prepare ContainerIterator for sharing code with ObjectIterator

1 files changed, 136 insertions, 0 deletions

diff --git a/iterator.go b/iterator.go
new file mode 100644
index 0000000..af01bbe
--- /dev/null
+++ b/iterator.go
@@ -0,0 +1,136 @@
+/******************************************************************************
+*
+*  Copyright 2018 Stefan Majewsky <majewsky@gmx.net>
+*
+*  Licensed under the Apache License, Version 2.0 (the "License");
+*  you may not use this file except in compliance with the License.
+*  You may obtain a copy of the License at
+*
+*      http://www.apache.org/licenses/LICENSE-2.0
+*
+*  Unless required by applicable law or agreed to in writing, software
+*  distributed under the License is distributed on an "AS IS" BASIS,
+*  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+*  See the License for the specific language governing permissions and
+*  limitations under the License.
+*
+******************************************************************************/
+
+package schwift
+
+import (
+	"encoding/json"
+	"strconv"
+	"strings"
+)
+
+//iteratorInterface allows iteratorBase to access public attributes of
+//ContainerIterator/ObjectIterator.
+type iteratorInterface interface {
+	getAccount() *Account
+	getContainerName() string
+	getPrefix() string
+	getHeaders() map[string]string
+	getOptions() *RequestOptions
+}
+
+func (i ContainerIterator) getAccount() *Account          { return i.Account }
+func (i ContainerIterator) getContainerName() string      { return "" }
+func (i ContainerIterator) getPrefix() string             { return i.Prefix }
+func (i ContainerIterator) getHeaders() map[string]string { return i.Headers }
+func (i ContainerIterator) getOptions() *RequestOptions   { return i.Options }
+
+//iteratorBase provides shared behavior for ContainerIterator and ObjectIterator.
+type iteratorBase struct {
+	i      iteratorInterface
+	marker string
+	eof    bool
+}
+
+func (b *iteratorBase) request(limit int, detailed bool) Request {
+	r := Request{
+		Method:        "GET",
+		ContainerName: b.i.getContainerName(),
+		Headers:       headersToHTTP(b.i.getHeaders()),
+		Options:       cloneRequestOptions(b.i.getOptions()),
+	}
+
+	if prefix := b.i.getPrefix(); prefix != "" {
+		r.Options.Values.Set("prefix", prefix)
+	}
+
+	if b.marker == "" {
+		r.Options.Values.Del("marker")
+	} else {
+		r.Options.Values.Set("marker", b.marker)
+	}
+
+	if limit < 0 {
+		r.Options.Values.Del("limit")
+	} else {
+		r.Options.Values.Set("limit", strconv.FormatUint(uint64(limit), 10))
+	}
+
+	if detailed {
+		r.Headers.Set("Accept", "application/json")
+		r.Options.Values.Set("format", "json")
+		r.ExpectStatusCodes = []int{200}
+	} else {
+		r.Headers.Set("Accept", "text/plain")
+		r.Options.Values.Set("format", "plain")
+		r.ExpectStatusCodes = []int{200, 204}
+	}
+
+	return r
+}
+
+func (b *iteratorBase) nextPage(limit int) ([]string, error) {
+	if b.eof {
+		return nil, nil
+	}
+	resp, err := b.request(limit, false).Do(b.i.getAccount().client)
+	if err != nil {
+		return nil, err
+	}
+
+	buf, err := collectResponseBody(resp)
+	if err != nil {
+		return nil, err
+	}
+	bufStr := strings.TrimSuffix(string(buf), "\n")
+	var result []string
+	if bufStr != "" {
+		result = strings.Split(bufStr, "\n")
+	}
+
+	if len(result) == 0 {
+		b.eof = true
+		b.marker = ""
+	} else {
+		b.eof = false
+		b.marker = result[len(result)-1]
+	}
+	return result, nil
+}
+
+func (b *iteratorBase) nextPageDetailed(limit int, data interface{}) error {
+	if b.eof {
+		return nil
+	}
+	resp, err := b.request(limit, true).Do(b.i.getAccount().client)
+	if err != nil {
+		return err
+	}
+
+	err = json.NewDecoder(resp.Body).Decode(&data)
+	closeErr := resp.Body.Close()
+	if err == nil {
+		err = closeErr
+	}
+	return err
+}
+
+func (b *iteratorBase) setMarker(marker string) {
+	b.marker = marker
+	b.eof = marker == ""
+}