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This article shows you how to read the interface interface from the go source code, which is concise and easy to understand, which will definitely brighten your eyes. I hope you can get something through the detailed introduction of this article.

Interfaces in go source code

In the http library, the get method:

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Func Get (url string) (resp * Response, err error)

Response:

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Type Response struct {

Status string / / e.g.200 OK

StatusCode int / / e.g. 200

Proto string / / e.g. "HTTP/1.0"

ProtoMajor int / / e.g. 1

ProtoMinor int / / e.g. 0

Header Header

Body io.ReadCloser

Io.ReadCloser:

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Type ReadCloser interface {

Reader

Closer

}

Reader:

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Type Reader interface {

Read (p [] byte) (n int, err error)

}

Closer:

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Type Closer interface {

Close () error

}

Whether it is reading files, network and other operations, the same Reader interface is implemented. When the [] byte is passed in, the read byte is placed in. Success returns the number of successes.

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Package main

Import (

"net/http"

"fmt"

"os"

)

Func main () {

Resp,err: = http.Get ("http://tmall.com")

If err! = nil {

Fmt.Println ("Error:", err)

Os.Exit (1)

}

/ / if the setting is larger, the read method will not automatically expand the capacity.

Bs:=make ([] byte,99999)

The / / read function puts the read data into the bs.

Resp.Body.Read (bs)

Fmt.Println (string (bs))

}

Write interface 1

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Type Writer interface {

Write (p [] byte) (n int, err error)

}

Io.opy1

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Package main

Import (

"net/http"

"fmt"

"os"

"io"

)

Func main () {

Resp,err: = http.Get ("http://tmall.com")

If err! = nil {

Fmt.Println ("Error:", err)

Os.Exit (1)

}

/ / read the information in resp.Body and write it to os.Stdout. Os.Stdout implements the write interface and resp.Body implements the read interface.

Io.Copy (os.Stdout,resp.Body)

}

Io.copy source code 1

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Func Copy (dst Writer, src Reader) (written int64, err error) {

Return copyBuffer (dst, src, nil)

}

-

Func CopyBuffer (dst Writer, src Reader, buf [] byte) (written int64, err error) {

If buf! = nil & & len (buf) = 0 {

Panic ("empty buffer in io.CopyBuffer")

}

Return copyBuffer (dst, src, buf)

}

-

Func copyBuffer (dst Writer, src Reader, buf [] byte) (written int64, err error) {

/ / If the reader has a WriteTo method, use it to do the copy.

/ / Avoids an allocation and a copy.

If wt, ok: = src. (WriterTo); ok {

Return wt.WriteTo (dst)

}

/ / Similarly, if the writer has a ReadFrom method, use it to do the copy.

If rt, ok: = dst. (ReaderFrom); ok {

Return rt.ReadFrom (src)

}

Size: = 32 * 1024

If l, ok: = src. (* LimitedReader); ok & & int64 (size) > l.N {

If l.N

< 1 { size = 1 } else { size = int(l.N) } } if buf == nil { buf = make([]byte, size)//分配 } for { //疯狂读取并写入 nr, er := src.Read(buf) if nr >

0 {

Nw, ew: = dst.Write (buf [0: nr])

If nw > 0 {

Written + = int64 (nw)

}

If ew! = nil {

Err = ew

Break

}

If nr! = nw {

Err = ErrShortWrite

Break

}

}

If er! = nil {

If er! = EOF {

Err = er

}

Break

}

}

Return written, err

}

Custom Writer function 1

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Package main

Import (

"net/http"

"fmt"

"os"

"io"

)

Type logWriter struct {}

Func main () {

Resp,err: = http.Get ("http://tmall.com")

If err! = nil {

Fmt.Println ("Error:", err)

Os.Exit (1)

}

Lw:= logWriter {}

/ / read the information in resp.Body and write it to os.Stdout. Os.Stdout implements the write interface and resp.Body implements the read interface.

Io.Copy (lw,resp.Body)

}

Func (logWriter) Write (bs [] byte) (int,error) {

Fmt.Println (string (bs))

Fmt.Println ("Just wrote this many bytes", len (bs))

Return len (bs), nil

}

The above content is how to read the interface interface from the go source code. Have you learned the knowledge or skills? If you want to learn more skills or enrich your knowledge reserve, you are welcome to follow the industry information channel.

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