RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-26 07:07:45 +00:00
Code Issues Activity Actions

LibRegex: Avoid excessive Vector copy when compiling regexps

Browse source 
Previously we would've copied the bytecode instead of moving the chunks
around, use the fancy new DisjointChunks<T> abstraction to make that
happen automagically.
This decreases vector copies and uses of memmove() by nearly 10x :^)
This commit is contained in:
Ali Mohammad Pur 2021-09-13 23:45:22 +04:30 • committed by Ali Mohammad Pur
parent 7e75a16e6f
commit bf0315ff8f
3 changed files with 53 additions and 23 deletions
Download patch file Download diff file Expand all files Collapse all files

42
Userland/Libraries/LibRegex/RegexByteCode.h
View file

@ -10,6 +10,7 @@
#include "RegexMatch.h"
#include "RegexOptions.h"
#include <AK/DisjointChunks.h>
#include <AK/Format.h>
#include <AK/Forward.h>
#include <AK/HashMap.h>
@ -139,7 +140,9 @@ struct CompareTypeAndValuePair {
class OpCode;
class ByteCode : public Vector<ByteCodeValueType> {
class ByteCode : public DisjointChunks<ByteCodeValueType> {
using Base = DisjointChunks<ByteCodeValueType>;
public:
ByteCode()
{
@ -150,6 +153,36 @@ public:
virtual ~ByteCode() = default;
ByteCode& operator=(ByteCode&&) = default;
ByteCode& operator=(Base&& value)
{
static_cast<Base&>(*this) = move(value);
return *this;
}
template<typename... Args>
void empend(Args&&... args)
{
if (is_empty())
Base::append({});
Base::last_chunk().empend(forward<Args>(args)...);
}
template<typename T>
void append(T&& value)
{
if (is_empty())
Base::append({});
Base::last_chunk().append(forward<T>(value));
}
template<typename T>
void prepend(T&& value)
{
if (is_empty())
return append(forward<T>(value));
Base::first_chunk().prepend(forward<T>(value));
}
void last_chunk() const = delete;
void first_chunk() const = delete;
void insert_bytecode_compare_values(Vector<CompareTypeAndValuePair>&& pairs)
{
@ -309,7 +342,7 @@ public:
VERIFY_NOT_REACHED();
}
void insert_bytecode_alternation(ByteCode left, ByteCode right)
void insert_bytecode_alternation(ByteCode&& left, ByteCode&& right)
{
// FORKJUMP _ALT
@ -320,7 +353,7 @@ public:
// LABEL _END
// Optimisation: Eliminate extra work by unifying common pre-and-postfix exprs.
Optimizer::append_alternation(*this, left, right);
Optimizer::append_alternation(*this, move(left), move(right));
}
template<typename T>
@ -476,8 +509,7 @@ public:
bytecode.empend(bytecode_to_repeat.size()); // Jump to the _END label
for (auto& op : bytecode_to_repeat)
bytecode.append(move(op));
bytecode.extend(move(bytecode_to_repeat));
// LABEL _END = bytecode.size()
bytecode_to_repeat = move(bytecode);