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Two tweaks to exit-port statistics.

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Add two functions for round_to_next_multiple_of() for uint32_t and
uint64_t.

Avoid division in every step of the loop over all ports.
This commit is contained in:
Karsten Loesing 2009-07-13 22:43:06 +02:00
parent 707a44a7b0
commit 8f1a973669
4 changed files with 48 additions and 28 deletions
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30
src/common/util.c
View File

@ -345,6 +345,36 @@ round_to_power_of_2(uint64_t u64)
return low;
}
/** Return the lowest x such that x is at least <b>number</b>, and x modulo
* <b>divisor</b> == 0. */
unsigned
round_to_next_multiple_of(unsigned number, unsigned divisor)
{
number += divisor - 1;
number -= number % divisor;
return number;
}
/** Return the lowest x such that x is at least <b>number</b>, and x modulo
* <b>divisor</b> == 0. */
uint32_t
round_uint32_to_next_multiple_of(uint32_t number, uint32_t divisor)
{
number += divisor - 1;
number -= number % divisor;
return number;
}
/** Return the lowest x such that x is at least <b>number</b>, and x modulo
* <b>divisor</b> == 0. */
uint64_t
round_uint64_to_next_multiple_of(uint64_t number, uint64_t divisor)
{
number += divisor - 1;
number -= number % divisor;
return number;
}
/* =====
* String manipulation
* ===== */

3
src/common/util.h
View File

@ -154,6 +154,9 @@ void tor_log_mallinfo(int severity);
/* Math functions */
int tor_log2(uint64_t u64) ATTR_CONST;
uint64_t round_to_power_of_2(uint64_t u64);
unsigned round_to_next_multiple_of(unsigned number, unsigned divisor);
uint32_t round_uint32_to_next_multiple_of(uint32_t number, uint32_t divisor);
uint64_t round_uint64_to_next_multiple_of(uint64_t number, uint64_t divisor);
/* String manipulation */

10
src/or/or.h
View File

@ -2669,16 +2669,6 @@ struct socks_request_t {
* every connection. */
};
/** Return the lowest x such that x is at least <b>number</b>, and x modulo
* <b>divisor</b> == 0. */
static INLINE unsigned
round_to_next_multiple_of(unsigned number, unsigned divisor)
{
number += divisor - 1;
number -= number % divisor;
return number;
}
/* all the function prototypes go here */
/********************************* buffers.c ***************************/

33
src/or/rephist.c
View File

@ -1332,7 +1332,7 @@ rep_hist_note_bytes_read(size_t num_bytes, time_t when)
#define EXIT_STATS_NUM_PORTS 65536
/** Reciprocal of threshold (= 0.01%) of total bytes that a port needs to
* see in order to be included in exit stats. */
#define EXIT_STATS_THRESHOLD 10000
#define EXIT_STATS_THRESHOLD_RECIPROCAL 10000
/* The following data structures are arrays and no fancy smartlists or maps,
* so that all write operations can be done in constant time. This comes at
@ -1354,7 +1354,7 @@ write_exit_stats(time_t when)
{
char t[ISO_TIME_LEN+1];
int r, i, comma;
uint64_t *b, total_bytes, other_bytes;
uint64_t *b, total_bytes, threshold_bytes, other_bytes;
uint32_t other_streams;
char *filename = get_datadir_fname("exit-stats");
@ -1381,13 +1381,14 @@ write_exit_stats(time_t when)
goto done;
/* Count the total number of bytes, so that we can attribute all
* observations below a threshold of 1 / EXIT_STATS_THRESHOLD of all
* bytes to a special port 'other'. */
* observations below a threshold of 1 / EXIT_STATS_THRESHOLD_RECIPROCAL
* of all bytes to a special port 'other'. */
total_bytes = 0;
for (i = 1; i < EXIT_STATS_NUM_PORTS; i++) {
total_bytes += exit_bytes_read[i];
total_bytes += exit_bytes_written[i];
}
threshold_bytes = total_bytes / EXIT_STATS_THRESHOLD_RECIPROCAL;
/* kibibytes-(read|written) port=kibibytes,.. */
for (r = 0; r < 2; r++) {
@ -1401,11 +1402,9 @@ write_exit_stats(time_t when)
other_bytes = 0;
for (i = 1; i < EXIT_STATS_NUM_PORTS; i++) {
if (b[i] > 0) {
if (exit_bytes_read[i] + exit_bytes_written[i] > 0 &&
(total_bytes / (exit_bytes_read[i] + exit_bytes_written[i])
< EXIT_STATS_THRESHOLD)) {
uint64_t num = round_to_next_multiple_of(b[i],
EXIT_STATS_ROUND_UP_BYTES);
if (exit_bytes_read[i] + exit_bytes_written[i] > threshold_bytes) {
uint64_t num = round_uint64_to_next_multiple_of(b[i],
EXIT_STATS_ROUND_UP_BYTES);
num /= 1024;
if (fprintf(out, "%s%d="U64_FORMAT,
comma++ ? "," : "", i,
@ -1415,8 +1414,8 @@ write_exit_stats(time_t when)
other_bytes += b[i];
}
}
other_bytes = round_to_next_multiple_of(other_bytes,
EXIT_STATS_ROUND_UP_BYTES);
other_bytes = round_uint64_to_next_multiple_of(other_bytes,
EXIT_STATS_ROUND_UP_BYTES);
other_bytes /= 1024;
if (fprintf(out, "%sother="U64_FORMAT"\n",
comma ? "," : "", other_bytes)<0)
@ -1429,11 +1428,9 @@ write_exit_stats(time_t when)
other_streams = 0;
for (i = 1; i < EXIT_STATS_NUM_PORTS; i++) {
if (exit_streams[i] > 0) {
if (exit_bytes_read[i] + exit_bytes_written[i] > 0 &&
(total_bytes / (exit_bytes_read[i] + exit_bytes_written[i])
< EXIT_STATS_THRESHOLD)) {
uint32_t num = round_to_next_multiple_of(exit_streams[i],
EXIT_STATS_ROUND_UP_STREAMS);
if (exit_bytes_read[i] + exit_bytes_written[i] > threshold_bytes) {
uint32_t num = round_uint32_to_next_multiple_of(exit_streams[i],
EXIT_STATS_ROUND_UP_STREAMS);
if (fprintf(out, "%s%d=%u",
comma++ ? "," : "", i, num)<0)
goto done;
@ -1441,8 +1438,8 @@ write_exit_stats(time_t when)
other_streams += exit_streams[i];
}
}
other_streams = round_to_next_multiple_of(other_streams,
EXIT_STATS_ROUND_UP_STREAMS);
other_streams = round_uint32_to_next_multiple_of(other_streams,
EXIT_STATS_ROUND_UP_STREAMS);
if (fprintf(out, "%sother=%u\n",
comma ? "," : "", other_streams)<0)
goto done;