Refactor: introduce private-API `Integer` class and update integer handling in `QPDFObjectHandle`.

m-holger
1 parent e50ee3b6
Showing 5 changed files with 158 additions and 38 deletions
include/qpdf/ObjectHandle.hh
libqpdf/QPDFObjectHandle.cc
libqpdf/qpdf/QPDFObjectHandle_private.hh
libqpdf/qpdf/QPDFObject_private.hh
qpdf/qpdf.testcov
@@ -27,7 +27,6 @@
 #include <qpdf/JSON.hh>
 #include <qpdf/QPDFExc.hh>
 #include <qpdf/QPDFObjGen.hh>
-#include <qpdf/Types.h>
 #include <cstdint>
 #include <memory>
@@ -42,6 +41,7 @@ namespace qpdf
     class Array;
     class BaseDictionary;
     class Dictionary;
+    class Integer;
     class Stream;
     enum typed : std::uint8_t { strict = 0, any_flag = 1, optional = 2, any = 3, error = 4 };
@@ -127,6 +127,7 @@ namespace qpdf
         inline void assign(qpdf_object_type_e required, BaseHandle&& other);
         std::string description() const;
+        std::invalid_argument invalid_error(std::string const& method) const;
         std::runtime_error type_error(char const* expected_type) const;
         QPDFExc type_error(char const* expected_type, std::string const& message) const;
         char const* type_name() const;
@@ -806,16 +806,36 @@ QPDFObjectHandle::getValueAsBool(bool&amp; value) const
     return false;
 }
-// Integer accessors
+// Integer methods
+
+Integer::Integer(long long value) :
+    BaseHandle(QPDFObject::create<QPDF_Integer>(value))
+{
+}
+
+QPDFObjectHandle
+QPDFObjectHandle::newInteger(long long value)
+{
+    return {QPDFObject::create<QPDF_Integer>(value)};
+}
+
+int64_t
+Integer::value() const
+{
+    auto* i = as<QPDF_Integer>();
+    if (!i) {
+        throw invalid_error("Integer");
+    }
+    return i->val;
+}
 long long
 QPDFObjectHandle::getIntValue() const
 {
-    if (auto integer = as<QPDF_Integer>()) {
-        return integer->val;
+    if (auto const integer = Integer(*this)) {
+        return integer;
     } else {
         typeWarning("integer", "returning 0");
-        QTC::TC("qpdf", "QPDFObjectHandle integer returning 0");
         return 0;
     }
 }
@@ -823,8 +843,8 @@ QPDFObjectHandle::getIntValue() const
 bool
 QPDFObjectHandle::getValueAsInt(long long& value) const
 {
-    if (auto integer = as<QPDF_Integer>()) {
-        value = integer->val;
+    if (auto const integer = Integer(*this)) {
+        value = integer;
         return true;
     }
     return false;
@@ -833,16 +853,18 @@ QPDFObjectHandle::getValueAsInt(long long&amp; value) const
 int
 QPDFObjectHandle::getIntValueAsInt() const
 {
-    long long v = getIntValue();
-    if (v < INT_MIN) {
+    try {
+        return Integer(*this);
+    } catch (std::underflow_error&) {
         warn("requested value of integer is too small; returning INT_MIN");
         return INT_MIN;
-    }
-    if (v > INT_MAX) {
+    } catch (std::overflow_error&) {
         warn("requested value of integer is too big; returning INT_MAX");
         return INT_MAX;
+    } catch (std::invalid_argument&) {
+        typeWarning("integer", "returning 0");
+        return 0;
     }
-    return static_cast<int>(v);
 }
 bool
@@ -858,12 +880,14 @@ QPDFObjectHandle::getValueAsInt(int&amp; value) const
 unsigned long long
 QPDFObjectHandle::getUIntValue() const
 {
-    long long v = getIntValue();
-    if (v < 0) {
+    try {
+        return Integer(*this);
+    } catch (std::underflow_error&) {
         warn("unsigned value request for negative number; returning 0");
         return 0;
-    } else {
-        return static_cast<unsigned long long>(v);
+    } catch (std::invalid_argument&) {
+        typeWarning("integer", "returning 0");
+        return 0;
     }
 }
@@ -880,16 +904,18 @@ QPDFObjectHandle::getValueAsUInt(unsigned long long&amp; value) const
 unsigned int
 QPDFObjectHandle::getUIntValueAsUInt() const
 {
-    long long v = getIntValue();
-    if (v < 0) {
+    try {
+        return Integer(*this);
+    } catch (std::underflow_error&) {
         warn("unsigned integer value request for negative number; returning 0");
         return 0;
-    }
-    if (v > UINT_MAX) {
+    } catch (std::overflow_error&) {
         warn("requested value of unsigned integer is too big; returning UINT_MAX");
         return UINT_MAX;
+    } catch (std::invalid_argument&) {
+        typeWarning("integer", "returning 0");
+        return 0;
     }
-    return static_cast<unsigned int>(v);
 }
 bool
@@ -1329,7 +1355,7 @@ QPDFObjectHandle::rotatePage(int angle, bool relative)
     }
     new_angle = (new_angle + 360) % 360;
     // Make this explicit even with new_angle == 0 since /Rotate can be inherited.
-    replaceKey("/Rotate", QPDFObjectHandle::newInteger(new_angle));
+    replaceKey("/Rotate", Integer(new_angle));
 }
 void
@@ -1595,12 +1621,11 @@ QPDFObjectHandle::parseContentStream_data(
                 QTC::TC("qpdf", "QPDFObjectHandle EOF in inline image");
                 warn(
                     context,
-                    QPDFExc(
-                        qpdf_e_damaged_pdf,
-                        description,
-                        "stream data",
-                        input.tell(),
-                        "EOF found while reading inline image"));
+                    {qpdf_e_damaged_pdf,
+                     description,
+                     "stream data",
+                     input.tell(),
+                     "EOF found while reading inline image"});
             } else {
                 QTC::TC("qpdf", "QPDFObjectHandle inline image token");
                 if (callbacks) {
@@ -1658,12 +1683,6 @@ QPDFObjectHandle::newNull()
 }
 QPDFObjectHandle
-QPDFObjectHandle::newInteger(long long value)
-{
-    return {QPDFObject::create<QPDF_Integer>(value)};
-}
-
-QPDFObjectHandle
 QPDFObjectHandle::newReal(std::string const& value)
 {
     return {QPDFObject::create<QPDF_Real>(value)};
@@ -1932,6 +1951,11 @@ QPDFObjectHandle::assertInitialized() const
     }
 }
+std::invalid_argument
+BaseHandle::invalid_error(std::string const& method) const
+{
+    return std::invalid_argument(method + " operation attempted on invalid object");
+}
 std::runtime_error
 BaseHandle::type_error(char const* expected_type) const
 {
@@ -1976,9 +2000,7 @@ void
 QPDFObjectHandle::assertType(char const* type_name, bool istype) const
 {
     if (!istype) {
-        throw std::runtime_error(
-            std::string("operation for ") + type_name + " attempted on object of type " +
-            QPDFObjectHandle(*this).getTypeName());
+        throw type_error(type_name);
     }
 }
@@ -7,6 +7,11 @@
 #include <qpdf/QPDF_private.hh>
 #include <qpdf/QUtil.hh>
+#include <concepts>
+#include <utility>
+
+using namespace std::literals;
+
 namespace qpdf
 {
     class Array final: public BaseHandle
@@ -285,6 +290,97 @@ namespace qpdf
         ~Dictionary() = default;
     };
+    class Integer final: public BaseHandle
+    {
+      public:
+        Integer() = default;
+        Integer(Integer const&) = default;
+        Integer(Integer&&) = default;
+        Integer& operator=(Integer const&) = default;
+        Integer& operator=(Integer&&) = default;
+        ~Integer() = default;
+
+        explicit Integer(long long value);
+
+        explicit Integer(std::integral auto value) :
+            Integer(static_cast<long long>(value))
+        {
+            if constexpr (
+                std::numeric_limits<decltype(value)>::max() >
+                std::numeric_limits<long long>::max()) {
+                if (value > std::numeric_limits<long long>::max()) {
+                    throw std::overflow_error("overflow constructing Integer");
+                }
+            }
+        }
+
+        Integer(QPDFObjectHandle const& oh) :
+            BaseHandle(oh.type_code() == ::ot_integer ? oh : QPDFObjectHandle())
+        {
+        }
+
+        Integer(QPDFObjectHandle&& oh) :
+            BaseHandle(oh.type_code() == ::ot_integer ? std::move(oh) : QPDFObjectHandle())
+        {
+        }
+
+        // Return the integer value. If the object is not a valid integer, throw a
+        // std::invalid_argument exception. If the object is out of range for the target type,
+        // throw a std::overflow_error or std::underflow_error exception.
+        template <std::integral T>
+        operator T() const
+        {
+            auto v = value();
+
+            if (std::cmp_greater(v, std::numeric_limits<T>::max())) {
+                throw std::overflow_error("Integer conversion overflow");
+            }
+            if (std::cmp_less(v, std::numeric_limits<T>::min())) {
+                throw std::underflow_error("Integer conversion underflow");
+            }
+            return static_cast<T>(v);
+        }
+
+        // Return the integer value. If the object is not a valid integer, throw a
+        // std::invalid_argument exception.
+        int64_t value() const;
+
+        // Return true if object value is equal to the 'rhs' value. Return false if the object is
+        // not a valid Integer.
+        friend bool
+        operator==(Integer const& lhs, std::integral auto rhs)
+        {
+            return lhs && std::cmp_equal(lhs.value(), rhs);
+        }
+
+        // Compare the object value to the 'rhs' value. Throw a std::invalid_argument exception if
+        // the object is not a valid Integer.
+        friend std::strong_ordering
+        operator<=>(Integer const& lhs, std::integral auto rhs)
+        {
+            if (!lhs) {
+                throw lhs.invalid_error("Integer");
+            }
+            if (std::cmp_less(lhs.value(), rhs)) {
+                return std::strong_ordering::less;
+            }
+            return std::cmp_greater(lhs.value(), rhs) ? std::strong_ordering::greater
+                                                      : std::strong_ordering::equal;
+        }
+    };
+
+    bool
+    operator==(std::integral auto lhs, Integer const& rhs)
+    {
+        return rhs == lhs;
+    }
+
+    std::strong_ordering
+    operator<=>(std::integral auto lhs, Integer const& rhs)
+    {
+        return rhs <=> lhs;
+    }
+
     class Name final: public BaseHandle
     {
       public:
@@ -27,6 +27,7 @@ namespace qpdf
     class Array;
     class BaseDictionary;
     class Dictionary;
+    class Integer;
     class Stream;
 } // namespace qpdf
@@ -123,6 +124,7 @@ class QPDF_Integer final
 {
     friend class QPDFObject;
     friend class qpdf::BaseHandle;
+    friend class qpdf::Integer;
     friend class QPDFObjectHandle;
     QPDF_Integer(long long val) :
@@ -277,7 +277,6 @@ QPDFParser bad token in parseRemainder 0
 QPDFParser eof in parse 0
 QPDFParser eof in parseRemainder 0
 QPDFObjectHandle boolean returning false 0
-QPDFObjectHandle integer returning 0 0
 QPDFObjectHandle real returning 0.0 0
 QPDFObjectHandle name returning dummy name 0
 QPDFObjectHandle string returning empty string 0