Hi Andy, Andy Wingo <wi...@pobox.com> writes: > Looks like a good start. Two comments: > > On Mon 01 Apr 2013 23:27, Mark H Weaver <m...@netris.org> writes: > > 1. I don't much like the addition of this call to this inline function. > Can we move all the non-fast-path code into some other function? That > would include the flush call as well.
Good idea! I've posted separate patches to do that here: "[PATCH] Move slow path out of 'scm_get_byte_or_eof' et al" http://lists.gnu.org/archive/html/guile-devel/2013-04/msg00032.html > 2. I think we probably need some tests. I've attached a new patch which adds tests. Note that this patch depends upon the "Move slow path out" patches referenced above. More thoughts? Thanks! Mark
>From 688dd519d7be102b9d5ce2193883c33d82f8df7b Mon Sep 17 00:00:00 2001 From: Mark H Weaver <m...@netris.org> Date: Sun, 31 Mar 2013 19:06:51 -0400 Subject: [PATCH] Peeks do not consume EOFs. Fixes <http://bugs.gnu.org/12216>. * libguile/ports-internal.h (struct scm_port_internal): Add 'pending_eof' flag. * libguile/ports.c (scm_i_set_pending_eof, scm_i_clear_pending_eof): New static functions. (scm_new_port_table_entry): Initialize 'pending_eof'. (scm_i_fill_input): Check for 'pending_eof'. (scm_i_peek_byte_or_eof): Set 'pending_eof' flag before returning EOF. (scm_end_input, scm_unget_byte, scm_seek): Clear 'pending_eof'. (scm_peek_char): Set 'pending_eof' flag before returning EOF. * test-suite/tests/ports.test ("pending EOF behavior"): Add tests. --- libguile/ports-internal.h | 1 + libguile/ports.c | 37 +++++++++++++++++-- test-suite/tests/ports.test | 84 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 119 insertions(+), 3 deletions(-) diff --git a/libguile/ports-internal.h b/libguile/ports-internal.h index 73a788f..333d4fb 100644 --- a/libguile/ports-internal.h +++ b/libguile/ports-internal.h @@ -48,6 +48,7 @@ struct scm_port_internal { scm_t_port_encoding_mode encoding_mode; scm_t_iconv_descriptors *iconv_descriptors; + int pending_eof; SCM alist; }; diff --git a/libguile/ports.c b/libguile/ports.c index ee14ca5..61bfc72 100644 --- a/libguile/ports.c +++ b/libguile/ports.c @@ -241,6 +241,18 @@ scm_set_port_input_waiting (scm_t_bits tc, int (*input_waiting) (SCM)) scm_ptobs[SCM_TC2PTOBNUM (tc)].input_waiting = input_waiting; } +static void +scm_i_set_pending_eof (SCM port) +{ + SCM_PORT_GET_INTERNAL (port)->pending_eof = 1; +} + +static void +scm_i_clear_pending_eof (SCM port) +{ + SCM_PORT_GET_INTERNAL (port)->pending_eof = 0; +} + SCM scm_i_port_alist (SCM port) { @@ -645,6 +657,7 @@ scm_new_port_table_entry (scm_t_bits tag) entry->input_cd = pti; /* XXX pointer to the internal port structure */ entry->output_cd = NULL; /* XXX unused */ + pti->pending_eof = 0; pti->alist = SCM_EOL; SCM_SET_CELL_TYPE (z, tag); @@ -1423,9 +1436,16 @@ static int scm_i_fill_input (SCM port) { scm_t_port *pt = SCM_PTAB_ENTRY (port); + scm_t_port_internal *pti = SCM_PORT_GET_INTERNAL (port); assert (pt->read_pos == pt->read_end); + if (pti->pending_eof) + { + pti->pending_eof = 0; + return EOF; + } + if (pt->read_buf == pt->putback_buf) { /* finished reading put-back chars. */ @@ -1481,7 +1501,10 @@ scm_i_peek_byte_or_eof (SCM port) if (pt->read_pos >= pt->read_end) { if (SCM_UNLIKELY (scm_i_fill_input (port) == EOF)) - return EOF; + { + scm_i_set_pending_eof (port); + return EOF; + } } return *pt->read_pos; @@ -1713,6 +1736,7 @@ scm_end_input (SCM port) long offset; scm_t_port *pt = SCM_PTAB_ENTRY (port); + scm_i_clear_pending_eof (port); if (pt->read_buf == pt->putback_buf) { offset = pt->read_end - pt->read_pos; @@ -1736,6 +1760,7 @@ scm_unget_byte (int c, SCM port) { scm_t_port *pt = SCM_PTAB_ENTRY (port); + scm_i_clear_pending_eof (port); if (pt->read_buf == pt->putback_buf) /* already using the put-back buffer. */ { @@ -1907,7 +1932,10 @@ SCM_DEFINE (scm_peek_char, "peek-char", 0, 1, 0, result = SCM_BOOL_F; } else if (c == EOF) - result = SCM_EOF_VAL; + { + scm_i_set_pending_eof (port); + result = SCM_EOF_VAL; + } else result = SCM_MAKE_CHAR (c); @@ -2006,7 +2034,10 @@ SCM_DEFINE (scm_seek, "seek", 3, 0, 0, SCM_MISC_ERROR ("port is not seekable", scm_cons (fd_port, SCM_EOL)); else - rv = ptob->seek (fd_port, off, how); + { + scm_i_clear_pending_eof (fd_port); + rv = ptob->seek (fd_port, off, how); + } return scm_from_off_t_or_off64_t (rv); } else /* file descriptor?. */ diff --git a/test-suite/tests/ports.test b/test-suite/tests/ports.test index 886ab24..7b6ee22 100644 --- a/test-suite/tests/ports.test +++ b/test-suite/tests/ports.test @@ -1110,6 +1110,90 @@ (char-ready?)))))) +;;;; pending-eof behavior + +(with-test-prefix "pending EOF behavior" + ;; Make a test port that will produce the given sequence. Each + ;; element of 'lst' may be either a character or #f (which means EOF). + (define (test-soft-port . lst) + (make-soft-port + (vector (lambda (c) #f) ; write char + (lambda (s) #f) ; write string + (lambda () #f) ; flush + (lambda () ; read char + (let ((c (car lst))) + (set! lst (cdr lst)) + c)) + (lambda () #f)) ; close + "rw")) + + (define (call-with-port p proc) + (dynamic-wind + (lambda () #f) + (lambda () (proc p)) + (lambda () (close-port p)))) + + (define (call-with-test-file str proc) + (let ((filename (test-file))) + (dynamic-wind + (lambda () (call-with-output-file filename + (lambda (p) (display str p)))) + (lambda () (call-with-input-file filename proc)) + (lambda () (delete-file (test-file)))))) + + (pass-if "peek-char does not swallow EOF (soft port)" + (call-with-port (test-soft-port #\a #f #\b) + (lambda (p) + (and (char=? #\a (peek-char p)) + (char=? #\a (read-char p)) + (eof-object? (peek-char p)) + (eof-object? (read-char p)) + (char=? #\b (peek-char p)) + (char=? #\b (read-char p)))))) + + (pass-if "unread clears pending EOF (soft port)" + (call-with-port (test-soft-port #\a #f #\b) + (lambda (p) + (and (char=? #\a (read-char p)) + (eof-object? (peek-char p)) + (begin (unread-char #\u p) + (char=? #\u (read-char p))))))) + + (pass-if "unread clears pending EOF (string port)" + (call-with-input-string "a" + (lambda (p) + (and (char=? #\a (read-char p)) + (eof-object? (peek-char p)) + (begin (unread-char #\u p) + (char=? #\u (read-char p))))))) + + (pass-if "unread clears pending EOF (file port)" + (call-with-test-file + "a" + (lambda (p) + (and (char=? #\a (read-char p)) + (eof-object? (peek-char p)) + (begin (unread-char #\u p) + (char=? #\u (read-char p))))))) + + (pass-if "seek clears pending EOF (string port)" + (call-with-input-string "a" + (lambda (p) + (and (char=? #\a (read-char p)) + (eof-object? (peek-char p)) + (begin (seek p 0 SEEK_SET) + (char=? #\a (read-char p))))))) + + (pass-if "seek clears pending EOF (file port)" + (call-with-test-file + "a" + (lambda (p) + (and (char=? #\a (read-char p)) + (eof-object? (peek-char p)) + (begin (seek p 0 SEEK_SET) + (char=? #\a (read-char p)))))))) + + ;;;; Close current-input-port, and make sure everyone can handle it. (with-test-prefix "closing current-input-port" -- 1.7.10.4
