commit 5ccd10bce323dfd9c4ade25bc508a722c1864952
author Lei Zhang <thestig@chromium.org> Wed Sep 21 19:31:06 2022 +0000
committer Pdfium LUCI CQ <pdfium-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed Sep 21 19:31:06 2022 +0000
tree 9f67ba8dc044c89982052f270ff5eebfbc323add
parent 7a92ada7c6192528edf555cc235c34db804de9c0

Change `CPDF_TextPage::m_CharIndices` to be a struct.

Use a well-defined struct to store the data, instead of using a
convention where even-indexed array values are indices and odd-indexed
array values are counts. Also change the stored values to ints, as there
may be more that UINT16_MAX characters.

Change-Id: I11f3b1ebaec71520f1b80c5d181b023585abf948
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/98291
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

core/fpdftext/cpdf_textpage.cpp

diff --git a/core/fpdftext/cpdf_textpage.cpp b/core/fpdftext/cpdf_textpage.cpp
index 8a20482..b6ed0df 100644
--- a/core/fpdftext/cpdf_textpage.cpp
+++ b/core/fpdftext/cpdf_textpage.cpp
@@ -294,28 +294,25 @@
 
   const int nCount = CountChars();
   if (nCount)
-    m_CharIndices.push_back(0);
+    m_CharIndices.push_back({0, 0});
 
+  bool skipped = false;
   for (int i = 0; i < nCount; ++i) {
     const CharInfo& charinfo = m_CharList[i];
     if (charinfo.m_CharType == CPDF_TextPage::CharType::kGenerated ||
         (charinfo.m_Unicode != 0 && !IsControlChar(charinfo)) ||
         (charinfo.m_Unicode == 0 && charinfo.m_CharCode != 0)) {
-      if (m_CharIndices.size() % 2) {
-        m_CharIndices.push_back(1);
-      } else {
-        m_CharIndices.back() += 1;
-      }
+      m_CharIndices.back().count++;
+      skipped = true;
     } else {
-      if (m_CharIndices.size() % 2) {
-        m_CharIndices.back() = i + 1;
+      if (skipped) {
+        m_CharIndices.push_back({i + 1, 0});
+        skipped = false;
       } else {
-        m_CharIndices.push_back(i + 1);
+        m_CharIndices.back().index = i + 1;
       }
     }
   }
-  if (m_CharIndices.size() % 2)
-    m_CharIndices.pop_back();
 }
 
 int CPDF_TextPage::CountChars() const {
@@ -324,22 +321,22 @@
 
 int CPDF_TextPage::CharIndexFromTextIndex(int text_index) const {
   int count = 0;
-  for (size_t i = 0; i < m_CharIndices.size(); i += 2) {
-    count += m_CharIndices[i + 1];
+  for (const auto& info : m_CharIndices) {
+    count += info.count;
     if (count > text_index)
-      return text_index - count + m_CharIndices[i + 1] + m_CharIndices[i];
+      return text_index - count + info.count + info.index;
   }
   return -1;
 }
 
 int CPDF_TextPage::TextIndexFromCharIndex(int char_index) const {
   int count = 0;
-  for (size_t i = 0; i < m_CharIndices.size(); i += 2) {
-    int text_index = char_index - m_CharIndices[i];
-    if (text_index < m_CharIndices[i + 1])
+  for (const auto& info : m_CharIndices) {
+    int text_index = char_index - info.index;
+    if (text_index < info.count)
       return text_index >= 0 ? text_index + count : -1;
 
-    count += m_CharIndices[i + 1];
+    count += info.count;
   }
   return -1;
 }

core/fpdftext/cpdf_textpage.h

diff --git a/core/fpdftext/cpdf_textpage.h b/core/fpdftext/cpdf_textpage.h
index 8c881bf..17954ca 100644
--- a/core/fpdftext/cpdf_textpage.h
+++ b/core/fpdftext/cpdf_textpage.h
@@ -14,7 +14,6 @@
 #include <vector>
 
 #include "core/fpdfapi/page/cpdf_pageobjectholder.h"
-#include "core/fxcrt/data_vector.h"
 #include "core/fxcrt/fx_coordinates.h"
 #include "core/fxcrt/unowned_ptr.h"
 #include "core/fxcrt/widestring.h"
@@ -103,6 +102,11 @@
     CFX_Matrix m_formMatrix;
   };
 
+  struct CharSegment {
+    int index;
+    int count;
+  };
+
   void Init();
   bool IsHyphen(wchar_t curChar) const;
   void ProcessObject();
@@ -137,7 +141,7 @@
       const std::function<bool(const CharInfo&)>& predicate) const;
 
   UnownedPtr<const CPDF_Page> const m_pPage;
-  DataVector<uint16_t> m_CharIndices;
+  std::vector<CharSegment> m_CharIndices;
   std::deque<CharInfo> m_CharList;
   std::deque<CharInfo> m_TempCharList;
   WideTextBuffer m_TextBuf;