newStream

git-svn-id: svn+q:///qpdf/trunk@991 71b93d88-0707-0410-a8cf-f5a4172ac649

11 files changed, 290 insertions, 30 deletions

diff --git a/include/qpdf/QPDFObjectHandle.hh b/include/qpdf/QPDFObjectHandle.hh
index e8d24d40..298e480b 100644
--- a/include/qpdf/QPDFObjectHandle.hh
+++ b/include/qpdf/QPDFObjectHandle.hh
@@ -28,6 +28,34 @@ class QPDF_Array;
 class QPDFObjectHandle
 {
   public:
+    // This class is used by replaceStreamData.  It provides an
+    // alternative way of associating stream data with a stream.  See
+    // comments on replaceStreamData and newStream for additional
+    // details.
+    class StreamDataProvider
+    {
+      public:
+	QPDF_DLL
+	virtual ~StreamDataProvider()
+	{
+	}
+	// The implementation of this function must write the
+	// unencrypted, raw stream data to the given pipeline.  Every
+	// call to provideStreamData for a given stream must write the
+	// same data.  The number of bytes written must agree with the
+	// length provided at the time the StreamDataProvider object
+	// was associated with the stream.  The object ID and
+	// generation passed to this method are those that belong to
+	// the stream on behalf of which the provider is called.  They
+	// may be ignored or used by the implementation for indexing
+	// or other purposes.  This information is made available just
+	// to make it more convenient to use a single
+	// StreamDataProvider object to provide data for multiple
+	// streams.
+	virtual void provideStreamData(int objid, int generation,
+				       Pipeline* pipeline) = 0;
+    };
+
     QPDF_DLL
     QPDFObjectHandle();
     QPDF_DLL
@@ -83,6 +111,30 @@ class QPDFObjectHandle
     static QPDFObjectHandle newDictionary(
 	std::map<std::string, QPDFObjectHandle> const& items);
 
+    // Create a new stream and associate it with the given qpdf
+    // object.  A subsequent call must be made to replaceStreamData()
+    // to provide data for the stream.  The stream's dictionary may be
+    // retrieved by calling getDict(), and the resulting dictionary
+    // may be modified.
+    QPDF_DLL
+    static QPDFObjectHandle newStream(QPDF* qpdf);
+
+    // Create a new stream and associate it with the given qpdf
+    // object.  Use the given buffer as the stream data.  The stream
+    // dictionary's /Length key will automatically be set to the size
+    // of the data buffer.  If additional keys are required, the
+    // stream's dictionary may be retrieved by calling getDict(), and
+    // the resulting dictionary may be modified.  This method is just
+    // a convient wrapper around the newStream() and
+    // replaceStreamData().  It is a convenience methods for streams
+    // that require no parameters beyond the stream length.  Note that
+    // you don't have to deal with compression yourself if you use
+    // QPDFWriter.  By default, QPDFWriter will automatically compress
+    // uncompressed stream data.  Example programs are provided that
+    // illustrate this.
+    QPDF_DLL
+    static QPDFObjectHandle newStream(QPDF* qpdf, PointerHolder<Buffer> data);
+
     // Accessor methods.  If an accessor method that is valid for only
     // a particular object type is called on an object of the wrong
     // type, an exception is thrown.
@@ -198,34 +250,17 @@ class QPDFObjectHandle
 			   QPDFObjectHandle const& filter,
 			   QPDFObjectHandle const& decode_parms);
 
-    class StreamDataProvider
-    {
-      public:
-	QPDF_DLL
-	virtual ~StreamDataProvider()
-	{
-	}
-	// See replaceStreamData below for details on how to override
-	// this method.
-	virtual void provideStreamData(int objid, int generation,
-				       Pipeline* pipeline) = 0;
-    };
     // As above, replace this stream's stream data.  Instead of
     // directly providing a buffer with the stream data, call the
-    // given provider's provideStreamData method.  The method is to
-    // write the unencrypted, raw stream data to the provided
-    // pipeline.  The stream's /Length key will be set to the length
-    // as provided.  This must match the number of bytes written to
-    // the pipeline.  The provider must write exactly the same data to
-    // the pipeline every time it is called.  The method is invoked
-    // with the object ID and generation number, which are just there
-    // to be available to the handler in case it is useful for
-    // indexing purposes.  This makes it easier to reuse the same
-    // StreamDataProvider object for multiple streams.  Although it is
-    // more complex to use this form of replaceStreamData, it makes it
-    // possible to avoid allocating memory for the stream data.
-    // Example programs are provided that use both forms of
-    // replaceStreamData.
+    // given provider's provideStreamData method.  See comments on the
+    // StreamDataProvider class (defined above) for details on the
+    // method.  The provider must write the number of bytes as
+    // indicated by the length parameter, and the data must be
+    // consistent with filter and decode_parms as provided.  Although
+    // it is more complex to use this form of replaceStreamData than
+    // the one that takes a buffer, it makes it possible to avoid
+    // allocating memory for the stream data.  Example programs are
+    // provided that use both forms of replaceStreamData.
     QPDF_DLL
     void replaceStreamData(PointerHolder<StreamDataProvider> provider,
 			   QPDFObjectHandle const& filter,
diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index cbc2450c..3869e00c 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -1779,7 +1779,11 @@ QPDF::resolveObjectsInStream(int obj_stream_number)
 QPDFObjectHandle
 QPDF::makeIndirectObject(QPDFObjectHandle oh)
 {
-    ObjGen o1 = (*(this->obj_cache.rbegin())).first;
+    ObjGen o1(0, 0);
+    if (! this->obj_cache.empty())
+    {
+	o1 = (*(this->obj_cache.rbegin())).first;
+    }
     ObjGen o2 = (*(this->xref_table.rbegin())).first;
     QTC::TC("qpdf", "QPDF indirect last obj from xref",
 	    (o2.obj > o1.obj) ? 1 : 0);
diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc
index 649ce3f0..19b4f94e 100644
--- a/libqpdf/QPDFObjectHandle.cc
+++ b/libqpdf/QPDFObjectHandle.cc
@@ -561,6 +561,30 @@ QPDFObjectHandle::newStream(QPDF* qpdf, int objid, int generation,
 				stream_dict, offset, length));
 }
 
+QPDFObjectHandle
+QPDFObjectHandle::newStream(QPDF* qpdf)
+{
+    QTC::TC("qpdf", "QPDFObjectHandle newStream");
+    std::map<std::string, QPDFObjectHandle> keys;
+    QPDFObjectHandle stream_dict = newDictionary(keys);
+    QPDFObjectHandle result = qpdf->makeIndirectObject(
+	QPDFObjectHandle(
+	    new QPDF_Stream(qpdf, 0, 0, stream_dict, 0, 0)));
+    result.dereference();
+    QPDF_Stream* stream = dynamic_cast<QPDF_Stream*>(result.obj.getPointer());
+    stream->setObjGen(result.getObjectID(), result.getGeneration());
+    return result;
+}
+
+QPDFObjectHandle
+QPDFObjectHandle::newStream(QPDF* qpdf, PointerHolder<Buffer> data)
+{
+    QTC::TC("qpdf", "QPDFObjectHandle newStream with data");
+    QPDFObjectHandle result = newStream(qpdf);
+    result.replaceStreamData(data, newNull(), newNull());
+    return result;
+}
+
 void
 QPDFObjectHandle::makeDirectInternal(std::set<int>& visited)
 {
@@ -649,7 +673,7 @@ QPDFObjectHandle::makeDirectInternal(std::set<int>& visited)
     }
     else
     {
-	throw std::logic_error("QPDFObjectHandle::makeIndirect: "
+	throw std::logic_error("QPDFObjectHandle::makeDirectInternal: "
 			       "unknown object type");
     }
 
diff --git a/libqpdf/QPDF_Stream.cc b/libqpdf/QPDF_Stream.cc
index 1f48b2c1..87c2daa9 100644
--- a/libqpdf/QPDF_Stream.cc
+++ b/libqpdf/QPDF_Stream.cc
@@ -40,6 +40,19 @@ QPDF_Stream::~QPDF_Stream()
 {
 }
 
+void
+QPDF_Stream::setObjGen(int objid, int generation)
+{
+    if (! ((this->objid == 0) && (this->generation == 0)))
+    {
+	throw std::logic_error(
+	    "attempt to set object ID and generation of a stream"
+	    " that already has them");
+    }
+    this->objid = objid;
+    this->generation = generation;
+}
+
 std::string
 QPDF_Stream::unparse()
 {
@@ -353,6 +366,12 @@ QPDF_Stream::pipeStreamData(Pipeline* pipeline, bool filter,
 		QUtil::int_to_string(desired_length) + " bytes");
 	}
     }
+    else if (this->offset == 0)
+    {
+	QTC::TC("qpdf", "QPDF_Stream pipe no stream data");
+	throw std::logic_error(
+	    "pipeStreamData called for stream with no data");
+    }
     else
     {
 	QTC::TC("qpdf", "QPDF_Stream pipe original stream data");
diff --git a/libqpdf/qpdf/QPDF_Stream.hh b/libqpdf/qpdf/QPDF_Stream.hh
index 1790121e..73261f39 100644
--- a/libqpdf/qpdf/QPDF_Stream.hh
+++ b/libqpdf/qpdf/QPDF_Stream.hh
@@ -31,6 +31,11 @@ class QPDF_Stream: public QPDFObject
 	QPDFObjectHandle const& decode_parms,
 	size_t length);
 
+    // Replace object ID and generation.  This may only be called if
+    // object ID and generation are 0.  It is used by QPDFObjectHandle
+    // when adding streams to files.
+    void setObjGen(int objid, int generation);
+
   private:
     void replaceFilterData(QPDFObjectHandle const& filter,
 			   QPDFObjectHandle const& decode_parms,
diff --git a/qpdf/qpdf.testcov b/qpdf/qpdf.testcov
index c880188e..49b03c42 100644
--- a/qpdf/qpdf.testcov
+++ b/qpdf/qpdf.testcov
@@ -178,3 +178,6 @@ QPDF_Stream pipe original stream data 0
 QPDF_Stream pipe replaced stream data 0
 QPDF_Stream pipe use stream provider 0
 QPDF_Stream provider length mismatch 0
+QPDFObjectHandle newStream 0
+QPDFObjectHandle newStream with data 0
+QPDF_Stream pipe no stream data 0
diff --git a/qpdf/qtest/qpdf.test b/qpdf/qtest/qpdf.test
index 6768ebd4..dc47af18 100644
--- a/qpdf/qtest/qpdf.test
+++ b/qpdf/qtest/qpdf.test
@@ -77,7 +77,7 @@ flush_tiff_cache();
 show_ntests();
 # ----------
 $td->notify("--- Miscellaneous Tests ---");
-$n_tests += 26;
+$n_tests += 28;
 
 $td->runtest("qpdf version",
 	     {$td->COMMAND => "qpdf --version"},
@@ -104,7 +104,6 @@ $td->runtest("replace stream data",
 $td->runtest("check output",
 	     {$td->FILE => "a.pdf"},
 	     {$td->FILE => "replaced-stream-data.out"});
-
 $td->runtest("replace stream data compressed",
 	     {$td->COMMAND => "test_driver 8 qstream.pdf"},
 	     {$td->FILE => "test8.out", $td->EXIT_STATUS => 0},
@@ -112,6 +111,13 @@ $td->runtest("replace stream data compressed",
 $td->runtest("check output",
 	     {$td->FILE => "a.pdf"},
 	     {$td->FILE => "replaced-stream-data-flate.out"});
+$td->runtest("new streams",
+	     {$td->COMMAND => "test_driver 9 minimal.pdf"},
+	     {$td->FILE => "test9.out", $td->EXIT_STATUS => 0},
+	     $td->NORMALIZE_NEWLINES);
+$td->runtest("new stream",
+	     {$td->FILE => "a.pdf"},
+	     {$td->FILE => "new-streams.pdf"});
 
 # Make sure we ignore decode parameters that we don't understand
 $td->runtest("unknown decode parameters",
diff --git a/qpdf/qtest/qpdf/minimal.pdf b/qpdf/qtest/qpdf/minimal.pdf
new file mode 100644
index 00000000..a7e01f91
--- /dev/null
+++ b/qpdf/qtest/qpdf/minimal.pdf
@@ -0,0 +1,79 @@
+%PDF-1.3
+1 0 obj
+<<
+  /Type /Catalog
+  /Pages 2 0 R
+>>
+endobj
+
+2 0 obj
+<<
+  /Type /Pages
+  /Kids [
+    3 0 R
+  ]
+  /Count 1
+>>
+endobj
+
+3 0 obj
+<<
+  /Type /Page
+  /Parent 2 0 R
+  /MediaBox [0 0 612 792]
+  /Contents 4 0 R
+  /Resources <<
+    /ProcSet 5 0 R
+    /Font <<
+      /F1 6 0 R
+    >>
+  >>
+>>
+endobj
+
+4 0 obj
+<<
+  /Length 44
+>>
+stream
+BT
+  /F1 24 Tf
+  72 720 Td
+  (Potato) Tj
+ET
+endstream
+endobj
+
+5 0 obj
+[
+  /PDF
+  /Text
+]
+endobj
+
+6 0 obj
+<<
+  /Type /Font
+  /Subtype /Type1
+  /Name /F1
+  /BaseFont /Helvetica
+  /Encoding /WinAnsiEncoding
+>>
+endobj
+
+xref
+0 7
+0000000000 65535 f 
+0000000009 00000 n 
+0000000063 00000 n 
+0000000135 00000 n 
+0000000307 00000 n 
+0000000403 00000 n 
+0000000438 00000 n 
+trailer <<
+  /Size 7
+  /Root 1 0 R
+>>
+startxref
+556
+%%EOF
diff --git a/qpdf/qtest/qpdf/new-streams.pdf b/qpdf/qtest/qpdf/new-streams.pdf
new file mode 100644
index 00000000..d3966a33
--- /dev/null
+++ b/qpdf/qtest/qpdf/new-streams.pdf
@@ -0,0 +1,54 @@
+%PDF-1.3
+%¿÷¢þ
+1 0 obj
+<< /Pages 2 0 R /QStream 3 0 R /RStream 4 0 R /Type /Catalog >>
+endobj
+2 0 obj
+<< /Count 1 /Kids [ 5 0 R ] /Type /Pages >>
+endobj
+3 0 obj
+<< /Length 20 >>
+stream
+data for new stream
+endstream
+endobj
+4 0 obj
+<< /Length 22 >>
+stream
+data for other stream
+endstream
+endobj
+5 0 obj
+<< /Contents 6 0 R /MediaBox [ 0 0 612 792 ] /Parent 2 0 R /Resources << /Font << /F1 7 0 R >> /ProcSet 8 0 R >> /Type /Page >>
+endobj
+6 0 obj
+<< /Length 44 >>
+stream
+BT
+  /F1 24 Tf
+  72 720 Td
+  (Potato) Tj
+ET
+endstream
+endobj
+7 0 obj
+<< /BaseFont /Helvetica /Encoding /WinAnsiEncoding /Name /F1 /Subtype /Type1 /Type /Font >>
+endobj
+8 0 obj
+[ /PDF /Text ]
+endobj
+xref
+0 9
+0000000000 65535 f 
+0000000015 00000 n 
+0000000094 00000 n 
+0000000153 00000 n 
+0000000222 00000 n 
+0000000293 00000 n 
+0000000436 00000 n 
+0000000529 00000 n 
+0000000636 00000 n 
+trailer << /Root 1 0 R /Size 9 /ID [<31415926535897932384626433832795><31415926535897932384626433832795>] >>
+startxref
+666
+%%EOF
diff --git a/qpdf/qtest/qpdf/test9.out b/qpdf/qtest/qpdf/test9.out
new file mode 100644
index 00000000..3489ba0c
--- /dev/null
+++ b/qpdf/qtest/qpdf/test9.out
@@ -0,0 +1,2 @@
+exception: pipeStreamData called for stream with no data
+test 9 done
diff --git a/qpdf/test_driver.cc b/qpdf/test_driver.cc
index e9739e92..09458227 100644
--- a/qpdf/test_driver.cc
+++ b/qpdf/test_driver.cc
@@ -398,6 +398,35 @@ void runtest(int n, char const* filename)
 	w.setStreamDataMode(qpdf_s_preserve);
 	w.write();
     }
+    else if (n == 9)
+    {
+	QPDFObjectHandle root = pdf.getRoot();
+	PointerHolder<Buffer> b1 = new Buffer(20);
+	unsigned char* bp = b1.getPointer()->getBuffer();
+	memcpy(bp, (char*)"data for new stream\n", 20); // no null!
+	QPDFObjectHandle qstream = QPDFObjectHandle::newStream(&pdf, b1);
+	QPDFObjectHandle rstream = QPDFObjectHandle::newStream(&pdf);
+	try
+	{
+	    rstream.getStreamData();
+	    std::cout << "oops -- getStreamData didn't throw" << std::endl;
+	}
+	catch (std::logic_error const& e)
+	{
+	    std::cout << "exception: " << e.what() << std::endl;
+	}
+	PointerHolder<Buffer> b2 = new Buffer(22);
+	bp = b2.getPointer()->getBuffer();
+	memcpy(bp, (char*)"data for other stream\n", 22); // no null!
+	rstream.replaceStreamData(
+	    b2, QPDFObjectHandle::newNull(), QPDFObjectHandle::newNull());
+	root.replaceKey("/QStream", qstream);
+	root.replaceKey("/RStream", rstream);
+	QPDFWriter w(pdf, "a.pdf");
+	w.setStaticID(true);
+	w.setStreamDataMode(qpdf_s_preserve);
+	w.write();
+    }
     else
     {
 	throw std::runtime_error(std::string("invalid test ") +