Add QPDFNameTreeObjectHelper

Jay Berkenbilt
1 parent d2f39759
Showing 8 changed files with 376 additions and 2 deletions
ChangeLog
include/qpdf/QPDFNameTreeObjectHelper.hh
libqpdf/QPDFNameTreeObjectHelper.cc
libqpdf/build.mk
qpdf/qtest/qpdf.test
qpdf/qtest/qpdf/name-tree.out
qpdf/qtest/qpdf/name-tree.pdf
qpdf/test_driver.cc
 2018-12-18  Jay Berkenbilt  <ejb@ql.org>
+	* Add QPDFNameTreeObjectHelper class. This class provides useful
+	methods for dealing with name trees, which are discussed in
+	section 7.9.6 of the PDF spec (ISO-32000).
+
 	* Preserve page labels when merging and splitting files. Prior
 	versions of qpdf simply preserved the page label information from
 	the first file, which usually wouldn't make any sense in the
+// Copyright (c) 2005-2018 Jay Berkenbilt
+//
+// This file is part of qpdf.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Versions of qpdf prior to version 7 were released under the terms
+// of version 2.0 of the Artistic License. At your option, you may
+// continue to consider qpdf to be licensed under those terms. Please
+// see the manual for additional information.
+
+#ifndef QPDFNAMETREEOBJECTHELPER_HH
+#define QPDFNAMETREEOBJECTHELPER_HH
+
+#include <qpdf/QPDFObjectHelper.hh>
+#include <qpdf/QPDFObjGen.hh>
+#include <map>
+
+#include <qpdf/DLL.h>
+
+// This is an object helper for name trees. See section 7.9.6 in the
+// PDF spec (ISO 32000) for a description of name trees. This
+// implementation disregards stated limits and sequencing and simply
+// builds a map from string object. If the array of values does not
+// contain a string where expected, this implementation silently skips
+// forward until it finds a string. When looking up items in the name
+// tree, use UTF-8 strings. All names are normalized for lookup
+// purposes.
+
+class QPDFNameTreeObjectHelper: public QPDFObjectHelper
+{
+  public:
+    QPDF_DLL
+    QPDFNameTreeObjectHelper(QPDFObjectHandle);
+    QPDF_DLL
+    virtual ~QPDFNameTreeObjectHelper();
+
+    // Return whether the number tree has an explicit entry for this
+    // number.
+    QPDF_DLL
+    bool hasName(std::string const& utf8);
+
+    // Find an object by name. If found, returns true and initializes
+    // oh.
+    QPDF_DLL
+    bool findObject(std::string const& utf8, QPDFObjectHandle& oh);
+
+    QPDF_DLL
+    std::map<std::string, QPDFObjectHandle> getAsMap() const;
+
+  private:
+    class Members
+    {
+        friend class QPDFNameTreeObjectHelper;
+
+      public:
+        QPDF_DLL
+        ~Members();
+
+      private:
+        Members();
+        Members(Members const&);
+
+        std::map<std::string, QPDFObjectHandle> entries;
+        std::set<QPDFObjGen> seen;
+    };
+
+    void updateMap(QPDFObjectHandle oh);
+
+    PointerHolder<Members> m;
+};
+
+#endif // QPDFNAMETREEOBJECTHELPER_HH
+#include <qpdf/QPDFNameTreeObjectHelper.hh>
+
+QPDFNameTreeObjectHelper::Members::~Members()
+{
+}
+
+QPDFNameTreeObjectHelper::Members::Members()
+{
+}
+
+QPDFNameTreeObjectHelper::QPDFNameTreeObjectHelper(QPDFObjectHandle oh) :
+    QPDFObjectHelper(oh),
+    m(new Members())
+{
+    updateMap(oh);
+}
+
+QPDFNameTreeObjectHelper::~QPDFNameTreeObjectHelper()
+{
+}
+
+void
+QPDFNameTreeObjectHelper::updateMap(QPDFObjectHandle oh)
+{
+    if (this->m->seen.count(oh.getObjGen()))
+    {
+        return;
+    }
+    this->m->seen.insert(oh.getObjGen());
+    QPDFObjectHandle names = oh.getKey("/Names");
+    if (names.isArray())
+    {
+        size_t nitems = names.getArrayNItems();
+        size_t i = 0;
+        while (i < nitems - 1)
+        {
+            QPDFObjectHandle name = names.getArrayItem(i);
+            if (name.isString())
+            {
+                ++i;
+                QPDFObjectHandle obj = names.getArrayItem(i);
+                this->m->entries[name.getUTF8Value()] = obj;
+            }
+            ++i;
+        }
+    }
+    QPDFObjectHandle kids = oh.getKey("/Kids");
+    if (kids.isArray())
+    {
+        size_t nitems = kids.getArrayNItems();
+        for (size_t i = 0; i < nitems; ++i)
+        {
+            updateMap(kids.getArrayItem(i));
+        }
+    }
+}
+
+bool
+QPDFNameTreeObjectHelper::hasName(std::string const& name)
+{
+    return this->m->entries.count(name) != 0;
+}
+
+bool
+QPDFNameTreeObjectHelper::findObject(
+    std::string const& name, QPDFObjectHandle& oh)
+{
+    std::map<std::string, QPDFObjectHandle>::iterator i =
+        this->m->entries.find(name);
+    if (i == this->m->entries.end())
+    {
+        return false;
+    }
+    oh = (*i).second;
+    return true;
+}
+
+std::map<std::string, QPDFObjectHandle>
+QPDFNameTreeObjectHelper::getAsMap() const
+{
+    return this->m->entries;
+}
@@ -40,6 +40,7 @@ SRCS_libqpdf = \
 	libqpdf/QPDFAnnotationObjectHelper.cc \
 	libqpdf/QPDFExc.cc \
 	libqpdf/QPDFFormFieldObjectHelper.cc \
+	libqpdf/QPDFNameTreeObjectHelper.cc \
 	libqpdf/QPDFNumberTreeObjectHelper.cc \
 	libqpdf/QPDFObjGen.cc \
 	libqpdf/QPDFObject.cc \
@@ -226,13 +226,17 @@ foreach my $input (@ext_inputs)
 }
 show_ntests();
 # ----------
-$td->notify("--- Number Trees ---");
-$n_tests += 1;
+$td->notify("--- Number and Name Trees ---");
+$n_tests += 2;
 $td->runtest("number trees",
 	     {$td->COMMAND => "test_driver 46 number-tree.pdf"},
 	     {$td->FILE => "number-tree.out", $td->EXIT_STATUS => 0},
 	     $td->NORMALIZE_NEWLINES);
+$td->runtest("name trees",
+	     {$td->COMMAND => "test_driver 48 name-tree.pdf"},
+	     {$td->FILE => "name-tree.out", $td->EXIT_STATUS => 0},
+	     $td->NORMALIZE_NEWLINES);
 show_ntests();
 # ----------
+01 one -> one!
+06 σιχ -> six!
+07 sev•n -> seven!
+11 elephant -> elephant?
+12 twelve -> twelve!
+15 fifteen -> fifteen!
+20 twenty -> twenty.
+22 twenty-two -> twenty-two!
+29 twenty-nine -> twenty-nine!
+test 48 done
+%PDF-1.3
+%¿÷¢þ
+%QDF-1.0
+
+1 0 obj
+<<
+  /Pages 2 0 R
+  /Type /Catalog
+>>
+endobj
+
+2 0 obj
+<<
+  /Count 1
+  /Kids [
+    3 0 R
+  ]
+  /Type /Pages
+>>
+endobj
+
+%% Page 1
+3 0 obj
+<<
+  /Contents 4 0 R
+  /MediaBox [
+    0
+    0
+    612
+    792
+  ]
+  /Parent 2 0 R
+  /Resources <<
+    /Font <<
+      /F1 6 0 R
+    >>
+    /ProcSet 7 0 R
+  >>
+  /Type /Page
+>>
+endobj
+
+%% Contents for page 1
+4 0 obj
+<<
+  /Length 5 0 R
+>>
+stream
+BT
+  /F1 24 Tf
+  72 720 Td
+  (Potato) Tj
+ET
+endstream
+endobj
+
+5 0 obj
+44
+endobj
+
+6 0 obj
+<<
+  /BaseFont /Helvetica
+  /Encoding /WinAnsiEncoding
+  /Name /F1
+  /Subtype /Type1
+  /Type /Font
+>>
+endobj
+
+7 0 obj
+[
+  /PDF
+  /Text
+]
+endobj
+
+8 0 obj
+<<
+  /Kids [
+    9 0 R
+    10 0 R
+  ]
+>>
+endobj
+
+9 0 obj
+<<
+  /Kids [
+    11 0 R
+    12 0 R
+  ]
+  /Limits [
+    0
+    19
+  ]
+>>
+endobj
+
+10 0 obj
+<<
+  /Limits [
+    20
+    29
+  ]
+  /Names [
+    (20 twenty) (twenty.)
+    (22 twenty-two) (twenty-two!)
+    (29 twenty-nine) (twenty-nine!)
+  ]
+>>
+endobj
+
+11 0 obj
+<<
+  /Limits [
+    (01 one)
+    <feff0030003700200073006500762022006e>
+  ]
+  /Names [
+    (01 one) (one!)
+    <feff00300036002003C303B903C7> (six!)
+    (07 sev€n) (seven!)
+  ]
+>>
+endobj
+
+12 0 obj
+<<
+  /Limits [
+    (11 elephant)
+    (15 fifteen)
+  ]
+  /Names [
+    (11 elephant) (elephant?)
+    (12 twelve) (twelve!)
+    (15 fifteen) (fifteen!)
+  ]
+>>
+endobj
+
+
+xref
+0 13
+0000000000 65535 f 
+0000000025 00000 n 
+0000000079 00000 n 
+0000000161 00000 n 
+0000000376 00000 n 
+0000000475 00000 n 
+0000000494 00000 n 
+0000000612 00000 n 
+0000000647 00000 n 
+0000000704 00000 n 
+0000000791 00000 n 
+0000000955 00000 n 
+0000001151 00000 n 
+trailer <<
+  /Root 1 0 R
+  /QTest 8 0 R
+  /Size 13
+  /ID [<2c3b7a6ec7fc61db8a5db4eebf57f540><2c3b7a6ec7fc61db8a5db4eebf57f540>]
+>>
+startxref
+1325
+%%EOF
@@ -7,6 +7,7 @@
 #include <qpdf/QPDFPageObjectHelper.hh>
 #include <qpdf/QPDFAcroFormDocumentHelper.hh>
 #include <qpdf/QPDFNumberTreeObjectHelper.hh>
+#include <qpdf/QPDFNameTreeObjectHelper.hh>
 #include <qpdf/QPDFPageLabelDocumentHelper.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/QTC.hh>
@@ -1706,6 +1707,29 @@ void runtest(int n, char const* filename1, char const* arg2)
                       << labels.at(i+1).unparse() << std::endl;
         }
     }
+    else if (n == 48)
+    {
+        // Test name tree. This test is crafted to work with
+        // name-tree.pdf
+        QPDFObjectHandle qtest = pdf.getTrailer().getKey("/QTest");
+        QPDFNameTreeObjectHelper ntoh(qtest);
+        std::map<std::string, QPDFObjectHandle> ntoh_map = ntoh.getAsMap();
+        for (std::map<std::string, QPDFObjectHandle>::iterator iter =
+                 ntoh_map.begin();
+             iter != ntoh_map.end(); ++iter)
+        {
+            std::cout << (*iter).first << " -> "
+                      << (*iter).second.getStringValue()
+                      << std::endl;
+        }
+        assert(ntoh.hasName("11 elephant"));
+        assert(ntoh.hasName("07 sev\xe2\x80\xa2n"));
+        assert(! ntoh.hasName("potato"));
+        QPDFObjectHandle oh;
+        assert(! ntoh.findObject("potato", oh));
+        assert(ntoh.findObject("07 sev\xe2\x80\xa2n", oh));
+        assert("seven!" == oh.getStringValue());
+    }
     else
     {
 	throw std::runtime_error(std::string("invalid test ") +