benchtests: Improve readability of JSON output

Add a small library to print JSON values and use it to improve the
readability of the benchmark output and the readability of the
benchmark code.

ChangeLog:

2014-04-11  Will Newton  <will.newton@linaro.org>

	* benchtests/Makefile (extra-objs): Add json-lib.o.
	(bench-func): Tidy up JSON output.
	* benchtests/bench-skeleton.c: Include json-lib.h.
	(main): Use JSON library functions to do output of
	benchmark results.
	* benchtests/bench-timing-type.c (main): Output the
	timing type simply, leaving formatting to the user.
	* benchtests/json-lib.c: New file.
	* benchtests/json-lib.h: Likewise.

1 files changed, 178 insertions, 0 deletions

diff --git a/benchtests/json-lib.c b/benchtests/json-lib.c
new file mode 100644
index 0000000000..6a5d18f063
--- /dev/null
+++ b/benchtests/json-lib.c
@@ -0,0 +1,178 @@
+/* Simple library for printing JSON data.
+   Copyright (C) 2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C 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 2.1 of the License, or (at your option) any later version.
+
+   The GNU C 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 the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <string.h>
+
+#include "json-lib.h"
+
+void
+json_init (json_ctx_t *ctx, unsigned int indent_level, FILE *fp)
+{
+  ctx->indent_level = indent_level;
+  ctx->fp = fp;
+  ctx->first_element = true;
+}
+
+static void
+do_indent (json_ctx_t *ctx)
+{
+  char indent_buf[ctx->indent_level + 1];
+
+  memset (indent_buf, ' ', ctx->indent_level + 1);
+  indent_buf[ctx->indent_level] = '\0';
+
+  fputs (indent_buf, ctx->fp);
+}
+
+void
+json_document_begin (json_ctx_t *ctx)
+{
+  do_indent (ctx);
+
+  fputs ("{\n", ctx->fp);
+
+  ctx->indent_level++;
+  ctx->first_element = true;
+}
+
+void
+json_document_end (json_ctx_t *ctx)
+{
+  ctx->indent_level--;
+
+  do_indent (ctx);
+
+  fputs ("\n}", ctx->fp);
+}
+
+void
+json_attr_object_begin (json_ctx_t *ctx, const char *name)
+{
+  if (!ctx->first_element)
+    fprintf (ctx->fp, ",\n");
+
+  do_indent (ctx);
+
+  fprintf (ctx->fp, "\"%s\": {\n", name);
+
+  ctx->indent_level++;
+  ctx->first_element = true;
+}
+
+void
+json_attr_object_end (json_ctx_t *ctx)
+{
+  ctx->indent_level--;
+  ctx->first_element = false;
+
+  fputs ("\n", ctx->fp);
+
+  do_indent (ctx);
+
+  fputs ("}", ctx->fp);
+}
+
+void
+json_attr_string (json_ctx_t *ctx, const char *name, const char *s)
+{
+  if (!ctx->first_element)
+    fprintf (ctx->fp, ",\n");
+  else
+    ctx->first_element = false;
+
+  do_indent (ctx);
+
+  fprintf (ctx->fp, "\"%s\": \"%s\"", name, s);
+}
+
+void
+json_attr_double (json_ctx_t *ctx, const char *name, double d)
+{
+  if (!ctx->first_element)
+    fprintf (ctx->fp, ",\n");
+  else
+    ctx->first_element = false;
+
+  do_indent (ctx);
+
+  fprintf (ctx->fp, "\"%s\": %g", name, d);
+}
+
+void
+json_array_begin (json_ctx_t *ctx, const char *name)
+{
+  if (!ctx->first_element)
+    fprintf (ctx->fp, ",\n");
+
+  do_indent (ctx);
+
+  fprintf (ctx->fp, "\"%s\": [", name);
+
+  ctx->indent_level++;
+  ctx->first_element = true;
+}
+
+void
+json_array_end (json_ctx_t *ctx)
+{
+  ctx->indent_level--;
+  ctx->first_element = false;
+
+  fputs ("]", ctx->fp);
+}
+
+void
+json_element_double (json_ctx_t *ctx, double d)
+{
+  if (!ctx->first_element)
+    fprintf (ctx->fp, ", %g", d);
+  else
+    {
+      fprintf (ctx->fp, "%g", d);
+      ctx->first_element = false;
+    }
+}
+
+void
+json_element_object_begin (json_ctx_t *ctx)
+{
+  if (!ctx->first_element)
+    fprintf (ctx->fp, ",");
+
+  fputs ("\n", ctx->fp);
+
+  do_indent (ctx);
+
+  fputs ("{\n", ctx->fp);
+
+  ctx->indent_level++;
+  ctx->first_element = true;
+}
+
+void
+json_element_object_end (json_ctx_t *ctx)
+{
+  ctx->indent_level--;
+  ctx->first_element = false;
+
+  fputs ("\n", ctx->fp);
+
+  do_indent (ctx);
+
+  fputs ("}", ctx->fp);
+}