[Libguestfs] [PATCH 35/46] lib: Add stringsbuf mini-library for constructing lists of strings.

[Richard W.M. Jones]

From: "Richard W.M. Jones" <rjones at redhat.com>

This is modelled on similar code in the daemon that we have used
successfully for a long time.

(cherry picked from commit 35278e4c186badb9e243628771da4cbd068ffaa0)
(cherry picked from commit 7fd3b1cc8a485544eca61cc3c8b0f9f2a3c18bb2)
---
 po/POTFILES            |  1 +
 src/Makefile.am        |  1 +
 src/guestfs-internal.h | 24 ++++++++++++++
 src/stringsbuf.c       | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 114 insertions(+)
 create mode 100644 src/stringsbuf.c

diff --git a/po/POTFILES b/po/POTFILES
index a98535e..7b28d38 100644
--- a/po/POTFILES
+++ b/po/POTFILES
@@ -270,6 +270,7 @@ src/match.c
 src/osinfo.c
 src/private-data.c
 src/proto.c
+src/stringsbuf.c
 src/tmpdirs.c
 src/utils.c
 test-tool/test-tool.c
diff --git a/src/Makefile.am b/src/Makefile.am
index 3473b01..359f79c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -113,6 +113,7 @@ libguestfs_la_SOURCES = \
 	osinfo.c \
 	private-data.c \
 	proto.c \
+	stringsbuf.c \
 	tmpdirs.c \
 	libguestfs.syms
 
diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
index c6b64fd..0675123 100644
--- a/src/guestfs-internal.h
+++ b/src/guestfs-internal.h
@@ -483,6 +483,30 @@ extern int guestfs___match6 (guestfs_h *g, const char *str, const pcre *re, char
 #define match3 guestfs___match3
 #define match6 guestfs___match6
 
+/* stringsbuf.c */
+struct stringsbuf {
+  char **argv;
+  size_t size;
+  size_t alloc;
+};
+#define DECLARE_STRINGSBUF(v) \
+  struct stringsbuf (v) = { .argv = NULL, .size = 0, .alloc = 0 }
+
+extern void guestfs___add_string_nodup (guestfs_h *g, struct stringsbuf *sb, char *str);
+extern void guestfs___add_string (guestfs_h *g, struct stringsbuf *sb, const char *str);
+extern void guestfs___add_sprintf (guestfs_h *g, struct stringsbuf *sb, const char *fs, ...)
+  __attribute__((format (printf,3,4)));
+extern void guestfs___end_stringsbuf (guestfs_h *g, struct stringsbuf *sb);
+
+extern void guestfs___free_stringsbuf (struct stringsbuf *sb);
+
+#ifdef HAVE_ATTRIBUTE_CLEANUP
+#define CLEANUP_FREE_STRINGSBUF __attribute__((cleanup(guestfs___cleanup_free_stringsbuf)))
+#else
+#define CLEANUP_FREE_STRINGSBUF
+#endif
+extern void guestfs___cleanup_free_stringsbuf (struct stringsbuf *sb);
+
 /* proto.c */
 extern int guestfs___send (guestfs_h *g, int proc_nr, uint64_t progress_hint, uint64_t optargs_bitmask, xdrproc_t xdrp, char *args);
 extern int guestfs___recv (guestfs_h *g, const char *fn, struct guestfs_message_header *hdr, struct guestfs_message_error *err, xdrproc_t xdrp, char *ret);
diff --git a/src/stringsbuf.c b/src/stringsbuf.c
new file mode 100644
index 0000000..df1dfd6
--- /dev/null
+++ b/src/stringsbuf.c
@@ -0,0 +1,88 @@
+/* libguestfs
+ * Copyright (C) 2013 Red Hat Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/* Note: Don't confuse this with stringsbuf in the daemon. */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+
+#include "guestfs.h"
+#include "guestfs-internal.h"
+
+void
+guestfs___add_string_nodup (guestfs_h *g, struct stringsbuf *sb, char *str)
+{
+  if (sb->size >= sb->alloc) {
+    sb->alloc += 64;
+    sb->argv = safe_realloc (g, sb->argv, sb->alloc * sizeof (char *));
+  }
+
+  sb->argv[sb->size] = str;
+  sb->size++;
+}
+
+void
+guestfs___add_string (guestfs_h *g, struct stringsbuf *sb, const char *str)
+{
+  guestfs___add_string_nodup (g, sb, safe_strdup (g, str));
+}
+
+void
+guestfs___add_sprintf (guestfs_h *g, struct stringsbuf *sb,
+                       const char *fs, ...)
+{
+  va_list args;
+  char *str;
+  int r;
+
+  va_start (args, fs);
+  r = vasprintf (&str, fs, args);
+  va_end (args);
+  if (r == -1)
+    g->abort_cb ();
+
+  guestfs___add_string_nodup (g, sb, str);
+}
+
+void
+guestfs___end_stringsbuf (guestfs_h *g, struct stringsbuf *sb)
+{
+  guestfs___add_string_nodup (g, sb, NULL);
+}
+
+void
+guestfs___free_stringsbuf (struct stringsbuf *sb)
+{
+  size_t i;
+
+  if (sb->argv) {
+    for (i = 0; i < sb->size; ++i)
+      free (sb->argv[i]);
+  }
+  free (sb->argv);
+}
+
+void
+guestfs___cleanup_free_stringsbuf (struct stringsbuf *sb)
+{
+  guestfs___free_stringsbuf (sb);
+}
-- 
1.8.3.1