From: Jeff Hostetler <git@jeffhostetler.com>
To: Josh Steadmon <steadmon@google.com>,
git@vger.kernel.org, gitster@pobox.com
Subject: Re: [PATCH v3 0/1] Write trace2 output to directories
Date: Thu, 21 Mar 2019 17:16:52 -0400 [thread overview]
Message-ID: <fc057cb5-c1c9-5466-1d45-c7d1e89a9894@jeffhostetler.com> (raw)
In-Reply-To: <cover.1553202340.git.steadmon@google.com>
On 3/21/2019 5:09 PM, Josh Steadmon wrote:
> Persistently enabling trace2 output is difficult because it requires
> specifying a full filename. This series teaches tr2_dst_get_trace_fd()
> to create files underneath a given directory provided as the target of
> the GIT_TR2_* envvars.
>
> Changes since V2:
> * No longer appends a suffix to filenames on the first creation attempt.
> * Renamed function & constant now that randomization is no longer used.
> * Simplified strbuf usage.
>
> Changes since V1:
> * No longer supports timestamp templates.
> * No longer supports filename prefixes.
> * Always creates filenames based on the final component of the trace2
> SID.
>
> Josh Steadmon (1):
> trace2: write to directory targets
>
> Documentation/technical/api-trace2.txt | 5 ++
> t/t0210-trace2-normal.sh | 15 ++++++
> trace2/tr2_dst.c | 63 +++++++++++++++++++++++++-
> 3 files changed, 81 insertions(+), 2 deletions(-)
>
> Range-diff against v2:
> 1: 59d8c6511b ! 1: ce5258610f trace2: write to directory targets
> @@ -23,8 +23,8 @@
>
> + If the target already exists and is a directory, the traces will be
> + written to files (one per process) underneath the given directory. They
> -+ will be named according to the last component of the SID followed by a
> -+ counter to avoid potential collisions.
> ++ will be named according to the last component of the SID (optionally
> ++ followed by a counter to avoid filename collisions).
> +
> `af_unix:[<socket_type>:]<absolute-pathname>`::
>
> @@ -37,7 +37,7 @@
> test_cmp expect actual
> '
>
> -+test_expect_success 'randomized filename' '
> ++test_expect_success 'automatic filename' '
> + test_when_finished "rm -r traces actual expect" &&
> + mkdir traces &&
> + GIT_TR2="$(pwd)/traces" test-tool trace2 001return 0 &&
> @@ -71,9 +71,9 @@
> #define TR2_ENVVAR_DST_DEBUG "GIT_TR2_DST_DEBUG"
>
> +/*
> -+ * How many attempts we will make at creating a random trace output path.
> ++ * How many attempts we will make at creating an automatically-named trace file.
> + */
> -+#define MAX_RANDOM_ATTEMPTS 10
> ++#define MAX_AUTO_ATTEMPTS 10
> +
> static int tr2_dst_want_warning(void)
> {
> @@ -82,45 +82,47 @@
> dst->need_close = 0;
> }
>
> -+static int tr2_dst_try_random_path(struct tr2_dst *dst, const char *tgt_prefix)
> ++static int tr2_dst_try_auto_path(struct tr2_dst *dst, const char *tgt_prefix)
> +{
> + int fd;
> + const char *last_slash, *sid = tr2_sid_get();
> -+ struct strbuf base_path = STRBUF_INIT, final_path = STRBUF_INIT;
> ++ struct strbuf path = STRBUF_INIT;
> ++ size_t base_path_len;
> + unsigned attempt_count;
> +
> + last_slash = strrchr(sid, '/');
> + if (last_slash)
> + sid = last_slash + 1;
> +
> -+ strbuf_addstr(&base_path, tgt_prefix);
> -+ if (!is_dir_sep(base_path.buf[base_path.len - 1]))
> -+ strbuf_addch(&base_path, '/');
> -+ strbuf_addstr(&base_path, sid);
> ++ strbuf_addstr(&path, tgt_prefix);
> ++ if (!is_dir_sep(path.buf[path.len - 1]))
> ++ strbuf_addch(&path, '/');
> ++ strbuf_addstr(&path, sid);
> ++ base_path_len = path.len;
> +
> -+ for (attempt_count = 0; attempt_count < MAX_RANDOM_ATTEMPTS; attempt_count++) {
> -+ strbuf_reset(&final_path);
> -+ strbuf_addbuf(&final_path, &base_path);
> -+ strbuf_addf(&final_path, ".%d", attempt_count);
> ++ for (attempt_count = 0; attempt_count < MAX_AUTO_ATTEMPTS; attempt_count++) {
> ++ if (attempt_count > 0) {
> ++ strbuf_setlen(&path, base_path_len);
> ++ strbuf_addf(&path, ".%d", attempt_count);
> ++ }
> +
> -+ fd = open(final_path.buf, O_WRONLY | O_CREAT | O_EXCL, 0666);
> ++ fd = open(path.buf, O_WRONLY | O_CREAT | O_EXCL, 0666);
> + if (fd != -1)
> + break;
> + }
> +
> + if (fd == -1) {
> + if (tr2_dst_want_warning())
> -+ warning("trace2: could not open '%s' for '%s' tracing: %s",
> -+ base_path.buf, dst->env_var_name, strerror(errno));
> ++ warning("trace2: could not open '%.*s' for '%s' tracing: %s",
> ++ (int) base_path_len, path.buf,
> ++ dst->env_var_name, strerror(errno));
> +
> + tr2_dst_trace_disable(dst);
> -+ strbuf_release(&base_path);
> -+ strbuf_release(&final_path);
> ++ strbuf_release(&path);
> + return 0;
> + }
> +
> -+ strbuf_release(&base_path);
> -+ strbuf_release(&final_path);
> ++ strbuf_release(&path);
> +
> + dst->fd = fd;
> + dst->need_close = 1;
> @@ -140,7 +142,7 @@
> - return tr2_dst_try_path(dst, tgt_value);
> + if (is_absolute_path(tgt_value)) {
> + if (is_directory(tgt_value))
> -+ return tr2_dst_try_random_path(dst, tgt_value);
> ++ return tr2_dst_try_auto_path(dst, tgt_value);
> + else
> + return tr2_dst_try_path(dst, tgt_value);
> + }
>
Looks good. Thanks.
Jeff
next prev parent reply other threads:[~2019-03-21 21:16 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-13 23:33 [PATCH 0/2] Randomize / timestamp trace2 targets Josh Steadmon
2019-03-13 23:33 ` [PATCH 1/2] date: make get_time() public Josh Steadmon
2019-03-13 23:33 ` [PATCH 2/2] trace2: randomize/timestamp trace2 targets Josh Steadmon
2019-03-13 23:49 ` Ævar Arnfjörð Bjarmason
2019-03-15 18:39 ` Jeff Hostetler
2019-03-15 19:26 ` Ævar Arnfjörð Bjarmason
2019-03-15 20:14 ` Jeff Hostetler
2019-03-15 20:43 ` Josh Steadmon
2019-03-15 20:49 ` Josh Steadmon
2019-03-18 1:40 ` Junio C Hamano
2019-03-19 3:17 ` Jeff King
2019-03-14 0:16 ` Jeff King
2019-03-14 6:07 ` Junio C Hamano
2019-03-14 14:34 ` [PATCH 0/2] Randomize / timestamp " Johannes Schindelin
2019-03-15 20:37 ` Josh Steadmon
2019-03-15 19:18 ` Jeff Hostetler
2019-03-15 20:38 ` Josh Steadmon
2019-03-18 12:50 ` Jeff Hostetler
2019-03-21 0:16 ` [PATCH v2 0/1] Write trace2 output to directories Josh Steadmon
2019-03-21 0:16 ` [PATCH v2 1/1] trace2: write to directory targets Josh Steadmon
2019-03-21 2:04 ` Junio C Hamano
2019-03-21 17:43 ` Jeff Hostetler
2019-03-22 3:30 ` Junio C Hamano
2019-03-22 14:20 ` Jeff Hostetler
2019-03-21 21:09 ` [PATCH v3 0/1] Write trace2 output to directories Josh Steadmon
2019-03-21 21:09 ` [PATCH v3 1/1] trace2: write to directory targets Josh Steadmon
2019-03-23 20:44 ` Ævar Arnfjörð Bjarmason
2019-03-24 12:33 ` Junio C Hamano
2019-03-24 14:51 ` Ævar Arnfjörð Bjarmason
2019-03-25 2:21 ` Junio C Hamano
2019-03-25 8:21 ` Ævar Arnfjörð Bjarmason
2019-03-25 16:29 ` Jeff Hostetler
2019-03-21 21:16 ` Jeff Hostetler [this message]
2019-03-22 5:23 ` [PATCH v3 0/1] Write trace2 output to directories Junio C Hamano
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