From 2a82f6e1e05b5791c264efd8f70a20aeadca7501 Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Fri, 22 Jun 2018 14:52:03 -0400
Subject: [PATCH] Add method to get count of objects in QPDF

---
 ChangeLog            |  3 +++
 include/qpdf/QPDF.hh |  6 ++++++
 libqpdf/QPDF.cc      | 26 +++++++++++++++++---------
 3 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 2463c250..dd19b0a2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2018-06-22  Jay Berkenbilt  <ejb@ql.org>
 
+	* Add new method QPDF::getObjectCount(). This gives an approximate
+	(upper bound) account of objects in the QPDF object.
+
 	* Don't leave files open when merging. This makes it possible
 	merge more files at once than the operating system's open file
 	limit. Fixes #154.
diff --git a/include/qpdf/QPDF.hh b/include/qpdf/QPDF.hh
index ad84fad5..681d233c 100644
--- a/include/qpdf/QPDF.hh
+++ b/include/qpdf/QPDF.hh
@@ -431,6 +431,12 @@ class QPDF
     QPDF_DLL
     void showXRefTable();
 
+    // Return the approximate number of indirect objects. It is
+    // approximate because not all objects in the file are preserved
+    // in all cases.
+    QPDF_DLL
+    size_t getObjectCount();
+
     // Returns a list of indirect objects for every object in the xref
     // table. Useful for discovering objects that are not otherwise
     // referenced.
diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index 4dc1e5ca..7d3c10e7 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -1218,6 +1218,22 @@ QPDF::showXRefTable()
     }
 }
 
+size_t
+QPDF::getObjectCount()
+{
+    // This method returns the next available indirect object number.
+    // makeIndirectObject uses it for this purpose.
+    QPDFObjGen o1(0, 0);
+    if (! this->m->obj_cache.empty())
+    {
+	o1 = (*(this->m->obj_cache.rbegin())).first;
+    }
+    QPDFObjGen o2 = (*(this->m->xref_table.rbegin())).first;
+    QTC::TC("qpdf", "QPDF indirect last obj from xref",
+	    (o2.getObj() > o1.getObj()) ? 1 : 0);
+    return std::max(o1.getObj(), o2.getObj());
+}
+
 std::vector<QPDFObjectHandle>
 QPDF::getAllObjects()
 {
@@ -1904,15 +1920,7 @@ QPDF::resolveObjectsInStream(int obj_stream_number)
 QPDFObjectHandle
 QPDF::makeIndirectObject(QPDFObjectHandle oh)
 {
-    QPDFObjGen o1(0, 0);
-    if (! this->m->obj_cache.empty())
-    {
-	o1 = (*(this->m->obj_cache.rbegin())).first;
-    }
-    QPDFObjGen o2 = (*(this->m->xref_table.rbegin())).first;
-    QTC::TC("qpdf", "QPDF indirect last obj from xref",
-	    (o2.getObj() > o1.getObj()) ? 1 : 0);
-    int max_objid = std::max(o1.getObj(), o2.getObj());
+    int max_objid = getObjectCount();
     QPDFObjGen next(max_objid + 1, 0);
     this->m->obj_cache[next] =
 	ObjCache(QPDFObjectHandle::ObjAccessor::getObject(oh), -1, -1);