X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fdynamic-string.c;h=b648eef6549a28ab9c3c1b77e0f1beb1074ddcc3;hb=51f4701be1545a3faa288dfe3993221a6a2fd81c;hp=8c675d14a63ddacd6b7ce56878a4a4b2baa6eeb1;hpb=b5d29991cc4722aec39c346c3f82291581e92aa0;p=openvswitch

diff --git a/lib/dynamic-string.c b/lib/dynamic-string.c
index 8c675d14..b648eef6 100644
--- a/lib/dynamic-string.c
+++ b/lib/dynamic-string.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@
 #include "timeval.h"
 #include "util.h"
 
+/* Initializes 'ds' as an empty string buffer. */
 void
 ds_init(struct ds *ds)
 {
@@ -31,12 +32,16 @@ ds_init(struct ds *ds)
     ds->allocated = 0;
 }
 
+/* Sets 'ds''s length to 0, effectively clearing any existing content.  Does
+ * not free any memory. */
 void
 ds_clear(struct ds *ds)
 {
     ds->length = 0;
 }
 
+/* Reduces 'ds''s length to no more than 'new_length'.  (If its length is
+ * already 'new_length' or less, does nothing.)  */
 void
 ds_truncate(struct ds *ds, size_t new_length)
 {
@@ -46,6 +51,9 @@ ds_truncate(struct ds *ds, size_t new_length)
     }
 }
 
+/* Ensures that at least 'min_length + 1' bytes (including space for a null
+ * terminator) are allocated for ds->string, allocating or reallocating memory
+ * as necessary. */
 void
 ds_reserve(struct ds *ds, size_t min_length)
 {
@@ -56,6 +64,9 @@ ds_reserve(struct ds *ds, size_t min_length)
     }
 }
 
+/* Appends space for 'n' bytes to the end of 'ds->string', increasing
+ * 'ds->length' by the same amount, and returns the first appended byte.  The
+ * caller should fill in all 'n' bytes starting at the return value. */
 char *
 ds_put_uninit(struct ds *ds, size_t n)
 {
@@ -239,6 +250,54 @@ ds_get_preprocessed_line(struct ds *ds, FILE *file)
     return EOF;
 }
 
+/* Reads a line from 'file' into 'ds' and does some preprocessing on it:
+ *
+ *    - If the line begins with #, prints it on stdout and reads the next line.
+ *
+ *    - Otherwise, if the line contains an # somewhere else, strips it and
+ *      everything following it (as a comment).
+ *
+ *    - If (after comment removal) the line contains only white space, prints
+ *      a blank line on stdout and reads the next line.
+ *
+ *    - Otherwise, returns the line to the caller.
+ *
+ * This is useful in some of the OVS tests, where we want to check that parsing
+ * and then re-formatting some kind of data does not change it, but we also
+ * want to be able to put comments in the input.
+ *
+ * Returns 0 if successful, EOF if no non-blank line was found. */
+int
+ds_get_test_line(struct ds *ds, FILE *file)
+{
+    for (;;) {
+        char *s, *comment;
+        int retval;
+
+        retval = ds_get_line(ds, file);
+        if (retval) {
+            return retval;
+        }
+
+        s = ds_cstr(ds);
+        if (*s == '#') {
+            puts(s);
+            continue;
+        }
+
+        comment = strchr(s, '#');
+        if (comment) {
+            *comment = '\0';
+        }
+        if (s[strspn(s, " \t\n")] == '\0') {
+            putchar('\n');
+            continue;
+        }
+
+        return 0;
+    }
+}
+
 char *
 ds_cstr(struct ds *ds)
 {
@@ -252,7 +311,7 @@ ds_cstr(struct ds *ds)
 const char *
 ds_cstr_ro(const struct ds *ds)
 {
-    return ds_cstr((struct ds *) ds);
+    return ds_cstr(CONST_CAST(struct ds *, ds));
 }
 
 /* Returns a null-terminated string representing the current contents of 'ds',