Introduce o3tl::string_view.hxx approximation of C++17 <string_view>

...and use it in configmgr/source/writemodfile.hxx

Change-Id: Ie683dc21010ed45cc454ff89bea0376994b351f2
Reviewed-on: https://gerrit.libreoffice.org/36270Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

configmgr/source/winreg.cxx

@@ -149,7 +149,7 @@ void dumpWindowsRegistryKey(HKEY hKey, OUString const & aKeyName, TempFile &aFil
             bool bHasNode = false;
             sal_Int32 nCloseNode = 0;
 
-            writeData(aFileHandle, "<item oor:path=\"");
+            aFileHandle.writeString("<item oor:path=\"");
             for(sal_Int32 nIndex = 0;; ++nIndex)
             {
                 OUString aNextPathPart = aPathAndNodes.getToken(nIndex, '\\');
@@ -160,13 +160,13 @@ void dumpWindowsRegistryKey(HKEY hKey, OUString const & aKeyName, TempFile &aFil
                     {
                         bHasNode = true;
                         nCloseNode++;
-                        writeData(aFileHandle, "\"><node oor:name=\"");
+                        aFileHandle.writeString("\"><node oor:name=\"");
                         sal_Int32 nCommandSeparator = aNextPathPart.lastIndexOf('#');
                         if(nCommandSeparator != -1)
                         {
                             OUString aNodeOp = aNextPathPart.copy(nCommandSeparator + 1);
                             writeAttributeValue(aFileHandle, aNextPathPart.copy(0, nCommandSeparator - 1));
-                            writeData(aFileHandle, "\" oor:op=\"");
+                            aFileHandle.writeString("\" oor:op=\"");
                             writeAttributeValue(aFileHandle, aNodeOp);
                         }
                         else
@@ -176,33 +176,34 @@ void dumpWindowsRegistryKey(HKEY hKey, OUString const & aKeyName, TempFile &aFil
                     }
                     else
                     {
-                        writeAttributeValue(aFileHandle, "/" + aNextPathPart);
+                        writeAttributeValue(
+                            aFileHandle, OUString("/" + aNextPathPart));
                     }
                 }
                 else
                 {
-                    writeData(aFileHandle, "\">");
+                    aFileHandle.writeString("\">");
                     break;
                 }
             }
 
-            writeData(aFileHandle, "<prop oor:name=\"");
+            aFileHandle.writeString("<prop oor:name=\"");
             writeAttributeValue(aFileHandle, aProp);
-            writeData(aFileHandle, "\"");
+            aFileHandle.writeString("\"");
             if(!aType.isEmpty())
             {
-                writeData(aFileHandle, " oor:type=\"");
+                aFileHandle.writeString(" oor:type=\"");
                 writeAttributeValue(aFileHandle, aType);
-                writeData(aFileHandle, "\"");
+                aFileHandle.writeString("\"");
             }
             if(bFinal)
-                writeData(aFileHandle, " oor:finalized=\"true\"");
-            writeData(aFileHandle, "><value>");
+                aFileHandle.writeString(" oor:finalized=\"true\"");
+            aFileHandle.writeString("><value>");
             writeValueContent(aFileHandle, aValue);
-            writeData(aFileHandle, "</value></prop>");
+            aFileHandle.writeString("</value></prop>");
             for(; nCloseNode > 0; nCloseNode--)
-                writeData(aFileHandle, "</node>");
-            writeData(aFileHandle, "</item>\n");
+                aFileHandle.writeString("</node>");
+            aFileHandle.writeString("</item>\n");
         }
         RegCloseKey(hCurKey);
     }
@@ -235,14 +236,13 @@ bool dumpWindowsRegistry(OUString* pFileURL, WinRegType eType)
             "cannot create temporary file");
     }
     aFileHandle.url = *pFileURL;
-    writeData(
-        aFileHandle,
-            "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<oor:items"
-            " xmlns:oor=\"http://openoffice.org/2001/registry\""
-            " xmlns:xs=\"http://www.w3.org/2001/XMLSchema\""
-            " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\">\n");
+    aFileHandle.writeString(
+        "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<oor:items"
+        " xmlns:oor=\"http://openoffice.org/2001/registry\""
+        " xmlns:xs=\"http://www.w3.org/2001/XMLSchema\""
+        " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\">\n");
     dumpWindowsRegistryKey(hKey, "", aFileHandle);
-    writeData(aFileHandle, "</oor:items>");
+    aFileHandle.writeString("</oor:items>");
     oslFileError e = aFileHandle.closeWithoutUnlink();
     if (e != osl_File_E_None)
         SAL_WARN("configmgr", "osl_closeFile failed with " << +e);

configmgr/source/writemodfile.hxx

@@ -21,6 +21,8 @@
 #define INCLUDED_CONFIGMGR_SOURCE_WRITEMODFILE_HXX
 
 #include <sal/config.h>
+
+#include <o3tl/string_view.hxx>
 #include <rtl/strbuf.hxx>
 
 namespace configmgr {
@@ -41,16 +43,15 @@ struct TempFile {
 #ifdef _WIN32
     oslFileError closeWithoutUnlink();
 #endif
-    void writeString(char const *begin, sal_Int32 length);
+    void writeString(o3tl::string_view text);
 
 private:
     TempFile(const TempFile&) = delete;
     TempFile& operator=(const TempFile&) = delete;
 };
 
-void writeData(TempFile &handle, OString const & text);
-void writeAttributeValue(TempFile &handle, OUString const & value);
-void writeValueContent(TempFile &handle, OUString const & value);
+void writeAttributeValue(TempFile &handle, o3tl::u16string_view value);
+void writeValueContent(TempFile &handle, o3tl::u16string_view value);
 
 void writeModFile(
     Components & components, OUString const & url, Data const & data);

o3tl/CppunitTest_o3tl_tests.mk

@@ -31,6 +31,7 @@ $(eval $(call gb_CppunitTest_add_exception_objects,o3tl_tests,\
 	o3tl/qa/test-cow_wrapper \
 	o3tl/qa/test-lru_map \
 	o3tl/qa/test-sorted_vector \
+	o3tl/qa/test-string_view \
 	o3tl/qa/test-typed_flags \
 	o3tl/qa/test-vector_pool \
 ))

o3tl/qa/test-string_view.cxx

+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <sal/config.h>
+
+#include <stdexcept>
+
+#include <cppunit/TestAssert.h>
+#include <cppunit/TestFixture.h>
+#include <cppunit/extensions/HelperMacros.h>
+
+#include <o3tl/string_view.hxx>
+
+namespace {
+
+class Test: public CppUnit::TestFixture {
+private:
+    CPPUNIT_TEST_SUITE(Test);
+    CPPUNIT_TEST(testCharLiteral);
+    CPPUNIT_TEST(testChar16Literal);
+    CPPUNIT_TEST(testChar32Literal);
+    CPPUNIT_TEST(testWcharLiteral);
+    CPPUNIT_TEST(testOperations);
+    CPPUNIT_TEST_SUITE_END();
+
+    void testCharLiteral() {
+        char * const s1 = const_cast<char *>("foo");
+        o3tl::string_view v1(s1);
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(3), v1.size());
+        char const * const s2 = "foo";
+        o3tl::string_view v2(s2);
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(3), v2.size());
+        char s3[] = "foo";
+        o3tl::string_view v3(s3);
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(3), v3.size());
+        o3tl::string_view v4("foo");
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(3), v4.size());
+    }
+
+    void testChar16Literal() {
+        char16_t * const s1 = const_cast<char16_t *>(u"foo");
+        o3tl::u16string_view v1(s1);
+        CPPUNIT_ASSERT_EQUAL(o3tl::u16string_view::size_type(3), v1.size());
+        char16_t const * const s2 = u"foo";
+        o3tl::u16string_view v2(s2);
+        CPPUNIT_ASSERT_EQUAL(o3tl::u16string_view::size_type(3), v2.size());
+        char16_t s3[] = u"foo";
+        o3tl::u16string_view v3(s3);
+        CPPUNIT_ASSERT_EQUAL(o3tl::u16string_view::size_type(3), v3.size());
+        o3tl::u16string_view v4(u"foo");
+        CPPUNIT_ASSERT_EQUAL(o3tl::u16string_view::size_type(3), v4.size());
+    }
+
+    void testChar32Literal() {
+        char32_t * const s1 = const_cast<char32_t *>(U"foo");
+        o3tl::u32string_view v1(s1);
+        CPPUNIT_ASSERT_EQUAL(o3tl::u32string_view::size_type(3), v1.size());
+        char32_t const * const s2 = U"foo";
+        o3tl::u32string_view v2(s2);
+        CPPUNIT_ASSERT_EQUAL(o3tl::u32string_view::size_type(3), v2.size());
+        char32_t s3[] = U"foo";
+        o3tl::u32string_view v3(s3);
+        CPPUNIT_ASSERT_EQUAL(o3tl::u32string_view::size_type(3), v3.size());
+        o3tl::u32string_view v4(U"foo");
+        CPPUNIT_ASSERT_EQUAL(o3tl::u32string_view::size_type(3), v4.size());
+    }
+
+    void testWcharLiteral() {
+        wchar_t * const s1 = const_cast<wchar_t *>(L"foo");
+        o3tl::wstring_view v1(s1);
+        CPPUNIT_ASSERT_EQUAL(o3tl::wstring_view::size_type(3), v1.size());
+        wchar_t const * const s2 = L"foo";
+        o3tl::wstring_view v2(s2);
+        CPPUNIT_ASSERT_EQUAL(o3tl::wstring_view::size_type(3), v2.size());
+        wchar_t s3[] = L"foo";
+        o3tl::wstring_view v3(s3);
+        CPPUNIT_ASSERT_EQUAL(o3tl::wstring_view::size_type(3), v3.size());
+        o3tl::wstring_view v4(L"foo");
+        CPPUNIT_ASSERT_EQUAL(o3tl::wstring_view::size_type(3), v4.size());
+    }
+
+    void testOperations() {
+        o3tl::string_view const v("fox");
+        auto npos = o3tl::string_view::npos;
+            // o3tl::basic_string_view::npos will be (implicitly) inline with
+            // C++17, but for now can't be passed as 'const T& expected'
+            // argument into CppUnit::assertEquals, so take this detour
+        CPPUNIT_ASSERT_EQUAL('f', *v.begin());
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::difference_type(3), v.end() - v.begin());
+        CPPUNIT_ASSERT_EQUAL('f', *v.cbegin());
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::difference_type(3), v.cend() - v.cbegin());
+        CPPUNIT_ASSERT_EQUAL('x', *v.rbegin());
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::difference_type(3), v.rend() - v.rbegin());
+        CPPUNIT_ASSERT_EQUAL('x', *v.crbegin());
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::difference_type(3), v.crend() - v.crbegin());
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(3), v.size());
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(3), v.length());
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::npos - 1, v.max_size());
+        CPPUNIT_ASSERT(!v.empty());
+        CPPUNIT_ASSERT_EQUAL('o', v[1]);
+        try {
+            v.at(o3tl::string_view::npos);
+            CPPUNIT_FAIL("missing exception");
+        } catch (std::out_of_range &) {}
+        CPPUNIT_ASSERT_EQUAL('f', v.at(0));
+        CPPUNIT_ASSERT_EQUAL('x', v.at(2));
+        try {
+            v.at(3);
+            CPPUNIT_FAIL("missing exception");
+        } catch (std::out_of_range &) {}
+        CPPUNIT_ASSERT_EQUAL('f', v.front());
+        CPPUNIT_ASSERT_EQUAL('x', v.back());
+        CPPUNIT_ASSERT_EQUAL('f', *v.data());
+        {
+            o3tl::string_view v1("fox");
+            v1.remove_prefix(2);
+            CPPUNIT_ASSERT_EQUAL('x', v1.front());
+            CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(1), v1.size());
+        }
+        {
+            o3tl::string_view v1("fox");
+            v1.remove_suffix(2);
+            CPPUNIT_ASSERT_EQUAL('f', v1.front());
+            CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(1), v1.size());
+        }
+        {
+            o3tl::string_view v1("fox");
+            o3tl::string_view v2("giraffe");
+            v1.swap(v2);
+            CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(7), v1.size());
+            CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(3), v2.size());
+        }
+        {
+            char a[2];
+            auto n = v.copy(a, 10, 1);
+            CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(2), n);
+            CPPUNIT_ASSERT_EQUAL('o', a[0]);
+            CPPUNIT_ASSERT_EQUAL('x', a[1]);
+        }
+        {
+            auto v1 = v.substr(1);
+            CPPUNIT_ASSERT_EQUAL('o', v1.front());
+            CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(2), v1.size());
+        }
+        CPPUNIT_ASSERT(v.compare(o3tl::string_view("foo")) > 0);
+        CPPUNIT_ASSERT(v.compare(0, 2, o3tl::string_view("foo")) < 0);
+        CPPUNIT_ASSERT_EQUAL(
+            0, v.compare(0, 2, o3tl::string_view("foo"), 0, 2));
+        CPPUNIT_ASSERT_EQUAL(0, v.compare("fox"));
+        CPPUNIT_ASSERT(v.compare(1, 2, "abc") > 0);
+        CPPUNIT_ASSERT_EQUAL(0, v.compare(1, 2, "oxx", 2));
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(1), v.find("ox"));
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(1), v.find('o'));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find("oxx", 0, 2));
+        CPPUNIT_ASSERT_EQUAL(npos, v.find("oxx"));
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(1), v.rfind("ox"));
+        CPPUNIT_ASSERT_EQUAL(o3tl::string_view::size_type(1), v.rfind('o'));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1),
+            v.rfind("oxx", o3tl::string_view::npos, 2));
+        CPPUNIT_ASSERT_EQUAL(npos, v.rfind("oxx"));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find_first_of("nop"));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find_first_of('o'));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find_first_of("nofx", 0, 2));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(0), v.find_first_of("nofx"));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find_last_of("nop"));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find_last_of('o'));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1),
+            v.find_last_of("nofx", o3tl::string_view::npos, 2));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(2), v.find_last_of("nofx"));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find_first_not_of("fx"));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find_first_not_of('f'));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find_first_not_of("fxo", 0, 2));
+        CPPUNIT_ASSERT_EQUAL(npos, v.find_first_not_of("fxo"));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find_last_not_of("fx"));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1), v.find_last_not_of('x'));
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::string_view::size_type(1),
+            v.find_last_not_of("fxo", o3tl::string_view::npos, 2));
+        CPPUNIT_ASSERT_EQUAL(npos, v.find_last_not_of("fxo"));
+    }
+};
+
+CPPUNIT_TEST_SUITE_REGISTRATION(Test);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */