operator <=( T_FSPath const& other ) const noexcept;
+	bool operator >( T_FSPath const& other ) const noexcept;
+	bool operator >=( T_FSPath const& other ) const noexcept;
 
 	//----------------------------------------------------------------------
 
@@ -108,13 +111,162 @@ class T_FSPath
 };
 M_DECLARE_SWAP( T_FSPath );
 M_DECLARE_HASH( T_FSPath );
-M_LSHIFT_OP( T_StringBuilder , T_FSPath );
+M_LSHIFT_OP( T_StringBuilder , T_FSPath const& );
+
+
+/*= FILESYSTEM ===============================================================*/
+
+class T_Filesystem
+{
+    public:
+	// Return the absolute path to the current directory
+	static T_FSPath currentDirectory( ) noexcept;
+
+};
 
 
 /*= T_FSPath =================================================================*/
 // FIXME: inline stuff should be moved
 
+inline T_FSPath::T_FSPath( ) noexcept
+	: root_{ } , components_{ } , valid_{ true }
+{ }
 
+/*----------------------------------------------------------------------------*/
+
+inline T_FSPath::T_FSPath(
+		T_FSPath const& other ) noexcept
+	: root_{ other.root_ } , components_{ other.components_ } ,
+		valid_{ other.valid_ }
+{ }
+
+inline T_FSPath& T_FSPath::operator =(
+		T_FSPath const& other ) noexcept
+{
+	root_ = other.root_;
+	components_ = other.components_;
+	valid_ = other.valid_;
+	return *this;
+}
+
+/*----------------------------------------------------------------------------*/
+
+inline T_FSPath::T_FSPath( T_FSPath&& other ) noexcept
+	: T_FSPath{ }
+{
+	swap( other );
+}
+
+inline T_FSPath& T_FSPath::operator =(
+		T_FSPath&& other ) noexcept
+{
+	root_ = T_String{ };
+	components_.free( );
+	valid_ = true;
+	return swap( other );
+}
+
+/*----------------------------------------------------------------------------*/
+
+inline T_FSPath& T_FSPath::swap(
+		T_FSPath& other ) noexcept
+{
+	using std::swap;
+	swap( root_ , other.root_ );
+	swap( components_ , other.components_ );
+	swap( valid_ , other.valid_ );
+	return *this;
+}
+
+inline M_DEFINE_SWAP( T_FSPath )
+{
+	lhs.swap( rhs );
+}
+
+/*----------------------------------------------------------------------------*/
+
+inline bool T_FSPath::isValid( ) const noexcept
+{
+	return valid_;
+}
+
+inline T_String const& T_FSPath::root( ) const noexcept
+{
+	return root_;
+}
+
+inline T_FSPath::T_Components const& T_FSPath::components( ) const noexcept
+{
+	return components_;
+}
+
+inline bool T_FSPath::isRelative( ) const noexcept
+{
+	return !root_;
+}
+
+inline bool T_FSPath::isAbsolute( ) const noexcept
+{
+	return bool( root_ );
+}
+
+/*----------------------------------------------------------------------------*/
+
+inline T_String T_FSPath::toString( ) const noexcept
+{
+	T_StringBuilder sb;
+	appendTo( sb );
+	return T_String{ std::move( sb ) };
+}
+
+inline M_DEFINE_HASH( T_FSPath )
+{
+	return item.computeHash( );
+}
+
+inline M_LSHIFT_OP( T_StringBuilder , T_FSPath const& )
+{
+	value.appendTo( obj );
+	return obj;
+}
+
+/*----------------------------------------------------------------------------*/
+
+inline bool T_FSPath::operator ==(
+		T_FSPath const& other ) const noexcept
+{
+	return compareTo( other ) == 0;
+}
+
+inline bool T_FSPath::operator !=(
+		T_FSPath const& other ) const noexcept
+{
+	return compareTo( other ) != 0;
+}
+
+inline bool T_FSPath::operator <(
+		T_FSPath const& other ) const noexcept
+{
+	return compareTo( other ) < 0;
+}
+
+inline bool T_FSPath::operator <=(
+		T_FSPath const& other ) const noexcept
+{
+	return compareTo( other ) <= 0;
+}
+
+inline bool T_FSPath::operator >(
+		T_FSPath const& other ) const noexcept
+{
+	return compareTo( other ) > 0;
+}
+
+inline bool T_FSPath::operator >=(
+		T_FSPath const& other ) const noexcept
+{
+	return compareTo( other ) >= 0;
+}
 
 
 } // namespace ebcl