Lukhnos: Optimized KeyValueBlobReader.

This commit is contained in:
ShikiSuen 2022-01-23 23:15:29 +08:00
parent a713cb324c
commit 8b9e5ca57e
2 changed files with 144 additions and 130 deletions

View File

@ -10,13 +10,13 @@
namespace vChewing {
KeyValueBlobReader::State KeyValueBlobReader::Next(KeyValue* out) {
KeyValueBlobReader::State KeyValueBlobReader::Next(KeyValue* out)
{
static auto new_line = [](char c) { return c == '\n' || c == '\r'; };
static auto blank = [](char c) { return c == ' ' || c == '\t'; };
static auto blank_or_newline = [](char c) { return blank(c) || new_line(c); };
static auto content_char = [](char c) {
return !blank(c) && !new_line(c);
};
static auto blank_or_newline
= [](char c) { return blank(c) || new_line(c); };
static auto content_char = [](char c) { return !blank(c) && !new_line(c); };
if (state_ == State::ERROR) {
return state_;
@ -80,21 +80,21 @@ KeyValueBlobReader::State KeyValueBlobReader::Next(KeyValue* out) {
SkipUntil(new_line);
if (out != nullptr) {
*out = KeyValue{
std::string_view{key_begin, key_length},
std::string_view{value_begin, value_length}};
*out = KeyValue { std::string_view { key_begin, key_length },
std::string_view { value_begin, value_length } };
}
state_ = State::HAS_PAIR;
return state_;
error:
state_ = State::ERROR;
return State::ERROR;
return state_;
}
KeyValueBlobReader::State KeyValueBlobReader::SkipUntilNot(
const std::function<bool(char)>& f) {
while (current_ != end_ &&* current_) {
const std::function<bool(char)>& f)
{
while (current_ != end_ && *current_) {
if (!f(*current_)) {
return State::CAN_CONTINUE;
}
@ -105,8 +105,9 @@ KeyValueBlobReader::State KeyValueBlobReader::SkipUntilNot(
}
KeyValueBlobReader::State KeyValueBlobReader::SkipUntil(
const std::function<bool(char)>& f) {
while (current_ != end_ &&* current_) {
const std::function<bool(char)>& f)
{
while (current_ != end_ && *current_) {
if (f(*current_)) {
return State::CAN_CONTINUE;
}
@ -116,8 +117,9 @@ KeyValueBlobReader::State KeyValueBlobReader::SkipUntil(
return State::END;
}
std::ostream& operator<<(std::ostream& os,
const KeyValueBlobReader::KeyValue& kv) {
std::ostream& operator<<(
std::ostream& os, const KeyValueBlobReader::KeyValue& kv)
{
os << "(key: " << kv.key << ", value: " << kv.value << ")";
return os;
}

View File

@ -31,7 +31,7 @@
namespace vChewing {
class KeyValueBlobReader {
public:
public:
enum class State : int {
// There are no more key-value pairs in this blob.
END = 0,
@ -44,11 +44,19 @@ class KeyValueBlobReader {
};
struct KeyValue {
constexpr KeyValue() : key(""), value("") {}
constexpr KeyValue()
: key("")
, value("")
{
}
constexpr KeyValue(std::string_view k, std::string_view v)
: key(k), value(v) {}
: key(k)
, value(v)
{
}
bool operator==(const KeyValue& another) const {
bool operator==(const KeyValue& another) const
{
return key == another.key && value == another.value;
}
@ -57,13 +65,17 @@ class KeyValueBlobReader {
};
KeyValueBlobReader(const char* blob, size_t size)
: current_(blob), end_(blob + size) {}
: current_(blob)
, end_(blob + size)
{
}
// Parse the next key-value pair and return the state of the reader. If `out`
// is passed, out will be set to the produced key-value pair if there is one.
// Parse the next key-value pair and return the state of the reader. If
// `out` is passed, out will be set to the produced key-value pair if there
// is one.
State Next(KeyValue* out = nullptr);
private:
private:
State SkipUntil(const std::function<bool(char)>& f);
State SkipUntilNot(const std::function<bool(char)>& f);