add utl::ByteReader pure class

which lets us skip the inefficiency of needing an extra buffer when
reading via XInputStream

Change-Id: Ic5334b7d11ea6a57bc1800f508fc69611a053af1
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/134348
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

3 files changed, 50 insertions, 3 deletions

diff --git a/unotools/source/streaming/streamhelper.cxx b/unotools/source/streaming/streamhelper.cxx
index b5f07e6a6a7f..39585ec5f369 100644
--- a/unotools/source/streaming/streamhelper.cxx
+++ b/unotools/source/streaming/streamhelper.cxx
@@ -22,8 +22,10 @@
 #include <com/sun/star/io/BufferSizeExceededException.hpp>
 #include <com/sun/star/io/IOException.hpp>
 #include <com/sun/star/io/NotConnectedException.hpp>
+#include <comphelper/servicehelper.hxx>
 #include <o3tl/safeint.hxx>
 #include <unotools/streamhelper.hxx>
+#include <unotools/bytereader.hxx>
 
 namespace utl
 {
@@ -118,6 +120,14 @@ void SAL_CALL OInputStreamHelper::acquire() SAL_NOEXCEPT
     cppu::WeakImplHelper<css::io::XInputStream, css::io::XSeekable>::acquire();
 }
 
+ByteReader::~ByteReader() {}
+
+const css::uno::Sequence< sal_Int8 > & ByteReader::getUnoTunnelId()
+{
+    static const comphelper::UnoIdInit implId;
+    return implId.getSeq();
+}
+
 } // namespace utl
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/unotools/source/streaming/streamwrap.cxx b/unotools/source/streaming/streamwrap.cxx
index ccd9b5033d2a..0ed933b530e3 100644
--- a/unotools/source/streaming/streamwrap.cxx
+++ b/unotools/source/streaming/streamwrap.cxx
@@ -78,6 +78,21 @@ sal_Int32 SAL_CALL OInputStreamWrapper::readBytes(css::uno::Sequence< sal_Int8 >
     return nRead;
 }
 
+sal_Int32 OInputStreamWrapper::readSomeBytes(sal_Int8* pData, sal_Int32 nBytesToRead)
+{
+    checkConnected();
+
+    if (nBytesToRead < 0)
+        throw css::io::BufferSizeExceededException(OUString(),static_cast<css::uno::XWeak*>(this));
+
+    std::scoped_lock aGuard( m_aMutex );
+
+    sal_uInt32 nRead = m_pSvStream->ReadBytes(static_cast<void*>(pData), nBytesToRead);
+    checkError();
+
+    return nRead;
+}
+
 sal_Int32 SAL_CALL OInputStreamWrapper::readSomeBytes(css::uno::Sequence< sal_Int8 >& aData, sal_Int32 nMaxBytesToRead)
 {
     checkError();
@@ -141,6 +156,14 @@ void OInputStreamWrapper::checkError() const
         throw css::io::NotConnectedException("utl::OInputStreamWrapper error " + e.toHexString(), const_cast<css::uno::XWeak*>(static_cast<const css::uno::XWeak*>(this)));
 }
 
+sal_Int64 SAL_CALL OInputStreamWrapper::getSomething( const css::uno::Sequence< sal_Int8 >& rIdentifier )
+{
+    if (rIdentifier == utl::ByteReader::getUnoTunnelId())
+        return reinterpret_cast<sal_Int64>(static_cast<utl::ByteReader*>(this));
+    return 0;
+}
+
+
 //= OSeekableInputStreamWrapper
 
 OSeekableInputStreamWrapper::~OSeekableInputStreamWrapper() = default;
diff --git a/unotools/source/ucbhelper/ucblockbytes.cxx b/unotools/source/ucbhelper/ucblockbytes.cxx
index 2d716f571586..b40be28f2225 100644
--- a/unotools/source/ucbhelper/ucblockbytes.cxx
+++ b/unotools/source/ucbhelper/ucblockbytes.cxx
@@ -27,6 +27,7 @@
 #include <tools/urlobj.hxx>
 #include <tools/solar.h>
 #include <ucbhelper/interactionrequest.hxx>
+#include <com/sun/star/lang/XUnoTunnel.hpp>
 #include <com/sun/star/task/XInteractionAbort.hpp>
 #include <com/sun/star/ucb/InteractiveNetworkConnectException.hpp>
 #include <com/sun/star/ucb/CommandFailedException.hpp>
@@ -57,6 +58,7 @@
 
 #include <comphelper/storagehelper.hxx>
 #include <ucbhelper/content.hxx>
+#include <unotools/bytereader.hxx>
 #include <mutex>
 
 using namespace ::com::sun::star::uno;
@@ -1092,7 +1094,6 @@ ErrCode UcbLockBytes::ReadAt(sal_uInt64 const nPos,
         return ERRCODE_IO_CANTSEEK;
     }
 
-    Sequence<sal_Int8> aData;
     sal_Int32          nSize;
 
     if(nCount > 0x7FFFFFFF)
@@ -1108,14 +1109,27 @@ ErrCode UcbLockBytes::ReadAt(sal_uInt64 const nPos,
                 return ERRCODE_IO_PENDING;
         }
 
-        nSize = xStream->readBytes( aData, sal_Int32(nCount) );
+        Reference< css::lang::XUnoTunnel > xTunnel( xStream, UNO_QUERY );
+        utl::ByteReader* pByteReader = nullptr;
+        if (xTunnel)
+            pByteReader = reinterpret_cast< utl::ByteReader* >( xTunnel->getSomething( utl::ByteReader::getUnoTunnelId() ) );
+
+        if (pByteReader)
+        {
+            nSize = pByteReader->readSomeBytes( static_cast<sal_Int8*>(pBuffer), sal_Int32(nCount) );
+        }
+        else
+        {
+            Sequence<sal_Int8> aData;
+            nSize = xStream->readBytes( aData, sal_Int32(nCount) );
+            memcpy (pBuffer, aData.getConstArray(), nSize);
+        }
     }
     catch (const IOException&)
     {
         return ERRCODE_IO_CANTREAD;
     }
 
-    memcpy (pBuffer, aData.getConstArray(), nSize);
     if (pRead)
         *pRead = static_cast<std::size_t>(nSize);