From dcc2b5252bfe66a23571ca003716c68c6715b9f6 Mon Sep 17 00:00:00 2001
From: Alex Karle <alex@alexkarle.com>
Date: Tue, 28 Dec 2021 12:35:08 -0500
Subject: [PATCH] Add experimental home-rolled strcpy in name of performance

The previous implemenation of strcat needs to repeatedly (for every
character in the lnkdes) go to the end of the lnkdes to append to it.

I thought it _might_ be faster to replace it with a persistent pointer
to the end of the buf, and it is, so it's worth checking it in, but I'll
revert this immediately because the code-clarity ain't worth the speed
boost!
---
 nihdoc.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/nihdoc.c b/nihdoc.c
index 230ea84..c6a9b15 100644
--- a/nihdoc.c
+++ b/nihdoc.c
@@ -7,7 +7,6 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <stdbool.h>
-#include <string.h>
 
 
 /* Global Constants and Enums */
@@ -17,6 +16,12 @@ char *FMT_STRS[] = {
     ['`'] = "code",
 };
 
+int FMT_LENS[] = {
+    ['_'] = 2,
+    ['*'] = 6,
+    ['`'] = 4,
+};
+
 enum Block {
     NONE,
     HEADER,
@@ -43,6 +48,7 @@ int hlvl = 0;
 bool fmts[256] = {false}; /* indexed by _ * ` */
 bool escape = false;
 char lnkdes[2048] = {0};
+char *lnkp = NULL;
 int indent = 0;
 int previndent = 0;
 int listdepth = 0;
@@ -143,18 +149,30 @@ void toggle_format() {
 void pushbuf() {
     /* push description onto lnkdes, with formatting! */
     char buf[12] = {0};
+    int len = 1;
     if (escape) {
         buf[0] = c;
         escape = false;
     } else if (c == '`' || c == '_' || c == '*') {
-        snprintf(buf, 12, "<%s%s>", fmts[c] ? "/" : "", FMT_STRS[c]);
+        if (fmts[c]) {
+            snprintf(buf, 12, "</%s>", FMT_STRS[c]);
+            len = 3 + FMT_LENS[c];
+        } else {
+            snprintf(buf, 12, "<%s>", FMT_STRS[c]);
+            len = 2 + FMT_LENS[c];
+        }
         fmts[c] ^= true;
     } else if (c == '\\') {
         escape = true;
+        len = 0;
     } else {
         buf[0] = c;
     }
-    strcat(lnkdes, buf);
+    /* copy into lnkdes starting at strp */
+    for (int i = 0; i < len; i++) {
+        *(lnkp++) = buf[i];
+    }
+    *lnkp = '\0';
 }
 
 int parse() {
@@ -255,6 +273,7 @@ int parse() {
                     maybe_startp();
                     in_link = DESC_PARSE;
                     lnkdes[0] = '\0';
+                    lnkp = lnkdes;
                 } else {
                     putesc(c);
                 }
--
libgit2 1.1.1