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mirror of synced 2024-11-15 11:33:23 +01:00
ImHex/lib/libimhex/include/hex/providers/buffered_reader.hpp
2022-11-02 08:24:00 +01:00

284 lines
9.1 KiB
C++

#pragma once
#include <span>
#include <vector>
#include <hex/providers/provider.hpp>
#include <hex/helpers/literals.hpp>
namespace hex::prv {
using namespace hex::literals;
class BufferedReader {
public:
explicit BufferedReader(Provider *provider, size_t bufferSize = 16_MiB)
: m_provider(provider), m_bufferAddress(provider->getBaseAddress()), m_maxBufferSize(bufferSize),
m_startAddress(provider->getBaseAddress()), m_endAddress(provider->getBaseAddress() + provider->getActualSize() - 1),
m_buffer(bufferSize) {
}
void seek(u64 address) {
this->m_startAddress = address;
}
void setEndAddress(u64 address) {
if (address >= this->m_provider->getActualSize())
address = this->m_provider->getActualSize() - 1;
this->m_endAddress = address;
}
[[nodiscard]] std::vector<u8> read(u64 address, size_t size) {
if (size > this->m_buffer.size()) {
std::vector<u8> result;
result.resize(size);
this->m_provider->read(address, result.data(), result.size());
return result;
}
this->updateBuffer(address, size);
auto result = &this->m_buffer[address - this->m_bufferAddress];
return { result, result + std::min(size, this->m_buffer.size()) };
}
[[nodiscard]] std::vector<u8> readReverse(u64 address, size_t size) {
if (size > this->m_buffer.size()) {
std::vector<u8> result;
result.resize(size);
this->m_provider->read(address, result.data(), result.size());
return result;
}
this->updateBuffer(address - std::min<u64>(address, this->m_buffer.size()), size);
auto result = &this->m_buffer[address - this->m_bufferAddress];
return { result, result + std::min(size, this->m_buffer.size()) };
}
class Iterator {
public:
using iterator_category = std::forward_iterator_tag;
using difference_type = std::ptrdiff_t;
using value_type = u8;
using pointer = const value_type*;
using reference = const value_type&;
Iterator(BufferedReader *reader, u64 address) : m_reader(reader), m_address(address) {}
Iterator& operator++() {
this->m_address++;
return *this;
}
Iterator operator++(int) {
auto copy = *this;
this->m_address++;
return copy;
}
Iterator& operator--() {
this->m_address--;
return *this;
}
Iterator operator--(int) {
auto copy = *this;
this->m_address--;
return copy;
}
Iterator& operator+=(i64 offset) {
this->m_address += offset;
return *this;
}
Iterator& operator-=(i64 offset) {
this->m_address -= offset;
return *this;
}
value_type operator*() const {
return (*this)[0];
}
[[nodiscard]] u64 getAddress() const {
return this->m_address;
}
void setAddress(u64 address) {
this->m_address = address;
}
difference_type operator-(const Iterator &other) const {
return this->m_address - other.m_address;
}
Iterator operator+(i64 offset) const {
return { this->m_reader, this->m_address + offset };
}
value_type operator[](i64 offset) const {
auto result = this->m_reader->read(this->m_address + offset, 1);
if (result.empty())
return 0x00;
return result[0];
}
friend bool operator== (const Iterator& left, const Iterator& right) { return left.m_address == right.m_address; };
friend bool operator!= (const Iterator& left, const Iterator& right) { return left.m_address != right.m_address; };
friend bool operator> (const Iterator& left, const Iterator& right) { return left.m_address > right.m_address; };
friend bool operator< (const Iterator& left, const Iterator& right) { return left.m_address < right.m_address; };
friend bool operator>= (const Iterator& left, const Iterator& right) { return left.m_address >= right.m_address; };
friend bool operator<= (const Iterator& left, const Iterator& right) { return left.m_address <= right.m_address; };
private:
BufferedReader *m_reader;
u64 m_address;
};
class ReverseIterator {
public:
using iterator_category = std::forward_iterator_tag;
using difference_type = std::ptrdiff_t;
using value_type = u8;
using pointer = const value_type*;
using reference = const value_type&;
ReverseIterator(BufferedReader *reader, u64 address) : m_reader(reader), m_address(address) {}
ReverseIterator& operator++() {
this->m_address--;
return *this;
}
ReverseIterator operator++(int) {
auto copy = *this;
this->m_address--;
return copy;
}
ReverseIterator& operator--() {
this->m_address++;
return *this;
}
ReverseIterator operator--(int) {
auto copy = *this;
this->m_address++;
return copy;
}
ReverseIterator& operator+=(i64 offset) {
this->m_address -= offset;
return *this;
}
ReverseIterator& operator-=(i64 offset) {
this->m_address += offset;
return *this;
}
value_type operator*() const {
return (*this)[0];
}
[[nodiscard]] u64 getAddress() const {
return this->m_address;
}
void setAddress(u64 address) {
this->m_address = address;
}
difference_type operator-(const ReverseIterator &other) const {
return other.m_address - this->m_address;
}
ReverseIterator operator+(i64 offset) const {
return { this->m_reader, this->m_address - offset };
}
value_type operator[](i64 offset) const {
auto result = this->m_reader->readReverse(this->m_address - offset, 1);
if (result.empty())
return 0x00;
return result[0];
}
friend bool operator== (const ReverseIterator& left, const ReverseIterator& right) { return left.m_address == right.m_address; };
friend bool operator!= (const ReverseIterator& left, const ReverseIterator& right) { return left.m_address != right.m_address; };
friend bool operator> (const ReverseIterator& left, const ReverseIterator& right) { return left.m_address > right.m_address; };
friend bool operator< (const ReverseIterator& left, const ReverseIterator& right) { return left.m_address < right.m_address; };
friend bool operator>= (const ReverseIterator& left, const ReverseIterator& right) { return left.m_address >= right.m_address; };
friend bool operator<= (const ReverseIterator& left, const ReverseIterator& right) { return left.m_address <= right.m_address; };
private:
BufferedReader *m_reader;
u64 m_address = 0x00;
};
Iterator begin() {
return { this, this->m_startAddress };
}
Iterator end() {
return { this, this->m_endAddress + 1 };
}
ReverseIterator rbegin() {
return { this, this->m_startAddress };
}
ReverseIterator rend() {
return { this, 0 };
}
private:
void updateBuffer(u64 address, size_t size) {
if (!this->m_bufferValid || address < this->m_bufferAddress || address + size > (this->m_bufferAddress + this->m_buffer.size())) {
const auto remainingBytes = (this->m_endAddress - address) + 1;
if (remainingBytes < this->m_maxBufferSize)
this->m_buffer.resize(remainingBytes);
else
this->m_buffer.resize(this->m_maxBufferSize);
this->m_provider->read(address, this->m_buffer.data(), this->m_buffer.size());
this->m_bufferAddress = address;
this->m_bufferValid = true;
}
}
private:
Provider *m_provider;
u64 m_bufferAddress = 0x00;
size_t m_maxBufferSize;
bool m_bufferValid = false;
u64 m_startAddress = 0x00, m_endAddress;
std::vector<u8> m_buffer;
};
}