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-rw-r--r--ChangeLog18
-rw-r--r--TODO4
-rw-r--r--examples/pdf-create.cc10
-rw-r--r--examples/pdf-invert-images.cc3
-rw-r--r--include/qpdf/QPDFObjectHandle.hh31
-rw-r--r--libqpdf/QPDFObjectHandle.cc5
-rw-r--r--libqpdf/QPDF_Stream.cc62
-rw-r--r--libqpdf/qpdf/QPDF_Stream.hh3
-rw-r--r--qpdf/qpdf.testcov2
-rw-r--r--qpdf/qtest/qpdf/replaced-stream-data-flate.pdfbin907 -> 1419 bytes
-rw-r--r--qpdf/test_driver.cc17
-rw-r--r--qpdf/test_large_file.cc10
12 files changed, 100 insertions, 65 deletions
diff --git a/ChangeLog b/ChangeLog
index 5e3092de..6fa4c45d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,21 @@
+2012-07-07 Jay Berkenbilt <ejb@ql.org>
+
+ * NOTE: BREAKING API CHANGE. Remove previously required length
+ parameter from the version QPDFObjectHandle::replaceStreamData
+ that uses a stream data provider. Prior to qpdf 3.0.0, you had to
+ compute the stream length in advance so that qpdf could internally
+ verify that the stream data had the same length every time the
+ provider was invoked. Now this requirement is enforced a
+ different way, and the length parameter is no longer required.
+ Note that I take API-breaking changes very seriously and only did
+ it in this case since the lack of need to know length in advance
+ could significantly simplify people's code. If you were
+ previously going to a lot of trouble to compute the length of the
+ new stream data in advance, you now no longer have to do that.
+ You can just drop the length parameter and remove any code that
+ was previously computing the length. Thanks to Tobias Hoffmann
+ for pointing out how annoying the original interface was.
+
2012-07-05 Jay Berkenbilt <ejb@ql.org>
* Add QPDFWriter methods to write to an already open stdio FILE*.
diff --git a/TODO b/TODO
index 40c113d6..9adbaa73 100644
--- a/TODO
+++ b/TODO
@@ -17,8 +17,8 @@ Next
* Document that your compiler has to support long long.
- * Figure out why we have to specify a stream's length in advance when
- providing stream data, and remove this restriction if possible.
+ * Make sure that the release notes call attention to the one API
+ breaking change: removal of length from replaceStreamData.
* Add a way to create new QPDFObjectHandles with a string
representation of them, such as
diff --git a/examples/pdf-create.cc b/examples/pdf-create.cc
index e1d75759..a9ad2389 100644
--- a/examples/pdf-create.cc
+++ b/examples/pdf-create.cc
@@ -17,7 +17,6 @@ class ImageProvider: public QPDFObjectHandle::StreamDataProvider
virtual ~ImageProvider();
virtual void provideStreamData(int objid, int generation,
Pipeline* pipeline);
- size_t getLength() const;
private:
int width;
@@ -45,12 +44,6 @@ ImageProvider::provideStreamData(int objid, int generation,
pipeline->finish();
}
-size_t
-ImageProvider::getLength() const
-{
- return 3 * width * height;
-}
-
void usage()
{
std::cerr << "Usage: " << whoami << " filename" << std::endl
@@ -111,8 +104,7 @@ static void create_pdf(char const* filename)
PointerHolder<QPDFObjectHandle::StreamDataProvider> provider(p);
image.replaceStreamData(provider,
QPDFObjectHandle::newNull(),
- QPDFObjectHandle::newNull(),
- p->getLength());
+ QPDFObjectHandle::newNull());
// Create direct objects as needed by the page dictionary.
QPDFObjectHandle procset = QPDFObjectHandle::newArray();
diff --git a/examples/pdf-invert-images.cc b/examples/pdf-invert-images.cc
index 2dc73251..997fc37c 100644
--- a/examples/pdf-invert-images.cc
+++ b/examples/pdf-invert-images.cc
@@ -141,8 +141,7 @@ int main(int argc, char* argv[])
image.replaceStreamData(
p,
QPDFObjectHandle::newNull(),
- QPDFObjectHandle::newNull(),
- inv->image_data[objid][gen]->getSize());
+ QPDFObjectHandle::newNull());
}
}
}
diff --git a/include/qpdf/QPDFObjectHandle.hh b/include/qpdf/QPDFObjectHandle.hh
index a61277a9..421b0144 100644
--- a/include/qpdf/QPDFObjectHandle.hh
+++ b/include/qpdf/QPDFObjectHandle.hh
@@ -294,18 +294,31 @@ class QPDFObjectHandle
// directly providing a buffer with the stream data, call the
// 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.
+ // method. 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.
+
+ // Note about stream length: for any given stream, the provider
+ // must provide the same amount of data each time it is called.
+ // This is critical for making linearization work properly.
+ // Versions of qpdf before 3.0.0 required a length to be specified
+ // here. Starting with version 3.0.0, this is no longer necessary
+ // (or permitted). The first time the stream data provider is
+ // invoked for a given stream, the actual length is stored.
+ // Subsequent times, it is enforced that the length be the same as
+ // the first time.
+
+ // If you have gotten a compile error here while building code
+ // that worked with older versions of qpdf, just omit the length
+ // parameter. You can also simplify your code by not having to
+ // compute the length in advance.
QPDF_DLL
void replaceStreamData(PointerHolder<StreamDataProvider> provider,
QPDFObjectHandle const& filter,
- QPDFObjectHandle const& decode_parms,
- size_t length);
+ QPDFObjectHandle const& decode_parms);
// return 0 for direct objects
QPDF_DLL
diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc
index 4d6c5f79..c8b67416 100644
--- a/libqpdf/QPDFObjectHandle.cc
+++ b/libqpdf/QPDFObjectHandle.cc
@@ -414,12 +414,11 @@ QPDFObjectHandle::replaceStreamData(PointerHolder<Buffer> data,
void
QPDFObjectHandle::replaceStreamData(PointerHolder<StreamDataProvider> provider,
QPDFObjectHandle const& filter,
- QPDFObjectHandle const& decode_parms,
- size_t length)
+ QPDFObjectHandle const& decode_parms)
{
assertType("Stream", isStream());
dynamic_cast<QPDF_Stream*>(obj.getPointer())->replaceStreamData(
- provider, filter, decode_parms, length);
+ provider, filter, decode_parms);
}
int
diff --git a/libqpdf/QPDF_Stream.cc b/libqpdf/QPDF_Stream.cc
index ed5fb5be..c089bcc1 100644
--- a/libqpdf/QPDF_Stream.cc
+++ b/libqpdf/QPDF_Stream.cc
@@ -380,24 +380,33 @@ QPDF_Stream::pipeStreamData(Pipeline* pipeline, bool filter,
this->stream_provider->provideStreamData(
this->objid, this->generation, &count);
qpdf_offset_t actual_length = count.getCount();
- qpdf_offset_t desired_length =
- this->stream_dict.getKey("/Length").getIntValue();
- if (actual_length == desired_length)
- {
- QTC::TC("qpdf", "QPDF_Stream pipe use stream provider");
- }
- else
- {
- QTC::TC("qpdf", "QPDF_Stream provider length mismatch");
- throw std::logic_error(
- "stream data provider for " +
- QUtil::int_to_string(this->objid) + " " +
- QUtil::int_to_string(this->generation) +
- " provided " +
- QUtil::int_to_string(actual_length) +
- " bytes instead of expected " +
- QUtil::int_to_string(desired_length) + " bytes");
- }
+ qpdf_offset_t desired_length = 0;
+ if (this->stream_dict.hasKey("/Length"))
+ {
+ desired_length = this->stream_dict.getKey("/Length").getIntValue();
+ if (actual_length == desired_length)
+ {
+ QTC::TC("qpdf", "QPDF_Stream pipe use stream provider");
+ }
+ else
+ {
+ QTC::TC("qpdf", "QPDF_Stream provider length mismatch");
+ throw std::logic_error(
+ "stream data provider for " +
+ QUtil::int_to_string(this->objid) + " " +
+ QUtil::int_to_string(this->generation) +
+ " provided " +
+ QUtil::int_to_string(actual_length) +
+ " bytes instead of expected " +
+ QUtil::int_to_string(desired_length) + " bytes");
+ }
+ }
+ else
+ {
+ QTC::TC("qpdf", "QPDF_Stream provider length not provided");
+ this->stream_dict.replaceKey(
+ "/Length", QPDFObjectHandle::newInteger(actual_length));
+ }
}
else if (this->offset == 0)
{
@@ -430,12 +439,11 @@ void
QPDF_Stream::replaceStreamData(
PointerHolder<QPDFObjectHandle::StreamDataProvider> provider,
QPDFObjectHandle const& filter,
- QPDFObjectHandle const& decode_parms,
- size_t length)
+ QPDFObjectHandle const& decode_parms)
{
this->stream_provider = provider;
this->stream_data = 0;
- replaceFilterData(filter, decode_parms, length);
+ replaceFilterData(filter, decode_parms, 0);
}
void
@@ -445,6 +453,14 @@ QPDF_Stream::replaceFilterData(QPDFObjectHandle const& filter,
{
this->stream_dict.replaceOrRemoveKey("/Filter", filter);
this->stream_dict.replaceOrRemoveKey("/DecodeParms", decode_parms);
- this->stream_dict.replaceKey("/Length",
- QPDFObjectHandle::newInteger((int)length));
+ if (length == 0)
+ {
+ QTC::TC("qpdf", "QPDF_Stream unknown stream length");
+ this->stream_dict.removeKey("/Length");
+ }
+ else
+ {
+ this->stream_dict.replaceKey(
+ "/Length", QPDFObjectHandle::newInteger((int)length));
+ }
}
diff --git a/libqpdf/qpdf/QPDF_Stream.hh b/libqpdf/qpdf/QPDF_Stream.hh
index e74ae201..ce46d994 100644
--- a/libqpdf/qpdf/QPDF_Stream.hh
+++ b/libqpdf/qpdf/QPDF_Stream.hh
@@ -30,8 +30,7 @@ class QPDF_Stream: public QPDFObject
void replaceStreamData(
PointerHolder<QPDFObjectHandle::StreamDataProvider> provider,
QPDFObjectHandle const& filter,
- QPDFObjectHandle const& decode_parms,
- size_t length);
+ QPDFObjectHandle const& decode_parms);
// Replace object ID and generation. This may only be called if
// object ID and generation are 0. It is used by QPDFObjectHandle
diff --git a/qpdf/qpdf.testcov b/qpdf/qpdf.testcov
index 93bbf88d..b2c98496 100644
--- a/qpdf/qpdf.testcov
+++ b/qpdf/qpdf.testcov
@@ -215,3 +215,5 @@ QPDFObjectHandle shallow copy dictionary 0
QPDFObjectHandle shallow copy scalar 0
QPDFObjectHandle newStream with string 0
QPDF unknown key not inherited 0
+QPDF_Stream provider length not provided 0
+QPDF_Stream unknown stream length 0
diff --git a/qpdf/qtest/qpdf/replaced-stream-data-flate.pdf b/qpdf/qtest/qpdf/replaced-stream-data-flate.pdf
index 8da1663f..02931170 100644
--- a/qpdf/qtest/qpdf/replaced-stream-data-flate.pdf
+++ b/qpdf/qtest/qpdf/replaced-stream-data-flate.pdf
Binary files differ
diff --git a/qpdf/test_driver.cc b/qpdf/test_driver.cc
index 89b422ac..8373bd04 100644
--- a/qpdf/test_driver.cc
+++ b/qpdf/test_driver.cc
@@ -478,7 +478,17 @@ void runtest(int n, char const* filename)
PointerHolder<QPDFObjectHandle::StreamDataProvider> p = provider;
qstream.replaceStreamData(
p, QPDFObjectHandle::newName("/FlateDecode"),
- QPDFObjectHandle::newNull(), b->getSize());
+ QPDFObjectHandle::newNull());
+ provider->badLength(false);
+ QPDFWriter w(pdf, "a.pdf");
+ w.setStaticID(true);
+ // Linearize to force the provider to be called multiple times.
+ w.setLinearization(true);
+ w.setStreamDataMode(qpdf_s_preserve);
+ w.write();
+
+ // Every time a provider pipes stream data, it has to provide
+ // the same amount of data.
provider->badLength(true);
try
{
@@ -489,11 +499,6 @@ void runtest(int n, char const* filename)
{
std::cout << "exception: " << e.what() << std::endl;
}
- provider->badLength(false);
- QPDFWriter w(pdf, "a.pdf");
- w.setStaticID(true);
- w.setStreamDataMode(qpdf_s_preserve);
- w.write();
}
else if (n == 9)
{
diff --git a/qpdf/test_large_file.cc b/qpdf/test_large_file.cc
index fc2c7bbc..f54adb33 100644
--- a/qpdf/test_large_file.cc
+++ b/qpdf/test_large_file.cc
@@ -109,7 +109,6 @@ class ImageProvider: public QPDFObjectHandle::StreamDataProvider
virtual ~ImageProvider();
virtual void provideStreamData(int objid, int generation,
Pipeline* pipeline);
- size_t getLength() const;
private:
int n;
@@ -142,12 +141,6 @@ ImageProvider::provideStreamData(int objid, int generation,
pipeline->finish();
}
-size_t
-ImageProvider::getLength() const
-{
- return width * height;
-}
-
void usage()
{
std::cerr << "Usage: " << whoami << " {read|write} {large|small} outfile"
@@ -229,8 +222,7 @@ static void create_pdf(char const* filename)
PointerHolder<QPDFObjectHandle::StreamDataProvider> provider(p);
image.replaceStreamData(provider,
QPDFObjectHandle::newNull(),
- QPDFObjectHandle::newNull(),
- p->getLength());
+ QPDFObjectHandle::newNull());
QPDFObjectHandle xobject = QPDFObjectHandle::newDictionary();
xobject.replaceKey("/Im1", image);
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-01 15:25:28 +0200