From ad382fea25747477f88afd28a69fa9f20a756f9b Mon Sep 17 00:00:00 2001
From: Dianne Skoll <dianne@skoll.ca>
Date: Fri, 11 Oct 2024 16:34:11 -0400
Subject: [PATCH] Print hash-table statistics with "-ds" debugging.

---
 src/main.c     |  6 ++++++
 src/protos.h   |  3 +++
 src/userfns.c  | 25 +++++++++++++++++++++++++
 src/var.c      | 25 +++++++++++++++++++++++++
 tests/test.cmp |  4 ++++
 5 files changed, 63 insertions(+)

diff --git a/src/main.c b/src/main.c
index 42775dae..60bc64d5 100644
--- a/src/main.c
+++ b/src/main.c
@@ -60,9 +60,15 @@ exitfunc(void)
     /* Kill any execution-time-limiter process */
     unlimit_execution_time();
 
+    int maxlen, total;
+    double avglen;
     if (DebugFlag & DB_PARSE_EXPR) {
         fflush(stdout);
         fflush(stderr);
+        get_var_hash_stats(&total, &maxlen, &avglen);
+        fprintf(stderr, " Var hash: total = %d; maxlen = %d; avglen = %.3f\n", total, maxlen, avglen);
+        get_userfunc_hash_stats(&total, &maxlen, &avglen);
+        fprintf(stderr, "Func hash: total = %d; maxlen = %d; avglen = %.3f\n", total, maxlen, avglen);
         UnsetAllUserFuncs();
         print_expr_nodes_stats();
     }
diff --git a/src/protos.h b/src/protos.h
index 25aea6ba..10dcead1 100644
--- a/src/protos.h
+++ b/src/protos.h
@@ -247,3 +247,6 @@ extern int _private_sub_overflow(int a, int b);
 void print_sysvar_tokens(void);
 void print_builtinfunc_tokens(void);
 void print_remind_tokens(void);
+void get_var_hash_stats(int *total, int *maxlen, double *avglen);
+void get_userfunc_hash_stats(int *total, int *maxlen, double *avglen);
+
diff --git a/src/userfns.c b/src/userfns.c
index fa65ad2f..a53aa3e4 100644
--- a/src/userfns.c
+++ b/src/userfns.c
@@ -401,3 +401,28 @@ UnsetAllUserFuncs(void)
         FuncHash[i] = NULL;
     }
 }
+
+void
+get_userfunc_hash_stats(int *total, int *maxlen, double *avglen)
+{
+    int len;
+    int i;
+    UserFunc *f;
+
+    *maxlen = 0;
+    *total = 0;
+
+    for (i=0; i<FUNC_HASH_SIZE; i++) {
+        len = 0;
+        f = FuncHash[i];
+        while(f) {
+            len++;
+            (*total)++;
+            f = f->next;
+        }
+        if (len > *maxlen) {
+            *maxlen = len;
+        }
+    }
+    *avglen = (double) *total / (double) FUNC_HASH_SIZE;
+}
diff --git a/src/var.c b/src/var.c
index 76cfa3f1..eb82cf17 100644
--- a/src/var.c
+++ b/src/var.c
@@ -1208,3 +1208,28 @@ print_sysvar_tokens(void)
         printf("$%s\n", SysVarArr[i].name);
     }
 }
+
+void
+get_var_hash_stats(int *total, int *maxlen, double *avglen)
+{
+    int len;
+    int i;
+    Var *v;
+
+    *maxlen = 0;
+    *total = 0;
+
+    for (i=0; i<VAR_HASH_SIZE; i++) {
+        len = 0;
+        v = VHashTbl[i];
+        while(v) {
+            len++;
+            (*total)++;
+            v = v->next;
+        }
+        if (len > *maxlen) {
+            *maxlen = len;
+        }
+    }
+    *avglen = (double) *total / (double) VAR_HASH_SIZE;
+}
diff --git a/tests/test.cmp b/tests/test.cmp
index a4f21900..b97adce3 100644
--- a/tests/test.cmp
+++ b/tests/test.cmp
@@ -5688,6 +5688,8 @@ Barf
 DEBUG +s
 # Don't want Remind to queue reminders
 EXIT
+ Var hash: total = 141; maxlen = 8; avglen = 2.203
+Func hash: total = 15; maxlen = 3; avglen = 0.469
  Expression nodes allocated: 128
 Expression nodes high-water: 73
     Expression nodes leaked: 0
@@ -13139,6 +13141,8 @@ Parsed expression: isany("foo", 1 + 1, 2:00 + 1, '2021-01-01' + 1, '2021-01-01@1
 "f" + "oo" => "foo"
 isany("foo", 2, 02:01, 2021-01-02, 2021-01-01@14:01, "foo", ?) => 1
 No reminders.
+ Var hash: total = 1; maxlen = 1; avglen = 0.016
+Func hash: total = 0; maxlen = 0; avglen = 0.000
  Expression nodes allocated: 512
 Expression nodes high-water: 499
     Expression nodes leaked: 0