X-Git-Url: http://nitlanguage.org diff --git a/lib/core/stream.nit b/lib/core/stream.nit index d884b62..b0486ef 100644 --- a/lib/core/stream.nit +++ b/lib/core/stream.nit @@ -122,14 +122,81 @@ abstract class Reader for i in [0 .. max[ do var b = raw_read_byte if b < 0 then break - buf[i] = b.to_b + buf[i] = b rd += 1 end return rd end # Reads a character. Returns `null` on EOF or timeout - fun read_char: nullable Char is abstract + # + # Returns unicode replacement character '�' if an + # invalid byte sequence is read. + # + # `read_char` may block if: + # + # * No byte could be read from the current buffer + # * An incomplete char is partially read, and more bytes are + # required for full decoding. + fun read_char: nullable Char do + if eof then return null + var cod = codec + var codet_sz = cod.codet_size + var lk = lookahead + var llen = lookahead_length + if llen < codet_sz then + llen += raw_read_bytes(lk.fast_cstring(llen), codet_sz - llen) + end + if llen < codet_sz then + lookahead_length = 0 + return 0xFFFD.code_point + end + var ret = cod.is_valid_char(lk, codet_sz) + var max_llen = cod.max_lookahead + while ret == 1 and llen < max_llen do + var rd = raw_read_bytes(lk.fast_cstring(llen), codet_sz) + if rd < codet_sz then + llen -= codet_sz + if llen > 0 then + lookahead.lshift(codet_sz, llen, codet_sz) + end + lookahead_length = llen.max(0) + return 0xFFFD.code_point + end + llen += codet_sz + ret = cod.is_valid_char(lk, llen) + end + if ret == 0 then + var c = cod.decode_char(lk) + var clen = c.u8char_len + llen -= clen + if llen > 0 then + lookahead.lshift(clen, llen, clen) + end + lookahead_length = llen + return c + end + if ret == 2 or ret == 1 then + llen -= codet_sz + if llen > 0 then + lookahead.lshift(codet_sz, llen, codet_sz) + end + lookahead_length = llen + return 0xFFFD.code_point + end + # Should not happen if the decoder works properly + var arr = new Array[Object] + arr.push "Decoder error: could not decode nor recover from byte sequence [" + for i in [0 .. llen[ do + arr.push lk[i] + arr.push ", " + end + arr.push "]" + var err = new IOError(arr.plain_to_s) + err.cause = last_error + last_error = err + return 0xFFFD.code_point + end # Reads a byte. Returns a negative value on error fun read_byte: Int do @@ -148,13 +215,16 @@ abstract class Reader # Reads a String of at most `i` length fun read(i: Int): String do + assert i >= 0 var cs = new CString(i) var rd = read_bytes_to_cstring(cs, i) + if rd < 0 then return "" return codec.decode_string(cs, rd) end # Reads up to `max` bytes from source fun read_bytes(max: Int): Bytes do + assert max >= 0 var cs = new CString(max) var rd = read_bytes_to_cstring(cs, max) return new Bytes(cs, rd, max) @@ -173,7 +243,7 @@ abstract class Reader else lookahead_length = 0 end - return rd + raw_read_bytes(bytes, max - rd) + return rd + raw_read_bytes(bytes.fast_cstring(rd), max - rd) end # Read a string until the end of the line. @@ -345,7 +415,11 @@ abstract class Reader # Is there something to read. # This function returns 'false' if there is something to read. - fun eof: Bool is abstract + fun eof: Bool do + if lookahead_length > 0 then return false + lookahead_length = raw_read_bytes(lookahead, 1) + return lookahead_length <= 0 + end # Read the next sequence of non whitespace characters. # @@ -410,37 +484,18 @@ end # Iterator returned by `Reader::each_line`. # See the aforementioned method for details. class LineIterator - super Iterator[String] + super CachedIterator[String] # The original stream var stream: Reader - redef fun is_ok + redef fun next_item do - var res = not stream.eof - if not res and close_on_finish then stream.close - return res - end - - redef fun item - do - var line = self.line - if line == null then - line = stream.read_line + if stream.eof then + if close_on_finish then stream.close + return null end - self.line = line - return line - end - - # The last line read (cache) - private var line: nullable String = null - - redef fun next - do - # force the read - if line == null then item - # drop the line - line = null + return stream.read_line end # Close the stream when the stream is at the EOF. @@ -477,7 +532,7 @@ abstract class Writer fun write(s: Text) is abstract # Write a single byte - fun write_byte(value: Byte) is abstract + fun write_byte(value: Int) is abstract # Write a single char fun write_char(c: Char) do @@ -500,17 +555,32 @@ interface Writable # The specific logic it let to the concrete subclasses fun write_to(stream: Writer) is abstract - # Like `write_to` but return a new String (may be quite large) + # Like `write_to` but return a new String (may be quite large). # - # This funtionality is anectodical, since the point - # of streamable object to to be efficienlty written to a - # stream without having to allocate and concatenate strings + # This functionality is anecdotal, since the point + # of a streamable object is to be efficiently written to a + # stream without having to allocate and concatenate strings. fun write_to_string: String do var stream = new StringWriter write_to(stream) return stream.to_s end + + # Like `write_to` but return a new Bytes (may be quite large) + # + # This functionality is anecdotal, since the point + # of a streamable object is to be efficiently written to a + # stream without having to allocate and concatenate buffers. + # + # Nevertheless, you might need this method if you want to know + # the byte size of a writable object. + fun write_to_bytes: Bytes + do + var stream = new BytesWriter + write_to(stream) + return stream.bytes + end end redef class Bytes @@ -525,201 +595,6 @@ redef class Text redef fun write_to(stream) do stream.write(self) end -# Input streams with a buffered input for efficiency purposes -abstract class BufferedReader - super Reader - redef fun read_char - do - if last_error != null then return null - if eof then - last_error = new IOError("Stream has reached eof") - return null - end - # TODO: Fix when supporting UTF-8 - var c = _buffer[_buffer_pos].to_i.code_point - _buffer_pos += 1 - return c - end - - redef fun read_byte - do - if last_error != null then return -1 - if eof then - last_error = new IOError("Stream has reached eof") - return -1 - end - var c = _buffer[_buffer_pos] - _buffer_pos += 1 - return c.to_i - end - - # Resets the internal buffer - fun buffer_reset do - _buffer_length = 0 - _buffer_pos = 0 - end - - # Peeks up to `n` bytes in the buffer - # - # The operation does not consume the buffer - # - # ~~~nitish - # var x = new FileReader.open("File.txt") - # assert x.peek(5) == x.read(5) - # ~~~ - fun peek(i: Int): Bytes do - if eof then return new Bytes.empty - var remsp = _buffer_length - _buffer_pos - if i <= remsp then - var bf = new Bytes.with_capacity(i) - bf.append_ns_from(_buffer, i, _buffer_pos) - return bf - end - var bf = new Bytes.with_capacity(i) - bf.append_ns_from(_buffer, remsp, _buffer_pos) - _buffer_pos = _buffer_length - read_intern(i - bf.length, bf) - remsp = _buffer_length - _buffer_pos - var full_len = bf.length + remsp - if full_len > _buffer_capacity then - var c = _buffer_capacity - while c < full_len do c = c * 2 + 2 - _buffer_capacity = c - end - var nns = new CString(_buffer_capacity) - bf.items.copy_to(nns, bf.length, 0, 0) - _buffer.copy_to(nns, remsp, _buffer_pos, bf.length) - _buffer = nns - _buffer_pos = 0 - _buffer_length = full_len - return bf - end - - redef fun read_bytes_to_cstring(buf, i) - do - if last_error != null then return 0 - var bbf = new Bytes(buf, 0, i) - return read_intern(i, bbf) - end - - # Fills `buf` with at most `i` bytes read from `self` - private fun read_intern(i: Int, buf: Bytes): Int do - if eof then return 0 - var p = _buffer_pos - var bufsp = _buffer_length - p - if bufsp >= i then - _buffer_pos += i - buf.append_ns_from(_buffer, i, p) - return i - end - _buffer_pos = _buffer_length - var readln = _buffer_length - p - buf.append_ns_from(_buffer, readln, p) - var rd = read_intern(i - readln, buf) - return rd + readln - end - - redef fun read_all_bytes - do - if last_error != null then return new Bytes.empty - var s = new Bytes.with_capacity(10) - var b = _buffer - while not eof do - var j = _buffer_pos - var k = _buffer_length - var rd_sz = k - j - s.append_ns_from(b, rd_sz, j) - _buffer_pos = k - fill_buffer - end - return s - end - - redef fun append_line_to(s) - do - var lb = new Bytes.with_capacity(10) - loop - # First phase: look for a '\n' - var i = _buffer_pos - while i < _buffer_length and _buffer[i] != 0xAu8 do - i += 1 - end - - var eol - if i < _buffer_length then - assert _buffer[i] == 0xAu8 - i += 1 - eol = true - else - eol = false - end - - # if there is something to append - if i > _buffer_pos then - # Copy from the buffer to the string - var j = _buffer_pos - while j < i do - lb.add(_buffer[j]) - j += 1 - end - _buffer_pos = i - else - assert end_reached - s.append lb.to_s - return - end - - if eol then - # so \n is found - s.append lb.to_s - return - else - # so \n is not found - if end_reached then - s.append lb.to_s - return - end - fill_buffer - end - end - end - - redef fun eof - do - if _buffer_pos < _buffer_length then return false - if end_reached then return true - fill_buffer - return _buffer_pos >= _buffer_length and end_reached - end - - # The buffer - private var buffer: CString = new CString(0) - - # The current position in the buffer - private var buffer_pos = 0 - - # Length of the current buffer (i.e. nuber of bytes in the buffer) - private var buffer_length = 0 - - # Capacity of the buffer - private var buffer_capacity = 0 - - # Fill the buffer - protected fun fill_buffer is abstract - - # Has the last fill_buffer reached the end - protected fun end_reached: Bool is abstract - - # Allocate a `_buffer` for a given `capacity`. - protected fun prepare_buffer(capacity: Int) - do - _buffer = new CString(capacity) - _buffer_pos = 0 # need to read - _buffer_length = 0 - _buffer_capacity = capacity - end -end - # A `Stream` that can be written to and read from abstract class Duplex super Reader @@ -733,7 +608,7 @@ end # # writer.write "Strings " # writer.write_char '&' -# writer.write_byte 0x20u8 +# writer.write_byte 0x20 # writer.write_bytes "bytes".to_bytes # # assert writer.to_s == "\\x53\\x74\\x72\\x69\\x6E\\x67\\x73\\x20\\x26\\x20\\x62\\x79\\x74\\x65\\x73" @@ -747,12 +622,12 @@ end # writer = new BytesWriter # # # Write just the character first half -# writer.write_byte 0xC2u8 +# writer.write_byte 0xC2 # assert writer.to_s == "\\xC2" # assert writer.bytes.to_s == "�" # # # Complete the character -# writer.write_byte 0xA2u8 +# writer.write_byte 0xA2 # assert writer.to_s == "\\xC2\\xA2" # assert writer.bytes.to_s == "¢" # ~~~ @@ -804,7 +679,7 @@ end # # writer.write "Strings " # writer.write_char '&' -# writer.write_byte 0x20u8 +# writer.write_byte 0x20 # writer.write_bytes "bytes".to_bytes # # assert writer.to_s == "Strings & bytes" @@ -834,17 +709,7 @@ class BytesReader # The current position in `bytes` private var cursor = 0 - redef fun read_char - do - if cursor >= bytes.length then return null - - var len = bytes.items.length_of_char_at(cursor) - var char = bytes.items.char_at(cursor) - cursor += len - return char - end - - redef fun read_byte + redef fun raw_read_byte do if cursor >= bytes.length then return -1