Re: [PATCH 1/2] test-lib-functions: make packetize() more efficient

> The packetize() function takes its input on stdin, and requires 4
> separate sub-processes to format a simple string. We can do much better
> by getting the length via the shell's "${#packet}" construct. The one
> caveat is that the shell can't put a NUL into a variable, so we'll have
> to continue to provide the stdin form for a few calls.
>
> There are a few other cleanups here in the touched code:
>
>  - the stdin form of packetize() had an extra stray "%s" when printing
>    the packet
>
>  - the converted calls in t5562 can be made simpler by redirecting
>    output as a block, rather than repeated appending
>
> Signed-off-by: Jeff King <peff@peff.net>
> ---
>  t/t5562-http-backend-content-length.sh | 19 ++++++++++++-------
>  t/test-lib-functions.sh                | 23 ++++++++++++++++-------
>  2 files changed, 28 insertions(+), 14 deletions(-)
>
> diff --git a/t/t5562-http-backend-content-length.sh b/t/t5562-http-backend-content-length.sh
> index 4a110b307e..3f4ac71f83 100755
> --- a/t/t5562-http-backend-content-length.sh
> +++ b/t/t5562-http-backend-content-length.sh
> @@ -53,15 +53,20 @@ test_expect_success 'setup' '
>  	test_commit c1 &&
>  	hash_head=$(git rev-parse HEAD) &&
>  	hash_prev=$(git rev-parse HEAD~1) &&
> -	printf "want %s" "$hash_head" | packetize >fetch_body &&
> -	printf 0000 >>fetch_body &&
> -	printf "have %s" "$hash_prev" | packetize >>fetch_body &&
> -	printf done | packetize >>fetch_body &&
> +	{
> +		packetize "want $hash_head" &&
> +		printf 0000 &&
> +		packetize "have $hash_prev" &&
> +		packetize "done"
> +	} >fetch_body &&

>  	test_copy_bytes 10 <fetch_body >fetch_body.trunc &&
>  	hash_next=$(git commit-tree -p HEAD -m next HEAD^{tree}) &&
> -	printf "%s %s refs/heads/newbranch\\0report-status\\n" "$ZERO_OID" "$hash_next" | packetize >push_body &&
> -	printf 0000 >>push_body &&
> -	echo "$hash_next" | git pack-objects --stdout >>push_body &&
> +	{
> +		printf "%s %s refs/heads/newbranch\\0report-status\\n" \
> +			"$ZERO_OID" "$hash_next" | packetize &&
> +		printf 0000 &&
> +		echo "$hash_next" | git pack-objects --stdout
> +	} >push_body &&
>  	test_copy_bytes 10 <push_body >push_body.trunc &&
>  	: >empty_body
>  '
> diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
> index 352c213d52..216918a58c 100644
> --- a/t/test-lib-functions.sh
> +++ b/t/test-lib-functions.sh
> @@ -1362,14 +1362,23 @@ nongit () {
>  	)
>  } 7>&2 2>&4
>
> -# convert stdin to pktline representation; note that empty input becomes an
> -# empty packet, not a flush packet (for that you can just print 0000 yourself).
> +# convert function arguments or stdin (if not arguments given) to pktline
> +# representation. If multiple arguments are given, they are separated by
> +# whitespace and put in a single packet. Note that data containing NULs must be
> +# given on stdin, and that empty input becomes an empty packet, not a flush
> +# packet (for that you can just print 0000 yourself).
>  packetize() {
> -	cat >packetize.tmp &&
> -	len=$(wc -c <packetize.tmp) &&
> -	printf '%04x%s' "$(($len + 4))" &&
> -	cat packetize.tmp &&
> -	rm -f packetize.tmp
> +	if test $# -gt 0
> +	then
> +		packet="$*"

> +		printf '%04x%s' "$((4 + ${#packet}))" "$packet"
> +	else
> +		cat >packetize.tmp &&
> +		len=$(wc -c <packetize.tmp) &&
> +		printf '%04x' "$(($len + 4))" &&
> +		cat packetize.tmp &&
> +		rm -f packetize.tmp
> +	fi
>  }