#pragma once
#include <iostream>
#include <utility>
#include <algorithm>
#include <string>
#include <cmath>
#include <memory>
class BufferedReader {
public:
explicit BufferedReader(PackageStream *stream) : stream(stream) {
buffer = new char[stream->PackageLen() + 1];
memset(buffer, 0, stream->PackageLen() + 1);
}
int32_t Read(char *output_buffer, int32_t buffer_len) {
int32_t buffer_size = BufferSize();
int32_t real_size = std::min<int32_t>(buffer_size, buffer_len);
memcpy(output_buffer, buffer, real_size);
memcpy(buffer, buffer + real_size,
buffer_size - real_size);
AddZero(buffer + buffer_size - real_size);
char* tmp_buf = new char[stream->PackageLen() + 1];
for (int32_t last_result = INT32_MAX;
real_size < buffer_len && last_result != 0;) {
last_result = this->stream->ReadPackage(tmp_buf);
int32_t add_size;
if (real_size + last_result > buffer_len) {
add_size = buffer_len - real_size;
memcpy(output_buffer + real_size, tmp_buf, add_size);
memcpy(buffer, tmp_buf + add_size,
real_size + last_result - buffer_len);
AddZero(buffer + real_size + last_result - buffer_len);
} else {
add_size = last_result;
memcpy(output_buffer + real_size, tmp_buf, add_size);
}
real_size += add_size;
}
delete[] tmp_buf;
return real_size;
}
~BufferedReader() {
delete[] buffer;
}
private:
void AddZero(char* c) const {
*c = 0;
}
int32_t BufferSize() const {
int i = 0;
while (buffer[i] != 0) {
i++;
}
return i;
}
PackageStream *stream;
char* buffer;
};