Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / ipxe / src / core / linebuf.c

diff --git a/qemu/roms/ipxe/src/core/linebuf.c b/qemu/roms/ipxe/src/core/linebuf.c
new file mode 100644 (file)
index 0000000..8fb2f86
--- /dev/null
+++ b/qemu/roms/ipxe/src/core/linebuf.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/**
+ * @file
+ *
+ * Line buffering
+ *
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <ipxe/linebuf.h>
+
+/**
+ * Retrieve buffered-up line
+ *
+ * @v linebuf          Line buffer
+ * @ret line           Buffered line, or NULL if no line ready to read
+ */
+char * buffered_line ( struct line_buffer *linebuf ) {
+       return ( linebuf->ready ? linebuf->data : NULL );
+}
+
+/**
+ * Discard line buffer contents
+ *
+ * @v linebuf          Line buffer
+ */
+void empty_line_buffer ( struct line_buffer *linebuf ) {
+       free ( linebuf->data );
+       linebuf->data = NULL;
+       linebuf->len = 0;
+       linebuf->ready = 0;
+}
+
+/**
+ * Buffer up received data by lines
+ *
+ * @v linebuf                  Line buffer
+ * @v data                     New data to add
+ * @v len                      Length of new data to add
+ * @ret len                    Consumed length, or negative error number
+ *
+ * After calling line_buffer(), use buffered_line() to determine
+ * whether or not a complete line is available.  Carriage returns and
+ * newlines will have been stripped, and the line will be
+ * NUL-terminated.  This buffered line is valid only until the next
+ * call to line_buffer() (or to empty_line_buffer()).
+ *
+ * Note that line buffers use dynamically allocated storage; you
+ * should call empty_line_buffer() before freeing a @c struct @c
+ * line_buffer.
+ */
+ssize_t line_buffer ( struct line_buffer *linebuf,
+                     const char *data, size_t len ) {
+       const char *eol;
+       size_t consume;
+       size_t new_len;
+       char *new_data;
+
+       /* Free any completed line from previous iteration */
+       if ( linebuf->ready )
+               empty_line_buffer ( linebuf );
+
+       /* Search for line terminator */
+       if ( ( eol = memchr ( data, '\n', len ) ) ) {
+               consume = ( eol - data + 1 );
+       } else {
+               consume = len;
+       }
+
+       /* Reallocate data buffer and copy in new data */
+       new_len = ( linebuf->len + consume );
+       new_data = realloc ( linebuf->data, ( new_len + 1 ) );
+       if ( ! new_data )
+               return -ENOMEM;
+       memcpy ( ( new_data + linebuf->len ), data, consume );
+       new_data[new_len] = '\0';
+       linebuf->data = new_data;
+       linebuf->len = new_len;
+
+       /* If we have reached end of line, trim the line and mark as ready */
+       if ( eol ) {
+               linebuf->data[--linebuf->len] = '\0'; /* trim NL */
+               if ( linebuf->data[linebuf->len - 1] == '\r' )
+                       linebuf->data[--linebuf->len] = '\0'; /* trim CR */
+               linebuf->ready = 1;
+       }
+
+       return consume;
+}