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gitea/vendor/github.com/couchbaselabs/go-couchbase/views.go
2019-02-05 11:52:51 -05:00

232 lines
5.6 KiB
Go

package couchbase
import (
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"math/rand"
"net/http"
"net/url"
"time"
)
// ViewRow represents a single result from a view.
//
// Doc is present only if include_docs was set on the request.
type ViewRow struct {
ID string
Key interface{}
Value interface{}
Doc *interface{}
}
// A ViewError is a node-specific error indicating a partial failure
// within a view result.
type ViewError struct {
From string
Reason string
}
func (ve ViewError) Error() string {
return "Node: " + ve.From + ", reason: " + ve.Reason
}
// ViewResult holds the entire result set from a view request,
// including the rows and the errors.
type ViewResult struct {
TotalRows int `json:"total_rows"`
Rows []ViewRow
Errors []ViewError
}
func (b *Bucket) randomBaseURL() (*url.URL, error) {
nodes := b.HealthyNodes()
if len(nodes) == 0 {
return nil, errors.New("no available couch rest URLs")
}
nodeNo := rand.Intn(len(nodes))
node := nodes[nodeNo]
b.RLock()
name := b.Name
pool := b.pool
b.RUnlock()
u, err := ParseURL(node.CouchAPIBase)
if err != nil {
return nil, fmt.Errorf("config error: Bucket %q node #%d CouchAPIBase=%q: %v",
name, nodeNo, node.CouchAPIBase, err)
} else if pool != nil {
u.User = pool.client.BaseURL.User
}
return u, err
}
const START_NODE_ID = -1
func (b *Bucket) randomNextURL(lastNode int) (*url.URL, int, error) {
nodes := b.HealthyNodes()
if len(nodes) == 0 {
return nil, -1, errors.New("no available couch rest URLs")
}
var nodeNo int
if lastNode == START_NODE_ID || lastNode >= len(nodes) {
// randomly select a node if the value of lastNode is invalid
nodeNo = rand.Intn(len(nodes))
} else {
// wrap around the node list
nodeNo = (lastNode + 1) % len(nodes)
}
b.RLock()
name := b.Name
pool := b.pool
b.RUnlock()
node := nodes[nodeNo]
u, err := ParseURL(node.CouchAPIBase)
if err != nil {
return nil, -1, fmt.Errorf("config error: Bucket %q node #%d CouchAPIBase=%q: %v",
name, nodeNo, node.CouchAPIBase, err)
} else if pool != nil {
u.User = pool.client.BaseURL.User
}
return u, nodeNo, err
}
// DocID is the document ID type for the startkey_docid parameter in
// views.
type DocID string
func qParam(k, v string) string {
format := `"%s"`
switch k {
case "startkey_docid", "endkey_docid", "stale":
format = "%s"
}
return fmt.Sprintf(format, v)
}
// ViewURL constructs a URL for a view with the given ddoc, view name,
// and parameters.
func (b *Bucket) ViewURL(ddoc, name string,
params map[string]interface{}) (string, error) {
u, err := b.randomBaseURL()
if err != nil {
return "", err
}
values := url.Values{}
for k, v := range params {
switch t := v.(type) {
case DocID:
values[k] = []string{string(t)}
case string:
values[k] = []string{qParam(k, t)}
case int:
values[k] = []string{fmt.Sprintf(`%d`, t)}
case bool:
values[k] = []string{fmt.Sprintf(`%v`, t)}
default:
b, err := json.Marshal(v)
if err != nil {
return "", fmt.Errorf("unsupported value-type %T in Query, "+
"json encoder said %v", t, err)
}
values[k] = []string{fmt.Sprintf(`%v`, string(b))}
}
}
if ddoc == "" && name == "_all_docs" {
u.Path = fmt.Sprintf("/%s/_all_docs", b.GetName())
} else {
u.Path = fmt.Sprintf("/%s/_design/%s/_view/%s", b.GetName(), ddoc, name)
}
u.RawQuery = values.Encode()
return u.String(), nil
}
// ViewCallback is called for each view invocation.
var ViewCallback func(ddoc, name string, start time.Time, err error)
// ViewCustom performs a view request that can map row values to a
// custom type.
//
// See the source to View for an example usage.
func (b *Bucket) ViewCustom(ddoc, name string, params map[string]interface{},
vres interface{}) (err error) {
if SlowServerCallWarningThreshold > 0 {
defer slowLog(time.Now(), "call to ViewCustom(%q, %q)", ddoc, name)
}
if ViewCallback != nil {
defer func(t time.Time) { ViewCallback(ddoc, name, t, err) }(time.Now())
}
u, err := b.ViewURL(ddoc, name, params)
if err != nil {
return err
}
req, err := http.NewRequest("GET", u, nil)
if err != nil {
return err
}
ah := b.authHandler(false /* bucket not yet locked */)
maybeAddAuth(req, ah)
res, err := doHTTPRequest(req)
if err != nil {
return fmt.Errorf("error starting view req at %v: %v", u, err)
}
defer res.Body.Close()
if res.StatusCode != 200 {
bod := make([]byte, 512)
l, _ := res.Body.Read(bod)
return fmt.Errorf("error executing view req at %v: %v - %s",
u, res.Status, bod[:l])
}
body, err := ioutil.ReadAll(res.Body)
if err := json.Unmarshal(body, vres); err != nil {
return nil
}
return nil
}
// View executes a view.
//
// The ddoc parameter is just the bare name of your design doc without
// the "_design/" prefix.
//
// Parameters are string keys with values that correspond to couchbase
// view parameters. Primitive should work fairly naturally (booleans,
// ints, strings, etc...) and other values will attempt to be JSON
// marshaled (useful for array indexing on on view keys, for example).
//
// Example:
//
// res, err := couchbase.View("myddoc", "myview", map[string]interface{}{
// "group_level": 2,
// "startkey_docid": []interface{}{"thing"},
// "endkey_docid": []interface{}{"thing", map[string]string{}},
// "stale": false,
// })
func (b *Bucket) View(ddoc, name string, params map[string]interface{}) (ViewResult, error) {
vres := ViewResult{}
if err := b.ViewCustom(ddoc, name, params, &vres); err != nil {
//error in accessing views. Retry once after a bucket refresh
b.Refresh()
return vres, b.ViewCustom(ddoc, name, params, &vres)
} else {
return vres, nil
}
}