1 files changed, 330 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/procfs/bcache/get.go b/vendor/github.com/prometheus/procfs/bcache/get.go
new file mode 100644
index 000000000..4d56f3d98
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/bcache/get.go
@@ -0,0 +1,330 @@
+// Copyright 2017 The Prometheus Authors
+// 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 bcache
+
+import (
+	"bufio"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+// ParsePseudoFloat parses the peculiar format produced by bcache's bch_hprint.
+func parsePseudoFloat(str string) (float64, error) {
+	ss := strings.Split(str, ".")
+
+	intPart, err := strconv.ParseFloat(ss[0], 64)
+	if err != nil {
+		return 0, err
+	}
+
+	if len(ss) == 1 {
+		// Pure integers are fine.
+		return intPart, nil
+	}
+	fracPart, err := strconv.ParseFloat(ss[1], 64)
+	if err != nil {
+		return 0, err
+	}
+	// fracPart is a number between 0 and 1023 divided by 100; it is off
+	// by a small amount. Unexpected bumps in time lines may occur because
+	// for bch_hprint .1 != .10 and .10 > .9 (at least up to Linux
+	// v4.12-rc3).
+
+	// Restore the proper order:
+	fracPart = fracPart / 10.24
+	return intPart + fracPart, nil
+}
+
+// Dehumanize converts a human-readable byte slice into a uint64.
+func dehumanize(hbytes []byte) (uint64, error) {
+	ll := len(hbytes)
+	if ll == 0 {
+		return 0, fmt.Errorf("zero-length reply")
+	}
+	lastByte := hbytes[ll-1]
+	mul := float64(1)
+	var (
+		mant float64
+		err error
+	)
+	// If lastByte is beyond the range of ASCII digits, it must be a
+	// multiplier.
+	if lastByte > 57 {
+		// Remove multiplier from slice.
+		hbytes = hbytes[:len(hbytes)-1]
+
+		const (
+			_ = 1 << (10 * iota)
+			KiB
+			MiB
+			GiB
+			TiB
+			PiB
+			EiB
+			ZiB
+			YiB
+		)
+
+		multipliers := map[rune]float64{
+			// Source for conversion rules:
+			// linux-kernel/drivers/md/bcache/util.c:bch_hprint()
+			'k': KiB,
+			'M': MiB,
+			'G': GiB,
+			'T': TiB,
+			'P': PiB,
+			'E': EiB,
+			'Z': ZiB,
+			'Y': YiB,
+		}
+		mul = float64(multipliers[rune(lastByte)])
+		mant, err = parsePseudoFloat(string(hbytes))
+		if err != nil {
+			return 0, err
+		}
+	} else {
+		// Not humanized by bch_hprint
+		mant, err = strconv.ParseFloat(string(hbytes), 64)
+		if err != nil {
+			return 0, err
+		}
+	}
+	res := uint64(mant * mul)
+	return res, nil
+}
+
+type parser struct {
+	uuidPath   string
+	subDir     string
+	currentDir string
+	err        error
+}
+
+func (p *parser) setSubDir(pathElements ...string) {
+	p.subDir = path.Join(pathElements...)
+	p.currentDir = path.Join(p.uuidPath, p.subDir)
+}
+
+func (p *parser) readValue(fileName string) uint64 {
+	if p.err != nil {
+		return 0
+	}
+	path := path.Join(p.currentDir, fileName)
+	byt, err := ioutil.ReadFile(path)
+	if err != nil {
+		p.err = fmt.Errorf("failed to read: %s", path)
+		return 0
+	}
+	// Remove trailing newline.
+	byt = byt[:len(byt)-1]
+	res, err := dehumanize(byt)
+	p.err = err
+	return res
+}
+
+// ParsePriorityStats parses lines from the priority_stats file.
+func parsePriorityStats(line string, ps *PriorityStats) (error) {
+	var (
+		value uint64
+		err error
+	)
+	switch {
+	case strings.HasPrefix(line, "Unused:"):
+		fields := strings.Fields(line)
+		rawValue := fields[len(fields)-1]
+		valueStr := strings.TrimSuffix(rawValue, "%")
+		value, err = strconv.ParseUint(valueStr, 10, 64)
+		if err != nil {
+			return err
+		}
+		ps.UnusedPercent = value
+	case strings.HasPrefix(line, "Metadata:"):
+		fields := strings.Fields(line)
+		rawValue := fields[len(fields)-1]
+		valueStr := strings.TrimSuffix(rawValue, "%")
+		value, err = strconv.ParseUint(valueStr, 10, 64)
+		if err != nil {
+			return err
+		}
+		ps.MetadataPercent = value
+	}
+	return nil
+}
+
+func (p *parser) getPriorityStats() PriorityStats {
+	var res PriorityStats
+
+	if p.err != nil {
+		return res
+	}
+
+	path := path.Join(p.currentDir, "priority_stats")
+
+	file, err := os.Open(path)
+	if err != nil {
+		p.err = fmt.Errorf("failed to read: %s", path)
+		return res
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		err = parsePriorityStats(scanner.Text(), &res)
+		if err != nil {
+			p.err = fmt.Errorf("failed to parse: %s (%s)", path, err)
+			return res
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		p.err = fmt.Errorf("failed to parse: %s (%s)", path, err)
+		return res
+	}
+	return res
+}
+
+// GetStats collects from sysfs files data tied to one bcache ID.
+func GetStats(uuidPath string) (*Stats, error) {
+	var bs Stats
+
+	par := parser{uuidPath: uuidPath}
+
+	// bcache stats
+
+	// dir <uuidPath>
+	par.setSubDir("")
+	bs.Bcache.AverageKeySize = par.readValue("average_key_size")
+	bs.Bcache.BtreeCacheSize = par.readValue("btree_cache_size")
+	bs.Bcache.CacheAvailablePercent = par.readValue("cache_available_percent")
+	bs.Bcache.Congested = par.readValue("congested")
+	bs.Bcache.RootUsagePercent = par.readValue("root_usage_percent")
+	bs.Bcache.TreeDepth = par.readValue("tree_depth")
+
+	// bcache stats (internal)
+
+	// dir <uuidPath>/internal
+	par.setSubDir("internal")
+	bs.Bcache.Internal.ActiveJournalEntries = par.readValue("active_journal_entries")
+	bs.Bcache.Internal.BtreeNodes = par.readValue("btree_nodes")
+	bs.Bcache.Internal.BtreeReadAverageDurationNanoSeconds = par.readValue("btree_read_average_duration_us")
+	bs.Bcache.Internal.CacheReadRaces = par.readValue("cache_read_races")
+
+	// bcache stats (period)
+
+	// dir <uuidPath>/stats_five_minute
+	par.setSubDir("stats_five_minute")
+	bs.Bcache.FiveMin.Bypassed = par.readValue("bypassed")
+	bs.Bcache.FiveMin.CacheHits = par.readValue("cache_hits")
+
+	bs.Bcache.FiveMin.Bypassed = par.readValue("bypassed")
+	bs.Bcache.FiveMin.CacheBypassHits = par.readValue("cache_bypass_hits")
+	bs.Bcache.FiveMin.CacheBypassMisses = par.readValue("cache_bypass_misses")
+	bs.Bcache.FiveMin.CacheHits = par.readValue("cache_hits")
+	bs.Bcache.FiveMin.CacheMissCollisions = par.readValue("cache_miss_collisions")
+	bs.Bcache.FiveMin.CacheMisses = par.readValue("cache_misses")
+	bs.Bcache.FiveMin.CacheReadaheads = par.readValue("cache_readaheads")
+
+	// dir <uuidPath>/stats_total
+	par.setSubDir("stats_total")
+	bs.Bcache.Total.Bypassed = par.readValue("bypassed")
+	bs.Bcache.Total.CacheHits = par.readValue("cache_hits")
+
+	bs.Bcache.Total.Bypassed = par.readValue("bypassed")
+	bs.Bcache.Total.CacheBypassHits = par.readValue("cache_bypass_hits")
+	bs.Bcache.Total.CacheBypassMisses = par.readValue("cache_bypass_misses")
+	bs.Bcache.Total.CacheHits = par.readValue("cache_hits")
+	bs.Bcache.Total.CacheMissCollisions = par.readValue("cache_miss_collisions")
+	bs.Bcache.Total.CacheMisses = par.readValue("cache_misses")
+	bs.Bcache.Total.CacheReadaheads = par.readValue("cache_readaheads")
+
+	if par.err != nil {
+		return nil, par.err
+	}
+
+	// bdev stats
+
+	reg := path.Join(uuidPath, "bdev[0-9]*")
+	bdevDirs, err := filepath.Glob(reg)
+	if err != nil {
+		return nil, err
+	}
+
+	bs.Bdevs = make([]BdevStats, len(bdevDirs))
+
+	for ii, bdevDir := range bdevDirs {
+		var bds = &bs.Bdevs[ii]
+
+		bds.Name = filepath.Base(bdevDir)
+
+		par.setSubDir(bds.Name)
+		bds.DirtyData = par.readValue("dirty_data")
+
+		// dir <uuidPath>/<bds.Name>/stats_five_minute
+		par.setSubDir(bds.Name, "stats_five_minute")
+		bds.FiveMin.Bypassed = par.readValue("bypassed")
+		bds.FiveMin.CacheBypassHits = par.readValue("cache_bypass_hits")
+		bds.FiveMin.CacheBypassMisses = par.readValue("cache_bypass_misses")
+		bds.FiveMin.CacheHits = par.readValue("cache_hits")
+		bds.FiveMin.CacheMissCollisions = par.readValue("cache_miss_collisions")
+		bds.FiveMin.CacheMisses = par.readValue("cache_misses")
+		bds.FiveMin.CacheReadaheads = par.readValue("cache_readaheads")
+
+		// dir <uuidPath>/<bds.Name>/stats_total
+		par.setSubDir("stats_total")
+		bds.Total.Bypassed = par.readValue("bypassed")
+		bds.Total.CacheBypassHits = par.readValue("cache_bypass_hits")
+		bds.Total.CacheBypassMisses = par.readValue("cache_bypass_misses")
+		bds.Total.CacheHits = par.readValue("cache_hits")
+		bds.Total.CacheMissCollisions = par.readValue("cache_miss_collisions")
+		bds.Total.CacheMisses = par.readValue("cache_misses")
+		bds.Total.CacheReadaheads = par.readValue("cache_readaheads")
+	}
+
+	if par.err != nil {
+		return nil, par.err
+	}
+
+	// cache stats
+
+	reg = path.Join(uuidPath, "cache[0-9]*")
+	cacheDirs, err := filepath.Glob(reg)
+	if err != nil {
+		return nil, err
+	}
+	bs.Caches = make([]CacheStats, len(cacheDirs))
+
+	for ii, cacheDir := range cacheDirs {
+		var cs = &bs.Caches[ii]
+		cs.Name = filepath.Base(cacheDir)
+
+		// dir is <uuidPath>/<cs.Name>
+		par.setSubDir(cs.Name)
+		cs.IOErrors = par.readValue("io_errors")
+		cs.MetadataWritten = par.readValue("metadata_written")
+		cs.Written = par.readValue("written")
+
+		ps := par.getPriorityStats()
+		cs.Priority = ps
+	}
+
+	if par.err != nil {
+		return nil, par.err
+	}
+
+	return &bs, nil
+}