Skip to content

src: avoid unnecessary string allocations in SPrintF impl #60052

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
addaleax wants to merge 2 commits into from
Closed

src: avoid unnecessary string allocations in SPrintF impl #60052

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
a0c6a1e
src: make ToLower/ToUpper input args more flexible
addaleax Sep 28, 2025
c9bad79
src: avoid unnecessary string allocations in SPrintF impl
addaleax Sep 28, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Next Next commit
src: make ToLower/ToUpper input args more flexible 
In particular, this enables passing `std::string_view` instead.
  • Loading branch information
@addaleax
addaleax committed Sep 28, 2025
commit a0c6a1e8df60a4b777c035dbcfc8bb538258c49f
24 changes: 16 additions & 8 deletions src/util-inl.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -194,21 +194,29 @@ char ToLower(char c) {
return std::tolower(c, std::locale::classic());
}

std::string ToLower(const std::string& in) {
std::string out(in.size(), 0);
for (size_t i = 0; i < in.size(); ++i)
out[i] = ToLower(in[i]);
template <typename T>
std::string ToLower(const T& in) {
auto it = std::cbegin(in);
auto end = std::cend(in);
std::string out(std::distance(it, end), 0);
size_t i;
for (i = 0; it != end; ++it, ++i) out[i] = ToLower(*it);
DCHECK_EQ(i, out.size());
return out;
}

char ToUpper(char c) {
return std::toupper(c, std::locale::classic());
}

std::string ToUpper(const std::string& in) {
std::string out(in.size(), 0);
for (size_t i = 0; i < in.size(); ++i)
out[i] = ToUpper(in[i]);
template <typename T>
std::string ToUpper(const T& in) {
auto it = std::cbegin(in);
auto end = std::cend(in);
std::string out(std::distance(it, end), 0);
size_t i;
for (i = 0; it != end; ++it, ++i) out[i] = ToUpper(*it);
DCHECK_EQ(i, out.size());
return out;
}

Expand Down
6 changes: 4 additions & 2 deletions src/util.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -366,11 +366,13 @@ inline v8::Local<v8::String> FIXED_ONE_BYTE_STRING(v8::Isolate* isolate,

// tolower() is locale-sensitive. Use ToLower() instead.
inline char ToLower(char c);
inline std::string ToLower(const std::string& in);
template <typename T>
inline std::string ToLower(const T& in);

// toupper() is locale-sensitive. Use ToUpper() instead.
inline char ToUpper(char c);
inline std::string ToUpper(const std::string& in);
template <typename T>
inline std::string ToUpper(const T& in);

// strcasecmp() is locale-sensitive. Use StringEqualNoCase() instead.
inline bool StringEqualNoCase(const char* a, const char* b);
Expand Down