Merge: Newstreams
[nit.git] / lib / standard / file.nit
index 3499c89..a7c48db 100644 (file)
@@ -27,6 +27,8 @@ in "C Header" `{
        #include <sys/stat.h>
        #include <unistd.h>
        #include <stdio.h>
+       #include <poll.h>
+       #include <errno.h>
 `}
 
 # File Abstract Stream
@@ -38,24 +40,47 @@ abstract class FStream
        # The FILE *.
        private var file: nullable NativeFile = null
 
+       # The status of a file. see POSIX stat(2).
        fun file_stat: FileStat do return _file.file_stat
 
        # File descriptor of this file
        fun fd: Int do return _file.fileno
+
+       # Sets the buffering mode for the current FStream
+       #
+       # If the buf_size is <= 0, its value will be 512 by default
+       #
+       # The mode is any of the buffer_mode enumeration in `Sys`:
+       #       - buffer_mode_full
+       #       - buffer_mode_line
+       #       - buffer_mode_none
+       fun set_buffering_mode(buf_size, mode: Int) do
+               if buf_size <= 0 then buf_size = 512
+               if _file.set_buffering_type(buf_size, mode) != 0 then
+                       last_error = new IOError("Error while changing buffering type for FStream, returned error {sys.errno.strerror}")
+               end
+       end
 end
 
 # File input stream
 class IFStream
        super FStream
        super BufferedIStream
+       super PollableIStream
        # Misc
 
        # Open the same file again.
        # The original path is reused, therefore the reopened file can be a different file.
        fun reopen
        do
-               if not eof then close
+               if not eof and not _file.address_is_null then close
+               last_error = null
                _file = new NativeFile.io_open_read(path.to_cstring)
+               if _file.address_is_null then
+                       last_error = new IOError("Error: Opening file at '{path.as(not null)}' failed with '{sys.errno.strerror}'")
+                       end_reached = true
+                       return
+               end
                end_reached = false
                _buffer_pos = 0
                _buffer.clear
@@ -63,7 +88,9 @@ class IFStream
 
        redef fun close
        do
+               if _file.address_is_null then return
                var i = _file.io_close
+               _buffer.clear
                end_reached = true
        end
 
@@ -77,7 +104,7 @@ class IFStream
                _buffer.length = nb
                _buffer_pos = 0
        end
-       
+
        # End of file?
        redef var end_reached: Bool = false
 
@@ -87,13 +114,21 @@ class IFStream
                self.path = path
                prepare_buffer(10)
                _file = new NativeFile.io_open_read(path.to_cstring)
-               assert not _file.address_is_null else
-                       print "Error: Opening file at '{path}' failed with '{sys.errno.strerror}'"
+               if _file.address_is_null then
+                       last_error = new IOError("Error: Opening file at '{path}' failed with '{sys.errno.strerror}'")
+                       end_reached = true
                end
        end
 
-       private init do end
-       private init without_file do end
+       init from_fd(fd: Int) do
+               self.path = ""
+               prepare_buffer(1)
+               _file = fd.fd_to_stream(read_only)
+               if _file.address_is_null then
+                       last_error = new IOError("Error: Converting fd {fd} to stream failed with '{sys.errno.strerror}'")
+                       end_reached = true
+               end
+       end
 end
 
 # File output stream
@@ -103,30 +138,52 @@ class OFStream
        
        redef fun write(s)
        do
-               assert _is_writable
+               if last_error != null then return
+               if not _is_writable then
+                       last_error = new IOError("Cannot write to non-writable stream")
+                       return
+               end
                if s isa FlatText then
                        write_native(s.to_cstring, s.length)
                else
                        for i in s.substrings do write_native(i.to_cstring, i.length)
                end
+               _file.flush
        end
 
        redef fun close
        do
+               if _file.address_is_null then
+                       if last_error != null then return
+                       last_error = new IOError("Cannot close unopened write stream")
+                       _is_writable = false
+                       return
+               end
                var i = _file.io_close
+               if i != 0 then
+                       last_error = new IOError("Close failed due to error {sys.errno.strerror}")
+               end
                _is_writable = false
        end
-
        redef var is_writable = false
        
        # Write `len` bytes from `native`.
        private fun write_native(native: NativeString, len: Int)
        do
-               assert _is_writable
+               if last_error != null then return
+               if not _is_writable then
+                       last_error = new IOError("Cannot write to non-writable stream")
+                       return
+               end
+               if _file.address_is_null then
+                       last_error = new IOError("Writing on a null stream")
+                       _is_writable = false
+                       return
+               end
                var err = _file.io_write(native, len)
                if err != len then
                        # Big problem
-                       printn("Problem in writing : ", err, " ", len, "\n")
+                       last_error = new IOError("Problem in writing : {err} {len} \n")
                end
        end
        
@@ -134,24 +191,50 @@ class OFStream
        init open(path: String)
        do
                _file = new NativeFile.io_open_write(path.to_cstring)
-               assert not _file.address_is_null else
-                       print "Error: Opening file at '{path}' failed with '{sys.errno.strerror}'"
-               end
                self.path = path
                _is_writable = true
+               if _file.address_is_null then
+                       last_error = new IOError("Error: Opening file at '{path}' failed with '{sys.errno.strerror}'")
+                       is_writable = false
+               end
+       end
+
+       # Creates a new File stream from a file descriptor
+       init from_fd(fd: Int) do
+               self.path = ""
+               _file = fd.fd_to_stream(wipe_write)
+               _is_writable = true
+                if _file.address_is_null then
+                        last_error = new IOError("Error: Opening stream from file descriptor {fd} failed with '{sys.errno.strerror}'")
+                       _is_writable = false
+               end
        end
-       
-       private init do end
-       private init without_file do end
 end
 
+redef class Int
+       # Creates a file stream from a file descriptor `fd` using the file access `mode`.
+       #
+       # NOTE: The `mode` specified must be compatible with the one used in the file descriptor.
+       private fun fd_to_stream(mode: NativeString): NativeFile is extern "file_int_fdtostream"
+end
+
+# Constant for read-only file streams
+private fun read_only: NativeString do return "r".to_cstring
+
+# Constant for write-only file streams
+#
+# If a stream is opened on a file with this method,
+# it will wipe the previous file if any.
+# Else, it will create the file.
+private fun wipe_write: NativeString do return "w".to_cstring
+
 ###############################################################################
 
+# Standard input stream.
 class Stdin
        super IFStream
-       super PollableIStream
 
-       private init do
+       init do
                _file = new NativeFile.native_stdin
                path = "/dev/stdin"
                prepare_buffer(1)
@@ -160,18 +243,20 @@ class Stdin
        redef fun poll_in: Bool is extern "file_stdin_poll_in"
 end
 
+# Standard output stream.
 class Stdout
        super OFStream
-       private init do
+       init do
                _file = new NativeFile.native_stdout
                path = "/dev/stdout"
                _is_writable = true
        end
 end
 
+# Standard error stream.
 class Stderr
        super OFStream
-       private init do
+       init do
                _file = new NativeFile.native_stderr
                path = "/dev/stderr"
                _is_writable = true
@@ -327,27 +412,49 @@ redef class String
 
        # Correctly join two path using the directory separator.
        #
-       # Using a standard "{self}/{path}" does not work when `self` is the empty string.
-       # This method ensure that the join is valid.
+       # Using a standard "{self}/{path}" does not work in the following cases:
        #
-       #     assert "hello".join_path("world")      ==  "hello/world"
-       #     assert "hel/lo".join_path("wor/ld")      ==  "hel/lo/wor/ld"
-       #     assert "".join_path("world")      ==  "world"
-       #     assert "/hello".join_path("/world")      ==  "/world"
+       # * `self` is empty.
+       # * `path` ends with `'/'`.
+       # * `path` starts with `'/'`.
        #
-       # Note: you may want to use `simplify_path` on the result
+       # This method ensures that the join is valid.
        #
-       # Note: I you want to join a great number of path, you can write
+       #     assert "hello".join_path("world")   == "hello/world"
+       #     assert "hel/lo".join_path("wor/ld") == "hel/lo/wor/ld"
+       #     assert "".join_path("world")        == "world"
+       #     assert "hello".join_path("/world")  == "/world"
+       #     assert "hello/".join_path("world")  == "hello/world"
+       #     assert "hello/".join_path("/world") == "/world"
        #
-       #     [p1, p2, p3, p4].join("/")
+       # Note: You may want to use `simplify_path` on the result.
+       #
+       # Note: This method works only with POSIX paths.
        fun join_path(path: String): String
        do
                if path.is_empty then return self
                if self.is_empty then return path
                if path.chars[0] == '/' then return path
+               if self.last == '/' then return "{self}{path}"
                return "{self}/{path}"
        end
 
+       # Convert the path (`self`) to a program name.
+       #
+       # Ensure the path (`self`) will be treated as-is by POSIX shells when it is
+       # used as a program name. In order to do that, prepend `./` if needed.
+       #
+       #     assert "foo".to_program_name == "./foo"
+       #     assert "/foo".to_program_name == "/foo"
+       #     assert "".to_program_name == "./" # At least, your shell will detect the error.
+       fun to_program_name: String do
+               if self.has_prefix("/") then
+                       return self
+               else
+                       return "./{self}"
+               end
+       end
+
        # Alias for `join_path`
        #
        #     assert "hello" / "world"      ==  "hello/world"
@@ -364,6 +471,70 @@ redef class String
        #     assert a/b/c == "/bar/baz/foobar"
        fun /(path: String): String do return join_path(path)
 
+       # Returns the relative path needed to go from `self` to `dest`.
+       #
+       #     assert "/foo/bar".relpath("/foo/baz") == "../baz"
+       #     assert "/foo/bar".relpath("/baz/bar") == "../../baz/bar"
+       #
+       # If `self` or `dest` is relative, they are considered relatively to `getcwd`.
+       #
+       # In some cases, the result is still independent of the current directory:
+       #
+       #     assert "foo/bar".relpath("..") == "../../.."
+       #
+       # In other cases, parts of the current directory may be exhibited:
+       #
+       #     var p = "../foo/bar".relpath("baz")
+       #     var c = getcwd.basename("")
+       #     assert p == "../../{c}/baz"
+       #
+       # For path resolution independent of the current directory (eg. for paths in URL),
+       # or to use an other starting directory than the current directory,
+       # just force absolute paths:
+       #
+       #     var start = "/a/b/c/d"
+       #     var p2 = (start/"../foo/bar").relpath(start/"baz")
+       #     assert p2 == "../../d/baz"
+       #
+       #
+       # Neither `self` or `dest` has to be real paths or to exist in directories since
+       # the resolution is only done with string manipulations and without any access to
+       # the underlying file system.
+       #
+       # If `self` and `dest` are the same directory, the empty string is returned:
+       #
+       #     assert "foo".relpath("foo") == ""
+       #     assert "foo/../bar".relpath("bar") == ""
+       #
+       # The empty string and "." designate both the current directory:
+       #
+       #     assert "".relpath("foo/bar")  == "foo/bar"
+       #     assert ".".relpath("foo/bar") == "foo/bar"
+       #     assert "foo/bar".relpath("")  == "../.."
+       #     assert "/" + "/".relpath(".") == getcwd
+       fun relpath(dest: String): String
+       do
+               var cwd = getcwd
+               var from = (cwd/self).simplify_path.split("/")
+               if from.last.is_empty then from.pop # case for the root directory
+               var to = (cwd/dest).simplify_path.split("/")
+               if to.last.is_empty then to.pop # case for the root directory
+
+               # Remove common prefixes
+               while not from.is_empty and not to.is_empty and from.first == to.first do
+                       from.shift
+                       to.shift
+               end
+
+               # Result is going up in `from` with ".." then going down following `to`
+               var from_len = from.length
+               if from_len == 0 then return to.join("/")
+               var up = "../"*(from_len-1) + ".."
+               if to.is_empty then return up
+               var res = up + "/" + to.join("/")
+               return res
+       end
+
        # Create a directory (and all intermediate directories if needed)
        fun mkdir
        do
@@ -445,7 +616,7 @@ redef class String
        end
 
        # returns files contained within the directory represented by self
-       fun files : Set[ String ] is extern import HashSet[String], HashSet[String].add, NativeString.to_s, String.to_cstring, HashSet[String].as(Set[String]) `{
+       fun files: Array[String] is extern import Array[String], Array[String].add, NativeString.to_s, String.to_cstring `{
                char *dir_path;
                DIR *dir;
 
@@ -457,22 +628,22 @@ redef class String
                }
                else
                {
-                       HashSet_of_String results;
+                       Array_of_String results;
                        String file_name;
                        struct dirent *de;
 
-                       results = new_HashSet_of_String();
+                       results = new_Array_of_String();
 
                        while ( ( de = readdir( dir ) ) != NULL )
                                if ( strcmp( de->d_name, ".." ) != 0 &&
                                        strcmp( de->d_name, "." ) != 0 )
                                {
                                        file_name = NativeString_to_s( strdup( de->d_name ) );
-                                       HashSet_of_String_add( results, file_name );
+                                       Array_of_String_add( results, file_name );
                                }
 
                        closedir( dir );
-                       return HashSet_of_String_as_Set_of_String( results );
+                       return results;
                }
        `}
 end
@@ -531,6 +702,10 @@ private extern class NativeFile `{ FILE* `}
        fun io_close: Int is extern "file_NativeFile_NativeFile_io_close_0"
        fun file_stat: FileStat is extern "file_NativeFile_NativeFile_file_stat_0"
        fun fileno: Int `{ return fileno(recv); `}
+       # Flushes the buffer, forcing the write operation
+       fun flush: Int is extern "fflush"
+       # Used to specify how the buffering will be handled for the current stream.
+       fun set_buffering_type(buf_length: Int, mode: Int): Int is extern "file_NativeFile_NativeFile_set_buffering_type_0"
 
        new io_open_read(path: NativeString) is extern "file_NativeFileCapable_NativeFileCapable_io_open_read_1"
        new io_open_write(path: NativeString) is extern "file_NativeFileCapable_NativeFileCapable_io_open_write_1"
@@ -541,6 +716,10 @@ end
 
 redef class Sys
 
+       init do
+               if stdout isa FStream then stdout.as(FStream).set_buffering_mode(256, buffer_mode_line)
+       end
+
        # Standard input
        var stdin: PollableIStream = new Stdin is protected writable
 
@@ -550,6 +729,89 @@ redef class Sys
        # Standard output for errors
        var stderr: OStream = new Stderr is protected writable
 
+       # Enumeration for buffer mode full (flushes when buffer is full)
+       fun buffer_mode_full: Int is extern "file_Sys_Sys_buffer_mode_full_0"
+       # Enumeration for buffer mode line (flushes when a `\n` is encountered)
+       fun buffer_mode_line: Int is extern "file_Sys_Sys_buffer_mode_line_0"
+       # Enumeration for buffer mode none (flushes ASAP when something is written)
+       fun buffer_mode_none: Int is extern "file_Sys_Sys_buffer_mode_none_0"
+
+       # returns first available stream to read or write to
+       # return null on interruption (possibly a signal)
+       protected fun poll( streams : Sequence[FStream] ) : nullable FStream
+       do
+               var in_fds = new Array[Int]
+               var out_fds = new Array[Int]
+               var fd_to_stream = new HashMap[Int,FStream]
+               for s in streams do
+                       var fd = s.fd
+                       if s isa IFStream then in_fds.add( fd )
+                       if s isa OFStream then out_fds.add( fd )
+
+                       fd_to_stream[fd] = s
+               end
+
+               var polled_fd = intern_poll( in_fds, out_fds )
+
+               if polled_fd == null then
+                       return null
+               else
+                       return fd_to_stream[polled_fd]
+               end
+       end
+
+       private fun intern_poll(in_fds: Array[Int], out_fds: Array[Int]) : nullable Int is extern import Array[Int].length, Array[Int].[], Int.as(nullable Int) `{
+               int in_len, out_len, total_len;
+               struct pollfd *c_fds;
+               sigset_t sigmask;
+               int i;
+               int first_polled_fd = -1;
+               int result;
+
+               in_len = Array_of_Int_length( in_fds );
+               out_len = Array_of_Int_length( out_fds );
+               total_len = in_len + out_len;
+               c_fds = malloc( sizeof(struct pollfd) * total_len );
+
+               /* input streams */
+               for ( i=0; i<in_len; i ++ ) {
+                       int fd;
+                       fd = Array_of_Int__index( in_fds, i );
+
+                       c_fds[i].fd = fd;
+                       c_fds[i].events = POLLIN;
+               }
+
+               /* output streams */
+               for ( i=0; i<out_len; i ++ ) {
+                       int fd;
+                       fd = Array_of_Int__index( out_fds, i );
+
+                       c_fds[i].fd = fd;
+                       c_fds[i].events = POLLOUT;
+               }
+
+               /* poll all fds, unlimited timeout */
+               result = poll( c_fds, total_len, -1 );
+
+               if ( result > 0 ) {
+                       /* analyse results */
+                       for ( i=0; i<total_len; i++ )
+                               if ( c_fds[i].revents & c_fds[i].events || /* awaited event */
+                                        c_fds[i].revents & POLLHUP ) /* closed */
+                               {
+                                       first_polled_fd = c_fds[i].fd;
+                                       break;
+                               }
+
+                       return Int_as_nullable( first_polled_fd );
+               }
+               else if ( result < 0 )
+                       fprintf( stderr, "Error in Stream:poll: %s\n", strerror( errno ) );
+
+               return null_Int();
+       `}
+
 end
 
 # Print `objects` on the standard output (`stdout`).