| FlatBuffers (binary) | Protocol Buffers LITE | Rapid JSON | FlatBuffers (JSON) | pugixml | Raw structs | |
|---|---|---|---|---|---|---|
| Decode + Traverse + Dealloc (1 million times, seconds) | 0.08 | 302 | 583 | 105 | 196 | 0.02 |
| Decode / Traverse / Dealloc (breakdown) | 0 / 0.08 / 0 | 220 / 0.15 / 81 | 294 / 0.9 / 287 | 70 / 0.08 / 35 | 41 / 3.9 / 150 | 0 / 0.02 / 0 |
| Encode (1 million times, seconds) | 3.2 | 185 | 650 | 169 | 273 | 0.15 |
| Wire format size (normal / zlib, bytes) | 344 / 220 | 228 / 174 | 1475 / 322 | 1029 / 298 | 1137 / 341 | 312 / 187 |
| Memory needed to store decoded wire (bytes / blocks) | 0 / 0 | 760 / 20 | 65689 / 4 | 328 / 1 | 34194 / 3 | 0 / 0 |
| Transient memory allocated during decode (KB) | 0 | 1 | 131 | 4 | 34 | 0 |
| Generated source code size (KB) | 4 | 61 | 0 | 4 | 0 | 0 |
| Field access in handwritten traversal code | typed accessors | typed accessors | manual error checking | typed accessors | manual error checking | typed but no safety |
| Library source code (KB) | 15 | some subset of 3800 | 87 | 43 | 327 | 0 |
- 下载flatbuffers源码
git clone https://github.com/google/flatbuffers.git
- cmake （源码中已包含cmake,也可自行下载）
- 编译出flatc
进入 flatbuffers/
1.cmake -G "Unix Makefiles"
2.make
1.可以将flatbufffers/java 中的源码copy进项目
2.将源码打包成jar(此处选用mvn打包)
- 安装mvn
1.去官网下载mvn源码mvn下载
2.在.bash_profile中加入如下配置
export M2_HOME="/Users/wangyang/apache-maven-3.5.3"
export PATH="$M2_HOME/bin:$PATH"
3.进入flatbuffers/
本质是将flatbuffers/java目录下源码打成jar，但是此目录下没有配置对应的pom.xml
本人尝试自己编写pom文件失败后，最后发现flatbuffers/目录下有此配置文件，坑，在此目录下运行以下命令，会生成target文件夹，在target/文件中找到flatbuffers-java-1.9.0-sources.jar
mvn install
namespace com.rolan.MyGame;//在java中相当于包名
include "mydefinitions.fbs";//可引入其它的schemas
attribute "priority";//属性
enum Color : byte { Red = 1, Green, Blue }//枚举
union Any { Monster, Weapon, Pickup }//联合体，类比于enum和 struct
struct Vec3 {//类似于table，但它针对不再添加修改的情形，一些常量，比table内存占用小访问速度更快，
x:float;
y:float;
z:float;
}
table Monster {//table类似于object，只能在末尾添加新的字段，可以rename
pos:Vec3;
mana:short = 150;
hp:short = 100;
name:string;
friendly:bool = false (deprecated, priority: 1);//不能删除不再使用的字段，可用deprecated标志
inventory:[ubyte];//[types]: ubyte bool short int float double long
color:Color = Blue;
test:Any;
}
root_type Monster;//根节点
括号里是别名
- 8 bit: byte (int8), ubyte (uint8), bool
- 16 bit: short (int16), ushort (uint16)
- 32 bit: int (int32), uint (uint32), float (float32)
- 64 bit: long (int64), ulong (uint64), double (float64)
根据schme文件编译生成java entity文件
flatc -j[--java] sample_schema.fbs
根据schme文件编译生成c++ 头文件
flatc -c[--cpp] sample_schema.fbs
根据.proto文件生成.fbs(将protobuffer格式转为flatbuffer)
flatc --proto Person.proto
根据.fbs文件和.bin文件生成json
flatc -t schema.fbs -- binary.bin
根据schme文件和 json数据文件生成所对应的flatbuffers格式的数据文件
flatc -b[--binary] sample_schema.fbs sample_json.json
了解其它相关命令官方文档
以下面这个scheme为例
namespace com.rolan.entity;
table PeopleList {
peoples : [People];
}
table People {
id : string;
index : long;
guid : string;
name : string;
gender : string;
company : string;
email : string;
friends : [Friend];
}
table Friend {
id : long;
name : string;
}
root_type PeopleList;
java层序列化到文件
FlatBufferBuilder builder = new FlatBufferBuilder(0);
int peopleList[] = new int[100];
for (int i = 0; i < peopleList.length; i++) {
int nameOffect1 = builder.createString("李四");
int nameOffect2 = builder.createString("张三");
int nameOffect3 = builder.createString("王五");
int friends[] = new int[3];
friends[0] = Friend.createFriend(builder, 3243544, nameOffect1);
friends[1] = Friend.createFriend(builder, 2341423, nameOffect2);
friends[2] = Friend.createFriend(builder, 1232432, nameOffect3);
int index = builder.createString("23412243");
int guid = builder.createString("xnvnsfsd");
int name = builder.createString("赵钱");
int gender = builder.createString("男");
int company = builder.createString("阿里妈妈");
int email = builder.createString("ye@163.com");
int friendsVector = People.createFriendsVector(builder, friends);
People.startPeople(builder);
People.addId(builder, index);
People.addIndex(builder, 3001);//001会被识别成int
People.addGuid(builder, guid);
People.addName(builder, name);
People.addGender(builder, gender);
People.addCompany(builder, company);
People.addEmail(builder, email);
People.addFriends(builder, friendsVector);
peopleList[i] = People.endPeople(builder);
}
int peoplesVector = PeopleList.createPeoplesVector(builder, peopleList);
PeopleList.startPeopleList(builder);
PeopleList.addPeoples(builder, peoplesVector);
int endPeopleList = PeopleList.endPeopleList(builder);
builder.finish(endPeopleList);
ByteBuffer bb = builder.dataBuffer();
File file = new File(getCacheDir() + "/test.bin");
try {
FileOutputStream fo = new FileOutputStream(file);
fo.write(bb.array(), bb.position(), bb.remaining());
fo.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
java反序列化
File file = new File(getCacheDir() + "/test.bin");
try {
byte[] bytes = Utils.toByteArray(file);
ByteBuffer wrap = ByteBuffer.wrap(bytes);
PeopleList rootAsPeopleList = PeopleList.getRootAsPeopleList(wrap);
People peoples = rootAsPeopleList.peoples(1);//取第1个
String company = peoples.company();
int peopleLength = peoples.friendsLength();
Toast.makeText(this,peoples.company(),Toast.LENGTH_SHORT).show();
} catch (IOException e) {
e.printStackTrace();
}
- 下载Protocol Buffers源码
https://github.com/google/protobuf.git
- 编译源码
- 进入protobuf/目录下
- ./autogen.sh
- ./configure
- make
- sudo make install
- 执行完上面步骤后即可全局执行protoc命令
protoc --version 查看当前版本
protoc --help 查看命令
- 编写 .proto文件
syntax = "proto2";
package protocal;
option java_package = "com.rolan.proto";
option java_outer_classname = "PersonEntity";
message People {
repeated Person person = 1;//可重复的，即数组
message Person {
required int32 id = 1;
required int64 index = 2;
optional string guid=3;
required string name = 4;
optional string gender=5;
optional string company=6;
optional string email = 7;
repeated Friend friend = 8;
message Friend {
required string id = 1;
required string name = 4;
}
}
}
- 编译出java文件
protoc -I=. --java_out=. addressbook.proto
- java层源码支持
1.可自行根据源码中protocol/java 编译出jar包 2.build.gradle引入
implementation 'com.google.protobuf:protobuf-java:3.5.1'
- 序列化
PersonEntity.People.Builder people = PersonEntity.People.newBuilder();
for (int i = 0; i < sampleSize; i++) {
PersonEntity.People.Person.Builder person = PersonEntity.People.Person.newBuilder();
PersonEntity.People.Person.Friend friend1 = PersonEntity.People.Person.Friend.newBuilder().setId("1111").setName("李四").build();
PersonEntity.People.Person.Friend friend2 = PersonEntity.People.Person.Friend.newBuilder().setId("2222").setName("张三").build();
PersonEntity.People.Person.Friend friend3 = PersonEntity.People.Person.Friend.newBuilder().setId("3333").setName("王五").build();
person.setId(i)
.setIndex(i)
.setGuid("guid" + i)
.setName("name:" + i)
.setGender(i % 2 == 0 ? "男" : "女")
.setCompany("加油宝：" + i)
.setEmail("sd@.com")
.addFriend(friend1)
.addFriend(friend2)
.addFriend(friend3)
.build();
people.addPerson(person);
}
PersonEntity.People build = people.build();
- 反序列化
byte[] bytes = Utils.toByteArray(file);
long startTime = System.currentTimeMillis();
PersonEntity.People people = PersonEntity.People.parseFrom(bytes);
PersonEntity.People.Person person = people.getPerson(1);
参考：http://coolpers.github.io/ https://www.jianshu.com/p/03a2e8918f8a