🔼 🐏 📼 Golang后端伺服器范本-第2部分（REST API） 🙉 🙇🏻 🎉

下面的Golang服务器模板已准备好在我们团队中转移知识。除培训外，模板的主要目标是减少在Go上对小型服务器任务进行原型设计的时间。

模板的第一部分专门用于HTTP服务器：

通过命令行和配置文件配置HTTP服务器
配置TLS HTTP服务器设置
路由器设置以及HTTP和教授处理程序的注册
设置HTTP流量日志记录，HTTP错误日志记录
HTTP基本和MS AD身份验证，JSON Web令牌
启动服务器，等待返回错误通道
使用上下文正确停止服务器和相关服务
自定义错误处理和自定义日志记录
带有版本，构建日期和提交的代码汇编

模板的第二部分专门介绍REST API的原型。
到项目存储库的链接保持不变。

REST API模板架构

在展台上测试模板的过程中，获得了以下结果。

在PostgreSQL的直接读取模式下-最高16,000 [get / sec]，并发1024，中位数60 [ms]。每个Get从两个表中请求数据，这些表的总大小为360,000,000行。JSON大小为1800个字节。
100 000 — 120 000 [get/sec], oncurrency 1024, 2 [ms]. Transfer rate 200-250 [MB/sec]
PostgreSQL — 10 000 [insert/sec].

- ,
- Marshal / Unmarshal JSON
SQLXX
- SQL
DB
JSON
- Marshal / Unmarshal JSON
- Unmarshal JSON
- JSON
HTTP
- GET, POST, PUT

1.

Model :
- Marshal / Unmarshal JSON
- -
SQLXX :
- SQL
DB :
- , SQL
JSON JSON :
- Marshal / Unmarshal JSON
- JSON
HTTP HTTP :
- HTTP
- HTTP
- (basic, MS AD, ...)
- token
- (body)
- (header)
- HSTS Strict-Transport-Security
- Content-Type (response)
- HTTP
- (header)
- defer recovery panic

REST API : FaaS, , gRPC.

2 Model

2.1. ,

2.1.1

, "Department" "Employee". .
, JOSN .
(-).

// Dept represent object "Department"
type Dept struct {
    Deptno int         `db:"deptno" json:"deptNumber" validate:"required"`
    Dname  string      `db:"dname" json:"deptName" validate:"required"`
    Loc    null.String `db:"loc" json:"deptLocation,nullempty"`
    Emps   []*Emp      `json:"emps,omitempty"`
}

// Emp represent object "Employee"
type Emp struct {
    Empno    int         `db:"empno" json:"empNo" validate:"required"`
    Ename    null.String `db:"ename" json:"empName,nullempty"`
    Job      null.String `db:"job" json:"job,nullempty"`
    Mgr      null.Int    `db:"mgr" json:"mgr,omitempty"`
    Hiredate null.String `db:"hiredate" json:"hiredate,nullempty"`
    Sal      null.Int    `db:"sal" json:"sal,nullempty" validate:"gte=0"`
    Comm     null.Int    `db:"comm" json:"comm,nullempty" validate:"gte=0"`
    Deptno   null.Int    `db:"deptno" json:"deptNumber,nullempty"`
}

.
( ).
, , - (, ). "" .
REST API , : Get, Create, Update.
context.Context — " ".
, , , , , . sync.Pool.

// DeptService represent basic interface for Dept
type DeptService interface {
    GetDept(ctx context.Context, out *Dept) (bool, error)
    GetDeptsPK(ctx context.Context, out *DeptPKs) error
    CreateDept(ctx context.Context, in *Dept, out *Dept) error
    UpdateDept(ctx context.Context, in *Dept, out *Dept)  (bool, error)
}

// EmpService represent basic interface for Emp
type EmpService interface {
    GetEmp(ctx context.Context, out *Emp) (bool, error)
    GetEmpsByDept(ctx context.Context, in *Dept, out *EmpSlice) error
    CreateEmp(ctx context.Context, in *Emp, out *Emp) error
    UpdateEmp(ctx context.Context, in *Emp, out *Emp)  (bool, error)
}

2.1.2

IBM MQ.

// Request represent a type for request
type Request struct {
    QObject               string //  
    QueueName             string //    
    QueueOptions          int32  // MQOO_OUTPUT, MQOO_BROWSE, MQOO_INPUT_AS_Q_DEF  
    QueueWaitInterval     int    //      seconds
    MsgIdHex              string //    Hex 
    CorrelIdHex           string //     Hex 
    MesFormat             string // MQFMT_NONE, MQFMT_STRING
    MesSyncpoint          int32  // MQPMO_NO_SYNCPOINT, MQPMO_SYNCPOINT
    MesOptions            int32  //
    BrowseOptions         int32  // MQGMO_BROWSE_FIRST, MQGMO_BROWSE_NEXT, ...
    Bufsize               int    //  
    Buf                   []byte `json:"-"` //   
}

// Response represent a type for response
type Response struct {
    QObject      string //  
    QueueName    string //    
    MsgId        []byte //    byte 
    MsgIdHex     string //    Hex 
    CorrelId     []byte //     byte 
    CorrelIdHex  string //     Hex 
    PutDate      string //     
    PutTime      string //     
    DataLen      int    //  
    ErrCode      string //  
    ErrMes       string //   
    ErrTrace     string //    
    CauseErrCode string //    - 
    CauseErrMes  string //    - 
    Buf          []byte //   
}

IBM MQ.

// QueueService represent basic service for queue
type QueueService interface {
    OpenQueue(ctx context.Context, req *Request, resp *Response) error
    CloseQueue(ctx context.Context, req *Request, resp *Response) error
    BrowseMessage(ctx context.Context, req *Request, resp *Response) error
    BrowseFirstMessage(ctx context.Context, req *Request, resp *Response) error
    BrowseNextMessage(ctx context.Context, req *Request, resp *Response) error
    BrowseUnderMessage(ctx context.Context, req *Request, resp *Response) error
    GetMessage(ctx context.Context, req *Request, resp *Response) error
    DeleteUnderMessage(ctx context.Context, req *Request, resp *Response) error
    PutMessage(ctx context.Context, req *Request, resp *Response) error
    RegisterCallback(ctx context.Context, req *Request, resp *Response) error
    DeregisterCallback(ctx context.Context, req *Request, resp *Response) error
}

2.2.

, :

— , . , "" > 0, "" not null.
— , " " >= " "
() — , " " >= " "
— , (PK, UK), .
— , (FK), .
— , .

1, 2 3 . 4, 5, 6 , , .

.
, , , .

.
" API". , DML . , API. , Oracle , API.
(View API), , .
Instead of Trigger DML API.

, — DML . ( Oracle ). API, .
.

, 1, 2 3 JSON .

3 1, 2 3 gopkg.in/go-playground/validator.
4 (PK, UK).
5 6 .

2.3.

REST API (JSON->Model->DB) (). , , JSON . API, (GC). ( GC).

GC — sync.Pool. . — sync.Pool.
, — sync.Pool, , , , .

sync.Pool :

Dept

// deptsPool represent depts pooling
var deptsPool = sync.Pool{
    New: func() interface{} { return new(Dept) },
}

// GetDept allocates a new struct or grabs a cached one
func GetDept() *Dept {
    p := deptsPool.Get().(*Dept)
    p.Reset()
    return p
}

// PutDept return struct to cache
func PutDept(p *Dept, isCascad bool) {
    if p != nil {
        PutEmpSlice(p.Emps, isCascad)
        p.Emps = nil
        deptsPool.Put(p)
    }
}

// Reset reset all fields in structure - use for sync.Pool
func (p *Dept) Reset() {
    p.Deptno = 0
    p.Dname = ""
    p.Loc.String = ""
    p.Loc.Valid = false
    if p.Emps != nil {
        EmpSlice(p.Emps).Reset()
    }
    p.Emps = nil
}

//EmpSlice represent slice of Emps
type EmpSlice []*Emp

// PutEmpSlice return struct to cache
func PutEmpSlice(p EmpSlice) {
    if p != nil {
        for i := range p {
            p[i] = nil //      
        }
        p = p[:0] //   
        empSlicePool.Put(p)
    }
}

, , 1000000 Get , 500 . .
, sync.Pool CPU, sync.Pool .
dept emp , .

2.4. Marshal / Unmarshal JSON

encoding/json .
:

. .
:

github.com/francoispqt/gojay
- NULL .
- sync.Pool encode. , 2 , , . — 512 .
- encode JSON.
github.com/mailru/easyjson
- NULL
- sync.Pool. 512 32768 ( ). encode JSON .
- encode JSON

github.com/mailru/easyjson.

, , / JSON .

//easyjson:json
type Dept struct {
    Deptno int         `db:"deptno" json:"deptNumber" validate:"required"`
    Dname  string      `db:"dname" json:"deptName" validate:"required"`
    Loc    null.String `db:"loc" json:"deptLocation,nullempty"`
    Emps   []*Emp      `json:"emps,omitempty"`
}

, easyjson NULL , gopkg.in/guregu/null.v4. , NULL , , "Loc null.String" "Loc sql.NullString".

easyjson model.go

Marshal / Unmarshal , JSON.

3. SQLXX

SQLXX :

, , Listen/notify PostgreSQL (jackc/pgx/stdlib lib/pq)

, .
, , SQL .

httpserver/sqlxx jmoiron/sqlx.

// DB is a wrapper around sqlx.DB
type DB struct {
    *sqlx.DB

    cfg     *Config
    sqlStms SQLStms // SQL 
}

// Tx is an sqlx wrapper around sqlx.Tx
type Tx struct {
    *sqlx.Tx
}

, , jmoiron/sqlx, , jackc/pgx.

3.1.

jmoiron/sqlx , : Beginx, Rollback, Commit, Select, Get, Exec.
.
INFO trace. , , , , .

func Commit(reqID uint64, tx *Tx) (myerr error) {
    //    
    defer func() {
        r := recover()
        if r != nil {
            msg := "PostgreSQL recover from panic: commit transaction: reqID"
            switch t := r.(type) {
            case string:
                myerr = myerror.New("4008", msg, reqID, t).PrintfInfo()
            case error:
                myerr = myerror.WithCause("4006", msg, t, reqID).PrintfInfo()
            default:
                myerr = myerror.New("4006", msg, reqID).PrintfInfo()
            }
        }
    }()

    //     
    if tx == nil {
        return myerror.New("4004", "Transaction is not defined: reqID", reqID).PrintfInfo()
    }

    if err := tx.Commit(); err != nil {
        return myerror.WithCause("4008", "Error commit the transaction: reqID", err, reqID).PrintfInfo()
    }
    return nil
}

interface{}, , , , .

func Select(reqID uint64, tx *Tx, sqlStm *SQLStm, dest interface{}, args ...interface{}) (myerr error) {
    if dest != nil && !reflect.ValueOf(dest).IsNil() {
        // ...
    }
    return myerror.New("4400", "Incorrect call - nil dest interface{} pointer: reqID", reqID).PrintfInfo()
}

reflect.ValueOf(in).IsNil() , .

3.2.

. .

// Config   
type Config struct {
    ConnectString   string //    
    Host            string // host 
    Port            string //   
    Dbname          string //  
    SslMode         string //  SSL
    User            string //     
    Pass            string //  
    ConnMaxLifetime int    //     
    MaxOpenConns    int    //    
    MaxIdleConns    int    //    
    DriverName      string //   "postgres" | "pgx" | "godror"
}

3.3. SQL

SQLXX SQL interface{}.
, SQL .

SQLXX SQL . SQL , , ( SQL ).

// SQLStm represent SQL text and sqlx.Stmt
type SQLStm struct {
    Text      string     //  SQL 
    Stmt      *sqlx.Stmt //  SQL 
    IsPrepare bool       // ,     SQL 
}

// SQLStms represent SQLStm map
type SQLStms map[string]*SQLStm

4. DB

DB :

4.1. , SQL

, (-) :

(PK) — API. GUID, , BTree .
(UK), , " ". UK .
(FK) PK. (FK), FK API . FK.

dept emp, , — .

DB SQL .
SQL : "GetDept", "GetDeptUK", "DeptExists" .. , SQL.

, SQL :

PK, , "GetDept"
UK, , "GetDeptUK"
PK UK, , "DeptExists"

, View API. SQL REST API . .

service.SQLStms = map[string]*sql.SQLStm{
    "GetDept":         &sql.SQLStm{"SELECT deptno, dname, loc FROM dept WHERE deptno = $1", nil, true},
    "GetDeptUK":       &sql.SQLStm{"SELECT deptno, dname, loc FROM dept WHERE deptno = $1", nil, true},
    "DeptExists":      &sql.SQLStm{"SELECT 1 FROM dept WHERE deptno = $1", nil, true},
    "GetDepts":        &sql.SQLStm{"SELECT deptno, dname, loc FROM dept", nil, true},
    "GetDeptsPK":      &sql.SQLStm{"SELECT deptno FROM dept", nil, true},
    "CreateDept":      &sql.SQLStm{"INSERT INTO dept (deptno, dname, loc) VALUES (:deptno, :dname, :loc)", nil, false},
    "UpdateDept":      &sql.SQLStm{"UPDATE dept SET dname = :dname, loc = :loc WHERE deptno = :deptno", nil, false},
    "EmpExists":       &sql.SQLStm{"SELECT 1 FROM emp WHERE empno = $1", nil, true},
    "GetEmp":          &sql.SQLStm{"SELECT empno, ename, job, mgr, hiredate, sal, comm, deptno FROM emp WHERE empno = $1", nil, true},
    "GetEmpUK":        &sql.SQLStm{"SELECT empno, ename, job, mgr, hiredate, sal, comm, deptno FROM emp WHERE empno = $1", nil, true},
    "GetEmpsByDept":   &sql.SQLStm{"SELECT empno, ename, job, mgr, hiredate, sal, comm, deptno FROM emp WHERE deptno = $1", nil, true},
    "GetEmpsPKByDept": &sql.SQLStm{"SELECT empno FROM emp WHERE deptno = $1", nil, true},
    "CreateEmp":       &sql.SQLStm{"INSERT INTO emp (empno, ename, job, mgr, hiredate, sal, comm, deptno) VALUES (:empno, :ename, :job, :mgr, :hiredate, :sal, :comm, :deptno)", nil, false},
    "UpdateEmp":       &sql.SQLStm{"UPDATE emp SET empno = :empno, ename = :ename, job = :job, mgr = :mgr, hiredate = :hiredate, sal = :sal, comm = :comm, deptno = :deptno WHERE empno = :empno", nil, false},
}

, SQL "".

4.2.

4.2.1 Get

Get . , .

func (s *Service) getDept(ctx context.Context, tx *mysql.Tx, out *model.Dept) (exists bool, myerr error) {

    //   
    if exists, myerr = s.db.Get(reqID, tx, "GetDept", out, out.Deptno); myerr != nil {
        return false, myerr
    }

    //   
    if exists {
        outEmps := model.GetEmpSlice() //   pool    
        if myerr = s.getEmpsByDept(ctx, tx, out, &outEmps); myerr != nil {
            return false, myerr
        }
        out.Emps = outEmps //     
    }

    return exists, nil
}

Get .

func (s *Service) GetDept(ctx context.Context, out *model.Dept) (exists bool, myerr error) {
    return s.getDept(ctx, nil, out)
}

4.2.2 Create

Create :

newDept, model.GetDept(). , .
. UK ( Dept ).
- Get(reqID, tx, "DeptExists", &foo, in.Deptno), — UK. args ...interface{}, .
- , — . .
PK
- . , SQL / 1 . , .
- API, , / PK, , Get(reqID, tx, "GetDeptUK", newDept, in.Deptno) UK.
- , FK newEmp.Deptno = null.Int{sql.NullInt64{int64(newDept.Deptno), true}} createEmp(ctx, tx, newEmp, nil).
- , .
— PK
- — JSON .
- HTTP .
- , nil out.

func (s *Service) createDept(ctx context.Context, tx *mysql.Tx, in *model.Dept, out *model.Dept) (myerr error) {

    newDept := model.GetDept()         //   pool      
    defer model.PutDept(newDept, true) //    pool

    { // ,        UK
        var foo int
        exists, myerr := s.db.Get(reqID, tx, "DeptExists", &foo, in.Deptno)
        if myerr != nil {
            return myerr
        }
        if exists {
            return myerror.New("4004", "Error create - row already exists: reqID, Deptno", reqID, in.Deptno).PrintfInfo()
        }
    } // ,        UK

    { //       PK
        rows, myerr := s.db.Exec(reqID, tx, "CreateDept", in)
        if myerr != nil {
            return myerr
        }
        //    
        if rows != 1 {
            return myerror.New("4004", "Error create: reqID, Deptno, rows", reqID, in.Deptno, rows).PrintfInfo()
        }

        //    -     ,   
        //    UK,    PK    
        exists, myerr := s.db.Get(reqID, tx, "GetDeptUK", newDept, in.Deptno)
        if myerr != nil {
            return myerr
        }
        if !exists {
            return myerror.New("4004", "Row does not exists after creating: reqID, Deptno", reqID, in.Deptno).PrintfInfo()
        }
    } //       PK

    { //       
        if in.Emps != nil {
            for _, newEmp := range in.Emps {
                //   PK     
                newEmp.Deptno = null.Int{sql.NullInt64{int64(newDept.Deptno), true}}

                //   
                if myerr = s.createEmp(ctx, tx, newEmp, nil); myerr != nil {
                    return myerr
                }
            }
        }
    } //       

    //     
    if out != nil {
        out.Deptno = newDept.Deptno //    PK
        exists, myerr := s.getDept(ctx, tx, out)
        if myerr != nil {
            return myerr
        }
        //     API
        if !exists {
            return myerror.New("4004", "Row does not exists after updating: reqID, PK", reqID, in.Deptno).PrintfInfo()
        }
    }
    return nil
}

Create :

rollback commit

func (s *Service) CreateDept(ctx context.Context, in *model.Dept, out *model.Dept) (myerr error) {
    var tx *mysql.Tx
    reqID := myctx.FromContextRequestID(ctx) // RequestID   context

    //   
    if tx, myerr = s.db.Beginx(reqID); myerr != nil {
        return myerr
    }

    //     
    if myerr = s.createDept(ctx, tx, in, out); myerr != nil {
        _ = s.db.Rollback(reqID, tx)
        return myerr
    }

    //  
    return s.db.Commit(reqID, tx)
}

4.2.3 Update

Update :

oldDept newDept, .
PK.
- — . .
- , . , .
- UK, UK.
- . , SQL 1 .
- API, , / , , P Get(reqID, tx, "GetDept", newDept, in.Deptno).
- , FK updateEmp(ctx, tx, inEmp, nil).
- ,
— PK

func (s *Service) updateDept(ctx context.Context, tx *mysql.Tx, in *model.Dept, out *model.Dept) (exists bool, myerr error) {

    oldDept := model.GetDept()         //   pool      
    defer model.PutDept(oldDept, true) //    pool

    newDept := model.GetDept()         //   pool      
    defer model.PutDept(newDept, true) //    pool

    { //         
        oldDept.Deptno = in.Deptno //    PK
        if exists, myerr = s.getDept(ctx, tx, oldDept); myerr != nil {
            return false, myerr
        }
        if !exists {
            mylog.PrintfDebugMsg("Row does not exists: reqID, PK", reqID, in.Deptno)
            return false, nil
        }
    } //         

    { //   /        
        //   UK
        //  Dept PK  UK  -     
        if oldDept.Deptno != in.Deptno {
            var foo int
            exists, myerr := s.db.Get(reqID, tx, "DeptExists", &foo, in.Deptno)
            if myerr != nil {
                return false, myerr
            }
            if exists {
                return false, myerror.New("4004", "Error update - row with UK already exists: reqID, Deptno", reqID, in.Deptno).PrintfInfo()
            }
        }
    } //   /        

    { //  
        rows, myerr := s.db.Exec(reqID, tx, "UpdateDept", in)
        if myerr != nil {
            return false, myerr
        }
        //    
        if rows != 1 {
            return false, myerror.New("4004", "Error update: reqID, Deptno, rows", reqID, in.Deptno, rows).PrintfInfo()
        }

        //   -     PK
        exists, myerr := s.db.Get(reqID, tx, "GetDept", newDept, in.Deptno)
        if myerr != nil {
            return false, myerr
        }
        if !exists {
            return false, myerror.New("4004", "Row does not exists after creating: reqID, PK", reqID, in.Deptno).PrintfInfo()
        }
    } //  

    { //       
        if in.Emps != nil {
            for _, inEmp := range in.Emps {
                //   PK     
                inEmp.Deptno = null.Int{sql.NullInt64{int64(in.Deptno), true}}

                //   
                if exists, myerr = s.updateEmp(ctx, tx, inEmp, nil); myerr != nil {
                    return false, myerr
                }
                //        -   
                if !exists {
                    if myerr = s.createEmp(ctx, tx, inEmp, nil); myerr != nil {
                        return false, myerr
                    }
                }
            }
        }
    } //       

    //     
    if out != nil {
        out.Deptno = in.Deptno //    PK
        if exists, myerr = s.getDept(ctx, tx, out); myerr != nil {
            return false, myerr
        }
        //     API
        if !exists {
            return false, myerror.New("4004", "Row does not exists after updating: reqID, PK", reqID, in.Deptno).PrintfInfo()
        }
    }
    return true, nil
}

Update :

rollback commit
, exists = false

func (s *Service) UpdateDept(ctx context.Context, in *model.Dept, out *model.Dept) (exists bool, myerr error) {
    var tx *mysql.Tx
    reqID := myctx.FromContextRequestID(ctx) // RequestID   context

    //   
    if tx, myerr = s.db.Beginx(reqID); myerr != nil {
        return false, myerr
    }

    //     
    if exists, myerr = s.updateDept(ctx, tx, in, out); myerr != nil {
        _ = s.db.Rollback(reqID, tx)
        return false, myerr
    }

    //            ,  
    if !exists {
        _ = s.db.Rollback(reqID, tx)
        return false, nil
    }

    //  
    if myerr = s.db.Commit(reqID, tx); myerr != nil {
        return false, myerr
    }
    return exists, nil
}

4.3

, .

. , backend , . / , .

3 dgraph-io/ristretto. PostgreSQL listen/notify.

5. JSON

JSON :

Marshal / Unmarshal JSON
JSON

JSON . - ( ).

JSON HTTP. , . []byte, JSON.

5.1. Marshal JSON

encode JSON github.com/mailru/easyjson .

, encode JSON Dept:

HTTP JSON buf []byte
, w.Buffer.BuildBytes(buf) ,
HTTP

func deptMarshal(reqID uint64, v *model.Dept, buf []byte) (outBuf []byte, myerr error) {
    w := jwriter.Writer{} //  EasyJSON Writer
    v.MarshalEasyJSON(&w) //  JSON    EasyJSON Writer

    if w.Error != nil {
        return nil, myerror.WithCause("6001", "Error Marshal: reqID", w.Error, reqID).PrintfInfo(1)
    }

    //     EasyJSON Writer   
    return w.Buffer.BuildBytes(buf), nil
    }

5.2. Unmarshal JSON

Decode JSON :

if err := vIn.UnmarshalJSON(inBuf); err != nil {
    return 0, nil, myerror.WithCause("6001", "Error Unmarshal: reqID, buf", err, reqID, string(inBuf)).PrintfInfo()
}

. mailru/easyjson decode , . make new, "" .
:

out.Emps = make([]*Emp, 0, 8) out.Emps = []*Emp(GetEmpSlice())
v1 = new(Emp) v1 = GetEmp()

5.3.

5.3.1. Get

Get :

: id — PK, , buf — JSON
: outBuf JSON ( buf)
JSON . vOut := model.GetDept() ( Dept — , Emp — ) defer model.PutDept(vOut, true). .

func (s *Service) GetDept(ctx context.Context, id int, buf []byte) (outBuf []byte, myerr error) {

    vOut := model.GetDept()         //   pool  
    defer model.PutDept(vOut, true) //   pool     

    vOut.Deptno = id                // PK     

    //   
    exists, myerr := s.deptService.GetDept(ctx, vOut)
    if myerr != nil {
        return nil, myerr
    }

    //  json
    if exists {
        return deptMarshal(reqID, vOut, buf)
    }

    return nil, nil //    - ,    
}

5.3.2. Create

Create :

inBuf — JSON
id — PK

func (s *Service) CreateDept(ctx context.Context, inBuf []byte, buf []byte) (id int, outBuf []byte, myerr error) {

    vIn := model.GetDept()         //   pool  
    defer model.PutDept(vIn, true) //   pool 

    vOut := model.GetDept()         //   pool  
    defer model.PutDept(vOut, true) //   pool 

    //  JSON  
    if err := vIn.UnmarshalJSON(inBuf); err != nil {
        return 0, nil, myerror.WithCause("6001", "Error Unmarshal: reqID, buf", err, reqID, string(inBuf)).PrintfInfo()
    }

    //   
    if myerr = s.deptService.CreateDept(ctx, vIn, vOut); myerr != nil {
        return 0, nil, myerr
    }

    //  json
    if outBuf, myerr = deptMarshal(reqID, vOut, buf); myerr != nil {
        return 0, nil, myerr
    }

    return vOut.Deptno, outBuf, myerr
}

5.3.3. Update

Update:

id — PK .
outBuf NO_DATA_FOUND

func (s *Service) UpdateDept(ctx context.Context, id int, inBuf []byte, buf []byte) (outBuf []byte, myerr error) {

    vIn := model.GetDept()         //   pool  
    defer model.PutDept(vIn, true) //   pool 

    vOut := model.GetDept()         //   pool  
    defer model.PutDept(vOut, true) //   pool 

    //  JSON  
    if err := vIn.UnmarshalJSON(inBuf); err != nil {
        return nil, myerror.WithCause("6001", "Error Unmarshal: reqID, buf", err, reqID, string(inBuf)).PrintfInfo()
    }

    //  ID 
    if id != vIn.Deptno {
        return nil, myerror.New("6001", "Resource ID does not corespond to JSON: resource.id, json.Deptno", id, vIn.Deptno).PrintfInfo()
    }

    //   
    exists, myerr := s.deptService.UpdateDept(ctx, vIn, vOut)
    if myerr != nil {
        return nil, myerr
    }

    //  json
    if exists {
        return deptMarshal(reqID, vOut, buf)
    }

    return nil, nil //    - ,    
}

5.4. JSON

encode JSON
.

3 JSON go.etcd.io/bbolt. PostgreSQL listen/notify.

6. HTTP

HTTP :

HTTP
HTTP
(basic, MS AD, ...)
token ( )
(body)
(header)
HSTS Strict-Transport-Security
Content-Type (response)
HTTP
(header)
defer recovery panic

. HTTP HTTP Golang.

, , :

defer . UML — RecoverWrap.func1, .
process. HTTP handler. UML process — .
HTTP handler. UML EchoHandler.func1 — .

. process, REST API.

( ).

6.1.

JSON, []byte http.ResponseWriter . GC. GC .

JSON http.ResponseWriter
JSON http.ResponseWriter

, sync.Pool:

[HTTP_POOL]
UseBufPool = true           //    
BufPooledSize = 512         //   ,       
BufPooledMaxSize = 32768    //

process .

var buf []byte
if s.cfg.UseBufPool && s.bytesPool != nil {
    buf = s.bytesPool.GetBuf()
}

, , encode JSON .
, JSON .
[]byte .

if responseBuf != nil && s.cfg.UseBufPool && s.bytesPool != nil {
    //          pool
    if cap(responseBuf) >= s.cfg.BufPooledSize && cap(responseBuf) <= s.cfg.BufPooledMaxSize {
        defer s.bytesPool.PutBuf(responseBuf)
    }
}

, . Pointer() []byte.

if reflect.ValueOf(buf).Pointer() != reflect.ValueOf(responseBuf).Pointer() {
    // ...
}

6.2. GET

process, :

URL ID — PK
JSON jsonService.GetDept(ctx, id, buf), buf .
. , header["RequestID"]

func (s *Service) GetDeptHandler(w http.ResponseWriter, r *http.Request) {
    //   process,   
    _ = s.process("GET", w, r, func(ctx context.Context, requestBuf []byte, buf []byte) ([]byte, Header, int, error) {
        reqID := myctx.FromContextRequestID(ctx) // RequestID   context

        //  PK  URL     
        vars := mux.Vars(r)
        idStr := vars["id"]
        id, err := strconv.Atoi(idStr)
        if err != nil {
            return nil, nil, http.StatusBadRequest, myerror.WithCause("8001", "Failed to process parameter 'id' invalid number: reqID, id", err, reqID, idStr).PrintfInfo()
        }

        //  JSON ,     
        responseBuf, err := s.jsonService.GetDept(ctx, id, buf)
        if err != nil {
            return nil, nil, http.StatusInternalServerError, err
        }

        //    
        if responseBuf == nil {
            return nil, nil, http.StatusNotFound, nil
        }

        //  
        header := Header{}
        header["Content-Type"] = "application/json; charset=utf-8"
        header["Errcode"] = "0"
        header["RequestID"] = fmt.Sprintf("%v", reqID)

        return responseBuf, header, http.StatusOK, nil
    })
}

6.3. POST

POST :

ID — PK

func (s *Service) CreateDeptHandler(w http.ResponseWriter, r *http.Request) {
    //   process,   
    _ = s.process("POST", w, r, func(ctx context.Context, requestBuf []byte, buf []byte) ([]byte, Header, int, error) {
        reqID := myctx.FromContextRequestID(ctx) // RequestID   context

        mylog.PrintfDebugMsg("START: reqID", reqID)

        //  JSON 
        id, responseBuf, err := s.jsonService.CreateDept(ctx, requestBuf, buf)
        if err != nil {
            return nil, nil, http.StatusInternalServerError, err
        }

        //  
        header := Header{}
        header["Content-Type"] = "application/json; charset=utf-8"
        header["Errcode"] = "0"
        header["Id"] = fmt.Sprintf("%v", id)
        header["RequestID"] = fmt.Sprintf("%v", reqID)

        return responseBuf, header, http.StatusOK, nil
    })
    }

6.4. PUT

PUT :

func (s *Service) UpdateDeptHandler(w http.ResponseWriter, r *http.Request) {
    //   process,   
    _ = s.process("PUT", w, r, func(ctx context.Context, requestBuf []byte, buf []byte) ([]byte, Header, int, error) {
        reqID := myctx.FromContextRequestID(ctx) // RequestID   context

        mylog.PrintfDebugMsg("START: reqID", reqID)

        //      
        vars := mux.Vars(r)
        idStr := vars["id"]
        id, err := strconv.Atoi(idStr)
        if err != nil {
            return nil, nil, http.StatusBadRequest, myerror.WithCause("8001", "Failed to process parameter 'id' invalid number: reqID, id", err, reqID, idStr).PrintfInfo()
        }

        //  JSON 
        responseBuf, err := s.jsonService.UpdateDept(ctx, id, requestBuf, buf)
        if err != nil {
            return nil, nil, http.StatusInternalServerError, err
        }

        //    
        if responseBuf == nil {
            return nil, nil, http.StatusNotFound, nil
        }

        //  
        header := Header{}
        header["Content-Type"] = "application/json; charset=utf-8"
        header["Errcode"] = "0"
        header["RequestID"] = fmt.Sprintf("%v", reqID)

        return responseBuf, header, http.StatusOK, nil
    })
}

6.5.

, httpserver/httpservice Handlers.

// Handler represent HTTP handler
type Handler struct {
    Path        string
    HundlerFunc func(http.ResponseWriter, *http.Request)
    Method      string
}

// Handlers represent HTTP handlers map
type Handlers map[string]Handler

httpservice.New. , service.recoverWrap().

service.Handlers = map[string]Handler{
    //  
    "EchoHandler":         Handler{"/echo", service.recoverWrap(service.EchoHandler), "POST"},
    "SinginHandler":       Handler{"/signin", service.recoverWrap(service.SinginHandler), "POST"},
    "JWTRefreshHandler":   Handler{"/refresh", service.recoverWrap(service.JWTRefreshHandler), "POST"},
    "HTTPLogHandler":      Handler{"/httplog", service.recoverWrap(service.HTTPLogHandler), "POST"},
    "HTTPErrorLogHandler": Handler{"/httperrlog", service.recoverWrap(service.HTTPErrorLogHandler), "POST"},
    "LogLevelHandler":     Handler{"/loglevel", service.recoverWrap(service.LogLevelHandler), "POST"},

    // JSON 
    "CreateDeptHandler": Handler{"/depts", service.recoverWrap(service.CreateDeptHandler), "POST"},
    "GetDeptHandler":    Handler{"/depts/{id:[0-9]+}", service.recoverWrap(service.GetDeptHandler), "GET"},
    "UpdateDeptHandler": Handler{"/depts/{id:[0-9]+}", service.recoverWrap(service.UpdateDeptHandler), "PUT"},
}

7.

7.1.

Oracle 3- :

VM.DenseIO2.8 — 8 Core Intel (16 virtual core), 120 Memory (GB), Oracle Linux 7.7
NVMe — 6.4 TB NVMe SSD Storage (1 drives) min 250k IOPS (4k block)
— 8.2 Network Bandwidth (Gbps)
— PostgreSQL 12. .
ApacheBench:
- concurrency level 4 16384
- 10 000 1 000 000 .
- 2 8 ApacheBench ( ApacheBench 1 )

测试台

7.2. GET

JSON — 1800 . Dept 10 Emp.
Dept — 33 000 000, Emp — 330 000 000 .

GET PostgreSQL
GET JSON BBolt ( 74 )
GET ( map)

Requests per second Concurrency.

get_db_memory_json1

每个请求时间依赖性图。[并发]的[ms]（对数标度）。

get_db_memory_json1

99％百分数[ms]与并发的关系图。

get_db_memory_json1

99％百分数[ms]与并发（对数刻度）的图表。

get_db_memory_json1

这就是以100,000 [＃/秒]的速度加载后端服务器并在BBolt（并发128）中缓存数据的样子。NVMe驱动器上的平均I / O延迟为0.02 [ms]（500,000 IOPS）。

get_db_memory_json1

Golang后端伺服器范本-第2部分（REST API）

1.

2 Model

2.1. ,

2.1.1

2.1.2

2.2.

2.3.

2.4. Marshal / Unmarshal JSON

3. SQLXX

3.1.

3.2.

3.3. SQL

4. DB

4.1. , SQL

4.2.

4.2.1 Get

4.2.2 Create

4.2.3 Update

4.3

5. JSON

5.1. Marshal JSON

5.2. Unmarshal JSON

5.3.

5.3.1. Get

5.3.2. Create

5.3.3. Update

5.4. JSON

6. HTTP

6.1.

6.2. GET

6.3. POST

6.4. PUT

6.5.

7.

7.1.

7.2. GET

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