[ovs-dev] [ovs-ofctl 05/10] ofp-parse: Factor out parse_ofp_add_flow_file() into new function.

[Ben Pfaff]

The new function ds_get_preprocessed_line() will be useful elsewhere in
an upcoming commit.
---
 lib/dynamic-string.c |   28 +++++++++++++++++++++++++++-
 lib/dynamic-string.h |    3 ++-
 lib/ofp-parse.c      |   26 ++++++--------------------
 3 files changed, 35 insertions(+), 22 deletions(-)

diff --git a/lib/dynamic-string.c b/lib/dynamic-string.c
index 3af7fc9..dbb33a3 100644
--- a/lib/dynamic-string.c
+++ b/lib/dynamic-string.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -207,6 +207,32 @@ ds_get_line(struct ds *ds, FILE *file)
     }
 }
 
+/* Reads a line from 'file' into 'ds', clearing anything initially in 'ds'.
+ * Deletes comments introduced by "#" and skips lines that contains only white
+ * space (after deleting comments).
+ *
+ * Returns 0 if successful, EOF if no non-blank line was found. */
+int
+ds_get_preprocessed_line(struct ds *ds, FILE *file)
+{
+    while (!ds_get_line(ds, file)) {
+        char *line = ds_cstr(ds);
+        char *comment;
+
+        /* Delete comments. */
+        comment = strchr(line, '#');
+        if (comment) {
+            *comment = '\0';
+        }
+
+        /* Return successfully unless the line is all spaces. */
+        if (line[strspn(line, " \t\n")] != '\0') {
+            return 0;
+        }
+    }
+    return EOF;
+}
+
 char *
 ds_cstr(struct ds *ds)
 {
diff --git a/lib/dynamic-string.h b/lib/dynamic-string.h
index db033c9..2961a01 100644
--- a/lib/dynamic-string.h
+++ b/lib/dynamic-string.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -54,6 +54,7 @@ void ds_put_strftime(struct ds *, const char *, const struct tm *)
 void ds_put_hex_dump(struct ds *ds, const void *buf_, size_t size,
                      uintptr_t ofs, bool ascii);
 int ds_get_line(struct ds *, FILE *);
+int ds_get_preprocessed_line(struct ds *, FILE *);
 
 char *ds_cstr(struct ds *);
 const char *ds_cstr_ro(const struct ds *);
diff --git a/lib/ofp-parse.c b/lib/ofp-parse.c
index 73c3ebc..f1a4cb4 100644
--- a/lib/ofp-parse.c
+++ b/lib/ofp-parse.c
@@ -874,27 +874,13 @@ bool
 parse_ofp_add_flow_file(struct list *packets, enum nx_flow_format *cur,
                         FILE *stream)
 {
-    struct ds s = DS_EMPTY_INITIALIZER;
-    bool ok = false;
+    struct ds s;
+    bool ok;
 
-    while (!ds_get_line(&s, stream)) {
-        char *line = ds_cstr(&s);
-        char *comment;
-
-        /* Delete comments. */
-        comment = strchr(line, '#');
-        if (comment) {
-            *comment = '\0';
-        }
-
-        /* Drop empty lines. */
-        if (line[strspn(line, " \t\n")] == '\0') {
-            continue;
-        }
-
-        parse_ofp_flow_mod_str(packets, cur, line, OFPFC_ADD);
-        ok = true;
-        break;
+    ds_init(&s);
+    ok = ds_get_preprocessed_line(&s, stream) == 0;
+    if (ok) {
+        parse_ofp_flow_mod_str(packets, cur, ds_cstr(&s), OFPFC_ADD);
     }
     ds_destroy(&s);
 
-- 
1.7.1