* platform/example is now a "stub" platform - it should compile anywhere, but

[pdclib.old] / platform / posix / functions / _PDCLIB / flushbuffer.c

diff --git a/platform/posix/functions/_PDCLIB/flushbuffer.c b/platform/posix/functions/_PDCLIB/flushbuffer.c
new file mode 100644 (file)
index 0000000..e68c6c4
--- /dev/null
+++ b/platform/posix/functions/_PDCLIB/flushbuffer.c
@@ -0,0 +1,111 @@
+/* $Id$ */
+
+/* _PDCLIB_flushbuffer( struct _PDCLIB_file_t * )
+
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+/* This is an example implementation of _PDCLIB_flushbuffer() fit for
+   use with POSIX kernels.
+*/
+
+#include <stdio.h>
+#include <string.h>
+
+#ifndef REGTEST
+#include <_PDCLIB_glue.h>
+
+#include </usr/include/errno.h>
+
+typedef long ssize_t;
+extern ssize_t write( int fd, const void * buf, size_t count );
+
+/* The number of attempts to complete an output buffer flushing before giving
+ *    up.
+ *    */
+#define _PDCLIB_IO_RETRIES 1
+
+/* What the system should do after an I/O operation did not succeed, before   */
+/* trying again. (Empty by default.)                                          */
+#define _PDCLIB_IO_RETRY_OP( stream )
+
+int _PDCLIB_flushbuffer( struct _PDCLIB_file_t * stream )
+{
+    if ( ! ( stream->status & _PDCLIB_FBIN ) )
+    {
+        /* TODO: Text stream conversion here */
+    }
+    /* No need to handle buffers > INT_MAX, as PDCLib doesn't allow them */
+    _PDCLIB_size_t written = 0;
+    int rc;
+    /* Keep trying to write data until everything is written, an error
+       occurs, or the configured number of retries is exceeded.
+    */
+    for ( unsigned int retries = _PDCLIB_IO_RETRIES; retries > 0; --retries )
+    {
+        rc = (int)write( stream->handle, stream->buffer + written, stream->bufidx - written );
+        if ( rc < 0 )
+        {
+            /* Write error */
+            switch ( errno )
+            {
+                /* See <_PDCLIB_config.h>. There should be differenciated errno
+                   handling here, possibly even a 1:1 mapping; but that is up
+                   to the individual platform.
+                */
+                case EBADF:
+                case EFAULT:
+                case EFBIG:
+                case EINTR:
+                case EINVAL:
+                case EIO:
+                case ENOSPC:
+                case EPIPE:
+                    _PDCLIB_errno = _PDCLIB_ERROR;
+                    break;
+                default:
+                    /* This should be something like EUNKNOWN. */
+                    _PDCLIB_errno = _PDCLIB_ERROR;
+                    break;
+            }
+            stream->status |= _PDCLIB_ERRORFLAG;
+            /* Move unwritten remains to begin of buffer. */
+            stream->bufidx -= written;
+            memmove( stream->buffer, stream->buffer + written, stream->bufidx );
+            return EOF;
+        }
+        written += (_PDCLIB_size_t)rc;
+        stream->pos.offset += rc;
+        if ( written == stream->bufidx )
+        {
+            /* Buffer written completely. */
+            stream->bufidx = 0;
+            return 0;
+        }
+    }
+    /* Number of retries exceeded. You probably want a different errno value
+       here.
+    */
+    _PDCLIB_errno = _PDCLIB_ERROR;
+    stream->status |= _PDCLIB_ERRORFLAG;
+    /* Move unwritten remains to begin of buffer. */
+    stream->bufidx -= written;
+    memmove( stream->buffer, stream->buffer + written, stream->bufidx );
+    return EOF;
+}
+
+#endif
+
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    /* Testing covered by ftell.c */
+    return TEST_RESULTS;
+}
+
+#endif
+