Do not use MD5SumValue for Description_md5()

Our profile says we spend about 5% of the time transforming the
hex digits into the binary format used by HashsumValue, all for
comparing them against the other strings. That makes no sense
at all.

According to callgrind, this reduces the overall instruction
count from 5,3 billion to 5 billion in my example, which
roughly matches the 5%.

2 files changed, 7 insertions, 3 deletions

diff --git a/apt-pkg/edsp/edsplistparser.cc b/apt-pkg/edsp/edsplistparser.cc
index c6fd528da..4119639a6 100644
--- a/apt-pkg/edsp/edsplistparser.cc
+++ b/apt-pkg/edsp/edsplistparser.cc
@@ -20,6 +20,7 @@
 #include <apt-pkg/tagfile.h>
 #include <apt-pkg/fileutl.h>
 #include <apt-pkg/pkgsystem.h>
+#include <apt-pkg/string_view.h>
 
 #include <array>
 
@@ -53,9 +54,9 @@ std::vector<std::string> edspLikeListParser::AvailableDescriptionLanguages()
 {
    return {};
 }
-MD5SumValue edspLikeListParser::Description_md5()
+APT::StringView edspLikeListParser::Description_md5()
 {
-   return MD5SumValue("");
+   return APT::StringView();
 }
 									/*}}}*/
 // ListParser::VersionHash - Compute a unique hash for this version	/*{{{*/
diff --git a/apt-pkg/edsp/edsplistparser.h b/apt-pkg/edsp/edsplistparser.h
index 84138d6a8..4904b6567 100644
--- a/apt-pkg/edsp/edsplistparser.h
+++ b/apt-pkg/edsp/edsplistparser.h
@@ -24,12 +24,15 @@
 #include <apt-pkg/tagfile.h>
 #endif
 
+namespace APT {
+   class StringView;
+}
 class APT_HIDDEN edspLikeListParser : public debListParser
 {
    public:
    virtual bool NewVersion(pkgCache::VerIterator &Ver) APT_OVERRIDE;
    virtual std::vector<std::string> AvailableDescriptionLanguages() APT_OVERRIDE;
-   virtual MD5SumValue Description_md5() APT_OVERRIDE;
+   virtual APT::StringView Description_md5() APT_OVERRIDE;
    virtual unsigned short VersionHash() APT_OVERRIDE;
 
    bool LoadReleaseInfo(pkgCache::RlsFileIterator &FileI,FileFd &File,