diff --git a/include/qpdf/BufferInputSource.hh b/include/qpdf/BufferInputSource.hh
index 53b221c..33adc5a 100644
--- a/include/qpdf/BufferInputSource.hh
+++ b/include/qpdf/BufferInputSource.hh
@@ -30,6 +30,8 @@ class QPDF_DLL_CLASS BufferInputSource: public InputSource
     // Otherwise, the caller owns the memory.
     QPDF_DLL
     BufferInputSource(std::string const& description, Buffer* buf, bool own_memory = false);
+
+    // NB This overload copies the string contents.
     QPDF_DLL
     BufferInputSource(std::string const& description, std::string const& contents);
     QPDF_DLL
diff --git a/include/qpdf/QPDF.hh b/include/qpdf/QPDF.hh
index 934a8e7..b02e13d 100644
--- a/include/qpdf/QPDF.hh
+++ b/include/qpdf/QPDF.hh
@@ -726,167 +726,14 @@ class QPDF
     void removePage(QPDFObjectHandle page);
     // End legacy page helpers
 
-    // Writer class is restricted to QPDFWriter so that only it can call certain methods.
-    class Writer
-    {
-        friend class QPDFWriter;
-
-      private:
-        static void
-        optimize(
-            QPDF& qpdf,
-            QPDFWriter::ObjTable const& obj,
-            std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
-        {
-            return qpdf.optimize(obj, skip_stream_parameters);
-        }
-
-        static void
-        getLinearizedParts(
-            QPDF& qpdf,
-            QPDFWriter::ObjTable const& obj,
-            std::vector<QPDFObjectHandle>& part4,
-            std::vector<QPDFObjectHandle>& part6,
-            std::vector<QPDFObjectHandle>& part7,
-            std::vector<QPDFObjectHandle>& part8,
-            std::vector<QPDFObjectHandle>& part9)
-        {
-            qpdf.getLinearizedParts(obj, part4, part6, part7, part8, part9);
-        }
-
-        static void
-        generateHintStream(
-            QPDF& qpdf,
-            QPDFWriter::NewObjTable const& new_obj,
-            QPDFWriter::ObjTable const& obj,
-            std::shared_ptr<Buffer>& hint_stream,
-            int& S,
-            int& O,
-            bool compressed)
-        {
-            return qpdf.generateHintStream(new_obj, obj, hint_stream, S, O, compressed);
-        }
-
-        static std::vector<QPDFObjGen>
-        getCompressibleObjGens(QPDF& qpdf)
-        {
-            return qpdf.getCompressibleObjVector();
-        }
-
-        static std::vector<bool>
-        getCompressibleObjSet(QPDF& qpdf)
-        {
-            return qpdf.getCompressibleObjSet();
-        }
-
-        static std::map<QPDFObjGen, QPDFXRefEntry> const&
-        getXRefTable(QPDF& qpdf)
-        {
-            return qpdf.getXRefTableInternal();
-        }
+    // End of the public API. The following classes and methods are for qpdf internal use only.
 
-        static size_t
-        tableSize(QPDF& qpdf)
-        {
-            return qpdf.tableSize();
-        }
-    };
-
-    // The Resolver class is restricted to QPDFObject so that only it can resolve indirect
-    // references.
-    class Resolver
-    {
-        friend class QPDFObject;
-        friend class QPDF_Unresolved;
-        friend class qpdf::BaseHandle;
-
-      private:
-        static std::shared_ptr<QPDFObject> const&
-        resolved(QPDF* qpdf, QPDFObjGen og)
-        {
-            return qpdf->resolve(og);
-        }
-    };
-
-    // StreamCopier class is restricted to QPDFObjectHandle so it can copy stream data.
-    class StreamCopier
-    {
-        friend class QPDFObjectHandle;
-
-      private:
-        static void
-        copyStreamData(QPDF* qpdf, QPDFObjectHandle const& dest, QPDFObjectHandle const& src)
-        {
-            qpdf->copyStreamData(dest, src);
-        }
-    };
-
-    // The ParseGuard class allows QPDFParser to detect re-entrant parsing. It also provides
-    // special access to allow the parser to create unresolved objects and dangling references.
-    class ParseGuard
-    {
-        friend class QPDFParser;
-
-      private:
-        ParseGuard(QPDF* qpdf) :
-            qpdf(qpdf)
-        {
-            if (qpdf) {
-                qpdf->inParse(true);
-            }
-        }
-
-        static std::shared_ptr<QPDFObject>
-        getObject(QPDF* qpdf, int id, int gen, bool parse_pdf)
-        {
-            return qpdf->getObjectForParser(id, gen, parse_pdf);
-        }
-
-        ~ParseGuard()
-        {
-            if (qpdf) {
-                qpdf->inParse(false);
-            }
-        }
-        QPDF* qpdf;
-    };
-
-    // Pipe class is restricted to QPDF_Stream.
-    class Pipe
-    {
-        friend class QPDF_Stream;
-        friend class qpdf::Stream;
-
-      private:
-        static bool
-        pipeStreamData(
-            QPDF* qpdf,
-            QPDFObjGen og,
-            qpdf_offset_t offset,
-            size_t length,
-            QPDFObjectHandle dict,
-            Pipeline* pipeline,
-            bool suppress_warnings,
-            bool will_retry)
-        {
-            return qpdf->pipeStreamData(
-                og, offset, length, dict, pipeline, suppress_warnings, will_retry);
-        }
-    };
-
-    // JobSetter class is restricted to QPDFJob.
-    class JobSetter
-    {
-        friend class QPDFJob;
-
-      private:
-        // Enable enhanced warnings for pdf file checking.
-        static void
-        setCheckMode(QPDF& qpdf, bool val)
-        {
-            qpdf.m->check_mode = val;
-        }
-    };
+    class Writer;
+    class Resolver;
+    class StreamCopier;
+    class ParseGuard;
+    class Pipe;
+    class JobSetter;
 
     // For testing only -- do not add to DLL
     static bool test_json_validators();
@@ -901,136 +748,13 @@ class QPDF
 
     static std::string const qpdf_version;
 
-    class ObjCache
-    {
-      public:
-        ObjCache() :
-            end_before_space(0),
-            end_after_space(0)
-        {
-        }
-        ObjCache(
-            std::shared_ptr<QPDFObject> object,
-            qpdf_offset_t end_before_space = 0,
-            qpdf_offset_t end_after_space = 0) :
-            object(object),
-            end_before_space(end_before_space),
-            end_after_space(end_after_space)
-        {
-        }
-
-        std::shared_ptr<QPDFObject> object;
-        qpdf_offset_t end_before_space;
-        qpdf_offset_t end_after_space;
-    };
-
-    class ObjCopier
-    {
-      public:
-        std::map<QPDFObjGen, QPDFObjectHandle> object_map;
-        std::vector<QPDFObjectHandle> to_copy;
-        QPDFObjGen::set visiting;
-    };
-
-    class EncryptionParameters
-    {
-        friend class QPDF;
-
-      public:
-        EncryptionParameters();
-
-      private:
-        bool encrypted;
-        bool encryption_initialized;
-        int encryption_V;
-        int encryption_R;
-        bool encrypt_metadata;
-        std::map<std::string, encryption_method_e> crypt_filters;
-        encryption_method_e cf_stream;
-        encryption_method_e cf_string;
-        encryption_method_e cf_file;
-        std::string provided_password;
-        std::string user_password;
-        std::string encryption_key;
-        std::string cached_object_encryption_key;
-        QPDFObjGen cached_key_og;
-        bool user_password_matched;
-        bool owner_password_matched;
-    };
-
-    class ForeignStreamData
-    {
-        friend class QPDF;
-
-      public:
-        ForeignStreamData(
-            std::shared_ptr<EncryptionParameters> encp,
-            std::shared_ptr<InputSource> file,
-            QPDFObjGen foreign_og,
-            qpdf_offset_t offset,
-            size_t length,
-            QPDFObjectHandle local_dict);
-
-      private:
-        std::shared_ptr<EncryptionParameters> encp;
-        std::shared_ptr<InputSource> file;
-        QPDFObjGen foreign_og;
-        qpdf_offset_t offset;
-        size_t length;
-        QPDFObjectHandle local_dict;
-    };
-
-    class CopiedStreamDataProvider: public QPDFObjectHandle::StreamDataProvider
-    {
-      public:
-        CopiedStreamDataProvider(QPDF& destination_qpdf);
-        ~CopiedStreamDataProvider() override = default;
-        bool provideStreamData(
-            QPDFObjGen const& og,
-            Pipeline* pipeline,
-            bool suppress_warnings,
-            bool will_retry) override;
-        void registerForeignStream(QPDFObjGen const& local_og, QPDFObjectHandle foreign_stream);
-        void registerForeignStream(QPDFObjGen const& local_og, std::shared_ptr<ForeignStreamData>);
-
-      private:
-        QPDF& destination_qpdf;
-        std::map<QPDFObjGen, QPDFObjectHandle> foreign_streams;
-        std::map<QPDFObjGen, std::shared_ptr<ForeignStreamData>> foreign_stream_data;
-    };
-
-    class StringDecrypter: public QPDFObjectHandle::StringDecrypter
-    {
-        friend class QPDF;
-
-      public:
-        StringDecrypter(QPDF* qpdf, QPDFObjGen og);
-        ~StringDecrypter() override = default;
-        void decryptString(std::string& val) override;
-
-      private:
-        QPDF* qpdf;
-        QPDFObjGen og;
-    };
-
-    class ResolveRecorder
-    {
-      public:
-        ResolveRecorder(QPDF* qpdf, QPDFObjGen og) :
-            qpdf(qpdf),
-            iter(qpdf->m->resolving.insert(og).first)
-        {
-        }
-        virtual ~ResolveRecorder()
-        {
-            this->qpdf->m->resolving.erase(iter);
-        }
-
-      private:
-        QPDF* qpdf;
-        std::set<QPDFObjGen>::const_iterator iter;
-    };
-
+    class ObjCache;
+    class ObjCopier;
+    class EncryptionParameters;
+    class ForeignStreamData;
+    class CopiedStreamDataProvider;
+    class StringDecrypter;
+    class ResolveRecorder;
     class JSONReactor;
 
     void parse(char const* password);
@@ -1200,200 +924,19 @@ class QPDF
     replaceForeignIndirectObjects(QPDFObjectHandle foreign, ObjCopier& obj_copier, bool top);
     void copyStreamData(QPDFObjectHandle dest_stream, QPDFObjectHandle src_stream);
 
-    // Linearization Hint table structures.
-    // Naming conventions:
-
-    // HSomething is the Something Hint Table or table header
-    // HSomethingEntry is an entry in the Something table
-
-    // delta_something + min_something = something
-    // nbits_something = number of bits required for something
-
-    // something_offset is the pre-adjusted offset in the file.  If >=
-    // H0_offset, H0_length must be added to get an actual file
-    // offset.
-
-    // PDF 1.4: Table F.4
-    struct HPageOffsetEntry
-    {
-        int delta_nobjects{0};              // 1
-        qpdf_offset_t delta_page_length{0}; // 2
-        // vectors' sizes = nshared_objects
-        int nshared_objects{0};                // 3
-        std::vector<int> shared_identifiers;   // 4
-        std::vector<int> shared_numerators;    // 5
-        qpdf_offset_t delta_content_offset{0}; // 6
-        qpdf_offset_t delta_content_length{0}; // 7
-    };
-
-    // PDF 1.4: Table F.3
-    struct HPageOffset
-    {
-        int min_nobjects{0};                // 1
-        qpdf_offset_t first_page_offset{0}; // 2
-        int nbits_delta_nobjects{0};        // 3
-        int min_page_length{0};             // 4
-        int nbits_delta_page_length{0};     // 5
-        int min_content_offset{0};          // 6
-        int nbits_delta_content_offset{0};  // 7
-        int min_content_length{0};          // 8
-        int nbits_delta_content_length{0};  // 9
-        int nbits_nshared_objects{0};       // 10
-        int nbits_shared_identifier{0};     // 11
-        int nbits_shared_numerator{0};      // 12
-        int shared_denominator{0};          // 13
-        // vector size is npages
-        std::vector<HPageOffsetEntry> entries;
-    };
-
-    // PDF 1.4: Table F.6
-    struct HSharedObjectEntry
-    {
-        // Item 3 is a 128-bit signature (unsupported by Acrobat)
-        int delta_group_length{0}; // 1
-        int signature_present{0};  // 2 -- always 0
-        int nobjects_minus_one{0}; // 4 -- always 0
-    };
-
-    // PDF 1.4: Table F.5
-    struct HSharedObject
-    {
-        int first_shared_obj{0};              // 1
-        qpdf_offset_t first_shared_offset{0}; // 2
-        int nshared_first_page{0};            // 3
-        int nshared_total{0};                 // 4
-        int nbits_nobjects{0};                // 5
-        int min_group_length{0};              // 6
-        int nbits_delta_group_length{0};      // 7
-        // vector size is nshared_total
-        std::vector<HSharedObjectEntry> entries;
-    };
-
-    // PDF 1.4: Table F.9
-    struct HGeneric
-    {
-        int first_object{0};                  // 1
-        qpdf_offset_t first_object_offset{0}; // 2
-        int nobjects{0};                      // 3
-        int group_length{0};                  // 4
-    };
-
-    // Other linearization data structures
-
-    // Initialized from Linearization Parameter dictionary
-    struct LinParameters
-    {
-        qpdf_offset_t file_size{0};        // /L
-        int first_page_object{0};          // /O
-        qpdf_offset_t first_page_end{0};   // /E
-        int npages{0};                     // /N
-        qpdf_offset_t xref_zero_offset{0}; // /T
-        int first_page{0};                 // /P
-        qpdf_offset_t H_offset{0};         // offset of primary hint stream
-        qpdf_offset_t H_length{0};         // length of primary hint stream
-    };
-
-    // Computed hint table value data structures.  These tables contain the computed values on which
-    // the hint table values are based.  They exclude things like number of bits and store actual
-    // values instead of mins and deltas.  File offsets are also absolute rather than being offset
-    // by the size of the primary hint table.  We populate the hint table structures from these
-    // during writing and compare the hint table values with these during validation.  We ignore
-    // some values for various reasons described in the code.  Those values are omitted from these
-    // structures.  Note also that object numbers are object numbers from the input file, not the
-    // output file.
-
-    // Naming convention: CHSomething is analogous to HSomething above.  "CH" is computed hint.
-
-    struct CHPageOffsetEntry
-    {
-        int nobjects{0};
-        int nshared_objects{0};
-        // vectors' sizes = nshared_objects
-        std::vector<int> shared_identifiers;
-    };
-
-    struct CHPageOffset
-    {
-        // vector size is npages
-        std::vector<CHPageOffsetEntry> entries;
-    };
-
-    struct CHSharedObjectEntry
-    {
-        CHSharedObjectEntry(int object) :
-            object(object)
-        {
-        }
-
-        int object;
-    };
-
-    // PDF 1.4: Table F.5
-    struct CHSharedObject
-    {
-        int first_shared_obj{0};
-        int nshared_first_page{0};
-        int nshared_total{0};
-        // vector size is nshared_total
-        std::vector<CHSharedObjectEntry> entries;
-    };
-
-    // No need for CHGeneric -- HGeneric is fine as is.
-
-    // Data structures to support optimization -- implemented in QPDF_optimization.cc
-
-    class ObjUser
-    {
-      public:
-        enum user_e { ou_bad, ou_page, ou_thumb, ou_trailer_key, ou_root_key, ou_root };
-
-        // type is set to ou_bad
-        ObjUser();
-
-        // type must be ou_root
-        ObjUser(user_e type);
-
-        // type must be one of ou_page or ou_thumb
-        ObjUser(user_e type, int 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;
-        int pageno;      // 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;
-    };
-
-    class PatternFinder: public InputSource::Finder
-    {
-      public:
-        PatternFinder(QPDF& qpdf, bool (QPDF::*checker)()) :
-            qpdf(qpdf),
-            checker(checker)
-        {
-        }
-        ~PatternFinder() override = default;
-        bool
-        check() override
-        {
-            return (this->qpdf.*checker)();
-        }
-
-      private:
-        QPDF& qpdf;
-        bool (QPDF::*checker)();
-    };
+    struct HPageOffsetEntry;
+    struct HPageOffset;
+    struct HSharedObjectEntry;
+    struct HSharedObject;
+    struct HGeneric;
+    struct LinParameters;
+    struct CHPageOffsetEntry;
+    struct CHPageOffset;
+    struct CHSharedObjectEntry;
+    struct CHSharedObject;
+    class ObjUser;
+    struct UpdateObjectMapsFrame;
+    class PatternFinder;
 
     // Methods to support pattern finding
     static bool validatePDFVersion(char const*&, std::string& version);
@@ -1490,88 +1033,7 @@ class QPDF
         return QIntC::to_ulonglong(i);
     }
 
-    class Members
-    {
-        friend class QPDF;
-        friend class ResolveRecorder;
-
-      public:
-        Members();
-        Members(Members const&) = delete;
-        ~Members() = default;
-
-      private:
-        std::shared_ptr<QPDFLogger> log;
-        unsigned long long unique_id{0};
-        QPDFTokenizer tokenizer;
-        std::shared_ptr<InputSource> file;
-        std::string last_object_description;
-        bool provided_password_is_hex_key{false};
-        bool ignore_xref_streams{false};
-        bool suppress_warnings{false};
-        size_t max_warnings{0};
-        bool attempt_recovery{true};
-        bool check_mode{false};
-        std::shared_ptr<EncryptionParameters> encp;
-        std::string pdf_version;
-        std::map<QPDFObjGen, QPDFXRefEntry> xref_table;
-        // Various tables are indexed by object id, with potential size id + 1
-        int xref_table_max_id{std::numeric_limits<int>::max() - 1};
-        qpdf_offset_t xref_table_max_offset{0};
-        std::set<int> deleted_objects;
-        std::map<QPDFObjGen, ObjCache> obj_cache;
-        std::set<QPDFObjGen> resolving;
-        QPDFObjectHandle trailer;
-        std::vector<QPDFObjectHandle> all_pages;
-        bool invalid_page_found{false};
-        std::map<QPDFObjGen, int> pageobj_to_pages_pos;
-        bool pushed_inherited_attributes_to_pages{false};
-        bool ever_pushed_inherited_attributes_to_pages{false};
-        bool ever_called_get_all_pages{false};
-        std::vector<QPDFExc> warnings;
-        std::map<unsigned long long, ObjCopier> object_copiers;
-        std::shared_ptr<QPDFObjectHandle::StreamDataProvider> copied_streams;
-        // copied_stream_data_provider is owned by copied_streams
-        CopiedStreamDataProvider* copied_stream_data_provider{nullptr};
-        bool reconstructed_xref{false};
-        bool fixed_dangling_refs{false};
-        bool immediate_copy_from{false};
-        bool in_parse{false};
-        bool parsed{false};
-        std::set<int> resolved_object_streams;
-
-        // Linearization data
-        qpdf_offset_t first_xref_item_offset{0}; // actual value from file
-        bool uncompressed_after_compressed{false};
-        bool linearization_warnings{false};
-
-        // Linearization parameter dictionary and hint table data: may be read from file or computed
-        // prior to writing a linearized file
-        QPDFObjectHandle lindict;
-        LinParameters linp;
-        HPageOffset page_offset_hints;
-        HSharedObject shared_object_hints;
-        HGeneric outline_hints;
-
-        // Computed linearization data: used to populate above tables during writing and to compare
-        // with them during validation. c_ means computed.
-        LinParameters c_linp;
-        CHPageOffset c_page_offset_data;
-        CHSharedObject c_shared_object_data;
-        HGeneric c_outline_data;
-
-        // Object ordering data for linearized files: initialized by calculateLinearizationData().
-        // Part numbers refer to the PDF 1.4 specification.
-        std::vector<QPDFObjectHandle> part4;
-        std::vector<QPDFObjectHandle> part6;
-        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;
-    };
+    class Members;
 
     // Keep all member variables inside the Members object, which we dynamically allocate. This
     // makes it possible to add new private members without breaking binary compatibility.
diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index 8b7f1fd..074d544 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -1,6 +1,6 @@
 #include <qpdf/qpdf-config.h> // include first for large file support
 
-#include <qpdf/QPDF.hh>
+#include <qpdf/QPDF_private.hh>
 
 #include <array>
 #include <atomic>
@@ -168,12 +168,6 @@ QPDF::StringDecrypter::StringDecrypter(QPDF* qpdf, QPDFObjGen og) :
 {
 }
 
-void
-QPDF::StringDecrypter::decryptString(std::string& val)
-{
-    qpdf->decryptString(val, og);
-}
-
 std::string const&
 QPDF::QPDFVersion()
 {
@@ -181,20 +175,6 @@ QPDF::QPDFVersion()
     return QPDF::qpdf_version;
 }
 
-QPDF::EncryptionParameters::EncryptionParameters() :
-    encrypted(false),
-    encryption_initialized(false),
-    encryption_V(0),
-    encryption_R(0),
-    encrypt_metadata(true),
-    cf_stream(e_none),
-    cf_string(e_none),
-    cf_file(e_none),
-    user_password_matched(false),
-    owner_password_matched(false)
-{
-}
-
 QPDF::Members::Members() :
     log(QPDFLogger::defaultLogger()),
     file(new InvalidInputSource()),
diff --git a/libqpdf/QPDFJob.cc b/libqpdf/QPDFJob.cc
index 6b1d6cb..f0e229d 100644
--- a/libqpdf/QPDFJob.cc
+++ b/libqpdf/QPDFJob.cc
@@ -13,7 +13,6 @@
 #include <qpdf/Pl_StdioFile.hh>
 #include <qpdf/Pl_String.hh>
 #include <qpdf/QIntC.hh>
-#include <qpdf/QPDF.hh>
 #include <qpdf/QPDFAcroFormDocumentHelper.hh>
 #include <qpdf/QPDFCryptoProvider.hh>
 #include <qpdf/QPDFEmbeddedFileDocumentHelper.hh>
@@ -27,6 +26,7 @@
 #include <qpdf/QPDFSystemError.hh>
 #include <qpdf/QPDFUsage.hh>
 #include <qpdf/QPDFWriter.hh>
+#include <qpdf/QPDF_private.hh>
 #include <qpdf/QTC.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/Util.hh>
diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc
index 4c001cd..f4c71cd 100644
--- a/libqpdf/QPDFObjectHandle.cc
+++ b/libqpdf/QPDFObjectHandle.cc
@@ -1495,19 +1495,23 @@ QPDFObjectHandle
 QPDFObjectHandle::parse(
     QPDF* context, std::string const& object_str, std::string const& object_description)
 {
-    auto input = std::shared_ptr<InputSource>(new BufferInputSource("parsed object", object_str));
-    QPDFTokenizer tokenizer;
+    // BufferInputSource does not modify the input, but Buffer either requires a string& or copies
+    // the string.
+    Buffer buf(const_cast<std::string&>(object_str));
+    auto input = BufferInputSource("parsed object", &buf);
+    qpdf::Tokenizer tokenizer;
     bool empty = false;
-    QPDFObjectHandle result = parse(input, object_description, tokenizer, empty, nullptr, context);
-    size_t offset = QIntC::to_size(input->tell());
+    auto result = QPDFParser(input, object_description, tokenizer, nullptr, context, false)
+                      .parse(empty, false);
+    size_t offset = QIntC::to_size(input.tell());
     while (offset < object_str.length()) {
         if (!isspace(object_str.at(offset))) {
             QTC::TC("qpdf", "QPDFObjectHandle trailing data in parse");
             throw QPDFExc(
                 qpdf_e_damaged_pdf,
-                input->getName(),
+                "parsed object",
                 object_description,
-                input->getLastOffset(),
+                input.getLastOffset(),
                 "trailing data found parsing object from string");
         }
         ++offset;
@@ -1614,51 +1618,52 @@ QPDFObjectHandle::parseContentStream_data(
     QPDF* context)
 {
     size_t stream_length = stream_data->getSize();
-    auto input =
-        std::shared_ptr<InputSource>(new BufferInputSource(description, stream_data.get()));
-    QPDFTokenizer tokenizer;
+    auto input = BufferInputSource(description, stream_data.get());
+    Tokenizer tokenizer;
     tokenizer.allowEOF();
+    auto sp_description = QPDFParser::make_description(description, "content");
     bool empty = false;
-    while (QIntC::to_size(input->tell()) < stream_length) {
+    while (QIntC::to_size(input.tell()) < stream_length) {
         // Read a token and seek to the beginning. The offset we get from this process is the
         // beginning of the next non-ignorable (space, comment) token. This way, the offset and
         // don't including ignorable content.
-        tokenizer.readToken(input, "content", true);
-        qpdf_offset_t offset = input->getLastOffset();
-        input->seek(offset, SEEK_SET);
+        tokenizer.nextToken(input, "content", true);
+        qpdf_offset_t offset = input.getLastOffset();
+        input.seek(offset, SEEK_SET);
         auto obj =
-            QPDFParser(*input, "content", tokenizer, nullptr, context, false).parse(empty, true);
+            QPDFParser(input, sp_description, "content", tokenizer, context).parse(empty, true);
         if (!obj) {
             // EOF
             break;
         }
-        size_t length = QIntC::to_size(input->tell() - offset);
+        size_t length = QIntC::to_size(input.tell() - offset);
 
         callbacks->handleObject(obj, QIntC::to_size(offset), length);
         if (obj.isOperator() && (obj.getOperatorValue() == "ID")) {
             // Discard next character; it is the space after ID that terminated the token.  Read
             // until end of inline image.
             char ch;
-            input->read(&ch, 1);
+            input.read(&ch, 1);
             tokenizer.expectInlineImage(input);
-            QPDFTokenizer::Token t = tokenizer.readToken(input, description, true);
-            offset = input->getLastOffset();
-            length = QIntC::to_size(input->tell() - offset);
-            if (t.getType() == QPDFTokenizer::tt_bad) {
+            tokenizer.nextToken(input, description);
+            offset = input.getLastOffset();
+            length = QIntC::to_size(input.tell() - offset);
+            if (tokenizer.getType() == QPDFTokenizer::tt_bad) {
                 QTC::TC("qpdf", "QPDFObjectHandle EOF in inline image");
                 warn(
                     context,
                     QPDFExc(
                         qpdf_e_damaged_pdf,
-                        input->getName(),
+                        description,
                         "stream data",
-                        input->tell(),
+                        input.tell(),
                         "EOF found while reading inline image"));
             } else {
-                std::string inline_image = t.getValue();
                 QTC::TC("qpdf", "QPDFObjectHandle inline image token");
                 callbacks->handleObject(
-                    QPDFObjectHandle::newInlineImage(inline_image), QIntC::to_size(offset), length);
+                    QPDFObjectHandle::newInlineImage(tokenizer.getValue()),
+                    QIntC::to_size(offset),
+                    length);
             }
         }
     }
diff --git a/libqpdf/QPDFTokenizer.cc b/libqpdf/QPDFTokenizer.cc
index 7ca4664..f156cab 100644
--- a/libqpdf/QPDFTokenizer.cc
+++ b/libqpdf/QPDFTokenizer.cc
@@ -52,10 +52,10 @@ QPDFWordTokenFinder::check()
 {
     // Find a word token matching the given string, preceded by a delimiter, and followed by a
     // delimiter or EOF.
-    QPDFTokenizer tokenizer;
-    QPDFTokenizer::Token t = tokenizer.readToken(is, "finder", true, str.size() + 2);
+    Tokenizer tokenizer;
+    tokenizer.nextToken(is, "finder", str.size() + 2);
     qpdf_offset_t pos = is.tell();
-    if (!(t == QPDFTokenizer::Token(QPDFTokenizer::tt_word, str))) {
+    if (tokenizer.getType() != tt::tt_word || tokenizer.getValue() != str) {
         QTC::TC("qpdf", "QPDFTokenizer finder found wrong word");
         return false;
     }
@@ -845,7 +845,7 @@ Tokenizer::findEI(InputSource& input)
         }
         inline_image_bytes = QIntC::to_size(input.tell() - pos - 2);
 
-        QPDFTokenizer check;
+        Tokenizer check;
         bool found_bad = false;
         // Look at the next 10 tokens or up to EOF. The next inline image's image data would look
         // like bad tokens, but there will always be at least 10 tokens between one inline image's
@@ -853,13 +853,13 @@ Tokenizer::findEI(InputSource& input)
         // all required as well as a BI and ID. If we get 10 good tokens in a row or hit EOF, we can
         // be pretty sure we've found the actual EI.
         for (int i = 0; i < 10; ++i) {
-            QPDFTokenizer::Token t = check.readToken(input, "checker", true);
-            QPDFTokenizer::token_type_e type = t.getType();
-            if (type == tt::tt_eof) {
+            check.nextToken(input, "checker");
+            auto typ = check.getType();
+            if (typ == tt::tt_eof) {
                 okay = true;
-            } else if (type == tt::tt_bad) {
+            } else if (typ == tt::tt_bad) {
                 found_bad = true;
-            } else if (t.isWord()) {
+            } else if (typ == tt::tt_word) {
                 // The qpdf tokenizer lumps alphabetic and otherwise uncategorized characters into
                 // "words". We recognize strings of alphabetic characters as potential valid
                 // operators for purposes of telling whether we're in valid content or not. It's not
@@ -868,13 +868,12 @@ Tokenizer::findEI(InputSource& input)
                 bool found_alpha = false;
                 bool found_non_printable = false;
                 bool found_other = false;
-                for (char ch: t.getValue()) {
-                    if (((ch >= 'a') && (ch <= 'z')) || ((ch >= 'A') && (ch <= 'Z')) ||
-                        (ch == '*')) {
+                for (char ch: check.getValue()) {
+                    if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || (ch == '*')) {
                         // Treat '*' as alpha since there are valid PDF operators that contain *
                         // along with alphabetic characters.
                         found_alpha = true;
-                    } else if ((static_cast<signed char>(ch) < 32) && (!isSpace(ch))) {
+                    } else if (static_cast<signed char>(ch) < 32 && !isSpace(ch)) {
                         // Compare ch as a signed char so characters outside of 7-bit will be < 0.
                         found_non_printable = true;
                         break;
diff --git a/libqpdf/QPDFWriter.cc b/libqpdf/QPDFWriter.cc
index c9b90cc..edad06f 100644
--- a/libqpdf/QPDFWriter.cc
+++ b/libqpdf/QPDFWriter.cc
@@ -14,9 +14,9 @@
 #include <qpdf/Pl_RC4.hh>
 #include <qpdf/Pl_StdioFile.hh>
 #include <qpdf/QIntC.hh>
-#include <qpdf/QPDF.hh>
 #include <qpdf/QPDFObjectHandle_private.hh>
 #include <qpdf/QPDFObject_private.hh>
+#include <qpdf/QPDF_private.hh>
 #include <qpdf/QTC.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/RC4.hh>
diff --git a/libqpdf/QPDF_Stream.cc b/libqpdf/QPDF_Stream.cc
index c846b5a..29e735b 100644
--- a/libqpdf/QPDF_Stream.cc
+++ b/libqpdf/QPDF_Stream.cc
@@ -10,8 +10,8 @@
 #include <qpdf/Pl_Flate.hh>
 #include <qpdf/Pl_QPDFTokenizer.hh>
 #include <qpdf/QIntC.hh>
-#include <qpdf/QPDF.hh>
 #include <qpdf/QPDFExc.hh>
+#include <qpdf/QPDF_private.hh>
 #include <qpdf/QTC.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/SF_ASCII85Decode.hh>
diff --git a/libqpdf/QPDF_encryption.cc b/libqpdf/QPDF_encryption.cc
index 9f39345..3abfc64 100644
--- a/libqpdf/QPDF_encryption.cc
+++ b/libqpdf/QPDF_encryption.cc
@@ -3,7 +3,7 @@
 
 #include <qpdf/assert_debug.h>
 
-#include <qpdf/QPDF.hh>
+#include <qpdf/QPDF_private.hh>
 
 #include <qpdf/QPDFExc.hh>
 
diff --git a/libqpdf/QPDF_linearization.cc b/libqpdf/QPDF_linearization.cc
index b183c07..01b1c77 100644
--- a/libqpdf/QPDF_linearization.cc
+++ b/libqpdf/QPDF_linearization.cc
@@ -1,6 +1,6 @@
 // See doc/linearization.
 
-#include <qpdf/QPDF.hh>
+#include <qpdf/QPDF_private.hh>
 
 #include <qpdf/BitStream.hh>
 #include <qpdf/BitWriter.hh>
diff --git a/libqpdf/QPDF_optimization.cc b/libqpdf/QPDF_optimization.cc
index d19c2c6..65916c7 100644
--- a/libqpdf/QPDF_optimization.cc
+++ b/libqpdf/QPDF_optimization.cc
@@ -2,22 +2,15 @@
 
 #include <qpdf/assert_debug.h>
 
-#include <qpdf/QPDF.hh>
+#include <qpdf/QPDF_private.hh>
 
 #include <qpdf/QPDFExc.hh>
 #include <qpdf/QPDFObjectHandle_private.hh>
 #include <qpdf/QPDFWriter_private.hh>
 #include <qpdf/QTC.hh>
 
-QPDF::ObjUser::ObjUser() :
-    ou_type(ou_bad),
-    pageno(0)
-{
-}
-
 QPDF::ObjUser::ObjUser(user_e type) :
-    ou_type(type),
-    pageno(0)
+    ou_type(type)
 {
     qpdf_assert_debug(type == ou_root);
 }
@@ -31,7 +24,6 @@ QPDF::ObjUser::ObjUser(user_e type, int pageno) :
 
 QPDF::ObjUser::ObjUser(user_e type, std::string const& key) :
     ou_type(type),
-    pageno(0),
     key(key)
 {
     qpdf_assert_debug((type == ou_trailer_key) || (type == ou_root_key));
@@ -40,16 +32,17 @@ QPDF::ObjUser::ObjUser(user_e type, std::string const& key) :
 bool
 QPDF::ObjUser::operator<(ObjUser const& rhs) const
 {
-    if (this->ou_type < rhs.ou_type) {
+    if (ou_type < rhs.ou_type) {
         return true;
-    } else if (this->ou_type == rhs.ou_type) {
-        if (this->pageno < rhs.pageno) {
+    }
+    if (ou_type == rhs.ou_type) {
+        if (pageno < rhs.pageno) {
             return true;
-        } else if (this->pageno == rhs.pageno) {
-            return (this->key < rhs.key);
+        }
+        if (pageno == rhs.pageno) {
+            return key < rhs.key;
         }
     }
-
     return false;
 }
 
diff --git a/libqpdf/QPDF_pages.cc b/libqpdf/QPDF_pages.cc
index ece5c32..749533f 100644
--- a/libqpdf/QPDF_pages.cc
+++ b/libqpdf/QPDF_pages.cc
@@ -1,4 +1,4 @@
-#include <qpdf/QPDF.hh>
+#include <qpdf/QPDF_private.hh>
 
 #include <qpdf/QPDFExc.hh>
 #include <qpdf/QPDFObjectHandle_private.hh>
diff --git a/libqpdf/qpdf/QPDFObject_private.hh b/libqpdf/qpdf/QPDFObject_private.hh
index db2da1c..8a9be46 100644
--- a/libqpdf/qpdf/QPDFObject_private.hh
+++ b/libqpdf/qpdf/QPDFObject_private.hh
@@ -7,8 +7,8 @@
 #include <qpdf/Constants.h>
 #include <qpdf/JSON.hh>
 #include <qpdf/JSON_writer.hh>
-#include <qpdf/QPDF.hh>
 #include <qpdf/QPDFObjGen.hh>
+#include <qpdf/QPDF_private.hh>
 #include <qpdf/Types.h>
 
 #include <map>
diff --git a/libqpdf/qpdf/QPDFParser.hh b/libqpdf/qpdf/QPDFParser.hh
index 6033f30..ae0c394 100644
--- a/libqpdf/qpdf/QPDFParser.hh
+++ b/libqpdf/qpdf/QPDFParser.hh
@@ -12,6 +12,8 @@ class QPDFParser
 {
   public:
     QPDFParser() = delete;
+
+    // This constructor is only used by QPDFObjectHandle::parse overload taking a QPDFTokenizer.
     QPDFParser(
         InputSource& input,
         std::string const& object_description,
@@ -24,16 +26,56 @@ class QPDFParser
         tokenizer(*tokenizer.m),
         decrypter(decrypter),
         context(context),
-        description(
-            std::make_shared<QPDFObject::Description>(
-                std::string(input.getName() + ", " + object_description + " at offset $PO"))),
+        description(make_description(input.getName(), object_description)),
         parse_pdf(parse_pdf)
     {
     }
-    virtual ~QPDFParser() = default;
+
+    QPDFParser(
+        InputSource& input,
+        std::string const& object_description,
+        qpdf::Tokenizer& tokenizer,
+        QPDFObjectHandle::StringDecrypter* decrypter,
+        QPDF* context,
+        bool parse_pdf) :
+        input(input),
+        object_description(object_description),
+        tokenizer(tokenizer),
+        decrypter(decrypter),
+        context(context),
+        description(make_description(input.getName(), object_description)),
+        parse_pdf(parse_pdf)
+    {
+    }
+
+    // Used by parseContentStream_data only
+    QPDFParser(
+        InputSource& input,
+        std::shared_ptr<QPDFObject::Description> sp_description,
+        std::string const& object_description,
+        qpdf::Tokenizer& tokenizer,
+        QPDF* context) :
+        input(input),
+        object_description(object_description),
+        tokenizer(tokenizer),
+        decrypter(nullptr),
+        context(context),
+        description(std::move(sp_description)),
+        parse_pdf(false)
+    {
+    }
+    ~QPDFParser() = default;
 
     QPDFObjectHandle parse(bool& empty, bool content_stream);
 
+    static std::shared_ptr<QPDFObject::Description>
+    make_description(std::string const& input_name, std::string const& object_description)
+    {
+        using namespace std::literals;
+        return std::make_shared<QPDFObject::Description>(
+            input_name + ", " + object_description + " at offset $PO");
+    }
+
   private:
     // Parser state.  Note:
     // state <= st_dictionary_value == (state = st_dictionary_key || state = st_dictionary_value)
@@ -83,7 +125,7 @@ class QPDFParser
     bool parse_pdf;
 
     std::vector<StackFrame> stack;
-    StackFrame* frame;
+    StackFrame* frame{nullptr};
     // Number of recent bad tokens. This will always be > 0 once a bad token has been encountered as
     // it only gets incremented or reset when a bad token is encountered.
     int bad_count{0};
@@ -92,9 +134,9 @@ class QPDFParser
     // Number of good tokens since last bad token. Irrelevant if bad_count == 0.
     int good_count{0};
     // Start offset including any leading whitespace.
-    qpdf_offset_t start;
+    qpdf_offset_t start{0};
     // Number of successive integer tokens.
-    int int_count = 0;
+    int int_count{0};
     long long int_buffer[2]{0, 0};
     qpdf_offset_t last_offset_buffer[2]{0, 0};
 };
diff --git a/libqpdf/qpdf/QPDF_private.hh b/libqpdf/qpdf/QPDF_private.hh
new file mode 100644
index 0000000..a7d9989
--- /dev/null
+++ b/libqpdf/qpdf/QPDF_private.hh
@@ -0,0 +1,559 @@
+#ifndef QPDF_PRIVATE_HH
+#define QPDF_PRIVATE_HH
+
+#include <qpdf/QPDF.hh>
+
+#include <qpdf/QPDFTokenizer_private.hh>
+
+// Writer class is restricted to QPDFWriter so that only it can call certain methods.
+class QPDF::Writer
+{
+    friend class QPDFWriter;
+
+  private:
+    static void
+    optimize(
+        QPDF& qpdf,
+        QPDFWriter::ObjTable const& obj,
+        std::function<int(QPDFObjectHandle&)> skip_stream_parameters)
+    {
+        qpdf.optimize(obj, skip_stream_parameters);
+    }
+
+    static void
+    getLinearizedParts(
+        QPDF& qpdf,
+        QPDFWriter::ObjTable const& obj,
+        std::vector<QPDFObjectHandle>& part4,
+        std::vector<QPDFObjectHandle>& part6,
+        std::vector<QPDFObjectHandle>& part7,
+        std::vector<QPDFObjectHandle>& part8,
+        std::vector<QPDFObjectHandle>& part9)
+    {
+        qpdf.getLinearizedParts(obj, part4, part6, part7, part8, part9);
+    }
+
+    static void
+    generateHintStream(
+        QPDF& qpdf,
+        QPDFWriter::NewObjTable const& new_obj,
+        QPDFWriter::ObjTable const& obj,
+        std::shared_ptr<Buffer>& hint_stream,
+        int& S,
+        int& O,
+        bool compressed)
+    {
+        qpdf.generateHintStream(new_obj, obj, hint_stream, S, O, compressed);
+    }
+
+    static std::vector<QPDFObjGen>
+    getCompressibleObjGens(QPDF& qpdf)
+    {
+        return qpdf.getCompressibleObjVector();
+    }
+
+    static std::vector<bool>
+    getCompressibleObjSet(QPDF& qpdf)
+    {
+        return qpdf.getCompressibleObjSet();
+    }
+
+    static std::map<QPDFObjGen, QPDFXRefEntry> const&
+    getXRefTable(QPDF& qpdf)
+    {
+        return qpdf.getXRefTableInternal();
+    }
+
+    static size_t
+    tableSize(QPDF& qpdf)
+    {
+        return qpdf.tableSize();
+    }
+};
+
+// The Resolver class is restricted to QPDFObject so that only it can resolve indirect
+// references.
+class QPDF::Resolver
+{
+    friend class QPDFObject;
+    friend class qpdf::BaseHandle;
+
+  private:
+    static std::shared_ptr<QPDFObject> const&
+    resolved(QPDF* qpdf, QPDFObjGen og)
+    {
+        return qpdf->resolve(og);
+    }
+};
+
+// StreamCopier class is restricted to QPDFObjectHandle so it can copy stream data.
+class QPDF::StreamCopier
+{
+    friend class QPDFObjectHandle;
+
+  private:
+    static void
+    copyStreamData(QPDF* qpdf, QPDFObjectHandle const& dest, QPDFObjectHandle const& src)
+    {
+        qpdf->copyStreamData(dest, src);
+    }
+};
+
+// The ParseGuard class allows QPDFParser to detect re-entrant parsing. It also provides
+// special access to allow the parser to create unresolved objects and dangling references.
+class QPDF::ParseGuard
+{
+    friend class QPDFParser;
+
+  private:
+    ParseGuard(QPDF* qpdf) :
+        qpdf(qpdf)
+    {
+        if (qpdf) {
+            qpdf->inParse(true);
+        }
+    }
+
+    static std::shared_ptr<QPDFObject>
+    getObject(QPDF* qpdf, int id, int gen, bool parse_pdf)
+    {
+        return qpdf->getObjectForParser(id, gen, parse_pdf);
+    }
+
+    ~ParseGuard()
+    {
+        if (qpdf) {
+            qpdf->inParse(false);
+        }
+    }
+    QPDF* qpdf;
+};
+
+// Pipe class is restricted to QPDF_Stream.
+class QPDF::Pipe
+{
+    friend class qpdf::Stream;
+
+  private:
+    static bool
+    pipeStreamData(
+        QPDF* qpdf,
+        QPDFObjGen og,
+        qpdf_offset_t offset,
+        size_t length,
+        QPDFObjectHandle dict,
+        Pipeline* pipeline,
+        bool suppress_warnings,
+        bool will_retry)
+    {
+        return qpdf->pipeStreamData(
+            og, offset, length, dict, pipeline, suppress_warnings, will_retry);
+    }
+};
+
+class QPDF::ObjCache
+{
+  public:
+    ObjCache() = default;
+    ObjCache(
+        std::shared_ptr<QPDFObject> object,
+        qpdf_offset_t end_before_space = 0,
+        qpdf_offset_t end_after_space = 0) :
+        object(std::move(object)),
+        end_before_space(end_before_space),
+        end_after_space(end_after_space)
+    {
+    }
+
+    std::shared_ptr<QPDFObject> object;
+    qpdf_offset_t end_before_space{0};
+    qpdf_offset_t end_after_space{0};
+};
+
+class QPDF::ObjCopier
+{
+  public:
+    std::map<QPDFObjGen, QPDFObjectHandle> object_map;
+    std::vector<QPDFObjectHandle> to_copy;
+    QPDFObjGen::set visiting;
+};
+
+class QPDF::EncryptionParameters
+{
+    friend class QPDF;
+
+  public:
+    EncryptionParameters() = default;
+
+  private:
+    bool encrypted{false};
+    bool encryption_initialized{false};
+    int encryption_V{0};
+    int encryption_R{0};
+    bool encrypt_metadata{true};
+    std::map<std::string, encryption_method_e> crypt_filters;
+    encryption_method_e cf_stream{e_none};
+    encryption_method_e cf_string{e_none};
+    encryption_method_e cf_file{e_none};
+    std::string provided_password;
+    std::string user_password;
+    std::string encryption_key;
+    std::string cached_object_encryption_key;
+    QPDFObjGen cached_key_og{};
+    bool user_password_matched{false};
+    bool owner_password_matched{false};
+};
+
+class QPDF::ForeignStreamData
+{
+    friend class QPDF;
+
+  public:
+    ForeignStreamData(
+        std::shared_ptr<EncryptionParameters> encp,
+        std::shared_ptr<InputSource> file,
+        QPDFObjGen foreign_og,
+        qpdf_offset_t offset,
+        size_t length,
+        QPDFObjectHandle local_dict);
+
+  private:
+    std::shared_ptr<EncryptionParameters> encp;
+    std::shared_ptr<InputSource> file;
+    QPDFObjGen foreign_og;
+    qpdf_offset_t offset;
+    size_t length;
+    QPDFObjectHandle local_dict;
+};
+
+class QPDF::CopiedStreamDataProvider: public QPDFObjectHandle::StreamDataProvider
+{
+  public:
+    CopiedStreamDataProvider(QPDF& destination_qpdf);
+    ~CopiedStreamDataProvider() override = default;
+    bool provideStreamData(
+        QPDFObjGen const& og, Pipeline* pipeline, bool suppress_warnings, bool will_retry) override;
+    void registerForeignStream(QPDFObjGen const& local_og, QPDFObjectHandle foreign_stream);
+    void registerForeignStream(QPDFObjGen const& local_og, std::shared_ptr<ForeignStreamData>);
+
+  private:
+    QPDF& destination_qpdf;
+    std::map<QPDFObjGen, QPDFObjectHandle> foreign_streams;
+    std::map<QPDFObjGen, std::shared_ptr<ForeignStreamData>> foreign_stream_data;
+};
+
+class QPDF::StringDecrypter final: public QPDFObjectHandle::StringDecrypter
+{
+    friend class QPDF;
+
+  public:
+    StringDecrypter(QPDF* qpdf, QPDFObjGen og);
+    ~StringDecrypter() final = default;
+    void
+    decryptString(std::string& val) final
+    {
+        qpdf->decryptString(val, og);
+    }
+
+  private:
+    QPDF* qpdf;
+    QPDFObjGen og;
+};
+
+// PDF 1.4: Table F.4
+struct QPDF::HPageOffsetEntry
+{
+    int delta_nobjects{0};              // 1
+    qpdf_offset_t delta_page_length{0}; // 2
+    // vectors' sizes = nshared_objects
+    int nshared_objects{0};                // 3
+    std::vector<int> shared_identifiers;   // 4
+    std::vector<int> shared_numerators;    // 5
+    qpdf_offset_t delta_content_offset{0}; // 6
+    qpdf_offset_t delta_content_length{0}; // 7
+};
+
+// PDF 1.4: Table F.3
+struct QPDF::HPageOffset
+{
+    int min_nobjects{0};                // 1
+    qpdf_offset_t first_page_offset{0}; // 2
+    int nbits_delta_nobjects{0};        // 3
+    int min_page_length{0};             // 4
+    int nbits_delta_page_length{0};     // 5
+    int min_content_offset{0};          // 6
+    int nbits_delta_content_offset{0};  // 7
+    int min_content_length{0};          // 8
+    int nbits_delta_content_length{0};  // 9
+    int nbits_nshared_objects{0};       // 10
+    int nbits_shared_identifier{0};     // 11
+    int nbits_shared_numerator{0};      // 12
+    int shared_denominator{0};          // 13
+    // vector size is npages
+    std::vector<HPageOffsetEntry> entries;
+};
+
+// PDF 1.4: Table F.6
+struct QPDF::HSharedObjectEntry
+{
+    // Item 3 is a 128-bit signature (unsupported by Acrobat)
+    int delta_group_length{0}; // 1
+    int signature_present{0};  // 2 -- always 0
+    int nobjects_minus_one{0}; // 4 -- always 0
+};
+
+// PDF 1.4: Table F.5
+struct QPDF::HSharedObject
+{
+    int first_shared_obj{0};              // 1
+    qpdf_offset_t first_shared_offset{0}; // 2
+    int nshared_first_page{0};            // 3
+    int nshared_total{0};                 // 4
+    int nbits_nobjects{0};                // 5
+    int min_group_length{0};              // 6
+    int nbits_delta_group_length{0};      // 7
+    // vector size is nshared_total
+    std::vector<HSharedObjectEntry> entries;
+};
+
+// PDF 1.4: Table F.9
+struct QPDF::HGeneric
+{
+    int first_object{0};                  // 1
+    qpdf_offset_t first_object_offset{0}; // 2
+    int nobjects{0};                      // 3
+    int group_length{0};                  // 4
+};
+
+// Other linearization data structures
+
+// Initialized from Linearization Parameter dictionary
+struct QPDF::LinParameters
+{
+    qpdf_offset_t file_size{0};        // /L
+    int first_page_object{0};          // /O
+    qpdf_offset_t first_page_end{0};   // /E
+    int npages{0};                     // /N
+    qpdf_offset_t xref_zero_offset{0}; // /T
+    int first_page{0};                 // /P
+    qpdf_offset_t H_offset{0};         // offset of primary hint stream
+    qpdf_offset_t H_length{0};         // length of primary hint stream
+};
+
+// Computed hint table value data structures.  These tables contain the computed values on which
+// the hint table values are based.  They exclude things like number of bits and store actual
+// values instead of mins and deltas.  File offsets are also absolute rather than being offset
+// by the size of the primary hint table.  We populate the hint table structures from these
+// during writing and compare the hint table values with these during validation.  We ignore
+// some values for various reasons described in the code.  Those values are omitted from these
+// structures.  Note also that object numbers are object numbers from the input file, not the
+// output file.
+
+// Naming convention: CHSomething is analogous to HSomething above.  "CH" is computed hint.
+
+struct QPDF::CHPageOffsetEntry
+{
+    int nobjects{0};
+    int nshared_objects{0};
+    // vectors' sizes = nshared_objects
+    std::vector<int> shared_identifiers;
+};
+
+struct QPDF::CHPageOffset
+{
+    // vector size is npages
+    std::vector<CHPageOffsetEntry> entries;
+};
+
+struct QPDF::CHSharedObjectEntry
+{
+    CHSharedObjectEntry(int object) :
+        object(object)
+    {
+    }
+
+    int object;
+};
+
+// PDF 1.4: Table F.5
+struct QPDF::CHSharedObject
+{
+    int first_shared_obj{0};
+    int nshared_first_page{0};
+    int nshared_total{0};
+    // vector size is nshared_total
+    std::vector<CHSharedObjectEntry> entries;
+};
+
+// 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_bad, ou_page, ou_thumb, ou_trailer_key, ou_root_key, ou_root };
+
+    ObjUser() = default;
+
+    // type must be ou_root
+    ObjUser(user_e type);
+
+    // type must be one of ou_page or ou_thumb
+    ObjUser(user_e type, int 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{ou_bad};
+    int 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:
+    PatternFinder(QPDF& qpdf, bool (QPDF::*checker)()) :
+        qpdf(qpdf),
+        checker(checker)
+    {
+    }
+    ~PatternFinder() final = default;
+    bool
+    check() final
+    {
+        return (this->qpdf.*checker)();
+    }
+
+  private:
+    QPDF& qpdf;
+    bool (QPDF::*checker)();
+};
+
+class QPDF::Members
+{
+    friend class QPDF;
+    friend class ResolveRecorder;
+
+  public:
+    Members();
+    Members(Members const&) = delete;
+    ~Members() = default;
+
+  private:
+    std::shared_ptr<QPDFLogger> log;
+    unsigned long long unique_id{0};
+    qpdf::Tokenizer tokenizer;
+    std::shared_ptr<InputSource> file;
+    std::string last_object_description;
+    bool provided_password_is_hex_key{false};
+    bool ignore_xref_streams{false};
+    bool suppress_warnings{false};
+    size_t max_warnings{0};
+    bool attempt_recovery{true};
+    bool check_mode{false};
+    std::shared_ptr<EncryptionParameters> encp;
+    std::string pdf_version;
+    std::map<QPDFObjGen, QPDFXRefEntry> xref_table;
+    // Various tables are indexed by object id, with potential size id + 1
+    int xref_table_max_id{std::numeric_limits<int>::max() - 1};
+    qpdf_offset_t xref_table_max_offset{0};
+    std::set<int> deleted_objects;
+    std::map<QPDFObjGen, ObjCache> obj_cache;
+    std::set<QPDFObjGen> resolving;
+    QPDFObjectHandle trailer;
+    std::vector<QPDFObjectHandle> all_pages;
+    bool invalid_page_found{false};
+    std::map<QPDFObjGen, int> pageobj_to_pages_pos;
+    bool pushed_inherited_attributes_to_pages{false};
+    bool ever_pushed_inherited_attributes_to_pages{false};
+    bool ever_called_get_all_pages{false};
+    std::vector<QPDFExc> warnings;
+    std::map<unsigned long long, ObjCopier> object_copiers;
+    std::shared_ptr<QPDFObjectHandle::StreamDataProvider> copied_streams;
+    // copied_stream_data_provider is owned by copied_streams
+    CopiedStreamDataProvider* copied_stream_data_provider{nullptr};
+    bool reconstructed_xref{false};
+    bool fixed_dangling_refs{false};
+    bool immediate_copy_from{false};
+    bool in_parse{false};
+    bool parsed{false};
+    std::set<int> resolved_object_streams;
+
+    // Linearization data
+    qpdf_offset_t first_xref_item_offset{0}; // actual value from file
+    bool uncompressed_after_compressed{false};
+    bool linearization_warnings{false};
+
+    // Linearization parameter dictionary and hint table data: may be read from file or computed
+    // prior to writing a linearized file
+    QPDFObjectHandle lindict;
+    LinParameters linp;
+    HPageOffset page_offset_hints;
+    HSharedObject shared_object_hints;
+    HGeneric outline_hints;
+
+    // Computed linearization data: used to populate above tables during writing and to compare
+    // with them during validation. c_ means computed.
+    LinParameters c_linp;
+    CHPageOffset c_page_offset_data;
+    CHSharedObject c_shared_object_data;
+    HGeneric c_outline_data;
+
+    // Object ordering data for linearized files: initialized by calculateLinearizationData().
+    // Part numbers refer to the PDF 1.4 specification.
+    std::vector<QPDFObjectHandle> part4;
+    std::vector<QPDFObjectHandle> part6;
+    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;
+};
+
+// JobSetter class is restricted to QPDFJob.
+class QPDF::JobSetter
+{
+    friend class QPDFJob;
+
+  private:
+    // Enable enhanced warnings for pdf file checking.
+    static void
+    setCheckMode(QPDF& qpdf, bool val)
+    {
+        qpdf.m->check_mode = val;
+    }
+};
+
+class QPDF::ResolveRecorder
+{
+  public:
+    ResolveRecorder(QPDF* qpdf, QPDFObjGen const& og) :
+        qpdf(qpdf),
+        iter(qpdf->m->resolving.insert(og).first)
+    {
+    }
+    virtual ~ResolveRecorder()
+    {
+        this->qpdf->m->resolving.erase(iter);
+    }
+
+  private:
+    QPDF* qpdf;
+    std::set<QPDFObjGen>::const_iterator iter;
+};
+
+#endif // QPDF_PRIVATE_HH