fbuf: New data structure for buffered file I/O.

[pspp] / src / data / sys-file-reader.c

diff --git a/src/data/sys-file-reader.c b/src/data/sys-file-reader.c
index b2db755732311d6c6ba8dda47044225edffa80c2..c0a7d4fc997d618b0aa6f106d6017b496b3d419b 100644 (file)
--- a/src/data/sys-file-reader.c
+++ b/src/data/sys-file-reader.c
@@ -19,6 +19,7 @@
 #include "data/sys-file-private.h"
 
 #include <errno.h>
+#include <fcntl.h>
 #include <float.h>
 #include <inttypes.h>
 #include <stdlib.h>
@@ -44,6 +45,7 @@
 #include "libpspp/array.h"
 #include "libpspp/assertion.h"
 #include "libpspp/compiler.h"
+#include "libpspp/fbuf.h"
 #include "libpspp/i18n.h"
 #include "libpspp/ll.h"
 #include "libpspp/message.h"
@@ -191,7 +193,7 @@ struct sfm_reader
     /* File state. */
     struct file_handle *fh;     /* File handle. */
     struct fh_lock *lock;       /* Mutual exclusion for file handle. */
-    FILE *file;                 /* File stream. */
+    struct fbuf *fbuf;          /* File stream. */
     off_t pos;                  /* Position in file. */
     bool error;                 /* I/O or corruption error? */
     struct caseproto *proto;    /* Format of output cases. */
@@ -412,13 +414,14 @@ sfm_open (struct file_handle *fh)
   if (r->lock == NULL)
     goto error;
 
-  r->file = fn_open (fh, "rb");
-  if (r->file == NULL)
+  int fd = fn_open (fh, O_RDONLY | O_BINARY, 0);
+  if (fd < 0)
     {
       msg (ME, _("Error opening `%s' for reading as a system file: %s."),
            fh_get_file_name (r->fh), strerror (errno));
       goto error;
     }
+  r->fbuf = fbuf_open_fd (fd);
 
   if (!read_dictionary (r))
     goto error;
@@ -906,15 +909,16 @@ sfm_close (struct any_reader *r_)
   struct sfm_reader *r = sfm_reader_cast (r_);
   bool error;
 
-  if (r->file)
+  if (r->fbuf)
     {
-      if (fn_close (r->fh, r->file) == EOF)
+      int error = fbuf_close (r->fbuf);
+      if (error)
         {
           msg (ME, _("Error closing system file `%s': %s."),
-               fh_get_file_name (r->fh), strerror (errno));
+               fh_get_file_name (r->fh), strerror (error));
           r->error = true;
         }
-      r->file = NULL;
+      r->fbuf = NULL;
     }
 
   any_read_info_destroy (&r->info);
@@ -3245,11 +3249,13 @@ static inline int
 read_bytes_internal (struct sfm_reader *r, bool eof_is_ok,
                      void *buf, size_t byte_cnt)
 {
-  size_t bytes_read = fread (buf, 1, byte_cnt, r->file);
+  size_t bytes_read = fbuf_read (r->fbuf, buf, byte_cnt);
   r->pos += bytes_read;
   if (bytes_read == byte_cnt)
     return 1;
-  else if (ferror (r->file))
+
+  int status = fbuf_get_status (r->fbuf);
+  if (status > 0)
     {
       sys_error (r, r->pos, _("System error: %s."), strerror (errno));
       return -1;
@@ -3480,9 +3486,10 @@ read_zheader (struct sfm_reader *r)
 static void
 seek (struct sfm_reader *r, off_t offset)
 {
-  if (fseeko (r->file, offset, SEEK_SET))
+  int error = fbuf_seek (r->fbuf, offset);
+  if (error)
     sys_error (r, 0, _("%s: seek failed (%s)."),
-               fh_get_file_name (r->fh), strerror (errno));
+               fh_get_file_name (r->fh), strerror (error));
   r->pos = offset;
 }
 
@@ -3500,26 +3507,26 @@ read_ztrailer (struct sfm_reader *r,
   unsigned int block_size;
   unsigned int n_blocks;
   unsigned int i;
-  struct stat s;
 
-  if (fstat (fileno (r->file), &s))
+  int seekable = fbuf_is_seekable (r->fbuf);
+  if (seekable < 0)
     {
       sys_error (r, 0, _("%s: stat failed (%s)."),
-                 fh_get_file_name (r->fh), strerror (errno));
+                 fh_get_file_name (r->fh), strerror (-seekable));
       return false;
     }
-
-  if (!S_ISREG (s.st_mode))
+  else if (!seekable)
     {
       /* We can't seek to the trailer and then back to the data in this file,
          so skip doing extra checks. */
       return true;
     }
 
-  if (r->ztrailer_ofs + ztrailer_len != s.st_size)
+  off_t size = fbuf_get_size (r->fbuf);
+  if (size >= 0 && r->ztrailer_ofs + ztrailer_len != size)
     sys_warn (r, r->pos,
               _("End of ZLIB trailer (0x%llx) is not file size (0x%llx)."),
-              r->ztrailer_ofs + ztrailer_len, (long long int) s.st_size);
+              r->ztrailer_ofs + ztrailer_len, (long long int) size);
 
   seek (r, r->ztrailer_ofs);