Changed to use pread() with files.

--HG--
branch : HEAD

diff --git a/src/lib/istream-file.c b/src/lib/istream-file.c
index e85687a5d8befcf200ffeb6b362f305cdadf39c5..a8f2f70961e8820a00ab22f879dbde76b8dc1b52 100644 (file)
--- a/src/lib/istream-file.c
+++ b/src/lib/istream-file.c
@@ -2,6 +2,8 @@
 
 /* @UNSAFE: whole file */
 
+#define _XOPEN_SOURCE 500 /* for pread() / Linux */
+
 #include "lib.h"
 #include "alarm-hup.h"
 #include "istream-internal.h"
@@ -113,18 +115,6 @@ static ssize_t _read(struct _istream *stream)
        if (stream->istream.closed)
                return -1;
 
-       if (fstream->skip_left > 0) {
-               i_assert(stream->skip == stream->pos);
-
-               if (fstream->file) {
-                       /* we're a file, so we can lseek() */
-                       i_stream_seek(&stream->istream,
-                                     stream->istream.v_offset);
-                       if (stream->istream.closed)
-                               return -1;
-               }
-       }
-
        stream->istream.stream_errno = 0;
 
        if (stream->pos == stream->buffer_size) {
@@ -169,7 +159,15 @@ static ssize_t _read(struct _istream *stream)
                        return -1;
                }
 
-               ret = read(stream->fd, stream->w_buffer + stream->pos, size);
+               if (fstream->file) {
+                       ret = pread(stream->fd,
+                                   stream->w_buffer + stream->pos, size,
+                                   stream->istream.start_offset +
+                                   stream->istream.v_offset);
+               } else {
+                       ret = read(stream->fd,
+                                  stream->w_buffer + stream->pos, size);
+               }
                if (ret == 0) {
                        /* EOF */
                        stream->istream.stream_errno = 0;
@@ -192,6 +190,7 @@ static ssize_t _read(struct _istream *stream)
                }
 
                if (ret > 0 && fstream->skip_left > 0) {
+                       i_assert(!fstream->file);
                        if (fstream->skip_left >= (size_t)ret) {
                                fstream->skip_left -= ret;
                                ret = 0;
@@ -212,40 +211,24 @@ static void _skip(struct _istream *stream, uoff_t count)
 {
        struct file_istream *fstream = (struct file_istream *) stream;
 
-       fstream->skip_left += count - (stream->pos - stream->skip);
-       stream->skip = stream->pos = 0;
+       if (!fstream->file)
+               fstream->skip_left += count - (stream->pos - stream->skip);
        stream->istream.v_offset += count;
+       stream->skip = stream->pos = 0;
 }
 
 static void _seek(struct _istream *stream, uoff_t v_offset)
 {
        struct file_istream *fstream = (struct file_istream *) stream;
-       uoff_t real_offset;
-       off_t ret;
-
-       real_offset = stream->istream.start_offset + v_offset;
-       if (real_offset > OFF_T_MAX) {
-               stream->istream.stream_errno = EOVERFLOW;
-               ret = -1;
-       } else {
-               ret = lseek(stream->fd, (off_t)real_offset, SEEK_SET);
-               if (ret < 0)
-                       stream->istream.stream_errno = errno;
-               else if (ret != (off_t)real_offset) {
-                       stream->istream.stream_errno = EINVAL;
-                       ret = -1;
-               } else {
-                       stream->skip = stream->pos = 0;
-                       fstream->skip_left = 0;
-               }
-       }
 
-       if (ret < 0)
-                i_stream_close(&stream->istream);
-       else {
-               stream->istream.stream_errno = 0;
-               stream->istream.v_offset = v_offset;
+       if (!fstream->file) {
+               stream->istream.stream_errno = ESPIPE;
+               return;
        }
+
+       stream->istream.stream_errno = 0;
+       stream->istream.v_offset = v_offset;
+       stream->skip = stream->pos = 0;
 }
 
 struct istream *i_stream_create_file(int fd, pool_t pool,