CPDF_SyntaxParser::SearchWord() is always backwards and for whole-words
Change-Id: Ic31d9cda5e919a754162e14e69cb63671a3fe8b9
Reviewed-on: https://pdfium-review.googlesource.com/4794
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fpdfapi/parser/cpdf_data_avail.cpp b/core/fpdfapi/parser/cpdf_data_avail.cpp
index 709874e..b13b982 100644
--- a/core/fpdfapi/parser/cpdf_data_avail.cpp
+++ b/core/fpdfapi/parser/cpdf_data_avail.cpp
@@ -748,7 +748,6 @@
bool CPDF_DataAvail::CheckEnd(DownloadHints* pHints) {
uint32_t req_pos = (uint32_t)(m_dwFileLen > 1024 ? m_dwFileLen - 1024 : 0);
uint32_t dwSize = (uint32_t)(m_dwFileLen - req_pos);
-
if (!m_pFileAvail->IsDataAvail(req_pos, dwSize)) {
pHints->AddSegment(req_pos, dwSize);
return false;
@@ -761,12 +760,10 @@
buffer, static_cast<size_t>(dwSize), false);
m_syntaxParser.InitParser(file, 0);
m_syntaxParser.SetPos(dwSize - 1);
-
- if (!m_syntaxParser.SearchWord("startxref", true, false, dwSize)) {
+ if (!m_syntaxParser.BackwardsSearchToWord("startxref", dwSize)) {
m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
return true;
}
-
m_syntaxParser.GetNextWord(nullptr);
bool bNumber;
diff --git a/core/fpdfapi/parser/cpdf_parser.cpp b/core/fpdfapi/parser/cpdf_parser.cpp
index fc98be5..12ec81b 100644
--- a/core/fpdfapi/parser/cpdf_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_parser.cpp
@@ -159,7 +159,7 @@
m_pDocument = pDocument;
bool bXRefRebuilt = false;
- if (m_pSyntax->SearchWord("startxref", true, false, 4096)) {
+ if (m_pSyntax->BackwardsSearchToWord("startxref", 4096)) {
m_SortedOffset.insert(m_pSyntax->GetPos());
m_pSyntax->GetKeyword();
diff --git a/core/fpdfapi/parser/cpdf_syntax_parser.cpp b/core/fpdfapi/parser/cpdf_syntax_parser.cpp
index 45a5a8a..e41736d 100644
--- a/core/fpdfapi/parser/cpdf_syntax_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_syntax_parser.cpp
@@ -90,7 +90,7 @@
return true;
}
-bool CPDF_SyntaxParser::GetCharAtBackward(FX_FILESIZE pos, uint8_t& ch) {
+bool CPDF_SyntaxParser::GetCharAtBackward(FX_FILESIZE pos, uint8_t* ch) {
pos += m_HeaderOffset;
if (pos >= m_FileLen)
return false;
@@ -105,7 +105,7 @@
if (!ReadChar(read_pos, read_size))
return false;
}
- ch = m_pFileBuf[pos - m_BufOffset];
+ *ch = m_pFileBuf[pos - m_BufOffset];
return true;
}
@@ -814,74 +814,38 @@
return true;
}
-// TODO(dsinclair): Split into a SearchWordForward and SearchWordBackwards
-// and drop the bool.
-bool CPDF_SyntaxParser::SearchWord(const CFX_ByteStringC& tag,
- bool bWholeWord,
- bool bForward,
- FX_FILESIZE limit) {
+bool CPDF_SyntaxParser::BackwardsSearchToWord(const CFX_ByteStringC& tag,
+ FX_FILESIZE limit) {
int32_t taglen = tag.GetLength();
if (taglen == 0)
return false;
FX_FILESIZE pos = m_Pos;
- int32_t offset = 0;
- if (!bForward)
- offset = taglen - 1;
-
- const uint8_t* tag_data = tag.raw_str();
- uint8_t byte;
+ int32_t offset = taglen - 1;
while (1) {
- if (bForward) {
- if (limit && pos >= m_Pos + limit)
- return false;
+ if (limit && pos <= m_Pos - limit)
+ return false;
- if (!GetCharAt(pos, byte))
- return false;
+ uint8_t byte;
+ if (!GetCharAtBackward(pos, &byte))
+ return false;
- } else {
- if (limit && pos <= m_Pos - limit)
- return false;
-
- if (!GetCharAtBackward(pos, byte))
- return false;
- }
-
- if (byte == tag_data[offset]) {
- if (bForward) {
- offset++;
- if (offset < taglen) {
- pos++;
- continue;
- }
- } else {
- offset--;
- if (offset >= 0) {
- pos--;
- continue;
- }
+ if (byte == tag[offset]) {
+ offset--;
+ if (offset >= 0) {
+ pos--;
+ continue;
}
-
- FX_FILESIZE startpos = bForward ? pos - taglen + 1 : pos;
- if (!bWholeWord || IsWholeWord(startpos, limit, tag, false)) {
- m_Pos = startpos;
+ if (IsWholeWord(pos, limit, tag, false)) {
+ m_Pos = pos;
return true;
}
}
-
- if (bForward) {
- offset = byte == tag_data[0] ? 1 : 0;
- pos++;
- } else {
- offset = byte == tag_data[taglen - 1] ? taglen - 2 : taglen - 1;
- pos--;
- }
-
+ offset = byte == tag[taglen - 1] ? taglen - 2 : taglen - 1;
+ pos--;
if (pos < 0)
return false;
}
-
- return false;
}
FX_FILESIZE CPDF_SyntaxParser::FindTag(const CFX_ByteStringC& tag,
diff --git a/core/fpdfapi/parser/cpdf_syntax_parser.h b/core/fpdfapi/parser/cpdf_syntax_parser.h
index f9a9bd9..4c5e252 100644
--- a/core/fpdfapi/parser/cpdf_syntax_parser.h
+++ b/core/fpdfapi/parser/cpdf_syntax_parser.h
@@ -46,11 +46,7 @@
CFX_ByteString GetKeyword();
void ToNextLine();
void ToNextWord();
- bool SearchWord(const CFX_ByteStringC& word,
- bool bWholeWord,
- bool bForward,
- FX_FILESIZE limit);
-
+ bool BackwardsSearchToWord(const CFX_ByteStringC& word, FX_FILESIZE limit);
FX_FILESIZE FindTag(const CFX_ByteStringC& tag, FX_FILESIZE limit);
void SetEncrypt(const CFX_RetainPtr<CPDF_CryptoHandler>& pCryptoHandler);
bool ReadBlock(uint8_t* pBuf, uint32_t size);
@@ -68,7 +64,7 @@
uint32_t GetDirectNum();
bool ReadChar(FX_FILESIZE read_pos, uint32_t read_size);
bool GetNextChar(uint8_t& ch);
- bool GetCharAtBackward(FX_FILESIZE pos, uint8_t& ch);
+ bool GetCharAtBackward(FX_FILESIZE pos, uint8_t* ch);
void GetNextWordInternal(bool* bIsNumber);
bool IsWholeWord(FX_FILESIZE startpos,
FX_FILESIZE limit,
