Restrict histograms to integral boundaries

4 files changed, 38 insertions, 148 deletions

diff --git a/src/core/lib/debug/stats.c b/src/core/lib/debug/stats.c
index 5079ed2ffa..a65dfe49b1 100644
--- a/src/core/lib/debug/stats.c
+++ b/src/core/lib/debug/stats.c
@@ -63,7 +63,7 @@ void grpc_stats_diff(const grpc_stats_data *b, const grpc_stats_data *a,
 }
 
 int grpc_stats_histo_find_bucket_slow(grpc_exec_ctx *exec_ctx, double value,
-                                      const double *table, int table_size) {
+                                      const int *table, int table_size) {
   GRPC_STATS_INC_HISTOGRAM_SLOW_LOOKUPS(exec_ctx);
   if (value < 0.0) return 0;
   if (value >= table[table_size - 1]) return table_size - 1;
@@ -92,7 +92,7 @@ size_t grpc_stats_histo_count(const grpc_stats_data *stats,
 }
 
 static double threshold_for_count_below(const gpr_atm *bucket_counts,
-                                        const double *bucket_boundaries,
+                                        const int *bucket_boundaries,
                                         int num_buckets, double count_below) {
   double count_so_far;
   double lower_bound;
@@ -163,7 +163,7 @@ char *grpc_stats_data_as_json(const grpc_stats_data *data) {
     gpr_asprintf(&tmp, "], \"%s_bkt\": [", grpc_stats_histogram_name[i]);
     gpr_strvec_add(&v, tmp);
     for (int j = 0; j < grpc_stats_histo_buckets[i]; j++) {
-      gpr_asprintf(&tmp, "%s%lf", j == 0 ? "" : ",",
+      gpr_asprintf(&tmp, "%s%d", j == 0 ? "" : ",",
                    grpc_stats_histo_bucket_boundaries[i][j]);
       gpr_strvec_add(&v, tmp);
     }
diff --git a/src/core/lib/debug/stats.h b/src/core/lib/debug/stats.h
index c440ab3b66..9d729c20f4 100644
--- a/src/core/lib/debug/stats.h
+++ b/src/core/lib/debug/stats.h
@@ -51,7 +51,7 @@ void grpc_stats_diff(const grpc_stats_data *b, const grpc_stats_data *a,
                      grpc_stats_data *c);
 char *grpc_stats_data_as_json(const grpc_stats_data *data);
 int grpc_stats_histo_find_bucket_slow(grpc_exec_ctx *exec_ctx, double value,
-                                      const double *table, int table_size);
+                                      const int *table, int table_size);
 double grpc_stats_histo_percentile(const grpc_stats_data *data,
                                    grpc_stats_histograms histogram,
                                    double percentile);
diff --git a/src/core/lib/debug/stats_data.c b/src/core/lib/debug/stats_data.c
index 9277ee57b2..47f482bd1b 100644
--- a/src/core/lib/debug/stats_data.c
+++ b/src/core/lib/debug/stats_data.c
@@ -50,146 +50,36 @@ const char *grpc_stats_histogram_name[GRPC_STATS_HISTOGRAM_COUNT] = {
     "tcp_write_size", "tcp_write_iov_size", "tcp_read_size",
     "tcp_read_offer", "tcp_read_iov_size",  "http2_send_message_size",
 };
-const double grpc_stats_table_0[64] = {0,
-                                       1,
-                                       2,
-                                       3,
-                                       4,
-                                       5.17974600698,
-                                       6.70744217421,
-                                       8.68571170472,
-                                       11.2474451301,
-                                       14.5647272503,
-                                       18.8603969544,
-                                       24.4230164536,
-                                       31.6262554885,
-                                       40.9539926456,
-                                       53.032819969,
-                                       68.6741343683,
-                                       88.9286433193,
-                                       115.156946285,
-                                       149.120933174,
-                                       193.102139541,
-                                       250.055009057,
-                                       323.805358672,
-                                       419.307378404,
-                                       542.976429747,
-                                       703.119998467,
-                                       910.495751121,
-                                       1179.03418281,
-                                       1526.77440013,
-                                       1977.07590065,
-                                       2560.18775048,
-                                       3315.28056941,
-                                       4293.07782286,
-                                       5559.26317765,
-                                       7198.89281155,
-                                       9322.10907382,
-                                       12071.5393129,
-                                       15631.8768886,
-                                       20242.2879738,
-                                       26212.4775761,
-                                       33943.4940145,
-                                       43954.6693961,
-                                       56918.5058232,
-                                       73705.8508152,
-                                       95444.3966128,
-                                       123594.433061,
-                                       160046.942783,
-                                       207250.628202,
-                                       268376.403469,
-                                       347530.401059,
-                                       450029.801797,
-                                       582760.01722,
-                                       754637.218056,
-                                       977207.279236,
-                                       1265421.37565,
-                                       1638640.32942,
-                                       2121935.1758,
-                                       2747771.31348,
-                                       3558189.37227,
-                                       4607629.29828,
-                                       5966587.36485,
-                                       7726351.7696,
-                                       10005134.9318,
-                                       12956014.428,
-                                       16777216.0};
+const int grpc_stats_table_0[64] = {
+    0,       1,       2,       3,       4,       6,        8,        11,
+    15,      20,      26,      34,      44,      57,       74,       96,
+    124,     160,     206,     265,     341,     439,      565,      727,
+    935,     1202,    1546,    1988,    2556,    3286,     4225,     5432,
+    6983,    8977,    11540,   14834,   19069,   24513,    31510,    40505,
+    52067,   66929,   86033,   110590,  142157,  182734,   234893,   301940,
+    388125,  498910,  641316,  824370,  1059674, 1362141,  1750943,  2250722,
+    2893155, 3718960, 4780478, 6144988, 7898976, 10153611, 13051794, 16777216};
 const uint8_t grpc_stats_table_1[87] = {
-    0,  1,  3,  3,  4,  6,  6,  7,  9,  9,  10, 12, 12, 13, 15, 15, 16, 18,
-    18, 19, 21, 21, 22, 24, 24, 25, 27, 27, 28, 30, 30, 31, 32, 34, 34, 36,
-    36, 37, 39, 39, 40, 42, 42, 43, 44, 46, 46, 47, 49, 49, 51, 51, 52, 53,
-    55, 55, 56, 58, 58, 59, 61, 61, 63, 63, 64, 65, 67, 67, 68, 70, 70, 71,
-    73, 73, 75, 75, 76, 77, 79, 79, 80, 82, 82, 83, 85, 85, 87};
-const double grpc_stats_table_2[64] = {0,
-                                       1,
-                                       2,
-                                       3,
-                                       4,
-                                       5,
-                                       6,
-                                       7,
-                                       8,
-                                       9,
-                                       10,
-                                       11,
-                                       12.0020736244,
-                                       13.0954337532,
-                                       14.2883963681,
-                                       15.5900350167,
-                                       17.0102498252,
-                                       18.5598427974,
-                                       20.2505999737,
-                                       22.0953810747,
-                                       24.1082173107,
-                                       26.3044181014,
-                                       28.7006875181,
-                                       31.315251333,
-                                       34.1679956422,
-                                       37.2806181177,
-                                       40.6767930374,
-                                       44.3823513489,
-                                       48.4254771375,
-                                       52.8369219909,
-                                       57.6502388927,
-                                       62.902037423,
-                                       68.6322622068,
-                                       74.8844967285,
-                                       81.7062948236,
-                                       89.1495423679,
-                                       97.2708519163,
-                                       106.131993291,
-                                       115.800363399,
-                                       126.34949884,
-                                       137.859635225,
-                                       150.418317437,
-                                       164.121065485,
-                                       179.072101023,
-                                       195.38514005,
-                                       213.184257818,
-                                       232.604832535,
-                                       253.794575043,
-                                       276.914652285,
-                                       302.140913126,
-                                       329.665225843,
-                                       359.696937452,
-                                       392.464465978,
-                                       428.217037783,
-                                       467.226583154,
-                                       509.78980457,
-                                       556.230433401,
-                                       606.901692163,
-                                       662.1889811,
-                                       722.512809492,
-                                       788.331994007,
-                                       860.147148411,
-                                       938.504491184,
-                                       1024.0};
-const uint8_t grpc_stats_table_3[52] = {
-    0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15, 16, 17,
-    18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
-    36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 52};
+    1,  1,  3,  3,  4,  6,  6,  8,  8,  9,  11, 11, 12, 14, 14, 15, 17, 17,
+    18, 20, 20, 21, 23, 23, 24, 25, 27, 27, 28, 30, 30, 31, 33, 33, 34, 35,
+    37, 37, 39, 39, 40, 41, 43, 43, 44, 46, 46, 47, 48, 50, 50, 51, 53, 53,
+    55, 55, 56, 57, 59, 59, 60, 62, 62, 63, 64, 66, 66, 67, 69, 69, 71, 71,
+    72, 73, 75, 75, 76, 78, 78, 79, 80, 82, 82, 83, 85, 85, 87};
+const int grpc_stats_table_2[64] = {
+    0,   1,   2,   3,   4,   5,   6,   7,   8,   9,   10,  11,  13,
+    15,  17,  19,  21,  23,  25,  28,  31,  34,  37,  41,  45,  49,
+    54,  59,  64,  70,  76,  83,  90,  98,  106, 115, 125, 136, 147,
+    159, 172, 186, 201, 218, 236, 255, 276, 299, 323, 349, 377, 408,
+    441, 477, 515, 556, 601, 649, 701, 757, 817, 881, 950, 1024};
+const uint8_t grpc_stats_table_3[104] = {
+    2,  2,  2,  6,  6,  6,  6,  9,  9,  9,  11,  11,  13,  13, 15, 15, 17, 17,
+    20, 20, 20, 23, 23, 23, 25, 25, 26, 28, 28,  30,  30,  32, 32, 35, 35, 35,
+    37, 37, 40, 40, 40, 41, 43, 43, 44, 46, 46,  48,  48,  50, 50, 52, 52, 55,
+    55, 55, 57, 57, 58, 59, 61, 61, 63, 63, 65,  65,  67,  67, 69, 69, 71, 71,
+    73, 73, 74, 76, 76, 77, 79, 79, 81, 81, 83,  83,  85,  85, 88, 88, 88, 89,
+    90, 92, 92, 93, 95, 95, 97, 97, 99, 99, 101, 101, 104, 104};
 const int grpc_stats_histo_buckets[6] = {64, 64, 64, 64, 64, 64};
 const int grpc_stats_histo_start[6] = {0, 64, 128, 192, 256, 320};
-const double *const grpc_stats_histo_bucket_boundaries[6] = {
+const int *const grpc_stats_histo_bucket_boundaries[6] = {
     grpc_stats_table_0, grpc_stats_table_2, grpc_stats_table_0,
     grpc_stats_table_0, grpc_stats_table_2, grpc_stats_table_0};
diff --git a/src/core/lib/debug/stats_data.h b/src/core/lib/debug/stats_data.h
index 4d1078dfdb..5350264c03 100644
--- a/src/core/lib/debug/stats_data.h
+++ b/src/core/lib/debug/stats_data.h
@@ -177,7 +177,7 @@ typedef enum {
       if (_val.uint < 4652218415073722368ull) {                                \
         GRPC_STATS_INC_HISTOGRAM(                                              \
             (exec_ctx), GRPC_STATS_HISTOGRAM_TCP_WRITE_IOV_SIZE,               \
-            grpc_stats_table_3[((_val.uint - 4622945017495814144ull) >> 49)]); \
+            grpc_stats_table_3[((_val.uint - 4622945017495814144ull) >> 48)]); \
       } else {                                                                 \
         GRPC_STATS_INC_HISTOGRAM(                                              \
             (exec_ctx), GRPC_STATS_HISTOGRAM_TCP_WRITE_IOV_SIZE,               \
@@ -249,7 +249,7 @@ typedef enum {
       if (_val.uint < 4652218415073722368ull) {                                \
         GRPC_STATS_INC_HISTOGRAM(                                              \
             (exec_ctx), GRPC_STATS_HISTOGRAM_TCP_READ_IOV_SIZE,                \
-            grpc_stats_table_3[((_val.uint - 4622945017495814144ull) >> 49)]); \
+            grpc_stats_table_3[((_val.uint - 4622945017495814144ull) >> 48)]); \
       } else {                                                                 \
         GRPC_STATS_INC_HISTOGRAM(                                              \
             (exec_ctx), GRPC_STATS_HISTOGRAM_TCP_READ_IOV_SIZE,                \
@@ -283,12 +283,12 @@ typedef enum {
       }                                                                        \
     }                                                                          \
   } while (false)
-extern const double grpc_stats_table_0[64];
+extern const int grpc_stats_table_0[64];
 extern const uint8_t grpc_stats_table_1[87];
-extern const double grpc_stats_table_2[64];
-extern const uint8_t grpc_stats_table_3[52];
+extern const int grpc_stats_table_2[64];
+extern const uint8_t grpc_stats_table_3[104];
 extern const int grpc_stats_histo_buckets[6];
 extern const int grpc_stats_histo_start[6];
-extern const double *const grpc_stats_histo_bucket_boundaries[6];
+extern const int *const grpc_stats_histo_bucket_boundaries[6];
 
 #endif /* GRPC_CORE_LIB_DEBUG_STATS_DATA_H */