commit 11da5229d103fd13300b88a0efbc1da0b3970782 Author: Nick Mathewson nickm@torproject.org Date: Fri Jul 10 08:18:15 2020 -0400
Refactor bwhist_get_bandwidth_lines()
We've done a lot to improve our internal APIs since we wrote this code, and it shows. We can just use a buf_t to build up the bandwidth lines, and save a bunch of stack fiddling.
Additionally, we can use a function to format a single line, and thereby get rid of the cheezy pattern that does
for (i=0;i<n;++i) { switch (i) { ... } ... } --- src/feature/stats/bwhist.c | 81 ++++++++++++++++++---------------------------- 1 file changed, 32 insertions(+), 49 deletions(-)
diff --git a/src/feature/stats/bwhist.c b/src/feature/stats/bwhist.c index 527f0128f..fef8a3b2d 100644 --- a/src/feature/stats/bwhist.c +++ b/src/feature/stats/bwhist.c @@ -324,6 +324,29 @@ bwhist_fill_bandwidth_history(char *buf, size_t len, const bw_array_t *b) return cp-buf; }
+/** Encode a single bandwidth history line into <b>buf</b>. */ +static void +bwhist_get_one_bandwidth_line(buf_t *buf, const char *desc, + const bw_array_t *b) +{ + /* [dirreq-](read|write)-history yyyy-mm-dd HH:MM:SS (n s) n,n,n... */ + /* The n,n,n part above. Largest representation of a uint64_t is 20 chars + * long, plus the comma. */ +#define MAX_HIST_VALUE_LEN (21*NUM_TOTALS) + + char tmp[MAX_HIST_VALUE_LEN]; + char end[ISO_TIME_LEN+1]; + + size_t slen = bwhist_fill_bandwidth_history(tmp, MAX_HIST_VALUE_LEN, b); + /* If we don't have anything to write, skip to the next entry. */ + if (slen == 0) + return; + + format_iso_time(end, b->next_period-NUM_SECS_BW_SUM_INTERVAL); + buf_add_printf(buf, "%s %s (%d s) %s\n", + desc, end, NUM_SECS_BW_SUM_INTERVAL, tmp); +} + /** Allocate and return lines for representing this server's bandwidth * history in its descriptor. We publish these lines in our extra-info * descriptor. @@ -331,56 +354,16 @@ bwhist_fill_bandwidth_history(char *buf, size_t len, const bw_array_t *b) char * bwhist_get_bandwidth_lines(void) { - char *buf, *cp; - char t[ISO_TIME_LEN+1]; - int r; - bw_array_t *b = NULL; - const char *desc = NULL; - size_t len; + buf_t *buf = buf_new();
- /* [dirreq-](read|write)-history yyyy-mm-dd HH:MM:SS (n s) n,n,n... */ -/* The n,n,n part above. Largest representation of a uint64_t is 20 chars - * long, plus the comma. */ -#define MAX_HIST_VALUE_LEN (21*NUM_TOTALS) - len = (67+MAX_HIST_VALUE_LEN)*4; - buf = tor_malloc_zero(len); - cp = buf; - for (r=0;r<4;++r) { - char tmp[MAX_HIST_VALUE_LEN]; - size_t slen; - switch (r) { - case 0: - b = write_array; - desc = "write-history"; - break; - case 1: - b = read_array; - desc = "read-history"; - break; - case 2: - b = dir_write_array; - desc = "dirreq-write-history"; - break; - case 3: - b = dir_read_array; - desc = "dirreq-read-history"; - break; - } - tor_assert(b); - slen = bwhist_fill_bandwidth_history(tmp, MAX_HIST_VALUE_LEN, b); - /* If we don't have anything to write, skip to the next entry. */ - if (slen == 0) - continue; - format_iso_time(t, b->next_period-NUM_SECS_BW_SUM_INTERVAL); - tor_snprintf(cp, len-(cp-buf), "%s %s (%d s) ", - desc, t, NUM_SECS_BW_SUM_INTERVAL); - cp += strlen(cp); - strlcat(cp, tmp, len-(cp-buf)); - cp += slen; - strlcat(cp, "\n", len-(cp-buf)); - ++cp; - } - return buf; + bwhist_get_one_bandwidth_line(buf, "write-history", write_array); + bwhist_get_one_bandwidth_line(buf, "read-history", read_array); + bwhist_get_one_bandwidth_line(buf, "dirreq-write-history", dir_write_array); + bwhist_get_one_bandwidth_line(buf, "dirreq-read-history", dir_read_array); + + char *result = buf_extract(buf, NULL); + buf_free(buf); + return result; }
/** Write a single bw_array_t into the Values, Ends, Interval, and Maximum