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#pragma once
#include "utility.h"
#include <util/generic/fwd.h>
#include <util/system/align.h>
#include <util/system/compiler.h>
#include <util/system/yassert.h>
#include <cstring>
class TBuffer {
public:
using TIterator = char*;
using TConstIterator = const char*;
TBuffer(size_t len = 0);
TBuffer(const char* buf, size_t len);
TBuffer(const TBuffer& b)
: Data_(nullptr)
, Len_(0)
, Pos_(0)
{
*this = b;
}
TBuffer(TBuffer&& b) noexcept;
TBuffer& operator=(TBuffer&& b) noexcept;
TBuffer& operator=(const TBuffer& b) {
if (this != &b) {
Assign(b.Data(), b.Size());
}
return *this;
}
~TBuffer();
inline void Clear() noexcept {
Pos_ = 0;
}
inline void EraseBack(size_t n) noexcept {
Y_ASSERT(n <= Pos_);
Pos_ -= n;
}
Y_REINITIALIZES_OBJECT inline void Reset() noexcept {
TBuffer().Swap(*this);
}
inline void Assign(const char* data, size_t len) {
Clear();
Append(data, len);
}
inline void Assign(const char* b, const char* e) {
Assign(b, e - b);
}
inline char* Data() noexcept {
return Data_;
}
inline const char* Data() const noexcept {
return Data_;
}
inline char* Pos() noexcept {
return Data_ + Pos_;
}
inline const char* Pos() const noexcept {
return Data_ + Pos_;
}
/// Used space in bytes (do not mix with Capacity!)
inline size_t Size() const noexcept {
return Pos_;
}
Y_PURE_FUNCTION inline bool Empty() const noexcept {
return !Size();
}
inline explicit operator bool() const noexcept {
return Size();
}
inline size_t Avail() const noexcept {
return Len_ - Pos_;
}
void Append(const char* buf, size_t len);
inline void Append(const char* b, const char* e) {
Append(b, e - b);
}
inline void Append(char ch) {
if (Len_ == Pos_) {
Reserve(Len_ + 1);
}
*(Data() + Pos_++) = ch;
}
void Fill(char ch, size_t len);
// Method is useful when first messages from buffer are processed, and
// the last message in buffer is incomplete, so we need to move partial
// message to the begin of the buffer and continue filling the buffer
// from the network.
inline void Chop(size_t pos, size_t count) {
const auto end = pos + count;
Y_ASSERT(end <= Pos_);
if (count == 0) {
return;
} else if (count == Pos_) {
Pos_ = 0;
} else {
memmove(Data_ + pos, Data_ + end, Pos_ - end);
Pos_ -= count;
}
}
inline void ChopHead(size_t count) {
Chop(0U, count);
}
inline void Proceed(size_t pos) {
// Y_ASSERT(pos <= Len_); // see discussion in REVIEW:29021
Resize(pos);
}
inline void Advance(size_t len) {
Resize(Pos_ + len);
}
inline void Reserve(size_t len) {
if (len > Len_) {
DoReserve(len);
}
}
inline void ReserveExactNeverCallMeInSaneCode(size_t len) {
if (len > Len_) {
Realloc(len);
}
}
inline void ShrinkToFit() {
if (Pos_ < Len_) {
Realloc(Pos_);
}
}
inline void Resize(size_t len) {
Reserve(len);
Pos_ = len;
}
// Method works like Resize, but allocates exact specified number of bytes
// rather than rounded up to next power of 2
// Use with care
inline void ResizeExactNeverCallMeInSaneCode(size_t len) {
ReserveExactNeverCallMeInSaneCode(len);
Pos_ = len;
}
inline size_t Capacity() const noexcept {
return Len_;
}
inline void AlignUp(size_t align, char fillChar = '\0') {
size_t diff = ::AlignUp(Pos_, align) - Pos_;
while (diff-- > 0) {
Append(fillChar);
}
}
inline char* data() noexcept {
return Data();
}
inline const char* data() const noexcept {
return Data();
}
inline size_t size() const noexcept {
return Size();
}
inline void Swap(TBuffer& r) noexcept {
DoSwap(Data_, r.Data_);
DoSwap(Len_, r.Len_);
DoSwap(Pos_, r.Pos_);
}
/*
* after this call buffer becomes empty
*/
void AsString(TString& s);
/*
* iterator-like interface
*/
inline TIterator Begin() noexcept {
return Data();
}
inline TIterator End() noexcept {
return Begin() + Size();
}
inline TConstIterator Begin() const noexcept {
return Data();
}
inline TConstIterator End() const noexcept {
return Begin() + Size();
}
bool operator==(const TBuffer& other) const noexcept {
if (Empty()) {
return other.Empty();
}
return Size() == other.Size() && 0 == std::memcmp(Data(), other.Data(), Size());
}
bool operator!=(const TBuffer& other) const noexcept {
return !(*this == other);
}
private:
void DoReserve(size_t len);
void Realloc(size_t len);
private:
char* Data_;
size_t Len_;
size_t Pos_;
};
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