Use pkgTagSection::Key in more places in src:apt

The speed critical paths were converted earlier, but the remaining
could benefit a tiny bit from this as well especially as we have the
facility now available and can therefore brush up the code in various
places in the process as well.

Also takes the time to add the hidden Exists method advertised in
the headers, but previously not implemented.

3 files changed, 29 insertions, 28 deletions

diff --git a/apt-pkg/deb/deblistparser.cc b/apt-pkg/deb/deblistparser.cc
index a1247dd98..6f47053a5 100644
--- a/apt-pkg/deb/deblistparser.cc
+++ b/apt-pkg/deb/deblistparser.cc
@@ -126,7 +126,7 @@ unsigned char debListParser::ParseMultiArch(bool const showErrors)	/*{{{*/
       {
 	 if (showErrors == true)
 	    _error->Warning("Architecture: all package '%s' can't be Multi-Arch: same",
-		  Section.FindS("Package").c_str());
+		  Package().c_str());
 	 MA = pkgCache::Version::No;
       }
       else
@@ -140,7 +140,7 @@ unsigned char debListParser::ParseMultiArch(bool const showErrors)	/*{{{*/
    {
       if (showErrors == true)
 	 _error->Warning("Unknown Multi-Arch type '%s' for package '%s'",
-	       MultiArch.to_string().c_str(), Section.FindS("Package").c_str());
+	       MultiArch.to_string().c_str(), Package().c_str());
       MA = pkgCache::Version::No;
    }
 
@@ -256,21 +256,20 @@ bool debListParser::NewVersion(pkgCache::VerIterator &Ver)
 // ListParser::AvailableDescriptionLanguages				/*{{{*/
 std::vector<std::string> debListParser::AvailableDescriptionLanguages()
 {
-   std::vector<std::string> const understood = APT::Configuration::getLanguages(true);
    std::vector<std::string> avail;
    static constexpr int prefixLen = 12;
    char buf[32] = "Description-";
-   if (Section.Exists("Description") == true)
-      avail.push_back("");
-   for (std::vector<std::string>::const_iterator lang = understood.begin(); lang != understood.end(); ++lang)
+   if (Section.Exists(pkgTagSection::Key::Description))
+      avail.emplace_back();
+   for (auto const &lang : APT::Configuration::getLanguages(true))
    {
-      if (unlikely(lang->size() > sizeof(buf) - prefixLen)) {
-	 _error->Warning("Ignoring translated description %s", lang->c_str());
+      if (unlikely(lang.size() > sizeof(buf) - prefixLen)) {
+	 _error->Warning("Ignoring translated description %s", lang.c_str());
 	 continue;
       }
-      memcpy(buf + prefixLen, lang->c_str(), lang->size());
-      if (Section.Exists(StringView(buf, prefixLen + lang->size())) == true)
-	 avail.push_back(*lang);
+      memcpy(buf + prefixLen, lang.c_str(), lang.size());
+      if (Section.Exists(StringView(buf, prefixLen + lang.size())) == true)
+	 avail.push_back(lang);
    }
    return avail;
 }
diff --git a/apt-pkg/deb/debrecords.cc b/apt-pkg/deb/debrecords.cc
index 8fb17ae0b..e2ffaefff 100644
--- a/apt-pkg/deb/debrecords.cc
+++ b/apt-pkg/deb/debrecords.cc
@@ -16,6 +16,7 @@
 #include <apt-pkg/fileutl.h>
 #include <apt-pkg/pkgcache.h>
 #include <apt-pkg/strutl.h>
+#include <apt-pkg/tagfile-keys.h>
 #include <apt-pkg/tagfile.h>
 
 #include <algorithm>
@@ -57,13 +58,13 @@ debRecordParserBase::debRecordParserBase() : Parser(), d(NULL) {}
 // RecordParserBase::FileName - Return the archive filename on the site	/*{{{*/
 string debRecordParserBase::FileName()
 {
-   return Section.FindS("Filename");
+   return Section.Find(pkgTagSection::Key::Filename).to_string();
 }
 									/*}}}*/
 // RecordParserBase::Name - Return the package name			/*{{{*/
 string debRecordParserBase::Name()
 {
-   string Result = Section.FindS("Package");
+   auto Result = Section.Find(pkgTagSection::Key::Package).to_string();
 
    // Normalize mixed case package names to lower case, like dpkg does
    // See Bug#807012 for details
@@ -75,7 +76,7 @@ string debRecordParserBase::Name()
 // RecordParserBase::Homepage - Return the package homepage		/*{{{*/
 string debRecordParserBase::Homepage()
 {
-   return Section.FindS("Homepage");
+   return Section.Find(pkgTagSection::Key::Homepage).to_string();
 }
 									/*}}}*/
 // RecordParserBase::Hashes - return the available archive hashes	/*{{{*/
@@ -88,7 +89,7 @@ HashStringList debRecordParserBase::Hashes() const
       if (hash.empty() == false)
 	 hashes.push_back(HashString(*type, hash));
    }
-   auto const size = Section.FindULL("Size", 0);
+   auto const size = Section.FindULL(pkgTagSection::Key::Size, 0);
    if (size != 0)
       hashes.FileSize(size);
    return hashes;
@@ -97,7 +98,7 @@ HashStringList debRecordParserBase::Hashes() const
 // RecordParserBase::Maintainer - Return the maintainer email		/*{{{*/
 string debRecordParserBase::Maintainer()
 {
-   return Section.FindS("Maintainer");
+   return Section.Find(pkgTagSection::Key::Maintainer).to_string();
 }
 									/*}}}*/
 // RecordParserBase::RecordField - Return the value of an arbitrary field	/*{{*/
@@ -134,20 +135,20 @@ string debRecordParserBase::LongDesc(std::string const &lang)
 	    break;
 	 else if (*l == "en")
 	 {
-	    orig = Section.FindS("Description");
+	    orig = Section.Find(pkgTagSection::Key::Description).to_string();
 	    if (orig.empty() == false)
 	       break;
 	 }
       }
       if (orig.empty() == true)
-	 orig = Section.FindS("Description");
+	 orig = Section.Find(pkgTagSection::Key::Description).to_string();
    }
    else
    {
       std::string const tagname = "Description-" + lang;
       orig = Section.FindS(tagname.c_str());
       if (orig.empty() == true && lang == "en")
-	 orig = Section.FindS("Description");
+	 orig = Section.Find(pkgTagSection::Key::Description).to_string();
    }
 
    char const * const codeset = nl_langinfo(CODESET);
@@ -165,17 +166,17 @@ static const char * const SourceVerSeparators = " ()";
 // RecordParserBase::SourcePkg - Return the source package name if any	/*{{{*/
 string debRecordParserBase::SourcePkg()
 {
-   string Res = Section.FindS("Source");
-   string::size_type Pos = Res.find_first_of(SourceVerSeparators);
-   if (Pos == string::npos)
-      return Res;
-   return string(Res,0,Pos);
+   auto Res = Section.Find(pkgTagSection::Key::Source).to_string();
+   auto const Pos = Res.find_first_of(SourceVerSeparators);
+   if (Pos != std::string::npos)
+      Res.erase(Pos);
+   return Res;
 }
 									/*}}}*/
 // RecordParserBase::SourceVer - Return the source version number if present	/*{{{*/
 string debRecordParserBase::SourceVer()
 {
-   string Pkg = Section.FindS("Source");
+   auto const Pkg = Section.Find(pkgTagSection::Key::Source).to_string();
    string::size_type Pos = Pkg.find_first_of(SourceVerSeparators);
    if (Pos == string::npos)
       return "";
diff --git a/apt-pkg/deb/debsrcrecords.h b/apt-pkg/deb/debsrcrecords.h
index b572d3427..1a0bbe0fd 100644
--- a/apt-pkg/deb/debsrcrecords.h
+++ b/apt-pkg/deb/debsrcrecords.h
@@ -12,6 +12,7 @@
 
 #include <apt-pkg/fileutl.h>
 #include <apt-pkg/srcrecords.h>
+#include <apt-pkg/tagfile-keys.h>
 #include <apt-pkg/tagfile.h>
 
 #include <string>
@@ -40,9 +41,9 @@ class APT_HIDDEN debSrcRecordParser : public pkgSrcRecords::Parser
    virtual bool Jump(unsigned long const &Off) APT_OVERRIDE {iOffset = Off; return Tags.Jump(Sect,Off);};
 
    virtual std::string Package() const APT_OVERRIDE;
-   virtual std::string Version() const APT_OVERRIDE {return Sect.FindS("Version");};
-   virtual std::string Maintainer() const APT_OVERRIDE {return Sect.FindS("Maintainer");};
-   virtual std::string Section() const APT_OVERRIDE {return Sect.FindS("Section");};
+   virtual std::string Version() const APT_OVERRIDE {return Sect.Find(pkgTagSection::Key::Version).to_string();};
+   virtual std::string Maintainer() const APT_OVERRIDE {return Sect.Find(pkgTagSection::Key::Maintainer).to_string();};
+   virtual std::string Section() const APT_OVERRIDE {return Sect.Find(pkgTagSection::Key::Section).to_string();};
    virtual const char **Binaries() APT_OVERRIDE;
    virtual bool BuildDepends(std::vector<BuildDepRec> &BuildDeps, bool const &ArchOnly, bool const &StripMultiArch = true) APT_OVERRIDE;
    virtual unsigned long Offset() APT_OVERRIDE {return iOffset;};