From 2d572ca660a799f924b4ea13688cc7ea083a5159 Mon Sep 17 00:00:00 2001
From: LIU Hao <lh_mouse@126.com>
Date: Tue, 11 Jun 2024 12:57:28 +0800
Subject: [PATCH] http_field_name: Cleanup

---
 poseidon/http/http_field_name.cpp | 97 ++++++++++++++++++++++---------
 1 file changed, 70 insertions(+), 27 deletions(-)

diff --git a/poseidon/http/http_field_name.cpp b/poseidon/http/http_field_name.cpp
index d49dd0e6..f66ecda4 100644
--- a/poseidon/http/http_field_name.cpp
+++ b/poseidon/http/http_field_name.cpp
@@ -5,6 +5,61 @@
 #include "http_field_name.hpp"
 #include "../utils.hpp"
 namespace poseidon {
+namespace {
+
+struct ci_reader_str
+  {
+    const char* cur;
+    const char* end;
+    int ch;
+
+    explicit
+    ci_reader_str(const cow_string& str) noexcept
+      {
+        this->cur = str.data();
+        this->end = str.data() + str.size();
+      }
+
+    int
+    get() noexcept
+      {
+        if(this->cur == this->end)
+          this->ch = -1;
+        else {
+          this->ch = (unsigned char) *(this->cur);
+          this->ch |= (('A' - this->ch - 1) & (this->ch - 'Z' - 1) & 0x100) >> 3;
+          this->cur ++;
+        }
+        return this->ch;
+      }
+  };
+
+struct ci_reader_sz
+  {
+    const char* cur;
+    int ch;
+
+    explicit
+    ci_reader_sz(const char* str) noexcept
+      {
+        this->cur = str;
+      }
+
+    int
+    get() noexcept
+      {
+        this->ch = (unsigned char) *(this->cur);
+        if(this->ch == 0)
+          this->ch = -1;
+        else {
+          this->ch |= (('A' - this->ch - 1) & (this->ch - 'Z' - 1) & 0x100) >> 3;
+          this->cur ++;
+        }
+        return this->ch;
+      }
+  };
+
+}  // namespace
 
 HTTP_Field_Name::
 ~HTTP_Field_Name()
@@ -15,41 +70,30 @@ int
 HTTP_Field_Name::
 compare(const char* cmps) const noexcept
   {
-    for(size_t k = 0;; ++k) {
-      int c1 = -1, c2 = -1;
-      if(k != this->m_str.size())
-        c1 = static_cast<uint8_t>(::rocket::ascii_to_lower(this->m_str[k]));
-      if(cmps[k] != 0)
-        c2 = static_cast<uint8_t>(::rocket::ascii_to_lower(cmps[k]));
-      if(c1 != c2)
-        return c1 - c2;
-      if(c1 == -1)
-        return 0;
-    }
+    ci_reader_str rs1(this->m_str);
+    ci_reader_sz rs2(cmps);
+    while((rs1.get() == rs2.get()) && (rs1.ch != -1));
+    return rs1.ch - rs2.ch;
   }
 
 int
 HTTP_Field_Name::
 compare(cow_stringR cmps) const noexcept
   {
-    for(size_t k = 0;; ++k) {
-      int c1 = -1, c2 = -1;
-      if(k != this->m_str.size())
-        c1 = static_cast<uint8_t>(::rocket::ascii_to_lower(this->m_str[k]));
-      if(k != cmps.size())
-        c2 = static_cast<uint8_t>(::rocket::ascii_to_lower(cmps[k]));
-      if(c1 != c2)
-        return c1 - c2;
-      if(c1 == -1)
-        return 0;
-    }
+    ci_reader_str rs1(this->m_str);
+    ci_reader_str rs2(cmps);
+    while((rs1.get() == rs2.get()) && (rs1.ch != -1));
+    return rs1.ch - rs2.ch;
   }
 
 int
 HTTP_Field_Name::
 compare(const HTTP_Field_Name& other) const noexcept
   {
-    return this->compare(other.m_str);
+    ci_reader_str rs1(this->m_str);
+    ci_reader_str rs2(other.m_str);
+    while((rs1.get() == rs2.get()) && (rs1.ch != -1));
+    return rs1.ch - rs2.ch;
   }
 
 size_t
@@ -57,10 +101,9 @@ HTTP_Field_Name::
 rdhash() const noexcept
   {
     // https://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function#FNV-1a_hash
+    ci_reader_str rs1(this->m_str);
     uint32_t hval = 2166136261;
-    for(size_t k = 0;  k != this->m_str.size();  ++k)
-      hval = (hval ^ static_cast<uint8_t>(::rocket::ascii_to_lower(this->m_str[k])))
-             * 16777619;
+    while(rs1.get() != -1) hval = (hval ^ (uint32_t) rs1.ch) * 16777619;
     return hval;
   }
 
@@ -79,7 +122,7 @@ canonicalize()
 
         case 'A' ... 'Z':
           // Convert this letter to lowercase.
-          this->m_str.mut(k) = ::rocket::ascii_to_lower(this->m_str[k]);
+          this->m_str.mut(k) = (char) (this->m_str[k] | 0x20);
           break;
 
         default: