Remove `QPDF_optimization.cc`: merge functionality into `QPDF_linearization.cc` …

…for improved structure and better code locality.

Remove `QPDF_optimization.cc`: merge functionality into `QPDF_linearization.cc` …
…for improved structure and better code locality.
m-holger
1 parent b84375c4
Showing 3 changed files with 287 additions and 299 deletions
libqpdf/CMakeLists.txt
libqpdf/QPDF_linearization.cc
libqpdf/QPDF_optimization.cc
@@ -93,7 +93,6 @@ set(libqpdf_SOURCES
   QPDF_json.cc
   QPDF_linearization.cc
   QPDF_objects.cc
-  QPDF_optimization.cc
   QPDF_pages.cc
   QTC.cc
   QUtil.cc
@@ -69,6 +69,293 @@ load_vector_vector(
     bit_stream.skipToNextByte();
 }
+QPDF::ObjUser::ObjUser(user_e type) :
+    ou_type(type)
+{
+    qpdf_expect(type == ou_root);
+}
+
+QPDF::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) :
+    ou_type(type),
+    key(key)
+{
+    qpdf_expect(type == ou_trailer_key || type == ou_root_key);
+}
+
+bool
+QPDF::ObjUser::operator<(ObjUser const& rhs) const
+{
+    if (ou_type < rhs.ou_type) {
+        return true;
+    }
+    if (ou_type == rhs.ou_type) {
+        if (pageno < rhs.pageno) {
+            return true;
+        }
+        if (pageno == rhs.pageno) {
+            return key < rhs.key;
+        }
+    }
+    return false;
+}
+
+QPDF::UpdateObjectMapsFrame::UpdateObjectMapsFrame(
+    QPDF::ObjUser const& ou, QPDFObjectHandle oh, bool top) :
+    ou(ou),
+    oh(oh),
+    top(top)
+{
+}
+
+void
+QPDF::optimize(
+    std::map<int, int> const& object_stream_data,
+    bool allow_changes,
+    std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
+{
+    m->lin.optimize_internal(object_stream_data, allow_changes, skip_stream_parameters);
+}
+
+void
+Lin::optimize(
+    QPDFWriter::ObjTable const& obj, std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
+{
+    optimize_internal(obj, true, skip_stream_parameters);
+}
+
+template <typename T>
+void
+Lin::optimize_internal(
+    T const& object_stream_data,
+    bool allow_changes,
+    std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
+{
+    if (!m->obj_user_to_objects.empty()) {
+        // already optimized
+        return;
+    }
+
+    // The PDF specification indicates that /Outlines is supposed to be an indirect reference. Force
+    // it to be so if it exists and is direct.  (This has been seen in the wild.)
+    QPDFObjectHandle root = qpdf.getRoot();
+    if (root.getKey("/Outlines").isDictionary()) {
+        QPDFObjectHandle outlines = root.getKey("/Outlines");
+        if (!outlines.isIndirect()) {
+            root.replaceKey("/Outlines", qpdf.makeIndirectObject(outlines));
+        }
+    }
+
+    // Traverse pages tree pushing all inherited resources down to the page level.  This also
+    // initializes m->all_pages.
+    m->pages.pushInheritedAttributesToPage(allow_changes, false);
+    // Traverse pages
+
+    size_t n = 0;
+    for (auto const& page: m->pages) {
+        updateObjectMaps(ObjUser(ObjUser::ou_page, n), page, skip_stream_parameters);
+        ++n;
+    }
+
+    // Traverse document-level items
+    for (auto const& [key, value]: m->trailer.as_dictionary()) {
+        if (key == "/Root") {
+            // handled separately
+        } else {
+            if (!value.null()) {
+                updateObjectMaps(
+                    ObjUser(ObjUser::ou_trailer_key, key), value, skip_stream_parameters);
+            }
+        }
+    }
+
+    for (auto const& [key, value]: root.as_dictionary()) {
+        // Technically, /I keys from /Thread dictionaries are supposed to be handled separately, but
+        // we are going to disregard that specification for now.  There is loads of evidence that
+        // pdlin and Acrobat both disregard things like this from time to time, so this is almost
+        // certain not to cause any problems.
+        if (!value.null()) {
+            updateObjectMaps(ObjUser(ObjUser::ou_root_key, key), value, skip_stream_parameters);
+        }
+    }
+
+    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);
+
+    filterCompressedObjects(object_stream_data);
+}
+
+void
+Lin::updateObjectMaps(
+    ObjUser const& first_ou,
+    QPDFObjectHandle first_oh,
+    std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
+{
+    QPDFObjGen::set visited;
+    std::vector<UpdateObjectMapsFrame> pending;
+    pending.emplace_back(first_ou, first_oh, true);
+    // Traverse the object tree from this point taking care to avoid crossing page boundaries.
+    std::unique_ptr<ObjUser> thumb_ou;
+    while (!pending.empty()) {
+        auto cur = pending.back();
+        pending.pop_back();
+
+        bool is_page_node = false;
+
+        if (cur.oh.isDictionaryOfType("/Page")) {
+            is_page_node = true;
+            if (!cur.top) {
+                continue;
+            }
+        }
+
+        if (cur.oh.isIndirect()) {
+            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);
+        }
+
+        if (cur.oh.isArray()) {
+            for (auto const& item: cur.oh.as_array()) {
+                pending.emplace_back(cur.ou, item, false);
+            }
+        } else if (cur.oh.isDictionary() || cur.oh.isStream()) {
+            QPDFObjectHandle dict = cur.oh;
+            bool is_stream = cur.oh.isStream();
+            int ssp = 0;
+            if (is_stream) {
+                dict = cur.oh.getDict();
+                if (skip_stream_parameters) {
+                    ssp = skip_stream_parameters(cur.oh);
+                }
+            }
+
+            for (auto& [key, value]: dict.as_dictionary()) {
+                if (value.null()) {
+                    continue;
+                }
+
+                if (is_page_node && (key == "/Thumb")) {
+                    // Traverse page thumbnail dictionaries as a special case. There can only ever
+                    // be one /Thumb key on a page, and we see at most one page node per call.
+                    thumb_ou = std::make_unique<ObjUser>(ObjUser::ou_thumb, cur.ou.pageno);
+                    pending.emplace_back(*thumb_ou, dict.getKey(key), false);
+                } else if (is_page_node && (key == "/Parent")) {
+                    // Don't traverse back up the page tree
+                } else if (
+                    ((ssp >= 1) && (key == "/Length")) ||
+                    ((ssp >= 2) && ((key == "/Filter") || (key == "/DecodeParms")))) {
+                    // Don't traverse into stream parameters that we are not going to write.
+                } else {
+                    pending.emplace_back(cur.ou, value, false);
+                }
+            }
+        }
+    }
+}
+
+void
+Lin::filterCompressedObjects(std::map<int, int> const& object_stream_data)
+{
+    if (object_stream_data.empty()) {
+        return;
+    }
+
+    // Transform object_to_obj_users and obj_user_to_objects so that they refer only to uncompressed
+    // objects.  If something is a user of a compressed object, then it is really a user of the
+    // object stream that contains it.
+
+    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) {
+            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));
+            }
+        }
+    }
+
+    for (auto const& i1: m->object_to_obj_users) {
+        QPDFObjGen const& og = i1.first;
+        // Loop over obj_users.
+        for (auto const& ou: i1.second) {
+            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);
+            }
+        }
+    }
+
+    m->obj_user_to_objects = t_obj_user_to_objects;
+    m->object_to_obj_users = t_object_to_obj_users;
+}
+
+void
+Lin::filterCompressedObjects(QPDFWriter::ObjTable const& obj)
+{
+    if (obj.getStreamsEmpty()) {
+        return;
+    }
+
+    // Transform object_to_obj_users and obj_user_to_objects so that they refer only to uncompressed
+    // objects.  If something is a user of a compressed object, then it is really a user of the
+    // object stream that contains it.
+
+    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) {
+            if (obj.contains(og)) {
+                if (auto const& i2 = obj[og].object_stream; i2 <= 0) {
+                    t_obj_user_to_objects[ou].insert(og);
+                } else {
+                    t_obj_user_to_objects[ou].insert(QPDFObjGen(i2, 0));
+                }
+            }
+        }
+    }
+
+    for (auto const& i1: m->object_to_obj_users) {
+        QPDFObjGen const& og = i1.first;
+        if (obj.contains(og)) {
+            // Loop over obj_users.
+            for (auto const& ou: i1.second) {
+                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);
+                }
+            }
+        }
+    }
+
+    m->obj_user_to_objects = t_obj_user_to_objects;
+    m->object_to_obj_users = t_object_to_obj_users;
+}
+
 void
 Lin::linearizationWarning(std::string_view msg)
 {
-// See the "Optimization" section of the manual.
-
-#include <qpdf/QPDF_private.hh>
-
-#include <qpdf/QPDFExc.hh>
-#include <qpdf/QPDFObjectHandle_private.hh>
-#include <qpdf/QPDFWriter_private.hh>
-#include <qpdf/QTC.hh>
-
-using Lin = QPDF::Doc::Linearization;
-using Pages = QPDF::Doc::Pages;
-
-QPDF::ObjUser::ObjUser(user_e type) :
-    ou_type(type)
-{
-    qpdf_assert_debug(type == ou_root);
-}
-
-QPDF::ObjUser::ObjUser(user_e type, size_t pageno) :
-    ou_type(type),
-    pageno(pageno)
-{
-    qpdf_assert_debug((type == ou_page) || (type == ou_thumb));
-}
-
-QPDF::ObjUser::ObjUser(user_e type, std::string const& key) :
-    ou_type(type),
-    key(key)
-{
-    qpdf_assert_debug((type == ou_trailer_key) || (type == ou_root_key));
-}
-
-bool
-QPDF::ObjUser::operator<(ObjUser const& rhs) const
-{
-    if (ou_type < rhs.ou_type) {
-        return true;
-    }
-    if (ou_type == rhs.ou_type) {
-        if (pageno < rhs.pageno) {
-            return true;
-        }
-        if (pageno == rhs.pageno) {
-            return key < rhs.key;
-        }
-    }
-    return false;
-}
-
-QPDF::UpdateObjectMapsFrame::UpdateObjectMapsFrame(
-    QPDF::ObjUser const& ou, QPDFObjectHandle oh, bool top) :
-    ou(ou),
-    oh(oh),
-    top(top)
-{
-}
-
-void
-QPDF::optimize(
-    std::map<int, int> const& object_stream_data,
-    bool allow_changes,
-    std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
-{
-    m->lin.optimize_internal(object_stream_data, allow_changes, skip_stream_parameters);
-}
-
-void
-Lin::optimize(
-    QPDFWriter::ObjTable const& obj, std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
-{
-    optimize_internal(obj, true, skip_stream_parameters);
-}
-
-template <typename T>
-void
-Lin::optimize_internal(
-    T const& object_stream_data,
-    bool allow_changes,
-    std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
-{
-    if (!m->obj_user_to_objects.empty()) {
-        // already optimized
-        return;
-    }
-
-    // The PDF specification indicates that /Outlines is supposed to be an indirect reference. Force
-    // it to be so if it exists and is direct.  (This has been seen in the wild.)
-    QPDFObjectHandle root = qpdf.getRoot();
-    if (root.getKey("/Outlines").isDictionary()) {
-        QPDFObjectHandle outlines = root.getKey("/Outlines");
-        if (!outlines.isIndirect()) {
-            root.replaceKey("/Outlines", qpdf.makeIndirectObject(outlines));
-        }
-    }
-
-    // Traverse pages tree pushing all inherited resources down to the page level.  This also
-    // initializes m->all_pages.
-    m->pages.pushInheritedAttributesToPage(allow_changes, false);
-    // Traverse pages
-
-    size_t n = 0;
-    for (auto const& page: m->pages) {
-        updateObjectMaps(ObjUser(ObjUser::ou_page, n), page, skip_stream_parameters);
-        ++n;
-    }
-
-    // Traverse document-level items
-    for (auto const& [key, value]: m->trailer.as_dictionary()) {
-        if (key == "/Root") {
-            // handled separately
-        } else {
-            if (!value.null()) {
-                updateObjectMaps(
-                    ObjUser(ObjUser::ou_trailer_key, key), value, skip_stream_parameters);
-            }
-        }
-    }
-
-    for (auto const& [key, value]: root.as_dictionary()) {
-        // Technically, /I keys from /Thread dictionaries are supposed to be handled separately, but
-        // we are going to disregard that specification for now.  There is loads of evidence that
-        // pdlin and Acrobat both disregard things like this from time to time, so this is almost
-        // certain not to cause any problems.
-        if (!value.null()) {
-            updateObjectMaps(ObjUser(ObjUser::ou_root_key, key), value, skip_stream_parameters);
-        }
-    }
-
-    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);
-
-    filterCompressedObjects(object_stream_data);
-}
-
-void
-Lin::updateObjectMaps(
-    ObjUser const& first_ou,
-    QPDFObjectHandle first_oh,
-    std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
-{
-    QPDFObjGen::set visited;
-    std::vector<UpdateObjectMapsFrame> pending;
-    pending.emplace_back(first_ou, first_oh, true);
-    // Traverse the object tree from this point taking care to avoid crossing page boundaries.
-    std::unique_ptr<ObjUser> thumb_ou;
-    while (!pending.empty()) {
-        auto cur = pending.back();
-        pending.pop_back();
-
-        bool is_page_node = false;
-
-        if (cur.oh.isDictionaryOfType("/Page")) {
-            is_page_node = true;
-            if (!cur.top) {
-                continue;
-            }
-        }
-
-        if (cur.oh.isIndirect()) {
-            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);
-        }
-
-        if (cur.oh.isArray()) {
-            for (auto const& item: cur.oh.as_array()) {
-                pending.emplace_back(cur.ou, item, false);
-            }
-        } else if (cur.oh.isDictionary() || cur.oh.isStream()) {
-            QPDFObjectHandle dict = cur.oh;
-            bool is_stream = cur.oh.isStream();
-            int ssp = 0;
-            if (is_stream) {
-                dict = cur.oh.getDict();
-                if (skip_stream_parameters) {
-                    ssp = skip_stream_parameters(cur.oh);
-                }
-            }
-
-            for (auto& [key, value]: dict.as_dictionary()) {
-                if (value.null()) {
-                    continue;
-                }
-
-                if (is_page_node && (key == "/Thumb")) {
-                    // Traverse page thumbnail dictionaries as a special case. There can only ever
-                    // be one /Thumb key on a page, and we see at most one page node per call.
-                    thumb_ou = std::make_unique<ObjUser>(ObjUser::ou_thumb, cur.ou.pageno);
-                    pending.emplace_back(*thumb_ou, dict.getKey(key), false);
-                } else if (is_page_node && (key == "/Parent")) {
-                    // Don't traverse back up the page tree
-                } else if (
-                    ((ssp >= 1) && (key == "/Length")) ||
-                    ((ssp >= 2) && ((key == "/Filter") || (key == "/DecodeParms")))) {
-                    // Don't traverse into stream parameters that we are not going to write.
-                } else {
-                    pending.emplace_back(cur.ou, value, false);
-                }
-            }
-        }
-    }
-}
-
-void
-Lin::filterCompressedObjects(std::map<int, int> const& object_stream_data)
-{
-    if (object_stream_data.empty()) {
-        return;
-    }
-
-    // Transform object_to_obj_users and obj_user_to_objects so that they refer only to uncompressed
-    // objects.  If something is a user of a compressed object, then it is really a user of the
-    // object stream that contains it.
-
-    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) {
-            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));
-            }
-        }
-    }
-
-    for (auto const& i1: m->object_to_obj_users) {
-        QPDFObjGen const& og = i1.first;
-        // Loop over obj_users.
-        for (auto const& ou: i1.second) {
-            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);
-            }
-        }
-    }
-
-    m->obj_user_to_objects = t_obj_user_to_objects;
-    m->object_to_obj_users = t_object_to_obj_users;
-}
-
-void
-Lin::filterCompressedObjects(QPDFWriter::ObjTable const& obj)
-{
-    if (obj.getStreamsEmpty()) {
-        return;
-    }
-
-    // Transform object_to_obj_users and obj_user_to_objects so that they refer only to uncompressed
-    // objects.  If something is a user of a compressed object, then it is really a user of the
-    // object stream that contains it.
-
-    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) {
-            if (obj.contains(og)) {
-                if (auto const& i2 = obj[og].object_stream; i2 <= 0) {
-                    t_obj_user_to_objects[ou].insert(og);
-                } else {
-                    t_obj_user_to_objects[ou].insert(QPDFObjGen(i2, 0));
-                }
-            }
-        }
-    }
-
-    for (auto const& i1: m->object_to_obj_users) {
-        QPDFObjGen const& og = i1.first;
-        if (obj.contains(og)) {
-            // Loop over obj_users.
-            for (auto const& ou: i1.second) {
-                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);
-                }
-            }
-        }
-    }
-
-    m->obj_user_to_objects = t_obj_user_to_objects;
-    m->object_to_obj_users = t_object_to_obj_users;
-}