Revert "improve perf of xmlreader::Pad"

This reverts commit de5af8315e014ce3408f66c6de3c9c4e841f8437.

Reason for revert: this commit needs bounds checking before it can reland

Change-Id: I686a533cc27fc4644cce918ca64bd168bba19617
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/115518
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 12 insertions, 16 deletions

diff --git a/include/xmlreader/pad.hxx b/include/xmlreader/pad.hxx
index 1f758c471338..3aa73d57eab4 100644
--- a/include/xmlreader/pad.hxx
+++ b/include/xmlreader/pad.hxx
@@ -47,8 +47,7 @@ private:
     SAL_DLLPRIVATE void flushSpan();
 
     Span span_;
-    sal_Int32 buflength_ = 0;
-    char buffer_[1024];
+    OStringBuffer buffer_{ 256 };
 };
 }
 
diff --git a/xmlreader/source/pad.cxx b/xmlreader/source/pad.cxx
index 74bb5ec63fb0..ce45f805f496 100644
--- a/xmlreader/source/pad.cxx
+++ b/xmlreader/source/pad.cxx
@@ -29,49 +29,46 @@ namespace xmlreader {
 
 void Pad::add(char const * begin, sal_Int32 length) {
     assert(
-        begin != nullptr && length >= 0 && !(span_.is() && buflength_ != 0));
+        begin != nullptr && length >= 0 && !(span_.is() && buffer_.getLength() != 0));
     if (length != 0) {
         flushSpan();
-        if (buflength_ == 0) {
+        if (buffer_.isEmpty()) {
             span_ = Span(begin, length);
         } else {
-            memcpy(buffer_ + buflength_, begin, length);
-            buflength_ += length;
+            buffer_.append(begin, length);
         }
     }
 }
 
 void Pad::addEphemeral(char const * begin, sal_Int32 length) {
     assert(
-        begin != nullptr && length >= 0 && !(span_.is() && buflength_ != 0));
+        begin != nullptr && length >= 0 && !(span_.is() && buffer_.getLength() != 0));
     if (length != 0) {
         flushSpan();
-        memcpy(buffer_ + buflength_, begin, length);
-        buflength_ += length;
+        buffer_.append(begin, length);
     }
 }
 
 void Pad::clear() {
-    assert(!(span_.is() && buflength_ != 0));
+    assert(!(span_.is() && buffer_.getLength() != 0));
     span_.clear();
-    buflength_ = 0;
+    buffer_.setLength(0);
 }
 
 Span Pad::get() const {
-    assert(!(span_.is() && buflength_ != 0));
+    assert(!(span_.is() && buffer_.getLength() != 0));
     if (span_.is()) {
         return span_;
-    } else if (buflength_ == 0) {
+    } else if (buffer_.isEmpty()) {
         return Span("");
     } else {
-        return Span(buffer_, buflength_);
+        return Span(buffer_.getStr(), buffer_.getLength());
     }
 }
 
 void Pad::flushSpan() {
     if (span_.is()) {
-        memcpy(buffer_ + buflength_, span_.begin, span_.length);
-        buflength_ += span_.length;
+        buffer_.append(span_.begin, span_.length);
         span_.clear();
     }
 }