summaryrefslogtreecommitdiff
path: root/libguile/filesys.c
diff options
context:
space:
mode:
authorLudovic Courtès <ludo@gnu.org>2013-04-07 23:43:21 +0200
committerLudovic Courtès <ludo@gnu.org>2013-04-07 23:47:38 +0200
commite0886e0780fc1f3ce1c80d0692c11adf3b68f682 (patch)
tree662ee84dfa4c708a3c703493929755d3d779ad50 /libguile/filesys.c
parent254d313a21f06739930032062678ff5360d248fd (diff)
downloadguile-e0886e0780fc1f3ce1c80d0692c11adf3b68f682.tar.gz
Change `sendfile' to loop until everything has been sent.
* libguile/filesys.c (scm_sendfile)[HAVE_SYS_SENDFILE_H && HAVE_SENDFILE]: Compare RESULT with C_COUNT. Loop until C_COUNT bytes have been sent. * doc/ref/posix.texi (File System): Update the description. Explain the new semantics. * test-suite/tests/filesys.test ("sendfile"): Rewrite using `pass-if-equal'. Check the return value for all the tests. ["file with offset past the end", "file with offset near the end"]: New tests.
Diffstat (limited to 'libguile/filesys.c')
-rw-r--r--libguile/filesys.c47
1 files changed, 34 insertions, 13 deletions
diff --git a/libguile/filesys.c b/libguile/filesys.c
index d318ae793..d2e565bf8 100644
--- a/libguile/filesys.c
+++ b/libguile/filesys.c
@@ -1111,9 +1111,10 @@ SCM_DEFINE (scm_copy_file, "copy-file", 2, 0, 0,
SCM_DEFINE (scm_sendfile, "sendfile", 3, 1, 0,
(SCM out, SCM in, SCM count, SCM offset),
"Send @var{count} bytes from @var{in} to @var{out}, both of which "
- "are either open file ports or file descriptors. When "
+ "must be either open file ports or file descriptors. When "
"@var{offset} is omitted, start reading from @var{in}'s current "
- "position; otherwise, start reading at @var{offset}.")
+ "position; otherwise, start reading at @var{offset}. Return "
+ "the number of bytes actually sent.")
#define FUNC_NAME s_scm_sendfile
{
#define VALIDATE_FD_OR_PORT(cvar, svar, pos) \
@@ -1126,9 +1127,9 @@ SCM_DEFINE (scm_sendfile, "sendfile", 3, 1, 0,
cvar = SCM_FPORT_FDES (svar); \
}
- size_t c_count;
+ ssize_t result SCM_UNUSED;
+ size_t c_count, total = 0;
scm_t_off c_offset;
- ssize_t result;
int in_fd, out_fd;
VALIDATE_FD_OR_PORT (out_fd, out, 1);
@@ -1139,9 +1140,30 @@ SCM_DEFINE (scm_sendfile, "sendfile", 3, 1, 0,
#if defined HAVE_SYS_SENDFILE_H && defined HAVE_SENDFILE
/* The Linux-style sendfile(2), which is different from the BSD-style. */
- result = sendfile_or_sendfile64 (out_fd, in_fd,
- SCM_UNBNDP (offset) ? NULL : &c_offset,
- c_count);
+ {
+ off_t *offset_ptr;
+
+ offset_ptr = SCM_UNBNDP (offset) ? NULL : &c_offset;
+
+ /* On Linux, when OUT_FD is a file, everything is transferred at once and
+ RESULT == C_COUNT. However, when OUT_FD is a pipe or other "slow"
+ device, fewer bytes may be transferred, hence the loop. RESULT == 0
+ means EOF on IN_FD, so leave the loop in that case. */
+ do
+ {
+ result = sendfile_or_sendfile64 (out_fd, in_fd, offset_ptr,
+ c_count - total);
+ if (result > 0)
+ /* At this point, either OFFSET_PTR is non-NULL and it has been
+ updated to the current offset in IN_FD, or it is NULL and IN_FD's
+ offset has been updated. */
+ total += result;
+ else if (result < 0 && (errno == EINTR || errno == EAGAIN))
+ /* Keep going. */
+ result = 0;
+ }
+ while (total < c_count && result > 0);
+ }
/* Quoting the Linux man page: "In Linux kernels before 2.6.33, out_fd
must refer to a socket. Since Linux 2.6.33 it can be any file."
@@ -1152,12 +1174,12 @@ SCM_DEFINE (scm_sendfile, "sendfile", 3, 1, 0,
#endif
{
char buf[8192];
- size_t result, left;
+ size_t left;
if (!SCM_UNBNDP (offset))
{
if (SCM_PORTP (in))
- scm_seek (in, offset, scm_from_int (SEEK_SET));
+ scm_seek (in, scm_from_off_t (c_offset), scm_from_int (SEEK_SET));
else
{
if (lseek_or_lseek64 (in_fd, c_offset, SEEK_SET) < 0)
@@ -1165,7 +1187,7 @@ SCM_DEFINE (scm_sendfile, "sendfile", 3, 1, 0,
}
}
- for (result = 0, left = c_count; result < c_count; )
+ for (total = 0, left = c_count; total < c_count; )
{
size_t asked, obtained;
@@ -1180,13 +1202,12 @@ SCM_DEFINE (scm_sendfile, "sendfile", 3, 1, 0,
if (obtained < asked)
SCM_SYSERROR;
- result += obtained;
+ total += obtained;
}
- return scm_from_size_t (result);
}
- return scm_from_ssize_t (result);
+ return scm_from_size_t (total);
#undef VALIDATE_FD_OR_PORT
}