add a simple container for HashStrings

APT supports more than just one HashString and even allows to enforce
the usage of a specific hash. This class is intended to help with
storage and passing around of the HashStrings.

The cherry-pick here the un-const-ification of HashType() compared to
f4c3850ea335545e297504941dc8c7a8f1c83358. The point of this commit is
adding infrastructure for the next one. All by itself, it just adds new
symbols.

Git-Dch: Ignore

1 files changed, 83 insertions, 1 deletions

diff --git a/apt-pkg/contrib/hashes.h b/apt-pkg/contrib/hashes.h
index 7a62f8a8f..5a4213868 100644
--- a/apt-pkg/contrib/hashes.h
+++ b/apt-pkg/contrib/hashes.h
@@ -17,6 +17,7 @@
 #include <apt-pkg/md5.h>
 #include <apt-pkg/sha1.h>
 #include <apt-pkg/sha2.h>
+#include <apt-pkg/macros.h>
 
 #include <cstring>
 #include <string>
@@ -41,7 +42,7 @@ class HashString
  protected:
    std::string Type;
    std::string Hash;
-   static const char* _SupportedHashes[10];
+   static const char * _SupportedHashes[10];
 
    // internal helper
    std::string GetHashForFile(std::string filename) const;
@@ -53,6 +54,8 @@ class HashString
 
    // get hash type used
    std::string HashType() { return Type; };
+   std::string HashType() const { return Type; };
+   std::string HashValue() const { return Hash; };
 
    // verify the given filename against the currently loaded hash
    bool VerifyFile(std::string filename) const;
@@ -64,11 +67,90 @@ class HashString
    // helper
    std::string toStr() const;                    // convert to str as "type:hash"
    bool empty() const;
+   bool operator==(HashString const &other) const;
+   bool operator!=(HashString const &other) const;
 
    // return the list of hashes we support
    static APT_CONST const char** SupportedHashes();
 };
 
+class HashStringList
+{
+   public:
+   /** find best hash if no specific one is requested
+    *
+    * @param type of the checksum to return, can be \b NULL
+    * @return If type is \b NULL (or the empty string) it will
+    *  return the 'best' hash; otherwise the hash which was
+    *  specifically requested. If no hash is found \b NULL will be returned.
+    */
+   HashString const * find(char const * const type) const;
+   HashString const * find(std::string const &type) const { return find(type.c_str()); }
+   /** check if the given hash type is supported
+    *
+    * @param type to check
+    * @return true if supported, otherwise false
+    */
+   static APT_PURE bool supported(char const * const type);
+   /** add the given #HashString to the list
+    *
+    * @param hashString to add
+    * @return true if the hash is added because it is supported and
+    *  not already a different hash of the same type included, otherwise false
+    */
+   bool push_back(const HashString &hashString);
+   /** @return size of the list of HashStrings */
+   size_t size() const { return list.size(); }
+
+   /** take the 'best' hash and verify file with it
+    *
+    * @param filename to verify
+    * @return true if the file matches the hashsum, otherwise false
+    */
+   bool VerifyFile(std::string filename) const;
+
+   /** is the list empty ?
+    *
+    * @return \b true if the list is empty, otherwise \b false
+    */
+   bool empty() const { return list.empty(); }
+
+   typedef std::vector<HashString>::const_iterator const_iterator;
+
+   /** iterator to the first element */
+   const_iterator begin() const { return list.begin(); }
+
+   /** iterator to the end element */
+   const_iterator end() const { return list.end(); }
+
+   /** start fresh with a clear list */
+   void clear() { list.clear(); }
+
+   /** compare two HashStringList for similarity.
+    *
+    * Two lists are similar if at least one hashtype is in both lists
+    * and the hashsum matches. All hashes are checked, if one doesn't
+    * match false is returned regardless of how many matched before.
+    */
+   bool operator==(HashStringList const &other) const;
+   bool operator!=(HashStringList const &other) const;
+
+   HashStringList() {}
+
+   // simplifying API-compatibility constructors
+   HashStringList(std::string const &hash) {
+      if (hash.empty() == false)
+	 list.push_back(HashString(hash));
+   }
+   HashStringList(char const * const hash) {
+      if (hash != NULL && hash[0] != '\0')
+	 list.push_back(HashString(hash));
+   }
+
+   private:
+   std::vector<HashString> list;
+};
+
 class Hashes
 {
    public: