add a way to better construct an OString of len X from a SvStream

5 files changed, 56 insertions, 2 deletions

diff --git a/tools/CppunitTest_tools_test.mk b/tools/CppunitTest_tools_test.mk
index 5808e3a5f18e..c39f0a2461f3 100644
--- a/tools/CppunitTest_tools_test.mk
+++ b/tools/CppunitTest_tools_test.mk
@@ -33,7 +33,7 @@ $(eval $(call gb_CppunitTest_CppunitTest,tools_test))
 $(eval $(call gb_CppunitTest_add_exception_objects,tools_test, \
     tools/qa/cppunit/test_reversemap \
     tools/qa/cppunit/test_pathutils \
-    tools/qa/cppunit/test_streamstate \
+    tools/qa/cppunit/test_stream \
 ))
 
 $(eval $(call gb_CppunitTest_add_api,tools_test, \
diff --git a/tools/Executable_tools_cppunittester_all.mk b/tools/Executable_tools_cppunittester_all.mk
index a5325f9d741b..d2fd13b3f0ba 100644
--- a/tools/Executable_tools_cppunittester_all.mk
+++ b/tools/Executable_tools_cppunittester_all.mk
@@ -59,7 +59,7 @@ $(eval $(call gb_Executable_add_exception_objects,tools_cppunittester_all, \
     tools/qa/cppunit/tools_cppunittester_all \
     tools/qa/cppunit/test_reversemap \
     tools/qa/cppunit/test_pathutils \
-    tools/qa/cppunit/test_streamstate \
+    tools/qa/cppunit/test_stream \
 ))
 
 $(eval $(call gb_Executable_add_api,tools_cppunittester_all, \
diff --git a/tools/inc/tools/stream.hxx b/tools/inc/tools/stream.hxx
index 5323e3cca40d..baaf758125c4 100644
--- a/tools/inc/tools/stream.hxx
+++ b/tools/inc/tools/stream.hxx
@@ -564,6 +564,10 @@ TOOLS_DLLPUBLIC SvStream& endlu( SvStream& rStr );
 /// call endlu() if eStreamCharSet==RTL_TEXTECODING_UNICODE otherwise endl()
 TOOLS_DLLPUBLIC SvStream& endlub( SvStream& rStr );
 
+//Attempt to read nSize bytes to an OString, returned rtl::OString's length is
+//number of bytes successfully read
+TOOLS_DLLPUBLIC rtl::OString readBytesAsOString(SvStream& rStr, sal_Size nSize);
+
 // --------------
 // - FileStream -
 // --------------
diff --git a/tools/qa/cppunit/test_streamstate.cxx b/tools/qa/cppunit/test_stream.cxx
index 182ad6c45561..ae098e5b836d 100644
--- a/tools/qa/cppunit/test_streamstate.cxx
+++ b/tools/qa/cppunit/test_stream.cxx
@@ -41,9 +41,11 @@ namespace
     {
     public:
         void test_stdstream();
+        void test_fastostring();
 
         CPPUNIT_TEST_SUITE(Test);
         CPPUNIT_TEST(test_stdstream);
+        CPPUNIT_TEST(test_fastostring);
         CPPUNIT_TEST_SUITE_END();
     };
 
@@ -120,6 +122,26 @@ namespace
         //failbit is rather subtle wrt e.g seeks
     }
 
+    void Test::test_fastostring()
+    {
+        char foo[] = "foobar";
+        SvMemoryStream aMemStream(RTL_CONSTASCII_STRINGPARAM(foo), STREAM_READ);
+
+        rtl::OString aOne = readBytesAsOString(aMemStream, 3);
+        CPPUNIT_ASSERT(aOne.equalsL(RTL_CONSTASCII_STRINGPARAM("foo")));
+
+        rtl::OString aTwo = readBytesAsOString(aMemStream, 3);
+        CPPUNIT_ASSERT(aTwo.equalsL(RTL_CONSTASCII_STRINGPARAM("bar")));
+
+        rtl::OString aThree = readBytesAsOString(aMemStream, 3);
+        CPPUNIT_ASSERT(!aThree.getLength());
+
+        aMemStream.Seek(0);
+
+        rtl::OString aFour = readBytesAsOString(aMemStream, 100);
+        CPPUNIT_ASSERT(aFour.equalsL(RTL_CONSTASCII_STRINGPARAM(foo)));
+    }
+
     CPPUNIT_TEST_SUITE_REGISTRATION(Test);
 }
 
diff --git a/tools/source/stream/stream.cxx b/tools/source/stream/stream.cxx
index a1f55392749a..312cd5f35b22 100644
--- a/tools/source/stream/stream.cxx
+++ b/tools/source/stream/stream.cxx
@@ -43,6 +43,7 @@
 
 #include <tools/solar.h>
 
+#include <comphelper/string.hxx>
 
 #define SWAPNIBBLES(c)      \
 unsigned char nSwapTmp=c;   \
@@ -2473,4 +2474,31 @@ void SvDataCopyStream::Assign( const SvDataCopyStream& )
 {
 }
 
+//Create a OString of nSize bytes from rStream
+rtl::OString readBytesAsOString(SvStream& rStrm, sal_Size nSize)
+{
+    using comphelper::string::rtl_string_alloc;
+
+    rtl_String *pStr = NULL;
+    if (nSize)
+    {
+        nSize = std::min(nSize, static_cast<sal_Size>(SAL_MAX_INT32));
+        //alloc a (ref-count 1) rtl_String of the desired length.
+        //rtl_String's buffer is uninitialized, except for null termination
+        pStr = rtl_string_alloc(sal::static_int_cast<sal_Int32>(nSize));
+        sal_Size nWasRead = rStrm.Read(pStr->buffer, nSize);
+        if (nWasRead != nSize)
+        {
+            //on (typically unlikely) short read set length to what we could
+            //read, and null terminate. Excess buffer capacity remains of
+            //course, could create a (true) replacement OString if it matters.
+            pStr->length = sal::static_int_cast<sal_Int32>(nWasRead);
+            pStr->buffer[pStr->length] = 0;
+        }
+    }
+
+    //take ownership of buffer and return, otherwise return empty string
+    return pStr ? rtl::OString(pStr, SAL_NO_ACQUIRE) : rtl::OString();
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */