diff options
| -rw-r--r-- | ChangeLog | 5 | ||||
| -rw-r--r-- | io.c | 178 | ||||
| -rw-r--r-- | test/ruby/test_readpartial.rb | 2 |
3 files changed, 161 insertions, 24 deletions
@@ -1,3 +1,8 @@ +Sun Jan 9 03:12:58 2005 Tanaka Akira <akr@m17n.org> + + * io.c (io_fread): warn nonblocking behavior. + (io_readpartial): new method IO#readpartial. + Sat Jan 8 04:38:47 2005 why the lucky stiff <why@ruby-lang.org> * lib/yaml.rb: Kernel#y requires an argument. @@ -944,6 +944,27 @@ rb_io_to_io(io) } /* reading functions */ +static long +read_buffered_data(ptr, len, f) + char *ptr; + long len; + FILE *f; +{ + long n; + +#ifdef READ_DATA_PENDING_COUNT + n = READ_DATA_PENDING_COUNT(f); + if (n <= 0) return 0; + if (n > len) n = len; + return fread(ptr, 1, n, f); +#else + for (n = 0; n < len && READ_DATA_PENDING(f); ++n) { + *ptr++ = getc(f); + } + return n; +#endif +} + long io_fread(ptr, len, fptr) char *ptr; @@ -952,32 +973,17 @@ io_fread(ptr, len, fptr) { long n = len; int c; + int saved_errno; while (n > 0) { -#ifdef READ_DATA_PENDING_COUNT - long i = READ_DATA_PENDING_COUNT(fptr->f); - if (i <= 0) { - rb_thread_wait_fd(fileno(fptr->f)); - rb_io_check_closed(fptr); - i = READ_DATA_PENDING_COUNT(fptr->f); - } - if (i > 0) { - if (i > n) i = n; - TRAP_BEG; - c = fread(ptr, 1, i, fptr->f); - TRAP_END; - if (c < 0) goto eof; - ptr += c; - n -= c; - if (c < i) goto eof; - continue; - } -#else - if (!READ_DATA_PENDING(fptr->f)) { - rb_thread_wait_fd(fileno(fptr->f)); - rb_io_check_closed(fptr); - } -#endif + c = read_buffered_data(ptr, n, fptr->f); + if (c < 0) goto eof; + if (c > 0) { + ptr += c; + if ((n -= c) <= 0) break; + } + rb_thread_wait_fd(fileno(fptr->f)); + rb_io_check_closed(fptr); TRAP_BEG; c = getc(fptr->f); TRAP_END; @@ -998,6 +1004,9 @@ io_fread(ptr, len, fptr) if (len > n) { clearerr(fptr->f); } + saved_errno = errno; + rb_warn("nonblocking IO#read is obsolete; use IO#readpartial or IO#sysread"); + errno = saved_errno; } if (len == n) return 0; } @@ -1092,6 +1101,126 @@ read_all(fptr, siz, str) return str; } +static VALUE +io_getpartial(int argc, VALUE *argv, VALUE io) +{ + OpenFile *fptr; + VALUE length, str; + long n, len; + + rb_scan_args(argc, argv, "11", &length, &str); + + if ((len = NUM2LONG(length)) < 0) { + rb_raise(rb_eArgError, "negative length %ld given", len); + } + + if (NIL_P(str)) { + str = rb_str_new(0, len); + } + else { + StringValue(str); + rb_str_modify(str); + rb_str_resize(str, len); + } + OBJ_TAINT(str); + + GetOpenFile(io, fptr); + rb_io_check_readable(fptr); + + if (len == 0) + return str; + + READ_CHECK(fptr->f); + if (RSTRING(str)->len != len) { + modified: + rb_raise(rb_eRuntimeError, "buffer string modified"); + } + n = read_buffered_data(RSTRING(str)->ptr, len, fptr->f); + if (n <= 0) { + again: + if (RSTRING(str)->len != len) goto modified; + TRAP_BEG; + n = read(fileno(fptr->f), RSTRING(str)->ptr, len); + TRAP_END; + if (n < 0) { + if (rb_io_wait_readable(fileno(fptr->f))) + goto again; + rb_sys_fail(fptr->path); + } + } + rb_str_resize(str, n); + + if (n == 0) + return Qnil; + else + return str; +} + +/* + * call-seq: + * ios.readpartial(maxlen[, outbuf]) => string, outbuf + * + * Reads at most <i>maxlen</i> bytes from the I/O stream but + * it blocks only if <em>ios</em> has no data immediately available. + * If the optional <i>outbuf</i> argument is present, + * it must reference a String, which will receive the data. + * It raises <code>EOFError</code> on end of file. + * + * readpartial is designed for streams such as pipe, socket, tty, etc. + * It blocks only when no data immediately available. + * This means that it blocks only when following all conditions hold. + * * the buffer in the IO object is empty. + * * the content of the stream is empty. + * * the stream is not reached to EOF. + * + * When readpartial blocks, it waits data or EOF on the stream. + * If some data is reached, readpartial returns with the data. + * If EOF is reached, readpartial raises EOFError. + * + * When readpartial doesn't blocks, it returns or raises immediately. + * If the buffer is not empty, it returns the data in the buffer. + * Otherwise if the stream has some content, + * it returns the data in the stream. + * Otherwise if the stream is reached to EOF, it raises EOFError. + * + * r, w = IO.pipe # buffer pipe content + * w << "abc" # "" "abc". + * r.readpartial(4096) #=> "abc" "" "" + * r.readpartial(4096) # blocks because buffer and pipe is empty. + * + * r, w = IO.pipe # buffer pipe content + * w << "abc" # "" "abc" + * w.close # "" "abc" EOF + * r.readpartial(4096) #=> "abc" "" EOF + * r.readpartial(4096) # raises EOFError + * + * r, w = IO.pipe # buffer pipe content + * w << "abc\ndef\n" # "" "abc\ndef\n" + * r.gets #=> "abc\n" "def\n" "" + * w << "ghi\n" # "def\n" "ghi\n" + * r.readpartial(4096) #=> "def\n" "" "ghi\n" + * r.readpartial(4096) #=> "ghi\n" "" "" + * + * Note that readpartial is nonblocking-flag insensitive. + * It blocks even if the nonblocking-flag is set. + * + * Also note that readpartial behaves similar to sysread in blocking mode. + * The behavior is identical when the buffer is empty. + * + */ + +static VALUE +io_readpartial(int argc, VALUE *argv, VALUE io) +{ + VALUE ret; + + ret = io_getpartial(argc, argv, io); + if (NIL_P(ret)) + rb_eof_error(); + else + return ret; +} + /* * call-seq: * ios.read([integer [, buffer]]) => string, buffer, or nil @@ -5409,6 +5538,7 @@ Init_IO() rb_define_method(rb_cIO, "readlines", rb_io_readlines, -1); + rb_define_method(rb_cIO, "readpartial", io_readpartial, -1); rb_define_method(rb_cIO, "read", io_read, -1); rb_define_method(rb_cIO, "write", io_write, 1); rb_define_method(rb_cIO, "gets", rb_io_gets_m, -1); diff --git a/test/ruby/test_readpartial.rb b/test/ruby/test_readpartial.rb index 526425dc57..3877e21f85 100644 --- a/test/ruby/test_readpartial.rb +++ b/test/ruby/test_readpartial.rb @@ -43,6 +43,7 @@ class TestReadPartial < Test::Unit::TestCase } end + if !File::ALT_SEPARATOR # read on pipe cannot timeout on Windows. def test_open_pipe pipe {|r, w| w << 'abc' @@ -67,6 +68,7 @@ class TestReadPartial < Test::Unit::TestCase } } end + end end |