Refactor `BaseDictionary` and `Dictionary` constructors, add `operator[]` for di…

…ctionary key access, and simplify null handling logic.

Refactor `BaseDictionary` and `Dictionary` constructors, add `operator[]` for di…
…ctionary key access, and simplify null handling logic.
m-holger
1 parent 722ca8e0
Showing 4 changed files with 101 additions and 18 deletions
include/qpdf/ObjectHandle.hh
libqpdf/QPDF_Dictionary.cc
libqpdf/qpdf/QPDFObjectHandle_private.hh
qpdf/qpdf.testcov
@@ -83,6 +83,8 @@ namespace qpdf
         QPDFObjectHandle operator[](size_t n) const;
         QPDFObjectHandle operator[](int n) const;
+        QPDFObjectHandle const& operator[](std::string const& key) const;
+
         std::shared_ptr<QPDFObject> copy(bool shallow = false) const;
         // Recursively remove association with any QPDF object. This method may only be called
         // during final destruction.
@@ -16,6 +16,19 @@ BaseDictionary::dict() const
     return nullptr; // unreachable
 }
+QPDFObjectHandle const&
+BaseHandle::operator[](std::string const& key) const
+{
+    if (auto d = as<QPDF_Dictionary>()) {
+        auto it = d->items.find(key);
+        if (it != d->items.end()) {
+            return it->second;
+        }
+    }
+    static const QPDFObjectHandle null_obj;
+    return null_obj;
+}
+
 bool
 BaseDictionary::hasKey(std::string const& key) const
 {
@@ -78,13 +91,28 @@ BaseDictionary::replaceKey(std::string const&amp; key, QPDFObjectHandle value)
     }
 }
+Dictionary::Dictionary(std::map<std::string, QPDFObjectHandle>&& dict) :
+    BaseDictionary(std::move(dict))
+{
+}
+
+Dictionary::Dictionary(std::shared_ptr<QPDFObject> const& obj) :
+    BaseDictionary(obj)
+{
+}
+
+Dictionary
+Dictionary::empty()
+{
+    return Dictionary(std::map<std::string, QPDFObjectHandle>());
+}
+
 void
 QPDFObjectHandle::checkOwnership(QPDFObjectHandle const& item) const
 {
     auto qpdf = getOwningQPDF();
     auto item_qpdf = item.getOwningQPDF();
     if (qpdf && item_qpdf && qpdf != item_qpdf) {
-        QTC::TC("qpdf", "QPDFObjectHandle check ownership");
         throw std::logic_error(
             "Attempting to add an object from a different QPDF. Use "
             "QPDF::copyForeignObject to add objects from another file.");
@@ -119,6 +119,14 @@ namespace qpdf
     class BaseDictionary: public BaseHandle
     {
       public:
+        // The following methods are not part of the public API.
+        bool hasKey(std::string const& key) const;
+        QPDFObjectHandle getKey(std::string const& key) const;
+        std::set<std::string> getKeys();
+        std::map<std::string, QPDFObjectHandle> const& getAsMap() const;
+        void removeKey(std::string const& key);
+        void replaceKey(std::string const& key, QPDFObjectHandle value);
+
         using iterator = std::map<std::string, QPDFObjectHandle>::iterator;
         using const_iterator = std::map<std::string, QPDFObjectHandle>::const_iterator;
         using reverse_iterator = std::map<std::string, QPDFObjectHandle>::reverse_iterator;
@@ -197,41 +205,87 @@ namespace qpdf
             return {};
         }
-        // The following methods are not part of the public API.
-        bool hasKey(std::string const& key) const;
-        QPDFObjectHandle getKey(std::string const& key) const;
-        std::set<std::string> getKeys();
-        std::map<std::string, QPDFObjectHandle> const& getAsMap() const;
-        void removeKey(std::string const& key);
-        void replaceKey(std::string const& key, QPDFObjectHandle value);
-
       protected:
         BaseDictionary() = default;
-        BaseDictionary(std::shared_ptr<QPDFObject> const& obj) :
-            BaseHandle(obj) {};
-        BaseDictionary(std::shared_ptr<QPDFObject>&& obj) :
-            BaseHandle(std::move(obj)) {};
+
+        explicit BaseDictionary(std::map<std::string, QPDFObjectHandle> const& dict) :
+            BaseHandle(QPDFObject::create<QPDF_Dictionary>(dict))
+        {
+        }
+
+        explicit BaseDictionary(std::map<std::string, QPDFObjectHandle>&& dict) :
+            BaseHandle(QPDFObject::create<QPDF_Dictionary>(std::move(dict)))
+        {
+        }
+
+        explicit BaseDictionary(std::shared_ptr<QPDFObject> const& obj) :
+            BaseHandle(obj)
+        {
+        }
+        explicit BaseDictionary(std::shared_ptr<QPDFObject>&& obj) :
+            BaseHandle(std::move(obj))
+        {
+        }
         BaseDictionary(BaseDictionary const&) = default;
         BaseDictionary& operator=(BaseDictionary const&) = default;
         BaseDictionary(BaseDictionary&&) = default;
         BaseDictionary& operator=(BaseDictionary&&) = default;
+
+        explicit BaseDictionary(QPDFObjectHandle const& oh) :
+            BaseHandle(oh.resolved_type_code() == ::ot_dictionary ? oh : QPDFObjectHandle())
+        {
+        }
+
+        explicit BaseDictionary(QPDFObjectHandle&& oh) :
+            BaseHandle(
+                oh.resolved_type_code() == ::ot_dictionary ? std::move(oh) : QPDFObjectHandle())
+        {
+        }
         ~BaseDictionary() = default;
         QPDF_Dictionary* dict() const;
     };
+    // Dictionary only defines con/destructors. All other methods are inherited from BaseDictionary.
     class Dictionary final: public BaseDictionary
     {
       public:
-        explicit Dictionary(std::shared_ptr<QPDFObject> const& obj) :
-            BaseDictionary(obj)
+        Dictionary() = default;
+        explicit Dictionary(std::map<std::string, QPDFObjectHandle>&& dict);
+        explicit Dictionary(std::shared_ptr<QPDFObject> const& obj);
+
+        static Dictionary empty();
+
+        Dictionary(Dictionary const&) = default;
+        Dictionary& operator=(Dictionary const&) = default;
+        Dictionary(Dictionary&&) = default;
+        Dictionary& operator=(Dictionary&&) = default;
+
+        Dictionary(QPDFObjectHandle const& oh) :
+            BaseDictionary(oh)
+        {
+        }
+
+        Dictionary&
+        operator=(QPDFObjectHandle const& oh)
+        {
+            assign(::ot_dictionary, oh);
+            return *this;
+        }
+
+        Dictionary(QPDFObjectHandle&& oh) :
+            BaseDictionary(std::move(oh))
         {
         }
-        explicit Dictionary(std::shared_ptr<QPDFObject>&& obj) :
-            BaseDictionary(std::move(obj))
+        Dictionary&
+        operator=(QPDFObjectHandle&& oh)
         {
+            assign(::ot_dictionary, std::move(oh));
+            return *this;
         }
+
+        ~Dictionary() = default;
     };
     class Name final: public BaseHandle
@@ -537,7 +537,6 @@ QPDFWriter preserve object streams 0
 QPDFWriter preserve object streams preserve unreferenced 0
 QPDFWriter exclude from object stream 0
 QPDF_pages findPage not found 0
-QPDFObjectHandle check ownership 0
 QPDFJob weak crypto error 0
 qpdf-c called qpdf_oh_is_initialized 0
 qpdf-c registered progress reporter 0