Merged branch stdio_rewrite back into trunk.

[pdclib] / functions / stdio / fwrite.c

diff --git a/functions/stdio/fwrite.c b/functions/stdio/fwrite.c
index 8765d0be7e23c70507c1779e359674fc948624b3..d3e58592f1c7eab5c1d0ac0bc0ec5f36b08d7a72 100644 (file)
--- a/functions/stdio/fwrite.c
+++ b/functions/stdio/fwrite.c
@@ -11,9 +11,73 @@
 
 #ifndef REGTEST
 
+#include <stdbool.h>
+#include <string.h>
+
 size_t fwrite( const void * _PDCLIB_restrict ptr, size_t size, size_t nmemb, struct _PDCLIB_file_t * _PDCLIB_restrict stream )
 {
-    return _PDCLIB_write( stream->handle, ptr, size * nmemb );
+    if ( _PDCLIB_prepwrite( stream ) == EOF )
+    {
+        return 0;
+    }
+    _PDCLIB_size_t offset = 0;
+    bool lineend = false;
+    size_t nmemb_i;
+    for ( nmemb_i = 0; nmemb_i < nmemb; ++nmemb_i )
+    {
+        for ( size_t size_i = 0; size_i < size; ++size_i )
+        {
+            /* TODO: Should line-buffered streams be flushed on '\n' or system EOL? */
+            if ( ( stream->buffer[ stream->bufidx++ ] == ((char*)ptr)[ nmemb_i * size + size_i ] ) == '\n' )
+            {
+                /* Remember last newline, in case we have to do a partial line-buffered flush */
+                offset = stream->bufidx;
+                lineend = true;
+            }
+            if ( stream->bufidx == stream->bufsize )
+            {
+                if ( _PDCLIB_flushbuffer( stream ) == EOF )
+                {
+                    /* Returning number of objects completely buffered */
+                    return nmemb_i;
+                }
+                lineend = false;
+            }
+        }
+    }
+    /* Fully-buffered streams are OK. Non-buffered streams must be flushed,
+       line-buffered streams only if there's a newline in the buffer.
+    */
+    switch ( stream->status & ( _IONBF | _IOLBF ) )
+    {
+        case _IONBF:
+            if ( _PDCLIB_flushbuffer( stream ) == EOF )
+            {
+                /* We are in a pinch here. We have an error, which requires a
+                   return value < nmemb. On the other hand, all objects have
+                   been written to buffer, which means all the caller had to
+                   do was removing the error cause, and re-flush the stream...
+                   Catch 22. We'll return a value one short, to indicate the
+                   error, and can't really do anything about the inconsistency.
+                */
+                return nmemb_i - 1;
+            }
+            break;
+        case _IOLBF:
+            {
+            size_t bufidx = stream->bufidx;
+            stream->bufidx = offset;
+            if ( _PDCLIB_flushbuffer( stream ) == EOF )
+            {
+                /* See comment above. */
+                stream->bufidx = bufidx;
+                return nmemb_i - 1;
+            }
+            stream->bufidx = bufidx - offset;
+            memmove( stream->buffer, stream->buffer + offset, stream->bufidx );
+            }
+    }
+    return nmemb_i;
 }
 
 #endif
@@ -24,6 +88,7 @@ size_t fwrite( const void * _PDCLIB_restrict ptr, size_t size, size_t nmemb, str
 int main( void )
 {
     FILE * fh;
+    remove( "testfile" );
     TESTCASE( ( fh = fopen( "testfile", "w" ) ) != NULL );
     TESTCASE( fwrite( "SUCCESS testing fwrite()\n", 1, 25, fh ) == 25 );
     TESTCASE( fclose( fh ) == 0 );
@@ -33,3 +98,4 @@ int main( void )
 }
 
 #endif
+