Make WordIterator and Snippet::MatchPositions use size_t instead of int for offsets into strings. This avoids some casts. I also added a typedef for Snippet::MatchPosition which cleans up a bit of the calling code a little.
Review URL: http://codereview.chromium.org/13064
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@6260 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/history/snippet.cc b/chrome/browser/history/snippet.cc
index d72209e5..a95de81 100644
--- a/chrome/browser/history/snippet.cc
+++ b/chrome/browser/history/snippet.cc
@@ -15,8 +15,8 @@
namespace {
-bool PairFirstLessThan(const std::pair<int,int>& a,
- const std::pair<int,int>& b) {
+bool PairFirstLessThan(const Snippet::MatchPosition& a,
+ const Snippet::MatchPosition& b) {
return a.first < b.first;
}
@@ -25,7 +25,7 @@
void CoalescePositionsFrom(size_t offset,
Snippet::MatchPositions* match_positions) {
DCHECK(offset < match_positions->size());
- std::pair<int,int>& pair((*match_positions)[offset]);
+ Snippet::MatchPosition& pair((*match_positions)[offset]);
++offset;
while (offset < match_positions->size() &&
pair.second >= (*match_positions)[offset].first) {
@@ -37,9 +37,12 @@
// Makes sure there is a pair in match_positions that contains the specified
// range. This keeps the pairs ordered in match_positions by first, and makes
// sure none of the pairs in match_positions touch each other.
-void AddMatch(int start, int end, Snippet::MatchPositions* match_positions) {
- DCHECK(start < end && match_positions);
- std::pair<int,int> pair(start, end);
+void AddMatch(size_t start,
+ size_t end,
+ Snippet::MatchPositions* match_positions) {
+ DCHECK(start < end);
+ DCHECK(match_positions);
+ Snippet::MatchPosition pair(start, end);
if (match_positions->empty()) {
match_positions->push_back(pair);
return;
@@ -97,11 +100,11 @@
// matches offset.
// wide_pos: current index in the wide string. This is the same as the return
// value.
-int AdvanceAndReturnWidePos(const char* utf8_string,
- int utf8_length,
- int offset,
- int* utf8_pos,
- int* wide_pos) {
+size_t AdvanceAndReturnWidePos(const char* utf8_string,
+ int32_t utf8_length,
+ int32_t offset,
+ int32_t* utf8_pos,
+ size_t* wide_pos) {
DCHECK(offset >= *utf8_pos && offset <= utf8_length);
UChar32 wide_char;
@@ -115,7 +118,7 @@
// Given a character break iterator over a UTF-8 string, set the iterator
// position to |*utf8_pos| and move by |count| characters. |count| can
// be either positive or negative.
-void MoveByNGraphemes(BreakIterator* bi, int count, int* utf8_pos) {
+void MoveByNGraphemes(BreakIterator* bi, int count, size_t* utf8_pos) {
// Ignore the return value. A side effect of the current position
// being set at or following |*utf8_pos| is exploited here.
// It's simpler than calling following(n) and then previous().
@@ -123,7 +126,7 @@
// snippet generation. If not, revisit the way we scan in ComputeSnippet.
bi->isBoundary(*utf8_pos);
bi->next(count);
- *utf8_pos = static_cast<int>(bi->current());
+ *utf8_pos = static_cast<size_t>(bi->current());
}
// The amount of context to include for a given hit. Note that it's counted
@@ -134,8 +137,8 @@
// from the previous match. The window size is counted in terms
// of graphemes rather than bytes in UTF-8.
bool IsNextMatchWithinSnippetWindow(BreakIterator* bi,
- int previous_match_end,
- int next_match_start) {
+ size_t previous_match_end,
+ size_t next_match_start) {
// If it's within a window in terms of bytes, it's certain
// that it's within a window in terms of graphemes as well.
if (next_match_start < previous_match_end + kSnippetContext)
@@ -168,8 +171,8 @@
for (size_t i = 0; i < offsets.size() - 3; i += 4) {
if (offsets[i] != column_num)
continue;
- const int start = atoi(offsets[i+2].c_str());
- const int end = start + atoi(offsets[i+3].c_str());
+ const size_t start = atoi(offsets[i + 2].c_str());
+ const size_t end = start + atoi(offsets[i + 3].c_str());
AddMatch(start, end, match_positions);
}
}
@@ -179,17 +182,16 @@
const std::string& utf8_string,
Snippet::MatchPositions* match_positions) {
DCHECK(match_positions);
- int utf8_pos = 0;
- int wide_pos = 0;
+ int32_t utf8_pos = 0;
+ size_t wide_pos = 0;
const char* utf8_cstring = utf8_string.c_str();
- const int utf8_length = static_cast<int>(utf8_string.size());
+ const int32_t utf8_length = static_cast<int32_t>(utf8_string.size());
for (Snippet::MatchPositions::iterator i = match_positions->begin();
i != match_positions->end(); ++i) {
i->first = AdvanceAndReturnWidePos(utf8_cstring, utf8_length,
i->first, &utf8_pos, &wide_pos);
- i->second =
- AdvanceAndReturnWidePos(utf8_cstring, utf8_length, i->second, &utf8_pos,
- &wide_pos);
+ i->second = AdvanceAndReturnWidePos(utf8_cstring, utf8_length,
+ i->second, &utf8_pos, &wide_pos);
}
}
@@ -198,17 +200,12 @@
// The length of snippets we try to produce.
// We can generate longer snippets but stop once we cross kSnippetMaxLength.
const size_t kSnippetMaxLength = 200;
-
-
const std::wstring kEllipsis = L" ... ";
- // Grab the size as an int to cut down on casts later.
- const int document_size = static_cast<int>(document.size());
-
UText* document_utext = NULL;
UErrorCode status = U_ZERO_ERROR;
document_utext = utext_openUTF8(document_utext, document.data(),
- document_size, &status);
+ document.size(), &status);
// Locale does not matter because there's no per-locale customization
// for character iterator.
scoped_ptr<BreakIterator> bi(
@@ -220,14 +217,14 @@
// context around each match. If matches are near enough each other (within
// kSnippetContext), we skip the "..." between them.
std::wstring snippet;
- int start = 0;
+ size_t start = 0;
for (size_t i = 0; i < match_positions.size(); ++i) {
// Some shorter names for the current match.
- const int match_start = match_positions[i].first;
- const int match_end = match_positions[i].second;
+ const size_t match_start = match_positions[i].first;
+ const size_t match_end = match_positions[i].second;
// Add the context, if any, to show before the match.
- int context_start = match_start;
+ size_t context_start = match_start;
MoveByNGraphemes(bi.get(), -kSnippetContext, &context_start);
start = std::max(start, context_start);
if (start < match_start) {
@@ -237,17 +234,17 @@
}
// Add the match.
- matches_.push_back(std::make_pair(static_cast<int>(snippet.size()), 0));
+ const size_t first = snippet.size();
snippet += UTF8ToWide(document.substr(match_start,
match_end - match_start));
- matches_.back().second = static_cast<int>(snippet.size());
+ matches_.push_back(std::make_pair(first, snippet.size()));
// Compute the context, if any, to show after the match.
- int end;
+ size_t end;
// Check if the next match falls within our snippet window.
if (i + 1 < match_positions.size() &&
IsNextMatchWithinSnippetWindow(bi.get(), match_end,
- match_positions[i + 1].first)) {
+ match_positions[i + 1].first)) {
// Yes, it's within the window. Make the end context extend just up
// to the next match.
end = match_positions[i + 1].first;
@@ -257,7 +254,7 @@
end = match_end;
MoveByNGraphemes(bi.get(), kSnippetContext, &end);
snippet += UTF8ToWide(document.substr(match_end, end - match_end));
- if (end < document_size)
+ if (end < document.size())
snippet += kEllipsis;
}
start = end;
