st_table_size_statistics.patch

From a8a96344fa3a77f1cf8f215c3e56caedf8f065bd Mon Sep 17 00:00:00 2001
From: tacinight <tacingiht@gmail.com>
Date: Wed, 4 Jul 2018 15:28:09 +0800
Subject: [PATCH] introduce USE_ST_OBJ_INFO_SIZE_DETAILS to do st_table size
 statistics

Signed-off-by: tacinight <tacingiht@gmail.com>
---
 include/ruby/ruby.h |  4 ++++
 st.c                | 22 ++++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index e225606c2f..58ae84e9ea 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -1062,6 +1062,10 @@ struct RRegexp {
 #define RHASH_EMPTY_P(h) (RHASH_SIZE(h) == 0)
 #define RHASH_SET_IFNONE(h, ifnone) rb_hash_set_ifnone((VALUE)h, ifnone)
 
+#ifndef USE_ST_OBJ_SIZE_DETAILS
+#define USE_ST_OBJ_SIZE_DETAILS 1
+#endif
+
 struct RFile {
     struct RBasic basic;
     struct rb_io_t *fptr;
diff --git a/st.c b/st.c
index 1a47525707..782331ccf4 100644
--- a/st.c
+++ b/st.c
@@ -158,6 +158,25 @@ static const struct st_hash_type type_strcasehash = {
     strcasehash,
 };
 
+#if USE_ST_OBJ_SIZE_DETAILS
+
+#define ST_INFO_SIZE_SIZE 64
+
+static size_t st_info_size_cnt[ST_INFO_SIZE_SIZE];
+
+__attribute__((destructor))
+static void
+st_info_show_results(void)
+{
+    int i;
+    
+    fprintf(stderr, "* st_info size statictics\n");
+    for (i = 0; i < ST_INFO_SIZE_SIZE; i++) {
+	fprintf(stderr, "%i\t%d\n", i, (int)st_info_size_cnt[i]);
+    }
+}
+#endif
+
 /* Value used to catch uninitialized entries/bins during debugging.
    There is a possibility for a false alarm, but its probability is
    extremely small.  */
@@ -684,6 +703,9 @@ st_clear(st_table *tab)
 void
 st_free_table(st_table *tab)
 {
+#if USE_ST_OBJ_SIZE_DETAILS
+st_info_size_cnt[tab->entry_power]++;
+#endif
     if (tab->bins != NULL)
         free(tab->bins);
     free(tab->entries);
-- 
2.11.0