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#include "nes/common/path-builder.hh"
namespace nes
{
path_builder::path_builder(char* buffer, u32 const buffer_length)
: buffer_{ buffer }
, buffer_length_{ buffer_length }
{
// Initialize the path to "/" if possible.
if (buffer_length > 0) { buffer_[actual_length_++] = '/'; }
}
auto path_builder::push(std::string_view component) -> bool
{
// Trim leading and trailing slashes
while (!component.empty() && component[0] == '/') { component = component.substr(1); }
while (!component.empty() && component[component.length() - 1] == '/') { component = component.substr(0, component.length() - 1); }
if (component.empty() || std::find(component.begin(), component.end(), '/') != component.end()) { return false; }
// Check if there is enough remaining capacity for "/<component>"
auto const add_leading_slash = actual_length_ == 0 || buffer_[actual_length_ - 1] != '/';
auto const length = component.length() + (add_leading_slash ? 1 : 0);
if (actual_length_ + length > buffer_length_) { return false; }
// Append "/<component>"
if (add_leading_slash) { buffer_[actual_length_++] = '/'; }
for (auto i = u32{ 0 }; i < component.length(); ++i) { buffer_[actual_length_++] = component[i]; }
return true;
}
auto path_builder::pop() -> bool
{
if (actual_length_ == 0 || buffer_[actual_length_ - 1] == '/') { return false; }
// Find the start of the last component.
auto last_start = actual_length_ - 1;
while (last_start > 0 && buffer_[last_start] != '/') { last_start -= 1; }
// Drop the slash if we are not at the root.
if (last_start == 0) { last_start += 1; }
// Drop everything including the trailing slash.
actual_length_ = last_start;
return true;
}
} // namespace nes
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