+ 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(); }
+
+ /** has the list at least one good entry
+ *
+ * similar to #empty, but handles forced hashes.
+ *
+ * @return if no hash is forced, same result as #empty,
+ * if one is forced \b true if this has is available, \b false otherwise
+ */
+ bool usable() const;
+
+ 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 by default,
+ * if one doesn't match false is returned regardless of how many
+ * matched before. If a hash is forced, only this hash is compared,
+ * all others are ignored.
+ */
+ 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;