Refactor QPDF_Array::at

Change the return type to a std::pair<bool, QPDFObjectHandle> in order to allow a default constructed object handle (which is currently returned to indicate failure) to become a valid object.

Refactor QPDF_Array::at
Change the return type to a std::pair<bool, QPDFObjectHandle> in order to allow a default constructed object handle (which is currently returned to indicate failure) to become a valid object.
m-holger · m-holger
1 parent 0afaaea2
Showing 4 changed files with 55 additions and 54 deletions
libqpdf/QPDFObjectHandle.cc
libqpdf/QPDF_Array.cc
libqpdf/qpdf/QPDF_Array.hh
libtests/sparse_array.cc
@@ -1021,8 +1021,9 @@ QPDFObjectHandle::getArrayItem(int n) const
 #endif
 {
     if (auto array = asArray()) {
-        if (auto result = array->at(n); result.obj != nullptr) {
-            return result;
+        auto result = array->at(n);
+        if (result.first) {
+            return result.second;
         } else {
             objectWarning("returning null for out of bounds array access");
             QTC::TC("qpdf", "QPDFObjectHandle array bounds");
@@ -1045,7 +1046,7 @@ QPDFObjectHandle::isRectangle() const
 {
     if (auto array = asArray()) {
         for (int i = 0; i < 4; ++i) {
-            if (auto item = array->at(i); !(item.obj && item.isNumber())) {
+            if (auto item = array->at(i).second; !item.isNumber()) {
                 return false;
             }
         }
@@ -1064,7 +1065,7 @@ QPDFObjectHandle::isMatrix() const
 {
     if (auto array = asArray()) {
         for (int i = 0; i < 6; ++i) {
-            if (auto item = array->at(i); !(item.obj && item.isNumber())) {
+            if (auto item = array->at(i).second; !item.isNumber()) {
                 return false;
             }
         }
@@ -1087,7 +1088,7 @@ QPDFObjectHandle::getArrayAsRectangle() const
         }
         double items[4];
         for (int i = 0; i < 4; ++i) {
-            if (!array->at(i).getValueAsNumber(items[i])) {
+            if (auto item = array->at(i).second; !item.getValueAsNumber(items[i])) {
                 return {};
             }
         }
@@ -1114,7 +1115,7 @@ QPDFObjectHandle::getArrayAsMatrix() const
         }
         double items[6];
         for (int i = 0; i < 6; ++i) {
-            if (!array->at(i).getValueAsNumber(items[i])) {
+            if (auto item = array->at(i).second; !item.getValueAsNumber(items[i])) {
                 return {};
             }
         }
@@ -1224,7 +1225,7 @@ QPDFObjectHandle
 QPDFObjectHandle::eraseItemAndGetOld(int at)
 {
     auto array = asArray();
-    auto result = (array && at < array->size() && at >= 0) ? array->at(at) : newNull();
+    auto result = (array && at < array->size() && at >= 0) ? array->at(at).second : newNull();
     eraseItem(at);
     return result;
 }
@@ -1764,7 +1765,7 @@ QPDFObjectHandle::arrayOrStreamToStreamArray(
     if (auto array = asArray()) {
         int n_items = array->size();
         for (int i = 0; i < n_items; ++i) {
-            QPDFObjectHandle item = array->at(i);
+            QPDFObjectHandle item = array->at(i).second;
             if (item.isStream()) {
                 result.push_back(item);
             } else {
@@ -2465,7 +2466,7 @@ QPDFObjectHandle::makeDirect(QPDFObjGen::set&amp; visited, bool stop_at_streams)
         auto array = asArray();
         int n = array->size();
         for (int i = 0; i < n; ++i) {
-            items.push_back(array->at(i));
+            items.push_back(array->at(i).second);
             items.back().makeDirect(visited, stop_at_streams);
         }
         this->obj = QPDF_Array::create(items);
@@ -184,16 +184,16 @@ QPDF_Array::writeJSON(int json_version, JSON::Writer&amp; p)
     p.writeEnd(']');
 }
-QPDFObjectHandle
+std::pair<bool, QPDFObjectHandle>
 QPDF_Array::at(int n) const noexcept
 {
     if (n < 0 || n >= size()) {
-        return {};
+        return {false, {}};
     } else if (sp) {
         auto const& iter = sp->elements.find(n);
-        return iter == sp->elements.end() ? null_oh : (*iter).second;
+        return {true, iter == sp->elements.end() ? null_oh : (*iter).second};
     } else {
-        return elements[size_t(n)];
+        return {true, elements[size_t(n)]};
     }
 }
@@ -30,7 +30,7 @@ class QPDF_Array: public QPDFValue
     {
         return sp ? sp->size : int(elements.size());
     }
-    QPDFObjectHandle at(int n) const noexcept;
+    std::pair<bool, QPDFObjectHandle> at(int n) const noexcept;
     bool setAt(int n, QPDFObjectHandle const& oh);
     std::vector<QPDFObjectHandle> getAsVector() const;
     void setFromVector(std::vector<QPDFObjectHandle> const& items);
@@ -21,69 +21,69 @@ main()
     a.push_back(QPDFObjectHandle::parse("null"));
     a.push_back(QPDFObjectHandle::parse("/Quack"));
     assert(a.size() == 5);
-    assert(a.at(0).isInteger() && (a.at(0).getIntValue() == 1));
-    assert(a.at(1).isString() && (a.at(1).getStringValue() == "potato"));
-    assert(a.at(2).isNull());
-    assert(a.at(3).isNull());
-    assert(a.at(4).isName() && (a.at(4).getName() == "/Quack"));
+    assert(a.at(0).second.isInteger() && (a.at(0).second.getIntValue() == 1));
+    assert(a.at(1).second.isString() && (a.at(1).second.getStringValue() == "potato"));
+    assert(a.at(2).second.isNull());
+    assert(a.at(3).second.isNull());
+    assert(a.at(4).second.isName() && (a.at(4).second.getName() == "/Quack"));
     a.insert(4, QPDFObjectHandle::parse("/BeforeQuack"));
     assert(a.size() == 6);
-    assert(a.at(0).isInteger() && (a.at(0).getIntValue() == 1));
-    assert(a.at(4).isName() && (a.at(4).getName() == "/BeforeQuack"));
-    assert(a.at(5).isName() && (a.at(5).getName() == "/Quack"));
+    assert(a.at(0).second.isInteger() && (a.at(0).second.getIntValue() == 1));
+    assert(a.at(4).second.isName() && (a.at(4).second.getName() == "/BeforeQuack"));
+    assert(a.at(5).second.isName() && (a.at(5).second.getName() == "/Quack"));
     a.insert(2, QPDFObjectHandle::parse("/Third"));
     assert(a.size() == 7);
-    assert(a.at(1).isString() && (a.at(1).getStringValue() == "potato"));
-    assert(a.at(2).isName() && (a.at(2).getName() == "/Third"));
-    assert(a.at(3).isNull());
-    assert(a.at(6).isName() && (a.at(6).getName() == "/Quack"));
+    assert(a.at(1).second.isString() && (a.at(1).second.getStringValue() == "potato"));
+    assert(a.at(2).second.isName() && (a.at(2).second.getName() == "/Third"));
+    assert(a.at(3).second.isNull());
+    assert(a.at(6).second.isName() && (a.at(6).second.getName() == "/Quack"));
     a.insert(0, QPDFObjectHandle::parse("/First"));
     assert(a.size() == 8);
-    assert(a.at(0).isName() && (a.at(0).getName() == "/First"));
-    assert(a.at(1).isInteger() && (a.at(1).getIntValue() == 1));
-    assert(a.at(7).isName() && (a.at(7).getName() == "/Quack"));
+    assert(a.at(0).second.isName() && (a.at(0).second.getName() == "/First"));
+    assert(a.at(1).second.isInteger() && (a.at(1).second.getIntValue() == 1));
+    assert(a.at(7).second.isName() && (a.at(7).second.getName() == "/Quack"));
     a.erase(6);
     assert(a.size() == 7);
-    assert(a.at(0).isName() && (a.at(0).getName() == "/First"));
-    assert(a.at(1).isInteger() && (a.at(1).getIntValue() == 1));
-    assert(a.at(5).isNull());
-    assert(a.at(6).isName() && (a.at(6).getName() == "/Quack"));
+    assert(a.at(0).second.isName() && (a.at(0).second.getName() == "/First"));
+    assert(a.at(1).second.isInteger() && (a.at(1).second.getIntValue() == 1));
+    assert(a.at(5).second.isNull());
+    assert(a.at(6).second.isName() && (a.at(6).second.getName() == "/Quack"));
     a.erase(6);
     assert(a.size() == 6);
-    assert(a.at(0).isName() && (a.at(0).getName() == "/First"));
-    assert(a.at(1).isInteger() && (a.at(1).getIntValue() == 1));
-    assert(a.at(3).isName() && (a.at(3).getName() == "/Third"));
-    assert(a.at(4).isNull());
-    assert(a.at(5).isNull());
+    assert(a.at(0).second.isName() && (a.at(0).second.getName() == "/First"));
+    assert(a.at(1).second.isInteger() && (a.at(1).second.getIntValue() == 1));
+    assert(a.at(3).second.isName() && (a.at(3).second.getName() == "/Third"));
+    assert(a.at(4).second.isNull());
+    assert(a.at(5).second.isNull());
     a.setAt(4, QPDFObjectHandle::parse("12"));
-    assert(a.at(4).isInteger() && (a.at(4).getIntValue() == 12));
+    assert(a.at(4).second.isInteger() && (a.at(4).second.getIntValue() == 12));
     a.setAt(4, QPDFObjectHandle::newNull());
-    assert(a.at(4).isNull());
+    assert(a.at(4).second.isNull());
     a.erase(a.size() - 1);
     assert(a.size() == 5);
-    assert(a.at(0).isName() && (a.at(0).getName() == "/First"));
-    assert(a.at(1).isInteger() && (a.at(1).getIntValue() == 1));
-    assert(a.at(3).isName() && (a.at(3).getName() == "/Third"));
-    assert(a.at(4).isNull());
+    assert(a.at(0).second.isName() && (a.at(0).second.getName() == "/First"));
+    assert(a.at(1).second.isInteger() && (a.at(1).second.getIntValue() == 1));
+    assert(a.at(3).second.isName() && (a.at(3).second.getName() == "/Third"));
+    assert(a.at(4).second.isNull());
     a.erase(a.size() - 1);
     assert(a.size() == 4);
-    assert(a.at(0).isName() && (a.at(0).getName() == "/First"));
-    assert(a.at(1).isInteger() && (a.at(1).getIntValue() == 1));
-    assert(a.at(3).isName() && (a.at(3).getName() == "/Third"));
+    assert(a.at(0).second.isName() && (a.at(0).second.getName() == "/First"));
+    assert(a.at(1).second.isInteger() && (a.at(1).second.getIntValue() == 1));
+    assert(a.at(3).second.isName() && (a.at(3).second.getName() == "/Third"));
     a.erase(a.size() - 1);
     assert(a.size() == 3);
-    assert(a.at(0).isName() && (a.at(0).getName() == "/First"));
-    assert(a.at(1).isInteger() && (a.at(1).getIntValue() == 1));
-    assert(a.at(2).isString() && (a.at(2).getStringValue() == "potato"));
+    assert(a.at(0).second.isName() && (a.at(0).second.getName() == "/First"));
+    assert(a.at(1).second.isInteger() && (a.at(1).second.getIntValue() == 1));
+    assert(a.at(2).second.isString() && (a.at(2).second.getStringValue() == "potato"));
     QPDF pdf;
     pdf.emptyPDF();
@@ -92,13 +92,13 @@ main()
     QPDF_Array& b = *obj->as<QPDF_Array>();
     b.setAt(5, pdf.newIndirectNull());
     b.setAt(7, "[0 1 2 3]"_qpdf);
-    assert(b.at(3).isNull());
-    assert(b.at(8).isNull());
-    assert(b.at(5).isIndirect());
+    assert(b.at(3).second.isNull());
+    assert(b.at(8).second.isNull());
+    assert(b.at(5).second.isIndirect());
     assert(b.unparse() == "[ null null null null null 3 0 R null [ 0 1 2 3 ] null null ]");
     auto c = b.copy(true);
     auto d = b.copy(false);
-    b.at(7).setArrayItem(2, "42"_qpdf);
+    b.at(7).second.setArrayItem(2, "42"_qpdf);
     assert(c->unparse() == "[ null null null null null 3 0 R null [ 0 1 42 3 ] null null ]");
     assert(d->unparse() == "[ null null null null null 3 0 R null [ 0 1 2 3 ] null null ]");