Re: [PATCH v8 1/2] json_writer: new routines to create data in JSON format

["René Scharfe" <l.s.r@web.de>]

Am 07.06.2018 um 16:12 schrieb git@jeffhostetler.com:
> From: Jeff Hostetler <jeffhost@microsoft.com>
> 
> Add a series of jw_ routines and "struct json_writer" structure to compose
> JSON data.  The resulting string data can then be output by commands wanting
> to support a JSON output format.
> 
> The json-writer routines can be used to generate structured data in a
> JSON-like format.  We say "JSON-like" because we do not enforce the Unicode
> (usually UTF-8) requirement on string fields.  Internally, Git does not
> necessarily have Unicode/UTF-8 data for most fields, so it is currently
> unclear the best way to enforce that requirement.  For example, on Linx
> pathnames can contain arbitrary 8-bit character data, so a command like
> "status" would not know how to encode the reported pathnames.  We may want
> to revisit this (or double encode such strings) in the future.
> 
> The initial use for the json-writer routines is for generating telemetry
> data for executed Git commands.  Later, we may want to use them in other
> commands, such as status.
> 
> Helped-by: René Scharfe <l.s.r@web.de>
> Helped-by: Wink Saville <wink@saville.com>
> Helped-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
> Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
> ---
>   Makefile                    |   2 +
>   json-writer.c               | 419 ++++++++++++++++++++++++++++++++
>   json-writer.h               | 113 +++++++++
>   t/helper/test-json-writer.c | 572 ++++++++++++++++++++++++++++++++++++++++++++
>   t/t0019-json-writer.sh      | 236 ++++++++++++++++++
>   5 files changed, 1342 insertions(+)
>   create mode 100644 json-writer.c
>   create mode 100644 json-writer.h
>   create mode 100644 t/helper/test-json-writer.c
>   create mode 100755 t/t0019-json-writer.sh
> 
> diff --git a/Makefile b/Makefile
> index a1d8775..4ae6946 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -666,6 +666,7 @@ TEST_PROGRAMS_NEED_X += test-fake-ssh
>  TEST_PROGRAMS_NEED_X += test-genrandom
>  TEST_PROGRAMS_NEED_X += test-hashmap
>  TEST_PROGRAMS_NEED_X += test-index-version
> +TEST_PROGRAMS_NEED_X += test-json-writer>  TEST_PROGRAMS_NEED_X += test-lazy-init-name-hash
>  TEST_PROGRAMS_NEED_X += test-line-buffer
>  TEST_PROGRAMS_NEED_X += test-match-trees

This doesn't apply cleanly on master, because most test helpers have
been combined into a single binary to reduce their disk footprint and
link times.  See efd71f8913 (t/helper: add an empty test-tool program)
for the overall rationale.

test-json-writer could become a built-in as well, I think.  You can see
e.g. in c932a5ff28 (t/helper: merge test-string-list into test-tool)
what needs to be done to convert a helper.

René