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#pragma once
/*
* Some parts are from upb - a minimalist implementation of protocol buffers.
*
* Copyright (c) 2008-2011 Google Inc. See LICENSE for details.
* Author: Josh Haberman <jhaberman@gmail.com>
*/
#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <string>
// #include <cassert>
namespace llmr {
struct pbf {
inline pbf(const unsigned char *data, uint32_t length);
inline pbf(const char *data, uint32_t length);
// inline pbf(const std::string& buffer);
inline bool next();
template <typename T = uint32_t> inline T varint();
inline int64_t svarint();
inline std::string string();
inline float float32();
inline double float64();
inline int64_t int64();
inline bool boolean();
template <typename T, typename... Args>
inline T *message(const Args&... args);
inline void skip();
inline void skipValue(uint32_t val);
inline void skipBytes(uint32_t bytes);
const uint8_t *data;
const uint8_t *end;
uint32_t value;
uint32_t tag;
};
pbf::pbf(const unsigned char *data, uint32_t length)
: data(data),
end(data + length)
{}
pbf::pbf(const char *data, uint32_t length)
: data((const unsigned char *)data),
end((const unsigned char *)data + length)
{}
// pbf::pbf(const std::string& buffer)
// : data((const unsigned char *)buffer.data()),
// end((const unsigned char *)buffer.data() + buffer.size())
// {}
bool pbf::next()
{
if (data < end) {
value = (uint32_t)varint();
tag = value >> 3;
return true;
}
return false;
}
template <typename T>
T pbf::varint()
{
uint8_t byte = 0x80;
T result = 0;
int bitpos;
for (bitpos = 0; bitpos < 70 && (byte & 0x80); bitpos += 7) {
if (data >= end) {
fprintf(stderr, "unterminated varint, unexpected end of buffer");
exit(1);
}
result |= ((T)(byte = *data) & 0x7F) << bitpos;
data++;
}
if (bitpos == 70 && (byte & 0x80)) {
fprintf(stderr, "unterminated varint (too long)");
exit(1);
}
return result;
}
int64_t pbf::svarint()
{
uint64_t n = varint();
return (n >> 1) ^ -(int64_t)(n & 1);
}
std::string pbf::string()
{
uint32_t bytes = (uint32_t)varint();
const char *string = (const char *)data;
skipBytes(bytes);
return std::string(string, bytes);
}
float pbf::float32()
{
skipBytes(4);
float result;
memcpy(&result, data - 4, 4);
return result;
}
double pbf::float64()
{
skipBytes(8);
double result;
memcpy(&result, data - 8, 8);
return result;
}
int64_t pbf::int64()
{
return (int64_t)varint();
}
bool pbf::boolean()
{
skipBytes(1);
return *(bool *)(data - 1);
}
template <typename T, typename... Args> T *pbf::message(const Args&... args)
{
uint32_t bytes = (uint32_t)varint();
T *result = new T(data, bytes, args...);
skipBytes(bytes);
return result;
}
void pbf::skip()
{
skipValue(value);
}
void pbf::skipValue(uint32_t val)
{
switch (val & 0x7) {
case 0: // varint
varint();
break;
case 1: // 64 bit
skipBytes(8);
break;
case 2: // string/message
skipBytes((uint32_t)varint());
break;
case 5: // 32 bit
skipBytes(4);
break;
default:
fprintf(stderr, "cannot skip unknown type %d", val & 0x7);
exit(1);
}
}
void pbf::skipBytes(uint32_t bytes)
{
data += bytes;
if (data > end) {
fprintf(stderr, "unexpected end of buffer");
exit(1);
}
}
} // end namespace llmr
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