Reserve space for result in ::FilterContents

This changes the implementation for the specific bug listed and
proactively fixes it in the other overrides. The general bug here is
that if you concat a WideString in a tight loop without first
reserving space, each call will cause an allocation size change and
memcpy. This is very expensive and causes ClusterFuzz cases to
timeout.

BUG=chromium:863295

Change-Id: I6c1d900a31b98cd9ddcf91d1ec0f3973c9cdfa26
Reviewed-on: https://pdfium-review.googlesource.com/38110
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

5 files changed, 5 insertions, 0 deletions

diff --git a/fxbarcode/oned/BC_OnedCodaBarWriter.cpp b/fxbarcode/oned/BC_OnedCodaBarWriter.cpp
index 42990f7f3a..c51b1c2eb9 100644
--- a/fxbarcode/oned/BC_OnedCodaBarWriter.cpp
+++ b/fxbarcode/oned/BC_OnedCodaBarWriter.cpp
@@ -109,6 +109,7 @@ bool CBC_OnedCodaBarWriter::CheckContentValidity(
 WideString CBC_OnedCodaBarWriter::FilterContents(
     const WideStringView& contents) {
   WideString filtercontents;
+  filtercontents.Reserve(contents.GetLength());
   wchar_t ch;
   for (size_t index = 0; index < contents.GetLength(); index++) {
     ch = contents[index];
diff --git a/fxbarcode/oned/BC_OnedCode39Writer.cpp b/fxbarcode/oned/BC_OnedCode39Writer.cpp
index f04dc195ea..9152155e29 100644
--- a/fxbarcode/oned/BC_OnedCode39Writer.cpp
+++ b/fxbarcode/oned/BC_OnedCode39Writer.cpp
@@ -73,6 +73,7 @@ bool CBC_OnedCode39Writer::CheckContentValidity(
 WideString CBC_OnedCode39Writer::FilterContents(
     const WideStringView& contents) {
   WideString filtercontents;
+  filtercontents.Reserve(contents.GetLength());
   for (size_t i = 0; i < contents.GetLength(); i++) {
     wchar_t ch = contents[i];
     if (ch == L'*' && (i == 0 || i == contents.GetLength() - 1)) {
diff --git a/fxbarcode/oned/BC_OnedEAN13Writer.cpp b/fxbarcode/oned/BC_OnedEAN13Writer.cpp
index 6818d432d6..1facf9ee26 100644
--- a/fxbarcode/oned/BC_OnedEAN13Writer.cpp
+++ b/fxbarcode/oned/BC_OnedEAN13Writer.cpp
@@ -62,6 +62,7 @@ bool CBC_OnedEAN13Writer::CheckContentValidity(const WideStringView& contents) {
 
 WideString CBC_OnedEAN13Writer::FilterContents(const WideStringView& contents) {
   WideString filtercontents;
+  filtercontents.Reserve(contents.GetLength());
   wchar_t ch;
   for (size_t i = 0; i < contents.GetLength(); i++) {
     ch = contents[i];
diff --git a/fxbarcode/oned/BC_OnedEAN8Writer.cpp b/fxbarcode/oned/BC_OnedEAN8Writer.cpp
index 6862ba87a1..b953c121b0 100644
--- a/fxbarcode/oned/BC_OnedEAN8Writer.cpp
+++ b/fxbarcode/oned/BC_OnedEAN8Writer.cpp
@@ -69,6 +69,7 @@ bool CBC_OnedEAN8Writer::CheckContentValidity(const WideStringView& contents) {
 
 WideString CBC_OnedEAN8Writer::FilterContents(const WideStringView& contents) {
   WideString filtercontents;
+  filtercontents.Reserve(contents.GetLength());
   wchar_t ch;
   for (size_t i = 0; i < contents.GetLength(); i++) {
     ch = contents[i];
diff --git a/fxbarcode/oned/BC_OnedUPCAWriter.cpp b/fxbarcode/oned/BC_OnedUPCAWriter.cpp
index daabe9eb3b..eb895294aa 100644
--- a/fxbarcode/oned/BC_OnedUPCAWriter.cpp
+++ b/fxbarcode/oned/BC_OnedUPCAWriter.cpp
@@ -52,6 +52,7 @@ bool CBC_OnedUPCAWriter::CheckContentValidity(const WideStringView& contents) {
 
 WideString CBC_OnedUPCAWriter::FilterContents(const WideStringView& contents) {
   WideString filtercontents;
+  filtercontents.Reserve(contents.GetLength());
   wchar_t ch;
   for (size_t i = 0; i < contents.GetLength(); i++) {
     ch = contents[i];