[v2] benchtests: Improve readability of JSON output
Commit Message
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:
2014-04-08 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.
---
benchtests/Makefile | 13 +--
benchtests/bench-skeleton.c | 39 +++++----
benchtests/bench-timing-type.c | 2 +-
benchtests/json-lib.c | 178 +++++++++++++++++++++++++++++++++++++++++
benchtests/json-lib.h | 47 +++++++++++
5 files changed, 256 insertions(+), 23 deletions(-)
create mode 100644 benchtests/json-lib.c
create mode 100644 benchtests/json-lib.h
Changes in v2:
- Fixes from Siddesh's review
- Added support for outputting complete documents
- Added support for arrays of objects
Comments
On Fri, Apr 11, 2014 at 11:00:03AM +0100, Will Newton wrote:
> 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:
>
> 2014-04-08 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.
Looks good to me.
Thanks,
Siddhesh
> ---
> benchtests/Makefile | 13 +--
> benchtests/bench-skeleton.c | 39 +++++----
> benchtests/bench-timing-type.c | 2 +-
> benchtests/json-lib.c | 178 +++++++++++++++++++++++++++++++++++++++++
> benchtests/json-lib.h | 47 +++++++++++
> 5 files changed, 256 insertions(+), 23 deletions(-)
> create mode 100644 benchtests/json-lib.c
> create mode 100644 benchtests/json-lib.h
>
> Changes in v2:
> - Fixes from Siddesh's review
> - Added support for outputting complete documents
> - Added support for arrays of objects
>
> diff --git a/benchtests/Makefile b/benchtests/Makefile
> index ca635cf..a788082 100644
> --- a/benchtests/Makefile
> +++ b/benchtests/Makefile
> @@ -100,6 +100,8 @@ cpp-srcs-left := $(binaries-benchset:=.c) $(binaries-bench:=.c)
> lib := nonlib
> include $(patsubst %,$(..)cppflags-iterator.mk,$(cpp-srcs-left))
>
> +extra-objs += json-lib.o
> +
> bench-deps := bench-skeleton.c bench-timing.h Makefile
>
> run-bench = $(test-wrapper-env) \
> @@ -126,9 +128,9 @@ bench-set: $(binaries-benchset)
> # so one could even execute them individually and process it using any JSON
> # capable language or tool.
> bench-func: $(binaries-bench)
> - { echo "{"; \
> - $(timing-type); \
> - echo " ,\"functions\": {"; \
> + { timing_type=$$($(timing-type)); \
> + echo "{\"timing_type\": \"$${timing_type}\","; \
> + echo " \"functions\": {"; \
> for run in $^; do \
> if ! [ "x$${run}" = "x$<" ]; then \
> echo ","; \
> @@ -136,14 +138,15 @@ bench-func: $(binaries-bench)
> echo "Running $${run}" >&2; \
> $(run-bench) $(DETAILED_OPT); \
> done; \
> - echo " }"; \
> + echo; \
> + echo " }"; \
> echo "}"; } > $(objpfx)bench.out-tmp; \
> if [ -f $(objpfx)bench.out ]; then \
> mv -f $(objpfx)bench.out $(objpfx)bench.out.old; \
> fi; \
> mv -f $(objpfx)bench.out-tmp $(objpfx)bench.out
>
> -$(timing-type) $(binaries-bench) $(binaries-benchset): %: %.o \
> +$(timing-type) $(binaries-bench) $(binaries-benchset): %: %.o $(objpfx)json-lib.o \
> $(sort $(filter $(common-objpfx)lib%,$(link-libc))) \
> $(addprefix $(csu-objpfx),start.o) $(+preinit) $(+postinit)
> $(+link)
> diff --git a/benchtests/bench-skeleton.c b/benchtests/bench-skeleton.c
> index 0c7d744..29d6bda 100644
> --- a/benchtests/bench-skeleton.c
> +++ b/benchtests/bench-skeleton.c
> @@ -23,6 +23,7 @@
> #include <time.h>
> #include <inttypes.h>
> #include "bench-timing.h"
> +#include "json-lib.h"
>
> volatile unsigned int dontoptimize = 0;
>
> @@ -50,6 +51,7 @@ main (int argc, char **argv)
> struct timespec runtime;
> timing_t start, end;
> bool detailed = false;
> + json_ctx_t json_ctx;
>
> if (argc == 2 && !strcmp (argv[1], "-d"))
> detailed = true;
> @@ -64,13 +66,13 @@ main (int argc, char **argv)
>
> iters = 1000 * res;
>
> + json_init (&json_ctx, 2, stdout);
> +
> /* Begin function. */
> - printf ("\"%s\": {\n", FUNCNAME);
> + json_attr_object_begin (&json_ctx, FUNCNAME);
>
> for (int v = 0; v < NUM_VARIANTS; v++)
> {
> - if (v)
> - putc (',', stdout);
> /* Run for approximately DURATION seconds. */
> clock_gettime (CLOCK_MONOTONIC_RAW, &runtime);
> runtime.tv_sec += DURATION;
> @@ -119,28 +121,31 @@ main (int argc, char **argv)
> d_total_s = total;
> d_iters = iters;
>
> - printf ("\"%s\": {\n", VARIANT (v));
> - printf ("\"duration\": %g, \"iterations\": %g, "
> - "\"max\": %g, \"min\": %g, \"mean\": %g\n",
> - d_total_s, d_total_i, max / d_iters, min / d_iters,
> - d_total_s / d_total_i);
> + /* Begin variant. */
> + json_attr_object_begin (&json_ctx, VARIANT (v));
> +
> + json_attr_double (&json_ctx, "duration", d_total_s);
> + json_attr_double (&json_ctx, "iterations", d_total_i);
> + json_attr_double (&json_ctx, "max", max / d_iters);
> + json_attr_double (&json_ctx, "min", min / d_iters);
> + json_attr_double (&json_ctx, "mean", d_total_s / d_total_i);
>
> if (detailed)
> {
> - printf (",\n\"timings\": [");
> + json_array_begin (&json_ctx, "timings");
> +
> for (int i = 0; i < NUM_SAMPLES (v); i++)
> - {
> - if (i > 0)
> - putc (',', stdout);
> - printf ("%g", RESULT (v, i));
> - }
> - puts ("]");
> + json_element_double (&json_ctx, RESULT (v, i));
> +
> + json_array_end (&json_ctx);
> }
> - puts ("}");
> +
> + /* End variant. */
> + json_attr_object_end (&json_ctx);
> }
>
> /* End function. */
> - puts ("}");
> + json_attr_object_end (&json_ctx);
>
> return 0;
> }
> diff --git a/benchtests/bench-timing-type.c b/benchtests/bench-timing-type.c
> index 903a61f..64219ff 100644
> --- a/benchtests/bench-timing-type.c
> +++ b/benchtests/bench-timing-type.c
> @@ -22,6 +22,6 @@
> int
> main (int argc, char **argv)
> {
> - printf ("\"timing-type\": \"%s\"\n", TIMING_TYPE);
> + puts (TIMING_TYPE);
> return 0;
> }
> diff --git a/benchtests/json-lib.c b/benchtests/json-lib.c
> new file mode 100644
> index 0000000..6a5d18f
> --- /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);
> +}
> diff --git a/benchtests/json-lib.h b/benchtests/json-lib.h
> new file mode 100644
> index 0000000..ed703c6
> --- /dev/null
> +++ b/benchtests/json-lib.h
> @@ -0,0 +1,47 @@
> +/* 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/>. */
> +
> +#ifndef __JSON_LIB_H__
> +#define __JSON_LIB_H__
> +
> +#include <stdbool.h>
> +#include <stdio.h>
> +
> +struct json_ctx
> +{
> + FILE *fp;
> + unsigned int indent_level;
> + bool first_element;
> +};
> +
> +typedef struct json_ctx json_ctx_t;
> +
> +void json_init (json_ctx_t *ctx, unsigned int indent_level, FILE *fp);
> +void json_document_begin (json_ctx_t *ctx);
> +void json_document_end (json_ctx_t *ctx);
> +void json_attr_object_begin (json_ctx_t *ctx, const char *name);
> +void json_attr_object_end (json_ctx_t *ctx);
> +void json_attr_string (json_ctx_t *ctx, const char *name, const char *s);
> +void json_attr_double (json_ctx_t *ctx, const char *name, double d);
> +void json_array_begin (json_ctx_t *ctx, const char *name);
> +void json_array_end (json_ctx_t *ctx);
> +void json_element_double (json_ctx_t *ctx, double d);
> +void json_element_object_begin (json_ctx_t *ctx);
> +void json_element_object_end (json_ctx_t *ctx);
> +
> +#endif
> --
> 1.8.1.4
>
@@ -100,6 +100,8 @@ cpp-srcs-left := $(binaries-benchset:=.c) $(binaries-bench:=.c)
lib := nonlib
include $(patsubst %,$(..)cppflags-iterator.mk,$(cpp-srcs-left))
+extra-objs += json-lib.o
+
bench-deps := bench-skeleton.c bench-timing.h Makefile
run-bench = $(test-wrapper-env) \
@@ -126,9 +128,9 @@ bench-set: $(binaries-benchset)
# so one could even execute them individually and process it using any JSON
# capable language or tool.
bench-func: $(binaries-bench)
- { echo "{"; \
- $(timing-type); \
- echo " ,\"functions\": {"; \
+ { timing_type=$$($(timing-type)); \
+ echo "{\"timing_type\": \"$${timing_type}\","; \
+ echo " \"functions\": {"; \
for run in $^; do \
if ! [ "x$${run}" = "x$<" ]; then \
echo ","; \
@@ -136,14 +138,15 @@ bench-func: $(binaries-bench)
echo "Running $${run}" >&2; \
$(run-bench) $(DETAILED_OPT); \
done; \
- echo " }"; \
+ echo; \
+ echo " }"; \
echo "}"; } > $(objpfx)bench.out-tmp; \
if [ -f $(objpfx)bench.out ]; then \
mv -f $(objpfx)bench.out $(objpfx)bench.out.old; \
fi; \
mv -f $(objpfx)bench.out-tmp $(objpfx)bench.out
-$(timing-type) $(binaries-bench) $(binaries-benchset): %: %.o \
+$(timing-type) $(binaries-bench) $(binaries-benchset): %: %.o $(objpfx)json-lib.o \
$(sort $(filter $(common-objpfx)lib%,$(link-libc))) \
$(addprefix $(csu-objpfx),start.o) $(+preinit) $(+postinit)
$(+link)
@@ -23,6 +23,7 @@
#include <time.h>
#include <inttypes.h>
#include "bench-timing.h"
+#include "json-lib.h"
volatile unsigned int dontoptimize = 0;
@@ -50,6 +51,7 @@ main (int argc, char **argv)
struct timespec runtime;
timing_t start, end;
bool detailed = false;
+ json_ctx_t json_ctx;
if (argc == 2 && !strcmp (argv[1], "-d"))
detailed = true;
@@ -64,13 +66,13 @@ main (int argc, char **argv)
iters = 1000 * res;
+ json_init (&json_ctx, 2, stdout);
+
/* Begin function. */
- printf ("\"%s\": {\n", FUNCNAME);
+ json_attr_object_begin (&json_ctx, FUNCNAME);
for (int v = 0; v < NUM_VARIANTS; v++)
{
- if (v)
- putc (',', stdout);
/* Run for approximately DURATION seconds. */
clock_gettime (CLOCK_MONOTONIC_RAW, &runtime);
runtime.tv_sec += DURATION;
@@ -119,28 +121,31 @@ main (int argc, char **argv)
d_total_s = total;
d_iters = iters;
- printf ("\"%s\": {\n", VARIANT (v));
- printf ("\"duration\": %g, \"iterations\": %g, "
- "\"max\": %g, \"min\": %g, \"mean\": %g\n",
- d_total_s, d_total_i, max / d_iters, min / d_iters,
- d_total_s / d_total_i);
+ /* Begin variant. */
+ json_attr_object_begin (&json_ctx, VARIANT (v));
+
+ json_attr_double (&json_ctx, "duration", d_total_s);
+ json_attr_double (&json_ctx, "iterations", d_total_i);
+ json_attr_double (&json_ctx, "max", max / d_iters);
+ json_attr_double (&json_ctx, "min", min / d_iters);
+ json_attr_double (&json_ctx, "mean", d_total_s / d_total_i);
if (detailed)
{
- printf (",\n\"timings\": [");
+ json_array_begin (&json_ctx, "timings");
+
for (int i = 0; i < NUM_SAMPLES (v); i++)
- {
- if (i > 0)
- putc (',', stdout);
- printf ("%g", RESULT (v, i));
- }
- puts ("]");
+ json_element_double (&json_ctx, RESULT (v, i));
+
+ json_array_end (&json_ctx);
}
- puts ("}");
+
+ /* End variant. */
+ json_attr_object_end (&json_ctx);
}
/* End function. */
- puts ("}");
+ json_attr_object_end (&json_ctx);
return 0;
}
@@ -22,6 +22,6 @@
int
main (int argc, char **argv)
{
- printf ("\"timing-type\": \"%s\"\n", TIMING_TYPE);
+ puts (TIMING_TYPE);
return 0;
}
new file mode 100644
@@ -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);
+}
new file mode 100644
@@ -0,0 +1,47 @@
+/* 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/>. */
+
+#ifndef __JSON_LIB_H__
+#define __JSON_LIB_H__
+
+#include <stdbool.h>
+#include <stdio.h>
+
+struct json_ctx
+{
+ FILE *fp;
+ unsigned int indent_level;
+ bool first_element;
+};
+
+typedef struct json_ctx json_ctx_t;
+
+void json_init (json_ctx_t *ctx, unsigned int indent_level, FILE *fp);
+void json_document_begin (json_ctx_t *ctx);
+void json_document_end (json_ctx_t *ctx);
+void json_attr_object_begin (json_ctx_t *ctx, const char *name);
+void json_attr_object_end (json_ctx_t *ctx);
+void json_attr_string (json_ctx_t *ctx, const char *name, const char *s);
+void json_attr_double (json_ctx_t *ctx, const char *name, double d);
+void json_array_begin (json_ctx_t *ctx, const char *name);
+void json_array_end (json_ctx_t *ctx);
+void json_element_double (json_ctx_t *ctx, double d);
+void json_element_object_begin (json_ctx_t *ctx);
+void json_element_object_end (json_ctx_t *ctx);
+
+#endif