/* Set by auto_save_1 if an error occurred during the last auto-save. */
static bool auto_save_error_occurred;
+/* If VALID_TIMESTAMP_FILE_SYSTEM, then TIMESTAMP_FILE_SYSTEM is the device
+ number of a file system where time stamps were observed to to work. */
+static bool valid_timestamp_file_system;
+static dev_t timestamp_file_system;
+
/* The symbol bound to coding-system-for-read when
insert-file-contents is called for recovering a file. This is not
an actual coding system name, but just an indicator to tell
+ XSAVE_INTEGER (state, 1)),
XSAVE_INTEGER (state, 2));
immediate_quit = 0;
+ /* Fast recycle this object for the likely next call. */
+ free_misc (state);
return make_number (nbytes);
}
return Qnil;
}
-/* Reposition FD to OFFSET, based on WHENCE. This acts like lseek
- except that it also tests for OFFSET being out of lseek's range. */
+/* Return the file offset that VAL represents, checking for type
+ errors and overflow. */
static off_t
-emacs_lseek (int fd, EMACS_INT offset, int whence)
+file_offset (Lisp_Object val)
{
- /* Use "&" rather than "&&" to suppress a bogus GCC warning; see
- <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43772>. */
- if (! ((offset >= TYPE_MINIMUM (off_t)) & (offset <= TYPE_MAXIMUM (off_t))))
+ if (RANGED_INTEGERP (0, val, TYPE_MAXIMUM (off_t)))
+ return XINT (val);
+
+ if (FLOATP (val))
{
- errno = EINVAL;
- return -1;
+ double v = XFLOAT_DATA (val);
+ if (0 <= v
+ && (sizeof (off_t) < sizeof v
+ ? v <= TYPE_MAXIMUM (off_t)
+ : v < TYPE_MAXIMUM (off_t)))
+ return v;
}
- return lseek (fd, offset, whence);
+
+ wrong_type_argument (intern ("file-offset"), val);
}
/* Return a special time value indicating the error number ERRNUM. */
(Lisp_Object filename, Lisp_Object visit, Lisp_Object beg, Lisp_Object end, Lisp_Object replace)
{
struct stat st;
- int file_status;
EMACS_TIME mtime;
int fd;
ptrdiff_t inserted = 0;
int save_errno = 0;
char read_buf[READ_BUF_SIZE];
struct coding_system coding;
- char buffer[1 << 14];
bool replace_handled = 0;
bool set_coding_system = 0;
Lisp_Object coding_system;
orig_filename = filename;
filename = ENCODE_FILE (filename);
- fd = -1;
-
-#ifdef WINDOWSNT
- {
- Lisp_Object tem = Vw32_get_true_file_attributes;
-
- /* Tell stat to use expensive method to get accurate info. */
- Vw32_get_true_file_attributes = Qt;
- file_status = stat (SSDATA (filename), &st);
- Vw32_get_true_file_attributes = tem;
- }
-#else
- file_status = stat (SSDATA (filename), &st);
-#endif /* WINDOWSNT */
-
- if (file_status == 0)
- mtime = get_stat_mtime (&st);
- else
+ fd = emacs_open (SSDATA (filename), O_RDONLY, 0);
+ if (fd < 0)
{
- badopen:
save_errno = errno;
if (NILP (visit))
report_file_error ("Opening input file", Fcons (orig_filename, Qnil));
mtime = time_error_value (save_errno);
st.st_size = -1;
- how_much = 0;
if (!NILP (Vcoding_system_for_read))
Fset (Qbuffer_file_coding_system, Vcoding_system_for_read);
goto notfound;
}
+ /* Replacement should preserve point as it preserves markers. */
+ if (!NILP (replace))
+ record_unwind_protect (restore_point_unwind, Fpoint_marker ());
+
+ record_unwind_protect (close_file_unwind, make_number (fd));
+
+ if (fstat (fd, &st) != 0)
+ report_file_error ("Input file status", Fcons (orig_filename, Qnil));
+ mtime = get_stat_mtime (&st);
+
/* This code will need to be changed in order to work on named
pipes, and it's probably just not worth it. So we should at
least signal an error. */
build_string ("not a regular file"), orig_filename);
}
- if (fd < 0)
- if ((fd = emacs_open (SSDATA (filename), O_RDONLY, 0)) < 0)
- goto badopen;
-
- /* Replacement should preserve point as it preserves markers. */
- if (!NILP (replace))
- record_unwind_protect (restore_point_unwind, Fpoint_marker ());
-
- record_unwind_protect (close_file_unwind, make_number (fd));
-
-
if (!NILP (visit))
{
if (!NILP (beg) || !NILP (end))
}
if (!NILP (beg))
- {
- if (! RANGED_INTEGERP (0, beg, TYPE_MAXIMUM (off_t)))
- wrong_type_argument (intern ("file-offset"), beg);
- beg_offset = XFASTINT (beg);
- }
+ beg_offset = file_offset (beg);
else
beg_offset = 0;
if (!NILP (end))
- {
- if (! RANGED_INTEGERP (0, end, TYPE_MAXIMUM (off_t)))
- wrong_type_argument (intern ("file-offset"), end);
- end_offset = XFASTINT (end);
- }
+ end_offset = file_offset (end);
else
{
if (not_regular)
{
int nread, bufpos;
- nread = emacs_read (fd, buffer, sizeof buffer);
+ nread = emacs_read (fd, read_buf, sizeof read_buf);
if (nread < 0)
error ("IO error reading %s: %s",
SSDATA (orig_filename), emacs_strerror (errno));
if (CODING_REQUIRE_DETECTION (&coding))
{
- coding_system = detect_coding_system ((unsigned char *) buffer,
+ coding_system = detect_coding_system ((unsigned char *) read_buf,
nread, nread, 1, 0,
coding_system);
setup_coding_system (coding_system, &coding);
bufpos = 0;
while (bufpos < nread && same_at_start < ZV_BYTE
- && FETCH_BYTE (same_at_start) == buffer[bufpos])
+ && FETCH_BYTE (same_at_start) == read_buf[bufpos])
same_at_start++, bufpos++;
/* If we found a discrepancy, stop the scan.
Otherwise loop around and scan the next bufferful. */
if (curpos == 0)
break;
/* How much can we scan in the next step? */
- trial = min (curpos, sizeof buffer);
+ trial = min (curpos, sizeof read_buf);
if (lseek (fd, curpos - trial, SEEK_SET) < 0)
report_file_error ("Setting file position",
Fcons (orig_filename, Qnil));
total_read = nread = 0;
while (total_read < trial)
{
- nread = emacs_read (fd, buffer + total_read, trial - total_read);
+ nread = emacs_read (fd, read_buf + total_read, trial - total_read);
if (nread < 0)
error ("IO error reading %s: %s",
SDATA (orig_filename), emacs_strerror (errno));
/* Compare with same_at_start to avoid counting some buffer text
as matching both at the file's beginning and at the end. */
while (bufpos > 0 && same_at_end > same_at_start
- && FETCH_BYTE (same_at_end - 1) == buffer[bufpos - 1])
+ && FETCH_BYTE (same_at_end - 1) == read_buf[bufpos - 1])
same_at_end--, bufpos--;
/* If we found a discrepancy, stop the scan.
report_file_error ("Setting file position",
Fcons (orig_filename, Qnil));
- total = st.st_size; /* Total bytes in the file. */
- how_much = 0; /* Bytes read from file so far. */
inserted = 0; /* Bytes put into CONVERSION_BUFFER so far. */
unprocessed = 0; /* Bytes not processed in previous loop. */
GCPRO1 (conversion_buffer);
- while (how_much < total)
+ while (1)
{
- /* We read one bunch by one (READ_BUF_SIZE bytes) to allow
- quitting while reading a huge while. */
- /* `try'' is reserved in some compilers (Microsoft C). */
- int trytry = min (total - how_much, READ_BUF_SIZE - unprocessed);
+ /* Read at most READ_BUF_SIZE bytes at a time, to allow
+ quitting while reading a huge file. */
/* Allow quitting out of the actual I/O. */
immediate_quit = 1;
QUIT;
- this = emacs_read (fd, read_buf + unprocessed, trytry);
+ this = emacs_read (fd, read_buf + unprocessed,
+ READ_BUF_SIZE - unprocessed);
immediate_quit = 0;
if (this <= 0)
break;
- how_much += this;
-
BUF_TEMP_SET_PT (XBUFFER (conversion_buffer),
BUF_Z (XBUFFER (conversion_buffer)));
decode_coding_c_string (&coding, (unsigned char *) read_buf,
so defer the removal till we reach the `handled' label. */
deferred_remove_unwind_protect = 1;
- /* At this point, HOW_MUCH should equal TOTAL, or should be <= 0
- if we couldn't read the file. */
-
if (this < 0)
error ("IO error reading %s: %s",
SDATA (orig_filename), emacs_strerror (errno));
/* Maybe make more room. */
if (gap_size < trytry)
{
- make_gap (total - gap_size);
- gap_size = GAP_SIZE;
+ make_gap (trytry - gap_size);
+ gap_size = GAP_SIZE - inserted;
}
/* Read from the file, capturing `quit'. When an
to be signaled after decoding the text we read. */
nbytes = internal_condition_case_1
(read_non_regular,
- format_save_value ("iii", (ptrdiff_t) fd, inserted, trytry),
+ make_save_value ("iii", (ptrdiff_t) fd, inserted, trytry),
Qerror, read_non_regular_quit);
if (NILP (nbytes))
}
}
- /* Now we have read all the file data into the gap.
- If it was empty, undo marking the buffer modified. */
+ /* Now we have either read all the file data into the gap,
+ or stop reading on I/O error or quit. If nothing was
+ read, undo marking the buffer modified. */
if (inserted == 0)
{
else
Vdeactivate_mark = Qt;
+ emacs_close (fd);
+
+ /* Discard the unwind protect for closing the file. */
+ specpdl_ptr--;
+
+ if (how_much < 0)
+ error ("IO error reading %s: %s",
+ SDATA (orig_filename), emacs_strerror (errno));
+
/* Make the text read part of the buffer. */
GAP_SIZE -= inserted;
GPT += inserted;
/* Put an anchor to ensure multi-byte form ends at gap. */
*GPT_ADDR = 0;
- emacs_close (fd);
-
- /* Discard the unwind protect for closing the file. */
- specpdl_ptr--;
-
- if (how_much < 0)
- error ("IO error reading %s: %s",
- SDATA (orig_filename), emacs_strerror (errno));
-
notfound:
if (NILP (coding_system))
if (read_quit)
Fsignal (Qquit, Qnil);
- /* ??? Retval needs to be dealt with in all cases consistently. */
+ /* Retval needs to be dealt with in all cases consistently. */
if (NILP (val))
- val = Fcons (orig_filename,
- Fcons (make_number (inserted),
- Qnil));
+ val = list2 (orig_filename, make_number (inserted));
RETURN_UNGCPRO (unbind_to (count, val));
}
instead of any buffer contents; END is ignored.
Optional fourth argument APPEND if non-nil means
- append to existing file contents (if any). If it is an integer,
+ append to existing file contents (if any). If it is a number,
seek to that offset in the file before writing.
Optional fifth argument VISIT, if t or a string, means
set the last-save-file-modtime of buffer to this file's modtime
(Lisp_Object start, Lisp_Object end, Lisp_Object filename, Lisp_Object append, Lisp_Object visit, Lisp_Object lockname, Lisp_Object mustbenew)
{
int desc;
+ int open_flags;
+ int mode;
+ off_t offset IF_LINT (= 0);
bool ok;
int save_errno = 0;
const char *fn;
#endif /* CLASH_DETECTION */
encoded_filename = ENCODE_FILE (filename);
-
fn = SSDATA (encoded_filename);
- desc = -1;
- if (!NILP (append))
+ open_flags = O_WRONLY | O_BINARY | O_CREAT;
+ open_flags |= EQ (mustbenew, Qexcl) ? O_EXCL : !NILP (append) ? 0 : O_TRUNC;
+ if (NUMBERP (append))
+ offset = file_offset (append);
+ else if (!NILP (append))
+ open_flags |= O_APPEND;
#ifdef DOS_NT
- desc = emacs_open (fn, O_WRONLY | O_BINARY, 0);
-#else /* not DOS_NT */
- desc = emacs_open (fn, O_WRONLY, 0);
-#endif /* not DOS_NT */
+ mode = S_IREAD | S_IWRITE;
+#else
+ mode = auto_saving ? auto_save_mode_bits : 0666;
+#endif
- if (desc < 0 && (NILP (append) || errno == ENOENT))
-#ifdef DOS_NT
- desc = emacs_open (fn,
- O_WRONLY | O_CREAT | O_BINARY
- | (EQ (mustbenew, Qexcl) ? O_EXCL : O_TRUNC),
- S_IREAD | S_IWRITE);
-#else /* not DOS_NT */
- desc = emacs_open (fn, O_WRONLY | O_TRUNC | O_CREAT
- | (EQ (mustbenew, Qexcl) ? O_EXCL : 0),
- auto_saving ? auto_save_mode_bits : 0666);
-#endif /* not DOS_NT */
+ desc = emacs_open (fn, open_flags, mode);
if (desc < 0)
{
record_unwind_protect (close_file_unwind, make_number (desc));
- if (!NILP (append) && !NILP (Ffile_regular_p (filename)))
+ if (NUMBERP (append))
{
- off_t ret;
-
- if (NUMBERP (append))
- ret = emacs_lseek (desc, XINT (append), SEEK_CUR);
- else
- ret = lseek (desc, 0, SEEK_END);
+ off_t ret = lseek (desc, offset, SEEK_SET);
if (ret < 0)
{
#ifdef CLASH_DETECTION
/* Discard the unwind protect for close_file_unwind. */
specpdl_ptr = specpdl + count1;
+ /* Some file systems have a bug where st_mtime is not updated
+ properly after a write. For example, CIFS might not see the
+ st_mtime change until after the file is opened again.
+
+ Attempt to detect this file system bug, and update MODTIME to the
+ newer st_mtime if the bug appears to be present. This introduces
+ a race condition, so to avoid most instances of the race condition
+ on non-buggy file systems, skip this check if the most recently
+ encountered non-buggy file system was the current file system.
+
+ A race condition can occur if some other process modifies the
+ file between the fstat above and the fstat below, but the race is
+ unlikely and a similar race between the last write and the fstat
+ above cannot possibly be closed anyway. */
+
+ if (EMACS_TIME_VALID_P (modtime)
+ && ! (valid_timestamp_file_system && st.st_dev == timestamp_file_system))
+ {
+ int desc1 = emacs_open (fn, O_WRONLY | O_BINARY, 0);
+ if (0 <= desc1)
+ {
+ struct stat st1;
+ if (fstat (desc1, &st1) == 0
+ && st.st_dev == st1.st_dev && st.st_ino == st1.st_ino)
+ {
+ EMACS_TIME modtime1 = get_stat_mtime (&st1);
+ if (EMACS_TIME_EQ (modtime, modtime1)
+ && st.st_size == st1.st_size)
+ {
+ timestamp_file_system = st.st_dev;
+ valid_timestamp_file_system = 1;
+ }
+ else
+ {
+ st.st_size = st1.st_size;
+ modtime = modtime1;
+ }
+ }
+ emacs_close (desc1);
+ }
+ }
+
/* Call write-region-post-annotation-function. */
while (CONSP (Vwrite_region_annotation_buffers))
{
}
if (!auto_saving)
- message_with_string ((INTEGERP (append)
+ message_with_string ((NUMBERP (append)
? "Updated %s"
: ! NILP (append)
? "Added to %s"
}
record_unwind_protect (do_auto_save_unwind,
- make_save_value (stream, 0));
+ make_save_pointer (stream));
record_unwind_protect (do_auto_save_unwind_1,
make_number (minibuffer_auto_raise));
minibuffer_auto_raise = 0;
}
\f
+void
+init_fileio (void)
+{
+ valid_timestamp_file_system = 0;
+}
+
void
syms_of_fileio (void)
{
HCoop / bpt / emacs.git / blobdiff