Refactor optimization structures: move `ObjUser` and `UpdateObjectMapsFrame` to …

…`Lin`, encapsulate optimization data within `Lin`, update usage across the codebase, and streamline related logic in `QPDF_linearization`.

Refactor optimization structures: move `ObjUser` and `UpdateObjectMapsFrame` to …
…`Lin`, encapsulate optimization data within `Lin`, update usage across the codebase, and streamline related logic in `QPDF_linearization`.
m-holger
1 parent bd4bc944
Showing 3 changed files with 78 additions and 92 deletions
include/qpdf/QPDF.hh
libqpdf/QPDF_linearization.cc
libqpdf/qpdf/QPDF_private.hh
@@ -797,8 +797,6 @@ class QPDF
     struct CHPageOffset;
     struct CHSharedObjectEntry;
     struct CHSharedObject;
-    class ObjUser;
-    struct UpdateObjectMapsFrame;
     class PatternFinder;
     // Methods to support pattern finding
@@ -69,20 +69,20 @@ load_vector_vector(
     bit_stream.skipToNextByte();
 }
-QPDF::ObjUser::ObjUser(user_e type) :
+Lin::ObjUser::ObjUser(user_e type) :
     ou_type(type)
 {
     qpdf_expect(type == ou_root);
 }
-QPDF::ObjUser::ObjUser(user_e type, size_t pageno) :
+Lin::ObjUser::ObjUser(user_e type, size_t pageno) :
     ou_type(type),
     pageno(pageno)
 {
     qpdf_expect(type == ou_page || type == ou_thumb);
 }
-QPDF::ObjUser::ObjUser(user_e type, std::string const& key) :
+Lin::ObjUser::ObjUser(user_e type, std::string const& key) :
     ou_type(type),
     key(key)
 {
@@ -90,7 +90,7 @@ QPDF::ObjUser::ObjUser(user_e type, std::string const&amp; key) :
 }
 bool
-QPDF::ObjUser::operator<(ObjUser const& rhs) const
+Lin::ObjUser::operator<(ObjUser const& rhs) const
 {
     if (ou_type < rhs.ou_type) {
         return true;
@@ -106,8 +106,8 @@ QPDF::ObjUser::operator&lt;(ObjUser const&amp; rhs) const
     return false;
 }
-QPDF::UpdateObjectMapsFrame::UpdateObjectMapsFrame(
-    QPDF::ObjUser const& ou, QPDFObjectHandle oh, bool top) :
+Lin::UpdateObjectMapsFrame::UpdateObjectMapsFrame(
+    ObjUser const& ou, QPDFObjectHandle oh, bool top) :
     ou(ou),
     oh(oh),
     top(top)
@@ -137,7 +137,7 @@ Lin::optimize_internal(
     bool allow_changes,
     std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
 {
-    if (!m->obj_user_to_objects.empty()) {
+    if (!obj_user_to_objects_.empty()) {
         // already optimized
         return;
     }
@@ -186,9 +186,9 @@ Lin::optimize_internal(
     }
     ObjUser root_ou = ObjUser(ObjUser::ou_root);
-    auto root_og = QPDFObjGen(root.getObjGen());
-    m->obj_user_to_objects[root_ou].insert(root_og);
-    m->object_to_obj_users[root_og].insert(root_ou);
+    auto root_og =root.id_gen();
+    obj_user_to_objects_[root_ou].insert(root_og);
+    object_to_obj_users_[root_og].insert(root_ou);
     filterCompressedObjects(object_stream_data);
 }
@@ -217,14 +217,14 @@ Lin::updateObjectMaps(
             }
         }
-        if (cur.oh.isIndirect()) {
+        if (cur.oh.indirect()) {
             QPDFObjGen og(cur.oh.getObjGen());
             if (!visited.add(og)) {
                 QTC::TC("qpdf", "QPDF opt loop detected");
                 continue;
             }
-            m->obj_user_to_objects[cur.ou].insert(og);
-            m->object_to_obj_users[og].insert(cur.ou);
+            obj_user_to_objects_[cur.ou].insert(og);
+            object_to_obj_users_[og].insert(cur.ou);
         }
         if (cur.oh.isArray()) {
@@ -280,34 +280,30 @@ Lin::filterCompressedObjects(std::map&lt;int, int&gt; const&amp; object_stream_data)
     std::map<ObjUser, std::set<QPDFObjGen>> t_obj_user_to_objects;
     std::map<QPDFObjGen, std::set<ObjUser>> t_object_to_obj_users;
-    for (auto const& i1: m->obj_user_to_objects) {
-        ObjUser const& ou = i1.first;
-        // Loop over objects.
-        for (auto const& og: i1.second) {
+    for (auto const& [ou, ogs]: obj_user_to_objects_) {
+        for (auto const& og: ogs) {
             auto i2 = object_stream_data.find(og.getObj());
             if (i2 == object_stream_data.end()) {
                 t_obj_user_to_objects[ou].insert(og);
             } else {
-                t_obj_user_to_objects[ou].insert(QPDFObjGen(i2->second, 0));
+                t_obj_user_to_objects[ou].insert({i2->second, 0});
             }
         }
     }
-    for (auto const& i1: m->object_to_obj_users) {
-        QPDFObjGen const& og = i1.first;
-        // Loop over obj_users.
-        for (auto const& ou: i1.second) {
+    for (auto const& [og, ous]: object_to_obj_users_) {
+        for (auto const& ou: ous) {
             auto i2 = object_stream_data.find(og.getObj());
             if (i2 == object_stream_data.end()) {
                 t_object_to_obj_users[og].insert(ou);
             } else {
-                t_object_to_obj_users[QPDFObjGen(i2->second, 0)].insert(ou);
+                t_object_to_obj_users[{i2->second, 0}].insert(ou);
             }
         }
     }
-    m->obj_user_to_objects = t_obj_user_to_objects;
-    m->object_to_obj_users = t_object_to_obj_users;
+    obj_user_to_objects_ = std::move(t_obj_user_to_objects);
+    object_to_obj_users_ = std::move(t_object_to_obj_users);
 }
 void
@@ -324,10 +320,8 @@ Lin::filterCompressedObjects(QPDFWriter::ObjTable const&amp; obj)
     std::map<ObjUser, std::set<QPDFObjGen>> t_obj_user_to_objects;
     std::map<QPDFObjGen, std::set<ObjUser>> t_object_to_obj_users;
-    for (auto const& i1: m->obj_user_to_objects) {
-        ObjUser const& ou = i1.first;
-        // Loop over objects.
-        for (auto const& og: i1.second) {
+    for (auto const& [ou, ogs]: obj_user_to_objects_) {
+        for (auto const& og: ogs) {
             if (obj.contains(og)) {
                 if (auto const& i2 = obj[og].object_stream; i2 <= 0) {
                     t_obj_user_to_objects[ou].insert(og);
@@ -338,22 +332,21 @@ Lin::filterCompressedObjects(QPDFWriter::ObjTable const&amp; obj)
         }
     }
-    for (auto const& i1: m->object_to_obj_users) {
-        QPDFObjGen const& og = i1.first;
+    for (auto const& [og, ous]: object_to_obj_users_) {
         if (obj.contains(og)) {
             // Loop over obj_users.
-            for (auto const& ou: i1.second) {
+            for (auto const& ou: ous) {
                 if (auto i2 = obj[og].object_stream; i2 <= 0) {
                     t_object_to_obj_users[og].insert(ou);
                 } else {
-                    t_object_to_obj_users[QPDFObjGen(i2, 0)].insert(ou);
+                    t_object_to_obj_users[{i2, 0}].insert(ou);
                 }
             }
         }
     }
-    m->obj_user_to_objects = t_obj_user_to_objects;
-    m->object_to_obj_users = t_object_to_obj_users;
+    obj_user_to_objects_ = std::move(t_obj_user_to_objects);
+    object_to_obj_users_ = std::move(t_object_to_obj_users);
 }
 void
@@ -793,12 +786,12 @@ qpdf_offset_t
 Lin::maxEnd(ObjUser const& ou)
 {
     no_ci_stop_if(
-        !m->obj_user_to_objects.contains(ou),
+        !obj_user_to_objects_.contains(ou),
         "no entry in object user table for requested object user" //
     );
     qpdf_offset_t end = 0;
-    for (auto const& og: m->obj_user_to_objects[ou]) {
+    for (auto const& og: obj_user_to_objects_[ou]) {
         no_ci_stop_if(
             !m->obj_cache.contains(og), "unknown object referenced in object user table" //
         );
@@ -1233,7 +1226,7 @@ Lin::calculateLinearizationData(T const&amp; object_stream_data)
     // actual offsets and lengths are not computed here, but anything related to object ordering is.
     util::assertion(
-        !m->object_to_obj_users.empty(),
+        !object_to_obj_users_.empty(),
         "INTERNAL ERROR: QPDF::calculateLinearizationData called before optimize()" //
     );
     // Note that we can't call optimize here because we don't know whether it should be called
@@ -1325,10 +1318,7 @@ Lin::calculateLinearizationData(T const&amp; object_stream_data)
     std::set<QPDFObjGen> lc_outlines;
     std::set<QPDFObjGen> lc_root;
-    for (auto& oiter: m->object_to_obj_users) {
-        QPDFObjGen const& og = oiter.first;
-        std::set<ObjUser>& ous = oiter.second;
-
+    for (auto& [og, ous]: object_to_obj_users_) {
         bool in_open_document = false;
         bool in_first_page = false;
         int other_pages = 0;
@@ -1500,11 +1490,11 @@ Lin::calculateLinearizationData(T const&amp; object_stream_data)
         ObjUser ou(ObjUser::ou_page, i);
         no_ci_stop_if(
-            !m->obj_user_to_objects.contains(ou),
+            !obj_user_to_objects_.contains(ou),
             "found unreferenced page while calculating linearization data" //
         );
-        for (auto const& og: m->obj_user_to_objects[ou]) {
+        for (auto const& og: obj_user_to_objects_[ou]) {
             if (lc_other_page_private.erase(og)) {
                 m->part7.emplace_back(qpdf.getObject(og));
                 ++m->c_page_offset_data.entries.at(i).nobjects;
@@ -1533,8 +1523,7 @@ Lin::calculateLinearizationData(T const&amp; object_stream_data)
     // we throw all remaining objects in arbitrary order.
     // Place the pages tree.
-    std::set<QPDFObjGen> pages_ogs =
-        m->obj_user_to_objects[ObjUser(ObjUser::ou_root_key, "/Pages")];
+    auto& pages_ogs = obj_user_to_objects_[{ObjUser::ou_root_key, "/Pages"}];
     no_ci_stop_if(
         pages_ogs.empty(), "found empty pages tree while calculating linearization data" //
     );
@@ -1559,8 +1548,7 @@ Lin::calculateLinearizationData(T const&amp; object_stream_data)
             // there's nothing to prevent it from having been in some set other than
             // lc_thumbnail_private.
         }
-        std::set<QPDFObjGen>& ogs = m->obj_user_to_objects[ObjUser(ObjUser::ou_thumb, i)];
-        for (auto const& og: ogs) {
+        for (auto const& og: obj_user_to_objects_[{ObjUser::ou_thumb, i}]) {
             if (lc_thumbnail_private.erase(og)) {
                 m->part9.emplace_back(qpdf.getObject(og));
             }
@@ -1591,7 +1579,7 @@ Lin::calculateLinearizationData(T const&amp; object_stream_data)
     size_t num_placed =
         m->part4.size() + m->part6.size() + m->part7.size() + m->part8.size() + m->part9.size();
-    size_t num_wanted = m->object_to_obj_users.size();
+    size_t num_wanted = object_to_obj_users_.size();
     no_ci_stop_if(
         // This can happen with damaged files, e.g. if the root is part of the the pages tree.
         num_placed != num_wanted,
@@ -1642,12 +1630,12 @@ Lin::calculateLinearizationData(T const&amp; object_stream_data)
         CHPageOffsetEntry& pe = m->c_page_offset_data.entries.at(i);
         ObjUser ou(ObjUser::ou_page, i);
         no_ci_stop_if(
-            !m->obj_user_to_objects.contains(ou),
+            !obj_user_to_objects_.contains(ou),
             "found unreferenced page while calculating linearization data" //
         );
-        for (auto const& og: m->obj_user_to_objects[ou]) {
-            if ((m->object_to_obj_users[og].size() > 1) && (obj_to_index.contains(og.getObj()))) {
+        for (auto const& og: obj_user_to_objects_[ou]) {
+            if (object_to_obj_users_[og].size() > 1 && obj_to_index.contains(og.getObj())) {
                 int idx = obj_to_index[og.getObj()];
                 ++pe.nshared_objects;
                 pe.shared_identifiers.push_back(idx);
@@ -364,40 +364,6 @@ struct QPDF::CHSharedObject
 // No need for CHGeneric -- HGeneric is fine as is.
-// Data structures to support optimization -- implemented in QPDF_optimization.cc
-
-class QPDF::ObjUser
-{
-  public:
-    enum user_e { ou_page = 1, ou_thumb, ou_trailer_key, ou_root_key, ou_root };
-
-    ObjUser() = delete;
-
-    // type must be ou_root
-    ObjUser(user_e type);
-
-    // type must be one of ou_page or ou_thumb
-    ObjUser(user_e type, size_t pageno);
-
-    // type must be one of ou_trailer_key or ou_root_key
-    ObjUser(user_e type, std::string const& key);
-
-    bool operator<(ObjUser const&) const;
-
-    user_e ou_type;
-    size_t pageno{0}; // if ou_page;
-    std::string key;  // if ou_trailer_key or ou_root_key
-};
-
-struct QPDF::UpdateObjectMapsFrame
-{
-    UpdateObjectMapsFrame(ObjUser const& ou, QPDFObjectHandle oh, bool top);
-
-    ObjUser const& ou;
-    QPDFObjectHandle oh;
-    bool top;
-};
-
 class QPDF::PatternFinder final: public InputSource::Finder
 {
   public:
@@ -743,6 +709,40 @@ class QPDF::Doc::Linearization: Common
         bool compressed);
   private:
+    // Data structures to support optimization -- implemented in QPDF_optimization.cc
+
+    class ObjUser
+    {
+      public:
+        enum user_e { ou_page = 1, ou_thumb, ou_trailer_key, ou_root_key, ou_root };
+
+        ObjUser() = delete;
+
+        // type must be ou_root
+        ObjUser(user_e type);
+
+        // type must be one of ou_page or ou_thumb
+        ObjUser(user_e type, size_t pageno);
+
+        // type must be one of ou_trailer_key or ou_root_key
+        ObjUser(user_e type, std::string const& key);
+
+        bool operator<(ObjUser const&) const;
+
+        user_e ou_type;
+        size_t pageno{0}; // if ou_page;
+        std::string key;  // if ou_trailer_key or ou_root_key
+    };
+
+    struct UpdateObjectMapsFrame
+    {
+        UpdateObjectMapsFrame(ObjUser const& ou, QPDFObjectHandle oh, bool top) ;
+
+        ObjUser const& ou;
+        QPDFObjectHandle oh;
+        bool top;
+    };
+
     // methods to support linearization checking -- implemented in QPDF_linearization.cc
     void readLinearizationData();
@@ -797,6 +797,10 @@ class QPDF::Doc::Linearization: Common
         std::function<int(QPDFObjectHandle&)> skip_stream_parameters);
     void filterCompressedObjects(std::map<int, int> const& object_stream_data);
     void filterCompressedObjects(QPDFWriter::ObjTable const& object_stream_data);
+
+    // Optimization data
+    std::map<ObjUser, std::set<QPDFObjGen>> obj_user_to_objects_;
+    std::map<QPDFObjGen, std::set<ObjUser>> object_to_obj_users_;
 };
 class QPDF::Doc::Objects: Common
@@ -1169,10 +1173,6 @@ class QPDF::Members: Doc
     std::vector<QPDFObjectHandle> part7;
     std::vector<QPDFObjectHandle> part8;
     std::vector<QPDFObjectHandle> part9;
-
-    // Optimization data
-    std::map<ObjUser, std::set<QPDFObjGen>> obj_user_to_objects;
-    std::map<QPDFObjGen, std::set<ObjUser>> object_to_obj_users;
 };
 // The Resolver class is restricted to QPDFObject and BaseHandle so that only it can resolve