size some stringbuffer to prevent re-alloc

found by the simple expidient of putting asserts in
the resize routine. Where an explicit const size is used,
I started with 32 and kept doubling until that site
did not need resizing anymore.

Change-Id: I998787edc940d0a3ba23b5ac37131ab9ecd300f4
Reviewed-on: https://gerrit.libreoffice.org/81138
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 12 insertions, 9 deletions

diff --git a/sal/osl/unx/file_url.cxx b/sal/osl/unx/file_url.cxx
index d149d31e1252..33fcd2952802 100644
--- a/sal/osl/unx/file_url.cxx
+++ b/sal/osl/unx/file_url.cxx
@@ -171,8 +171,8 @@ bool decodeFromUtf8(std::u16string_view text, OString * result) {
     assert(result != nullptr);
     auto p = text.data();
     auto const end = p + text.size();
-    OUStringBuffer ubuf;
-    OStringBuffer bbuf;
+    OUStringBuffer ubuf(static_cast<int>(text.size()));
+    OStringBuffer bbuf(PATH_MAX);
     while (p < end) {
         rtl::uri::detail::EscapeType t;
         sal_uInt32 c = rtl::uri::detail::readUcs4(&p, end, true, RTL_TEXTENCODING_UTF8, &t);
@@ -935,15 +935,16 @@ oslFileError osl::detail::convertUrlToPathname(OUString const & url, OString * p
 
 oslFileError osl::detail::convertPathnameToUrl(OString const & pathname, OUString * url) {
     assert(url != nullptr);
-    OUStringBuffer buf("file:");
+    OUStringBuffer buf(10+pathname.getLength());
+    buf.append("file:");
     if (pathname.startsWith("/")) {
         buf.append("//");
             // so if pathname should ever start with "//" that isn't mistaken for an authority
             // component
     }
     for (sal_Size convert = pathname.getLength();;) {
-        OUStringBuffer ubuf;
         auto n = std::max(convert, sal_Size(PATH_MAX)); // approximation of required converted size
+        OUStringBuffer ubuf(static_cast<int>(n));
         auto s = ubuf.appendUninitialized(n);
         sal_uInt32 info;
         sal_Size converted;
diff --git a/sal/osl/unx/tempfile.cxx b/sal/osl/unx/tempfile.cxx
index cc29a6f59625..84f44cbd4b32 100644
--- a/sal/osl/unx/tempfile.cxx
+++ b/sal/osl/unx/tempfile.cxx
@@ -193,15 +193,17 @@ static oslFileError osl_create_temp_file_impl_(
 
     len_base_dir = rtl_uString_getLength(pustr_base_directory);
 
-    rtl_uStringbuffer_newFromStr_WithLength(
+    rtl_uString_new_WithLength(
         &tmp_file_path,
-        rtl_uString_getStr(const_cast<rtl_uString*>(pustr_base_directory)),
-        len_base_dir);
+        (len_base_dir + 1 + RAND_NAME_LENGTH));
+    capacity = len_base_dir + 1 + RAND_NAME_LENGTH;
 
-    rtl_uStringbuffer_ensureCapacity(
+    rtl_uStringbuffer_insert(
         &tmp_file_path,
         &capacity,
-        (len_base_dir + 1 + RAND_NAME_LENGTH));
+        0,
+        rtl_uString_getStr(const_cast<rtl_uString*>(pustr_base_directory)),
+        len_base_dir);
 
     offset_file_name = len_base_dir;