Lukhnos: Optimized KeyValueBlobReader.
This commit is contained in:
ShikiSuen
parent
a713cb324c
commit
8b9e5ca57e
|
|
@ -10,116 +10,118 @@
|
|||
|
||||
namespace vChewing {
|
||||
|
||||
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);
|
||||
};
|
||||
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); };
|
||||
|
||||
if (state_ == State::ERROR) {
|
||||
if (state_ == State::ERROR) {
|
||||
return state_;
|
||||
}
|
||||
|
||||
const char* key_begin = nullptr;
|
||||
size_t key_length = 0;
|
||||
const char* value_begin = nullptr;
|
||||
size_t value_length = 0;
|
||||
|
||||
while (true) {
|
||||
state_ = SkipUntilNot(blank_or_newline);
|
||||
if (state_ != State::CAN_CONTINUE) {
|
||||
return state_;
|
||||
}
|
||||
|
||||
// Check if it's a comment line; if so, read until end of line.
|
||||
if (*current_ != '#') {
|
||||
break;
|
||||
}
|
||||
state_ = SkipUntil(new_line);
|
||||
if (state_ != State::CAN_CONTINUE) {
|
||||
return state_;
|
||||
}
|
||||
}
|
||||
|
||||
// No need to check whether* current_ is a content_char, since content_char
|
||||
// is defined as not blank and not new_line.
|
||||
|
||||
key_begin = current_;
|
||||
state_ = SkipUntilNot(content_char);
|
||||
if (state_ != State::CAN_CONTINUE) {
|
||||
goto error;
|
||||
}
|
||||
key_length = current_ - key_begin;
|
||||
|
||||
// There should be at least one blank character after the key string.
|
||||
if (!blank(*current_)) {
|
||||
goto error;
|
||||
}
|
||||
|
||||
state_ = SkipUntilNot(blank);
|
||||
if (state_ != State::CAN_CONTINUE) {
|
||||
goto error;
|
||||
}
|
||||
|
||||
if (!content_char(*current_)) {
|
||||
goto error;
|
||||
}
|
||||
|
||||
value_begin = current_;
|
||||
// value must only contain content characters, blanks not are allowed.
|
||||
// also, there's no need to check the state after this, since we will always
|
||||
// emit the value. This also avoids the situation where trailing spaces in a
|
||||
// line would become part of the value.
|
||||
SkipUntilNot(content_char);
|
||||
value_length = current_ - value_begin;
|
||||
|
||||
// Unconditionally skip until the end of the line. This prevents the case
|
||||
// like "foo bar baz\n" where baz should not be treated as the Next key.
|
||||
SkipUntil(new_line);
|
||||
|
||||
if (out != nullptr) {
|
||||
*out = KeyValue { std::string_view { key_begin, key_length },
|
||||
std::string_view { value_begin, value_length } };
|
||||
}
|
||||
state_ = State::HAS_PAIR;
|
||||
return state_;
|
||||
}
|
||||
|
||||
const char* key_begin = nullptr;
|
||||
size_t key_length = 0;
|
||||
const char* value_begin = nullptr;
|
||||
size_t value_length = 0;
|
||||
|
||||
while (true) {
|
||||
state_ = SkipUntilNot(blank_or_newline);
|
||||
if (state_ != State::CAN_CONTINUE) {
|
||||
return state_;
|
||||
}
|
||||
|
||||
// Check if it's a comment line; if so, read until end of line.
|
||||
if (*current_ != '#') {
|
||||
break;
|
||||
}
|
||||
state_ = SkipUntil(new_line);
|
||||
if (state_ != State::CAN_CONTINUE) {
|
||||
return state_;
|
||||
}
|
||||
}
|
||||
|
||||
// No need to check whether* current_ is a content_char, since content_char
|
||||
// is defined as not blank and not new_line.
|
||||
|
||||
key_begin = current_;
|
||||
state_ = SkipUntilNot(content_char);
|
||||
if (state_ != State::CAN_CONTINUE) {
|
||||
goto error;
|
||||
}
|
||||
key_length = current_ - key_begin;
|
||||
|
||||
// There should be at least one blank character after the key string.
|
||||
if (!blank(*current_)) {
|
||||
goto error;
|
||||
}
|
||||
|
||||
state_ = SkipUntilNot(blank);
|
||||
if (state_ != State::CAN_CONTINUE) {
|
||||
goto error;
|
||||
}
|
||||
|
||||
if (!content_char(*current_)) {
|
||||
goto error;
|
||||
}
|
||||
|
||||
value_begin = current_;
|
||||
// value must only contain content characters, blanks not are allowed.
|
||||
// also, there's no need to check the state after this, since we will always
|
||||
// emit the value. This also avoids the situation where trailing spaces in a
|
||||
// line would become part of the value.
|
||||
SkipUntilNot(content_char);
|
||||
value_length = current_ - value_begin;
|
||||
|
||||
// Unconditionally skip until the end of the line. This prevents the case
|
||||
// like "foo bar baz\n" where baz should not be treated as the Next key.
|
||||
SkipUntil(new_line);
|
||||
|
||||
if (out != nullptr) {
|
||||
*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;
|
||||
state_ = State::ERROR;
|
||||
return state_;
|
||||
}
|
||||
|
||||
KeyValueBlobReader::State KeyValueBlobReader::SkipUntilNot(
|
||||
const std::function<bool(char)>& f) {
|
||||
while (current_ != end_ &&* current_) {
|
||||
if (!f(*current_)) {
|
||||
return State::CAN_CONTINUE;
|
||||
const std::function<bool(char)>& f)
|
||||
{
|
||||
while (current_ != end_ && *current_) {
|
||||
if (!f(*current_)) {
|
||||
return State::CAN_CONTINUE;
|
||||
}
|
||||
++current_;
|
||||
}
|
||||
++current_;
|
||||
}
|
||||
|
||||
return State::END;
|
||||
return State::END;
|
||||
}
|
||||
|
||||
KeyValueBlobReader::State KeyValueBlobReader::SkipUntil(
|
||||
const std::function<bool(char)>& f) {
|
||||
while (current_ != end_ &&* current_) {
|
||||
if (f(*current_)) {
|
||||
return State::CAN_CONTINUE;
|
||||
const std::function<bool(char)>& f)
|
||||
{
|
||||
while (current_ != end_ && *current_) {
|
||||
if (f(*current_)) {
|
||||
return State::CAN_CONTINUE;
|
||||
}
|
||||
++current_;
|
||||
}
|
||||
++current_;
|
||||
}
|
||||
|
||||
return State::END;
|
||||
return State::END;
|
||||
}
|
||||
|
||||
std::ostream& operator<<(std::ostream& os,
|
||||
const KeyValueBlobReader::KeyValue& kv) {
|
||||
os << "(key: " << kv.key << ", value: " << kv.value << ")";
|
||||
return os;
|
||||
std::ostream& operator<<(
|
||||
std::ostream& os, const KeyValueBlobReader::KeyValue& kv)
|
||||
{
|
||||
os << "(key: " << kv.key << ", value: " << kv.value << ")";
|
||||
return os;
|
||||
}
|
||||
|
||||
} // namespace vChewing
|
||||
} // namespace vChewing
|
||||
|
|
|
|||
|
|
@ -31,49 +31,61 @@
|
|||
namespace vChewing {
|
||||
|
||||
class KeyValueBlobReader {
|
||||
public:
|
||||
enum class State : int {
|
||||
// There are no more key-value pairs in this blob.
|
||||
END = 0,
|
||||
// The reader has produced a new key-value pair.
|
||||
HAS_PAIR = 1,
|
||||
// An error is encountered and the parsing stopped.
|
||||
ERROR = -1,
|
||||
// Internal-only state: the parser can continue parsing.
|
||||
CAN_CONTINUE = 2
|
||||
};
|
||||
public:
|
||||
enum class State : int {
|
||||
// There are no more key-value pairs in this blob.
|
||||
END = 0,
|
||||
// The reader has produced a new key-value pair.
|
||||
HAS_PAIR = 1,
|
||||
// An error is encountered and the parsing stopped.
|
||||
ERROR = -1,
|
||||
// Internal-only state: the parser can continue parsing.
|
||||
CAN_CONTINUE = 2
|
||||
};
|
||||
|
||||
struct KeyValue {
|
||||
constexpr KeyValue() : key(""), value("") {}
|
||||
constexpr KeyValue(std::string_view k, std::string_view v)
|
||||
: key(k), value(v) {}
|
||||
struct KeyValue {
|
||||
constexpr KeyValue()
|
||||
: key("")
|
||||
, value("")
|
||||
{
|
||||
}
|
||||
constexpr KeyValue(std::string_view k, std::string_view v)
|
||||
: key(k)
|
||||
, value(v)
|
||||
{
|
||||
}
|
||||
|
||||
bool operator==(const KeyValue& another) const {
|
||||
return key == another.key && value == another.value;
|
||||
bool operator==(const KeyValue& another) const
|
||||
{
|
||||
return key == another.key && value == another.value;
|
||||
}
|
||||
|
||||
std::string_view key;
|
||||
std::string_view value;
|
||||
};
|
||||
|
||||
KeyValueBlobReader(const char* blob, size_t size)
|
||||
: current_(blob)
|
||||
, end_(blob + size)
|
||||
{
|
||||
}
|
||||
|
||||
std::string_view key;
|
||||
std::string_view value;
|
||||
};
|
||||
// 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);
|
||||
|
||||
KeyValueBlobReader(const char* blob, size_t size)
|
||||
: current_(blob), end_(blob + size) {}
|
||||
private:
|
||||
State SkipUntil(const std::function<bool(char)>& f);
|
||||
State SkipUntilNot(const std::function<bool(char)>& f);
|
||||
|
||||
// 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:
|
||||
State SkipUntil(const std::function<bool(char)>& f);
|
||||
State SkipUntilNot(const std::function<bool(char)>& f);
|
||||
|
||||
const char* current_;
|
||||
const char* end_;
|
||||
State state_ = State::CAN_CONTINUE;
|
||||
const char* current_;
|
||||
const char* end_;
|
||||
State state_ = State::CAN_CONTINUE;
|
||||
};
|
||||
|
||||
std::ostream& operator<<(std::ostream&, const KeyValueBlobReader::KeyValue&);
|
||||
|
||||
} // namespace vChewing
|
||||
} // namespace vChewing
|
||||
|
||||
#endif // SOURCE_ENGINE_KEYVALUEBLOBREADER_H_
|
||||
#endif // SOURCE_ENGINE_KEYVALUEBLOBREADER_H_
|
||||
|
|
|
|||
Loading…
Reference in New Issue