Files
react-native/ReactCommon/react/renderer/mapbuffer/primitives.h
T
Andrei Shikov 5b489d5f95 Use vector for dynamic data in MapBufferBuilder
Summary:
Replaces dynamic manually managed array with a vector of bytes, removing the need for managing memory manually.

This approach is a little bit slower than before, as vector is allocating memory more conservatively. This can be improved in the future by providing an estimate for the data size.

Changelog: [Internal]

Reviewed By: javache

Differential Revision: D33611759

fbshipit-source-id: a0e5e57c4e413206a9f891cd5630ecc9088a9bf7
2022-01-17 13:15:49 -08:00

100 lines
2.8 KiB
C++

/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#pragma once
#include <glog/logging.h>
// TODO T83483191: Enable CHECK_CONSISTENCY only in debug mode or test
// environments (or just in demand) #define CHECK_CONSISTENCY 1
constexpr static int32_t NULL_VALUE = 0;
// Value used to verify if the data is serialized with LittleEndian order
constexpr static uint16_t ALIGNMENT = 0xFE;
using Key = uint16_t;
using Byte = uint8_t;
namespace facebook {
namespace react {
struct Header {
uint16_t alignment; // alignment of serialization
uint16_t count; // amount of items in the map
uint32_t bufferSize; // Amount of bytes used to store the map in memory
};
static_assert(sizeof(Header) == 8, "MapBuffer header size is incorrect.");
struct __attribute__((__packed__)) Bucket {
Key key;
uint64_t data;
Bucket(Key key, uint64_t data) : key(key), data(data){};
};
static_assert(sizeof(Bucket) == 10, "MapBuffer bucket size is incorrect.");
constexpr static int32_t KEY_SIZE = sizeof(Key);
constexpr static int32_t HEADER_SIZE = sizeof(Header);
constexpr static int32_t INT_SIZE = sizeof(int32_t);
constexpr static int32_t DOUBLE_SIZE = sizeof(double);
constexpr static int32_t UINT8_SIZE = sizeof(uint8_t);
constexpr static int32_t UINT16_SIZE = sizeof(uint16_t);
constexpr static int32_t UINT64_SIZE = sizeof(uint64_t);
constexpr static int32_t HEADER_ALIGNMENT_OFFSET = offsetof(Header, alignment);
constexpr static int32_t HEADER_COUNT_OFFSET = offsetof(Header, count);
constexpr static int32_t HEADER_BUFFER_SIZE_OFFSET =
offsetof(Header, bufferSize);
constexpr static int32_t MAX_VALUE_SIZE = UINT64_SIZE;
// 10 bytes : 2 key + 8 value
constexpr static int32_t BUCKET_SIZE = KEY_SIZE + UINT64_SIZE;
/**
* Returns the offset of the key received by parameter.
*/
inline int32_t getKeyOffset(Key key) {
return HEADER_SIZE + BUCKET_SIZE * key;
}
/**
* Returns the offset of the value associated to the key received by parameter.
*/
inline int32_t getValueOffset(Key key) {
return getKeyOffset(key) + KEY_SIZE;
}
inline void
checkKeyConsistency(const Header &header, const uint8_t *data, Key key) {
#ifdef CHECK_CONSISTENCY
if (key >= header.count) {
LOG(ERROR) << "Error: Key is higher than size of Map - key '" << key
<< "' - size: '" << header.count << "'";
assert(false && "Error while reading key");
}
Key storedKey = 0;
memcpy(
reinterpret_cast<Key *>(&storedKey),
reinterpret_cast<const Key *>(data + getKeyOffset(key)),
KEY_SIZE);
if (storedKey != key) {
LOG(ERROR) << "Error while reading key, expecting '" << key << "' found: '"
<< storedKey << "'";
assert(false && "Error while reading key");
}
#endif
}
} // namespace react
} // namespace facebook