firehol/netdata

// SPDX-License-Identifier: GPL-3.0-or-later

package clickhouse

import (
    "encoding/csv"
    "fmt"
    "io"
    "net/http"
    "net/url"
    "slices"

    "github.com/netdata/netdata/go/plugins/plugin/go.d/pkg/web"
)

const precision = 1000

func (c *ClickHouse) collect() (map[string]int64, error) {
    mx := make(map[string]int64)

    if err := c.collectSystemEvents(mx); err != nil {
        return nil, err
    }
    if err := c.collectSystemMetrics(mx); err != nil {
        return nil, err
    }
    if err := c.collectSystemAsyncMetrics(mx); err != nil {
        return nil, err
    }
    if err := c.collectSystemParts(mx); err != nil {
        return nil, err
    }
    if err := c.collectSystemDisks(mx); err != nil {
        return nil, err
    }
    if err := c.collectLongestRunningQueryTime(mx); err != nil {
        return nil, err
    }

    return mx, nil
}

func (c *ClickHouse) doHTTP(req *http.Request, assign func(column, value string, lineEnd bool)) error {
    return web.DoHTTP(c.httpClient).Request(req, func(body io.Reader) error {
        return readCSVResponseData(body, assign)
    })
}

func readCSVResponseData(reader io.Reader, assign func(column, value string, lineEnd bool)) error {
    r := csv.NewReader(reader)
    r.ReuseRecord = true

    var columns []string

    for {
        record, err := r.Read()
        if err != nil {
            if err == io.EOF {
                break
            }
            return err
        }

        if len(columns) == 0 {
            columns = slices.Clone(record)
            continue
        }

        if len(columns) != len(record) {
            return fmt.Errorf("column count mismatch: %d vs %d", len(columns), len(record))
        }

        for i, l := 0, len(record); i < l; i++ {
            assign(columns[i], record[i], i == l-1)
        }
    }

    return nil
}

func makeURLQuery(q string) string {
    return url.Values{"query": {q}}.Encode()
}