Cleanup and improve snippet code a bit

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Jeremy 2024-03-03 11:49:15 -06:00
parent 862b546532
commit ec264aa0eb
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@ -14,11 +14,16 @@ namespace cpptrace {
namespace detail {
constexpr std::int64_t max_size = 1024 * 1024 * 10; // 10 MiB
struct line_range {
std::size_t begin;
std::size_t end; // one past the end
};
class snippet_manager {
bool loaded_contents;
std::string contents;
// for index i, gives the index in `contents` of one past the end of the line (i.e. the \n or contents.end())
std::vector<std::size_t> line_table;
// 1-based indexing
std::vector<line_range> line_table;
public:
snippet_manager(const std::string& path) : loaded_contents(false) {
std::ifstream file;
@ -43,13 +48,12 @@ namespace detail {
}
}
std::string get_line(std::size_t line) const { // 0-indexed line TODO: reconsider
if(!loaded_contents || line >= line_table.size()) {
// takes a 1-index line
std::string get_line(std::size_t line) const {
if(!loaded_contents || line > line_table.size()) {
return "";
} else if(line == 0) {
return contents.substr(0, line_table[line]);
} else {
return contents.substr(line_table[line - 1] + 1, line_table[line] - line_table[line - 1] - 1);
return contents.substr(line_table[line].begin, line_table[line].end - line_table[line].begin);
}
}
@ -62,15 +66,21 @@ namespace detail {
}
private:
void build_line_table() {
std::size_t pos = 0;
line_table.push_back({0, 0});
std::size_t pos = 0; // stores the start of the current line
while(true) {
std::size_t new_pos = contents.find('\n', pos);
if(new_pos == std::string::npos) {
line_table.push_back(contents.size());
// find the end of the current line
std::size_t terminator_pos = contents.find('\n', pos);
if(terminator_pos == std::string::npos) {
line_table.push_back({pos, contents.size()});
break;
} else {
line_table.push_back(new_pos);
pos = new_pos + 1;
std::size_t end_pos = terminator_pos; // one past the end of the current line
if(end_pos > 0 && contents[end_pos - 1] == '\r') {
end_pos--;
}
line_table.push_back({pos, end_pos});
pos = terminator_pos + 1;
}
}
}
@ -92,13 +102,13 @@ namespace detail {
// how wide the margin for the line number should be
constexpr std::size_t margin_width = 8;
// 1-indexed line
std::string get_snippet(const std::string& path, std::size_t target_line, std::size_t context_size, bool color) {
target_line--;
const auto& manager = get_manager(path);
if(!manager.ok()) {
return "";
}
auto begin = target_line <= context_size ? 0 : target_line - context_size;
auto begin = target_line <= context_size + 1 ? 1 : target_line - context_size;
auto original_begin = begin;
auto end = std::min(target_line + context_size, manager.num_lines() - 1);
std::vector<std::string> lines;