commit e8e1dfec684164b8b093ea5a00bd45a06b03447d
author Lei Zhang <thestig@chromium.org> Fri Apr 01 20:28:00 2022 +0000
committer Pdfium LUCI CQ <pdfium-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Apr 01 20:28:00 2022 +0000
tree 8e751a7fc01049bce4b7b1c833d2f46cab6696e4
parent 1cd4bc85e5ce753fa5c63bf69721cca1fabaa3ef

Rewrite GetStyleType() to avoid using tuples.

Tuples are hard to read, so avoid using them and just return the
existing struct that the tuple values come from.

Make other GetStyleType() improvements as well:
- Reverse the style data array, so it can be searched in order, instead
  of writing a for-loop to search it in reverse order.
- Make GetStyleType() take a ByteStringView. Then use that to create
  other ByteStringViews for comparisons, which is cheaper than creating
  ByteStrings.

Change-Id: I44fd0743a529b402e039b43f8d0142c5eb626b73
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/91938
Reviewed-by: Nigi <nigi@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

core/fxge/cfx_fontmapper.cpp

diff --git a/core/fxge/cfx_fontmapper.cpp b/core/fxge/cfx_fontmapper.cpp
index fa2b353..22f519b 100644
--- a/core/fxge/cfx_fontmapper.cpp
+++ b/core/fxge/cfx_fontmapper.cpp
@@ -8,7 +8,6 @@
 
 #include <algorithm>
 #include <memory>
-#include <tuple>
 #include <utility>
 #include <vector>
 
@@ -207,34 +206,29 @@
   uint32_t style;
 };
 
-const FX_FontStyle kFontStyles[] = {
-    {"Bold", 4, FXFONT_FORCE_BOLD},
-    {"Italic", 6, FXFONT_ITALIC},
-    {"BoldItalic", 10, FXFONT_FORCE_BOLD | FXFONT_ITALIC},
-    {"Reg", 3, FXFONT_NORMAL},
+constexpr FX_FontStyle kFontStyles[] = {
     {"Regular", 7, FXFONT_NORMAL},
+    {"Reg", 3, FXFONT_NORMAL},
+    {"BoldItalic", 10, FXFONT_FORCE_BOLD | FXFONT_ITALIC},
+    {"Italic", 6, FXFONT_ITALIC},
+    {"Bold", 4, FXFONT_FORCE_BOLD},
 };
 
-// <exists, index, length>
-std::tuple<bool, uint32_t, size_t> GetStyleType(const ByteString& bsStyle,
-                                                bool reverse_search) {
-  if (bsStyle.IsEmpty())
-    return std::make_tuple(false, FXFONT_NORMAL, 0);
+const FX_FontStyle* GetStyleType(ByteStringView font_name,
+                                 bool reverse_search) {
+  if (font_name.IsEmpty())
+    return nullptr;
 
-  for (int i = pdfium::size(kFontStyles) - 1; i >= 0; --i) {
-    const FX_FontStyle* pStyle = kFontStyles + i;
-    if (!pStyle || pStyle->len > bsStyle.GetLength())
+  for (const FX_FontStyle& style : kFontStyles) {
+    if (style.len > font_name.GetLength())
       continue;
 
-    if (reverse_search) {
-      if (bsStyle.Last(pStyle->len) == pStyle->name)
-        return std::make_tuple(true, pStyle->style, pStyle->len);
-    } else {
-      if (bsStyle.First(pStyle->len) == pStyle->name)
-        return std::make_tuple(true, pStyle->style, pStyle->len);
-    }
+    ByteStringView style_view =
+        reverse_search ? font_name.Last(style.len) : font_name.First(style.len);
+    if (style_view == style.name)
+      return &style;
   }
-  return std::make_tuple(false, FXFONT_NORMAL, 0);
+  return nullptr;
 }
 
 bool CheckSupportThirdPartFont(const ByteString& name, int* pitch_family) {
@@ -584,14 +578,11 @@
     }
     if (!has_hyphen) {
       size_t nLen = family.GetLength();
-      bool has_style_type;
-      uint32_t style_type;
-      size_t len;
-      std::tie(has_style_type, style_type, len) =
-          GetStyleType(family, /*reverse_search=*/true);
-      if (has_style_type) {
-        family = family.First(nLen - len);
-        nStyle |= style_type;
+      const FX_FontStyle* style_result =
+          GetStyleType(family.AsStringView(), /*reverse_search=*/true);
+      if (style_result) {
+        family = family.First(nLen - style_result->len);
+        nStyle |= style_result->style;
       }
     }
     pitch_family = GetPitchFamilyFromFlags(flags);
@@ -606,20 +597,17 @@
     bool is_first_item = true;
     while (i < style.GetLength()) {
       ByteString buf = ParseStyle(style, i);
-      bool has_style_type;
-      uint32_t style_type;
-      size_t len;
-      std::tie(has_style_type, style_type, len) =
-          GetStyleType(buf, /*reverse_search=*/false);
-      if ((i && !is_style_available) || (!i && !has_style_type)) {
+      const FX_FontStyle* style_result =
+          GetStyleType(buf.AsStringView(), /*reverse_search=*/false);
+      if ((i && !is_style_available) || (!i && !style_result)) {
         family = subst_name;
         base_font = kNumStandardFonts;
         break;
       }
-      if (has_style_type)
+      if (style_result)
         is_style_available = true;
 
-      if (FontStyleIsForceBold(style_type)) {
+      if (FontStyleIsForceBold(style_result->style)) {
         // If we're already bold, then we're double bold, use special weight.
         if (FontStyleIsForceBold(nStyle)) {
           weight = FXFONT_FW_BOLD_BOLD;
@@ -630,9 +618,10 @@
 
         is_first_item = false;
       }
-      if (FontStyleIsItalic(style_type) && FontStyleIsForceBold(style_type)) {
+      if (FontStyleIsItalic(style_result->style) &&
+          FontStyleIsForceBold(style_result->style)) {
         nStyle |= FXFONT_ITALIC;
-      } else if (FontStyleIsItalic(style_type)) {
+      } else if (FontStyleIsItalic(style_result->style)) {
         if (is_first_item) {
           nStyle |= FXFONT_ITALIC;
         } else {