Add DigestRegistry

This allows a digest function to be computed given its name, rather
than hard-coding the specific digest class.

7 files changed, 168 insertions, 0 deletions

diff --git a/paludis/util/digest_registry.cc b/paludis/util/digest_registry.cc
new file mode 100644
index 000000000..ec7ab1e61
--- /dev/null
+++ b/paludis/util/digest_registry.cc
@@ -0,0 +1,70 @@
+/* vim: set sw=4 sts=4 et foldmethod=syntax : */
+
+/*
+ * Copyright (c) 2011 David Leverton
+ *
+ * This file is part of the Paludis package manager. Paludis is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU General
+ * Public License version 2, as published by the Free Software Foundation.
+ *
+ * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <paludis/util/digest_registry.hh>
+#include <paludis/util/pimp-impl.hh>
+#include <paludis/util/singleton-impl.hh>
+#include <map>
+
+using namespace paludis;
+
+namespace
+{
+    typedef std::map<std::string, DigestRegistry::Function> FunctionMap;
+}
+
+namespace paludis
+{
+    template <>
+    struct Imp<DigestRegistry>
+    {
+        FunctionMap functions;
+    };
+}
+
+DigestRegistry::DigestRegistry()
+{
+}
+
+DigestRegistry::~DigestRegistry()
+{
+}
+
+DigestRegistry::Function
+DigestRegistry::get(const std::string & algo) const
+{
+    FunctionMap::const_iterator it(_imp->functions.find(algo));
+    if (_imp->functions.end() == it)
+        return Function();
+    return it->second;
+}
+
+void
+DigestRegistry::register_function(const std::string & algo, const Function & func)
+{
+    _imp->functions.insert(std::make_pair(algo, func));
+}
+
+namespace paludis
+{
+    template class Pimp<DigestRegistry>;
+    template class Singleton<DigestRegistry>;
+}
+
+
diff --git a/paludis/util/digest_registry.hh b/paludis/util/digest_registry.hh
new file mode 100644
index 000000000..cfa86ceea
--- /dev/null
+++ b/paludis/util/digest_registry.hh
@@ -0,0 +1,73 @@
+/* vim: set sw=4 sts=4 et foldmethod=syntax : */
+
+/*
+ * Copyright (c) 2011 David Leverton
+ *
+ * This file is part of the Paludis package manager. Paludis is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU General
+ * Public License version 2, as published by the Free Software Foundation.
+ *
+ * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef PALUDIS_GUARD_PALUDIS_UTIL_DIGEST_REGISTRY_HH
+#define PALUDIS_GUARD_PALUDIS_UTIL_DIGEST_REGISTRY_HH 1
+
+#include <iosfwd>
+#include <string>
+#include <paludis/util/attributes.hh>
+#include <paludis/util/pimp.hh>
+#include <paludis/util/singleton.hh>
+#include <functional>
+
+namespace paludis
+{
+    class PALUDIS_VISIBLE DigestRegistry :
+        public Singleton<DigestRegistry>
+    {
+        friend class Singleton<DigestRegistry>;
+
+        public:
+            typedef std::function<std::string (std::istream &)> Function;
+
+            Function get(const std::string & algo) const;
+
+            template <typename T_>
+            class Registration
+            {
+                public:
+                    Registration(const std::string & algo)
+                    {
+                        get_instance()->register_function(algo, do_digest<T_>);
+                    }
+            };
+
+        private:
+            DigestRegistry();
+            ~DigestRegistry();
+
+            Pimp<DigestRegistry> _imp;
+
+            void register_function(const std::string & algo, const Function & func);
+
+            template <typename T_>
+            static std::string
+            do_digest(std::istream & stream)
+            {
+                T_ digest(stream);
+                return digest.hexsum();
+            }
+    };
+
+    extern template class Pimp<DigestRegistry>;
+    extern template class Singleton<DigestRegistry>;
+}
+
+#endif
diff --git a/paludis/util/files.m4 b/paludis/util/files.m4
index 2e8efb49f..219d7a45c 100644
--- a/paludis/util/files.m4
+++ b/paludis/util/files.m4
@@ -23,6 +23,7 @@ add(`create_iterator',                   `hh', `fwd', `impl', `gtest')
 add(`damerau_levenshtein',               `hh', `cc', `gtest')
 add(`destringify',                       `hh', `cc', `gtest')
 add(`deferred_construction_ptr',         `hh', `cc', `fwd', `gtest')
+add(`digest_registry',                   `hh', `cc')
 add(`discard_output_stream',             `hh', `cc')
 add(`elf',                               `hh', `cc')
 add(`elf_dynamic_section',               `hh', `cc')
diff --git a/paludis/util/md5.cc b/paludis/util/md5.cc
index 114d4a1ff..727ee16b0 100644
--- a/paludis/util/md5.cc
+++ b/paludis/util/md5.cc
@@ -18,6 +18,7 @@
  */
 
 #include <paludis/util/md5.hh>
+#include <paludis/util/digest_registry.hh>
 #include <sstream>
 #include <istream>
 #include <iomanip>
@@ -237,3 +238,8 @@ const uint32_t MD5::_t[64] = {
     0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
 };
 
+namespace
+{
+    DigestRegistry::Registration<MD5> registration("MD5");
+}
+
diff --git a/paludis/util/rmd160.cc b/paludis/util/rmd160.cc
index 024459b24..394cf60c9 100644
--- a/paludis/util/rmd160.cc
+++ b/paludis/util/rmd160.cc
@@ -19,6 +19,7 @@
 
 #include "rmd160.hh"
 #include <paludis/util/attributes.hh>
+#include <paludis/util/digest_registry.hh>
 #include <sstream>
 #include <istream>
 #include <iomanip>
@@ -229,3 +230,8 @@ const uint32_t RMD160::_kp[5] = {
     0x50a28be6, 0x5c4dd124, 0x6d703ef3, 0x7a6d76e9, 0x00000000
 };
 
+namespace
+{
+    DigestRegistry::Registration<RMD160> registration("RMD160");
+}
+
diff --git a/paludis/util/sha1.cc b/paludis/util/sha1.cc
index fc2b54f70..70920174f 100644
--- a/paludis/util/sha1.cc
+++ b/paludis/util/sha1.cc
@@ -21,6 +21,7 @@
 
 #include <paludis/util/sha1.hh>
 #include <paludis/util/byte_swap.hh>
+#include <paludis/util/digest_registry.hh>
 #include <sstream>
 #include <istream>
 #include <iomanip>
@@ -209,3 +210,8 @@ SHA1::hexsum() const
     return result.str();
 }
 
+namespace
+{
+    DigestRegistry::Registration<SHA1> registration("SHA1");
+}
+
diff --git a/paludis/util/sha256.cc b/paludis/util/sha256.cc
index d9900f573..b44b11fe5 100644
--- a/paludis/util/sha256.cc
+++ b/paludis/util/sha256.cc
@@ -19,6 +19,7 @@
 
 #include "sha256.hh"
 #include <paludis/util/attributes.hh>
+#include <paludis/util/digest_registry.hh>
 #include <istream>
 #include <iomanip>
 #include <sstream>
@@ -226,3 +227,8 @@ paludis::SHA256::_k[64] = {
     0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 };
 
+namespace
+{
+    DigestRegistry::Registration<SHA256> registration("SHA256");
+}
+