From eff0c22e59e65b6b63e854ff41eb091278e05714 Mon Sep 17 00:00:00 2001
From: Julian Andres Klode <jak@debian.org>
Date: Thu, 7 Jan 2016 19:16:23 +0100
Subject: Switch performance critical code to use APT::StringView

This improves performance of the cache generation on my
ARM platform (4x Cortex A15) by about 10% to 20% from
2.35-2.50 to 2.1 seconds.
---
 apt-pkg/contrib/hashsum_template.h | 26 +++++++++++++++++++++++++-
 apt-pkg/contrib/strutl.cc          |  7 ++++++-
 apt-pkg/contrib/strutl.h           |  7 ++++++-
 3 files changed, 37 insertions(+), 3 deletions(-)

(limited to 'apt-pkg/contrib')

diff --git a/apt-pkg/contrib/hashsum_template.h b/apt-pkg/contrib/hashsum_template.h
index d0ea0971e..42248f6ac 100644
--- a/apt-pkg/contrib/hashsum_template.h
+++ b/apt-pkg/contrib/hashsum_template.h
@@ -13,6 +13,9 @@
 
 #include <string>
 #include <cstring>
+#ifdef APT_PKG_EXPOSE_STRING_VIEW
+#include <apt-pkg/string_view.h>
+#endif
 
 #include <apt-pkg/strutl.h>
 
@@ -80,7 +83,16 @@ class HashSumValue
    {
       return Hex2Num(Str,Sum,sizeof(Sum));
    }
-
+#ifdef APT_PKG_EXPOSE_STRING_VIEW
+   APT_HIDDEN bool Set(APT::StringView Str)
+   {
+      return Hex2Num(Str,Sum,sizeof(Sum));
+   }
+   APT_HIDDEN bool Set(const char *Str)
+   {
+      return Hex2Num(APT::StringView(Str),Sum,sizeof(Sum));
+   }
+#endif
    inline void Set(unsigned char S[N/8])
    {
       for (int I = 0; I != sizeof(Sum); ++I)
@@ -92,6 +104,18 @@ class HashSumValue
          memset(Sum,0,sizeof(Sum));
          Set(Str);
    }
+#ifdef APT_PKG_EXPOSE_STRING_VIEW
+   APT_HIDDEN explicit HashSumValue(APT::StringView const &Str)
+   {
+         memset(Sum,0,sizeof(Sum));
+         Set(Str);
+   }
+   APT_HIDDEN explicit HashSumValue(const char *Str)
+   {
+         memset(Sum,0,sizeof(Sum));
+         Set(Str);
+   }
+#endif
    HashSumValue()
    {
       memset(Sum,0,sizeof(Sum));
diff --git a/apt-pkg/contrib/strutl.cc b/apt-pkg/contrib/strutl.cc
index b9bfc2c98..856e5ee9f 100644
--- a/apt-pkg/contrib/strutl.cc
+++ b/apt-pkg/contrib/strutl.cc
@@ -1113,13 +1113,18 @@ static int HexDigit(int c)
 // ---------------------------------------------------------------------
 /* The length of the buffer must be exactly 1/2 the length of the string. */
 bool Hex2Num(const string &Str,unsigned char *Num,unsigned int Length)
+{
+   return Hex2Num(APT::StringView(Str), Num, Length);
+}
+
+bool Hex2Num(const APT::StringView Str,unsigned char *Num,unsigned int Length)
 {
    if (Str.length() != Length*2)
       return false;
    
    // Convert each digit. We store it in the same order as the string
    int J = 0;
-   for (string::const_iterator I = Str.begin(); I != Str.end();J++, I += 2)
+   for (auto I = Str.begin(); I != Str.end();J++, I += 2)
    {
       int first_half = HexDigit(I[0]);
       int second_half;
diff --git a/apt-pkg/contrib/strutl.h b/apt-pkg/contrib/strutl.h
index a8bbc38af..c5c8e2382 100644
--- a/apt-pkg/contrib/strutl.h
+++ b/apt-pkg/contrib/strutl.h
@@ -22,6 +22,9 @@
 #include <cstring>
 #include <vector>
 #include <iostream>
+#ifdef APT_PKG_EXPOSE_STRING_VIEW
+#include <apt-pkg/string_view.h>
+#endif
 #include <time.h>
 #include <stddef.h>
 
@@ -75,7 +78,9 @@ bool StrToNum(const char *Str,unsigned long long &Res,unsigned Len,unsigned Base
 bool Base256ToNum(const char *Str,unsigned long &Res,unsigned int Len);
 bool Base256ToNum(const char *Str,unsigned long long &Res,unsigned int Len);
 bool Hex2Num(const std::string &Str,unsigned char *Num,unsigned int Length);
-
+#ifdef APT_PKG_EXPOSE_STRING_VIEW
+APT_HIDDEN bool Hex2Num(const APT::StringView Str,unsigned char *Num,unsigned int Length);
+#endif
 // input changing string split
 bool TokSplitString(char Tok,char *Input,char **List,
 		    unsigned long ListMax);
-- 
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