Allow propagation of errors and retry through StreamDataProvider

StreamDataProvider::provideStreamData now has a rich enough API for it
to effectively proxy to pipeStreamData.

4 files changed, 99 insertions, 18 deletions

diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index 3177d38b..6219509e 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -68,27 +68,37 @@ QPDF::ForeignStreamData::ForeignStreamData(
 
 QPDF::CopiedStreamDataProvider::CopiedStreamDataProvider(
     QPDF& destination_qpdf) :
+    QPDFObjectHandle::StreamDataProvider(true),
     destination_qpdf(destination_qpdf)
 {
 }
 
-void
+bool
 QPDF::CopiedStreamDataProvider::provideStreamData(
-    int objid, int generation, Pipeline* pipeline)
+    int objid, int generation, Pipeline* pipeline,
+    bool suppress_warnings, bool will_retry)
 {
     PointerHolder<ForeignStreamData> foreign_data =
         this->foreign_stream_data[QPDFObjGen(objid, generation)];
+    bool result = false;
     if (foreign_data.getPointer())
     {
-        destination_qpdf.pipeForeignStreamData(
-            foreign_data, pipeline, 0, qpdf_dl_none);
+        result = destination_qpdf.pipeForeignStreamData(
+            foreign_data, pipeline, suppress_warnings, will_retry);
+        QTC::TC("qpdf", "QPDF copy foreign with data",
+                result ? 0 : 1);
     }
     else
     {
         QPDFObjectHandle foreign_stream =
             this->foreign_streams[QPDFObjGen(objid, generation)];
-        foreign_stream.pipeStreamData(pipeline, 0, qpdf_dl_none);
+        result = foreign_stream.pipeStreamData(
+            pipeline, nullptr, 0, qpdf_dl_none,
+            suppress_warnings, will_retry);
+        QTC::TC("qpdf", "QPDF copy foreign with foreign_stream",
+                result ? 0 : 1);
     }
+    return result;
 }
 
 void
@@ -2851,8 +2861,7 @@ bool
 QPDF::pipeForeignStreamData(
     PointerHolder<ForeignStreamData> foreign,
     Pipeline* pipeline,
-    int encode_flags,
-    qpdf_stream_decode_level_e decode_level)
+    bool suppress_warnings, bool will_retry)
 {
     if (foreign->encp->encrypted)
     {
@@ -2863,7 +2872,7 @@ QPDF::pipeForeignStreamData(
         foreign->foreign_objid, foreign->foreign_generation,
         foreign->offset, foreign->length,
         foreign->local_dict, foreign->is_attachment_stream,
-        pipeline, false, false);
+        pipeline, suppress_warnings, will_retry);
 }
 
 void
diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc
index dca59216..ab77fb73 100644
--- a/libqpdf/QPDFObjectHandle.cc
+++ b/libqpdf/QPDFObjectHandle.cc
@@ -36,6 +36,36 @@ class TerminateParsing
 {
 };
 
+QPDFObjectHandle::StreamDataProvider::StreamDataProvider(
+    bool supports_retry) :
+    supports_retry(supports_retry)
+{
+}
+
+void
+QPDFObjectHandle::StreamDataProvider::provideStreamData(
+    int objid, int generation, Pipeline* pipeline)
+{
+    throw std::logic_error(
+        "you must override provideStreamData -- see QPDFObjectHandle.hh");
+}
+
+bool
+QPDFObjectHandle::StreamDataProvider::provideStreamData(
+    int objid, int generation, Pipeline* pipeline,
+    bool suppress_warnings, bool will_retry)
+{
+    throw std::logic_error(
+        "you must override provideStreamData -- see QPDFObjectHandle.hh");
+    return false;
+}
+
+bool
+QPDFObjectHandle::StreamDataProvider::supportsRetry()
+{
+    return this->supports_retry;
+}
+
 class CoalesceProvider: public QPDFObjectHandle::StreamDataProvider
 {
   public:
@@ -1135,14 +1165,29 @@ QPDFObjectHandle::getRawStreamData()
 }
 
 bool
-QPDFObjectHandle::pipeStreamData(Pipeline* p,
+QPDFObjectHandle::pipeStreamData(Pipeline* p, bool* filtering_attempted,
                                  int encode_flags,
                                  qpdf_stream_decode_level_e decode_level,
                                  bool suppress_warnings, bool will_retry)
 {
     assertStream();
     return dynamic_cast<QPDF_Stream*>(obj.getPointer())->pipeStreamData(
-	p, encode_flags, decode_level, suppress_warnings, will_retry);
+	p, filtering_attempted, encode_flags, decode_level,
+        suppress_warnings, will_retry);
+}
+
+bool
+QPDFObjectHandle::pipeStreamData(Pipeline* p,
+                                 int encode_flags,
+                                 qpdf_stream_decode_level_e decode_level,
+                                 bool suppress_warnings, bool will_retry)
+{
+    assertStream();
+    bool filtering_attempted;
+    dynamic_cast<QPDF_Stream*>(obj.getPointer())->pipeStreamData(
+	p, &filtering_attempted, encode_flags, decode_level,
+        suppress_warnings, will_retry);
+    return filtering_attempted;
 }
 
 bool
diff --git a/libqpdf/QPDF_Stream.cc b/libqpdf/QPDF_Stream.cc
index dd2796e8..48c1ccf9 100644
--- a/libqpdf/QPDF_Stream.cc
+++ b/libqpdf/QPDF_Stream.cc
@@ -163,7 +163,7 @@ PointerHolder<Buffer>
 QPDF_Stream::getStreamData(qpdf_stream_decode_level_e decode_level)
 {
     Pl_Buffer buf("stream data buffer");
-    if (! pipeStreamData(&buf, 0, decode_level, false, false))
+    if (! pipeStreamData(&buf, nullptr, 0, decode_level, false, false))
     {
 	throw QPDFExc(qpdf_e_unsupported, qpdf->getFilename(),
                       "", this->offset,
@@ -177,7 +177,12 @@ PointerHolder<Buffer>
 QPDF_Stream::getRawStreamData()
 {
     Pl_Buffer buf("stream data buffer");
-    pipeStreamData(&buf, 0, qpdf_dl_none, false, false);
+    if (! pipeStreamData(&buf, nullptr, 0, qpdf_dl_none, false, false))
+    {
+	throw QPDFExc(qpdf_e_unsupported, qpdf->getFilename(),
+                      "", this->offset,
+                      "error getting raw stream data");
+    }
     QTC::TC("qpdf", "QPDF_Stream getRawStreamData");
     return buf.getBuffer();
 }
@@ -467,7 +472,7 @@ QPDF_Stream::filterable(std::vector<std::string>& filters,
 }
 
 bool
-QPDF_Stream::pipeStreamData(Pipeline* pipeline,
+QPDF_Stream::pipeStreamData(Pipeline* pipeline, bool* filterp,
                             int encode_flags,
                             qpdf_stream_decode_level_e decode_level,
                             bool suppress_warnings, bool will_retry)
@@ -480,7 +485,14 @@ QPDF_Stream::pipeStreamData(Pipeline* pipeline,
     bool early_code_change = true;
     bool specialized_compression = false;
     bool lossy_compression = false;
-    bool filter = (! ((encode_flags == 0) && (decode_level == qpdf_dl_none)));
+    bool ignored;
+    if (filterp == nullptr)
+    {
+        filterp = &ignored;
+    }
+    bool& filter = *filterp;
+    filter = (! ((encode_flags == 0) && (decode_level == qpdf_dl_none)));
+    bool success = true;
     if (filter)
     {
 	filter = filterable(filters, specialized_compression, lossy_compression,
@@ -505,6 +517,7 @@ QPDF_Stream::pipeStreamData(Pipeline* pipeline,
     if (pipeline == 0)
     {
 	QTC::TC("qpdf", "QPDF_Stream pipeStreamData with null pipeline");
+        // Return value is whether we can filter in this case.
 	return filter;
     }
 
@@ -625,8 +638,21 @@ QPDF_Stream::pipeStreamData(Pipeline* pipeline,
     else if (this->stream_provider.getPointer())
     {
 	Pl_Count count("stream provider count", pipeline);
-	this->stream_provider->provideStreamData(
-	    this->objid, this->generation, &count);
+        if (this->stream_provider->supportsRetry())
+        {
+            if (! this->stream_provider->provideStreamData(
+                    this->objid, this->generation, &count,
+                    suppress_warnings, will_retry))
+            {
+                filter = false;
+                success = false;
+            }
+        }
+        else
+        {
+            this->stream_provider->provideStreamData(
+                this->objid, this->generation, &count);
+        }
 	qpdf_offset_t actual_length = count.getCount();
 	qpdf_offset_t desired_length = 0;
         if (this->stream_dict.hasKey("/Length"))
@@ -674,6 +700,7 @@ QPDF_Stream::pipeStreamData(Pipeline* pipeline,
                                          will_retry))
         {
             filter = false;
+            success = false;
         }
     }
 
@@ -704,7 +731,7 @@ QPDF_Stream::pipeStreamData(Pipeline* pipeline,
                      " for content normalization in the manual."));
     }
 
-    return filter;
+    return success;
 }
 
 void
diff --git a/libqpdf/qpdf/QPDF_Stream.hh b/libqpdf/qpdf/QPDF_Stream.hh
index b6428cc9..da9f91a0 100644
--- a/libqpdf/qpdf/QPDF_Stream.hh
+++ b/libqpdf/qpdf/QPDF_Stream.hh
@@ -31,7 +31,7 @@ class QPDF_Stream: public QPDFObject
     PointerHolder<QPDFObjectHandle::StreamDataProvider> getStreamDataProvider() const;
 
     // See comments in QPDFObjectHandle.hh for these methods.
-    bool pipeStreamData(Pipeline*,
+    bool pipeStreamData(Pipeline*, bool* tried_filtering,
                         int encode_flags,
                         qpdf_stream_decode_level_e decode_level,
                         bool suppress_warnings, bool will_retry);