kraken

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// Copyright (c) 2016-2019 Uber Technologies, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//     http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package tagmodels
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import (
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	"fmt"
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	"io"
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	"net/url"
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)
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const (
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	// Filters.
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	LimitQ  string = "limit"
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	OffsetQ string = "offset"
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)
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// List Response with pagination. Models tagserver reponse to list and
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// listRepository.
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type ListResponse struct {
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	Links struct {
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		Next string `json:"next"`
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		Self string `json:"self"`
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	}
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	Size   int      `json:"size"`
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	Result []string `json:"result"`
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}
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// GetOffset returns offset token from the ListResponse struct.
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// Returns token if present, io.EOF if Next is empty, error otherwise.
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func (resp ListResponse) GetOffset() (string, error) {
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	if resp.Links.Next == "" {
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		return "", io.EOF
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	}
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	nextUrl, err := url.Parse(resp.Links.Next)
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	if err != nil {
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		return "", err
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	}
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	val, err := url.ParseQuery(nextUrl.RawQuery)
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	if err != nil {
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		return "", err
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	}
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	offset := val.Get(OffsetQ)
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	if offset == "" {
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		return "", fmt.Errorf("invalid offset in %s", resp.Links.Next)
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	}
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	return offset, nil
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}
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