github.com/cayleygraph/cayley@v0.7.7/client/client.go (about)

     1  package client
     2  
     3  import (
     4  	"fmt"
     5  	"io"
     6  	"net/http"
     7  	"net/url"
     8  
     9  	"github.com/cayleygraph/quad"
    10  	"github.com/cayleygraph/quad/pquads"
    11  )
    12  
    13  func New(addr string) *Client {
    14  	return &Client{addr: addr, cli: http.DefaultClient}
    15  }
    16  
    17  type Client struct {
    18  	addr string
    19  	cli  *http.Client
    20  }
    21  
    22  func (c *Client) SetHttpClient(cli *http.Client) {
    23  	c.cli = cli
    24  }
    25  func (c *Client) url(s string, q map[string]string) string {
    26  	addr := c.addr + s
    27  	if len(q) != 0 {
    28  		p := make(url.Values, len(q))
    29  		for k, v := range q {
    30  			p.Set(k, v)
    31  		}
    32  		addr += "?" + p.Encode()
    33  	}
    34  	return addr
    35  }
    36  
    37  type errRequestFailed struct {
    38  	Status     string
    39  	StatusCode int
    40  }
    41  
    42  func (e errRequestFailed) Error() string {
    43  	return fmt.Sprintf("request failed: %d %v", e.StatusCode, e.Status)
    44  }
    45  func (c *Client) QuadReader() (quad.ReadCloser, error) {
    46  	resp, err := http.Get(c.url("/api/v2/read", map[string]string{
    47  		"format": "pquads",
    48  	}))
    49  	if err != nil {
    50  		return nil, err
    51  	}
    52  	if resp.StatusCode != http.StatusOK {
    53  		resp.Body.Close()
    54  		return nil, errRequestFailed{StatusCode: resp.StatusCode, Status: resp.Status}
    55  	}
    56  	r := pquads.NewReader(resp.Body, 10*1024*1024)
    57  	r.SetCloser(resp.Body)
    58  	return r, nil
    59  }
    60  
    61  type funcCloser struct {
    62  	f      func() error
    63  	closed bool
    64  }
    65  
    66  func (c funcCloser) Close() error {
    67  	if c.closed {
    68  		return nil
    69  	}
    70  	c.closed = true
    71  	return c.f()
    72  }
    73  func (c *Client) QuadWriter() (quad.WriteCloser, error) {
    74  	pr, pw := io.Pipe()
    75  	req, err := http.NewRequest("POST", c.url("/api/v2/write", nil), pr)
    76  	if err != nil {
    77  		return nil, err
    78  	}
    79  	req.Header.Set("Content-Type", pquads.ContentType)
    80  	errc := make(chan error, 1)
    81  	go func() {
    82  		defer func() {
    83  			close(errc)
    84  			pr.Close()
    85  		}()
    86  		resp, err := c.cli.Do(req)
    87  		if resp != nil && resp.Body != nil {
    88  			defer resp.Body.Close()
    89  		}
    90  		if err == nil && resp.StatusCode != http.StatusOK {
    91  			err = errRequestFailed{StatusCode: resp.StatusCode, Status: resp.Status}
    92  		}
    93  		errc <- err
    94  	}()
    95  	qw := pquads.NewWriter(pw, &pquads.Options{
    96  		Full:   false,
    97  		Strict: false,
    98  	})
    99  	qw.SetCloser(funcCloser{f: func() error {
   100  		pw.Close()
   101  		return <-errc
   102  	}})
   103  	return qw, nil
   104  }