diff options
Diffstat (limited to 'vendor/github.com/prometheus/client_golang/prometheus/vec.go')
| -rw-r--r-- | vendor/github.com/prometheus/client_golang/prometheus/vec.go | 491 |
1 files changed, 278 insertions, 213 deletions
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/vec.go b/vendor/github.com/prometheus/client_golang/prometheus/vec.go index 7f3eef9a4..cea158249 100644 --- a/vendor/github.com/prometheus/client_golang/prometheus/vec.go +++ b/vendor/github.com/prometheus/client_golang/prometheus/vec.go @@ -20,200 +20,253 @@ import ( "github.com/prometheus/common/model" ) -// MetricVec is a Collector to bundle metrics of the same name that -// differ in their label values. MetricVec is usually not used directly but as a -// building block for implementations of vectors of a given metric -// type. GaugeVec, CounterVec, SummaryVec, and UntypedVec are examples already -// provided in this package. -type MetricVec struct { - mtx sync.RWMutex // Protects the children. - children map[uint64][]metricWithLabelValues - desc *Desc - - newMetric func(labelValues ...string) Metric - hashAdd func(h uint64, s string) uint64 // replace hash function for testing collision handling +// metricVec is a Collector to bundle metrics of the same name that differ in +// their label values. metricVec is not used directly (and therefore +// unexported). It is used as a building block for implementations of vectors of +// a given metric type, like GaugeVec, CounterVec, SummaryVec, and HistogramVec. +// It also handles label currying. It uses basicMetricVec internally. +type metricVec struct { + *metricMap + + curry []curriedLabelValue + + // hashAdd and hashAddByte can be replaced for testing collision handling. + hashAdd func(h uint64, s string) uint64 hashAddByte func(h uint64, b byte) uint64 } -// newMetricVec returns an initialized MetricVec. The concrete value is -// returned for embedding into another struct. -func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *MetricVec { - return &MetricVec{ - children: map[uint64][]metricWithLabelValues{}, - desc: desc, - newMetric: newMetric, +// newMetricVec returns an initialized metricVec. +func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *metricVec { + return &metricVec{ + metricMap: &metricMap{ + metrics: map[uint64][]metricWithLabelValues{}, + desc: desc, + newMetric: newMetric, + }, hashAdd: hashAdd, hashAddByte: hashAddByte, } } -// metricWithLabelValues provides the metric and its label values for -// disambiguation on hash collision. -type metricWithLabelValues struct { - values []string - metric Metric -} +// DeleteLabelValues removes the metric where the variable labels are the same +// as those passed in as labels (same order as the VariableLabels in Desc). It +// returns true if a metric was deleted. +// +// It is not an error if the number of label values is not the same as the +// number of VariableLabels in Desc. However, such inconsistent label count can +// never match an actual metric, so the method will always return false in that +// case. +// +// Note that for more than one label value, this method is prone to mistakes +// caused by an incorrect order of arguments. Consider Delete(Labels) as an +// alternative to avoid that type of mistake. For higher label numbers, the +// latter has a much more readable (albeit more verbose) syntax, but it comes +// with a performance overhead (for creating and processing the Labels map). +// See also the CounterVec example. +func (m *metricVec) DeleteLabelValues(lvs ...string) bool { + h, err := m.hashLabelValues(lvs) + if err != nil { + return false + } -// Describe implements Collector. The length of the returned slice -// is always one. -func (m *MetricVec) Describe(ch chan<- *Desc) { - ch <- m.desc + return m.metricMap.deleteByHashWithLabelValues(h, lvs, m.curry) } -// Collect implements Collector. -func (m *MetricVec) Collect(ch chan<- Metric) { - m.mtx.RLock() - defer m.mtx.RUnlock() +// Delete deletes the metric where the variable labels are the same as those +// passed in as labels. It returns true if a metric was deleted. +// +// It is not an error if the number and names of the Labels are inconsistent +// with those of the VariableLabels in Desc. However, such inconsistent Labels +// can never match an actual metric, so the method will always return false in +// that case. +// +// This method is used for the same purpose as DeleteLabelValues(...string). See +// there for pros and cons of the two methods. +func (m *metricVec) Delete(labels Labels) bool { + h, err := m.hashLabels(labels) + if err != nil { + return false + } - for _, metrics := range m.children { - for _, metric := range metrics { - ch <- metric.metric + return m.metricMap.deleteByHashWithLabels(h, labels, m.curry) +} + +func (m *metricVec) curryWith(labels Labels) (*metricVec, error) { + var ( + newCurry []curriedLabelValue + oldCurry = m.curry + iCurry int + ) + for i, label := range m.desc.variableLabels { + val, ok := labels[label] + if iCurry < len(oldCurry) && oldCurry[iCurry].index == i { + if ok { + return nil, fmt.Errorf("label name %q is already curried", label) + } + newCurry = append(newCurry, oldCurry[iCurry]) + iCurry++ + } else { + if !ok { + continue // Label stays uncurried. + } + newCurry = append(newCurry, curriedLabelValue{i, val}) } } + if l := len(oldCurry) + len(labels) - len(newCurry); l > 0 { + return nil, fmt.Errorf("%d unknown label(s) found during currying", l) + } + + return &metricVec{ + metricMap: m.metricMap, + curry: newCurry, + hashAdd: m.hashAdd, + hashAddByte: m.hashAddByte, + }, nil } -// GetMetricWithLabelValues returns the Metric for the given slice of label -// values (same order as the VariableLabels in Desc). If that combination of -// label values is accessed for the first time, a new Metric is created. -// -// It is possible to call this method without using the returned Metric to only -// create the new Metric but leave it at its start value (e.g. a Summary or -// Histogram without any observations). See also the SummaryVec example. -// -// Keeping the Metric for later use is possible (and should be considered if -// performance is critical), but keep in mind that Reset, DeleteLabelValues and -// Delete can be used to delete the Metric from the MetricVec. In that case, the -// Metric will still exist, but it will not be exported anymore, even if a -// Metric with the same label values is created later. See also the CounterVec -// example. -// -// An error is returned if the number of label values is not the same as the -// number of VariableLabels in Desc. -// -// Note that for more than one label value, this method is prone to mistakes -// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as -// an alternative to avoid that type of mistake. For higher label numbers, the -// latter has a much more readable (albeit more verbose) syntax, but it comes -// with a performance overhead (for creating and processing the Labels map). -// See also the GaugeVec example. -func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) { +func (m *metricVec) getMetricWithLabelValues(lvs ...string) (Metric, error) { h, err := m.hashLabelValues(lvs) if err != nil { return nil, err } - return m.getOrCreateMetricWithLabelValues(h, lvs), nil + return m.metricMap.getOrCreateMetricWithLabelValues(h, lvs, m.curry), nil } -// GetMetricWith returns the Metric for the given Labels map (the label names -// must match those of the VariableLabels in Desc). If that label map is -// accessed for the first time, a new Metric is created. Implications of -// creating a Metric without using it and keeping the Metric for later use are -// the same as for GetMetricWithLabelValues. -// -// An error is returned if the number and names of the Labels are inconsistent -// with those of the VariableLabels in Desc. -// -// This method is used for the same purpose as -// GetMetricWithLabelValues(...string). See there for pros and cons of the two -// methods. -func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) { +func (m *metricVec) getMetricWith(labels Labels) (Metric, error) { h, err := m.hashLabels(labels) if err != nil { return nil, err } - return m.getOrCreateMetricWithLabels(h, labels), nil + return m.metricMap.getOrCreateMetricWithLabels(h, labels, m.curry), nil } -// WithLabelValues works as GetMetricWithLabelValues, but panics if an error -// occurs. The method allows neat syntax like: -// httpReqs.WithLabelValues("404", "POST").Inc() -func (m *MetricVec) WithLabelValues(lvs ...string) Metric { - metric, err := m.GetMetricWithLabelValues(lvs...) - if err != nil { - panic(err) +func (m *metricVec) hashLabelValues(vals []string) (uint64, error) { + if err := validateLabelValues(vals, len(m.desc.variableLabels)-len(m.curry)); err != nil { + return 0, err + } + + var ( + h = hashNew() + curry = m.curry + iVals, iCurry int + ) + for i := 0; i < len(m.desc.variableLabels); i++ { + if iCurry < len(curry) && curry[iCurry].index == i { + h = m.hashAdd(h, curry[iCurry].value) + iCurry++ + } else { + h = m.hashAdd(h, vals[iVals]) + iVals++ + } + h = m.hashAddByte(h, model.SeparatorByte) } - return metric + return h, nil } -// With works as GetMetricWith, but panics if an error occurs. The method allows -// neat syntax like: -// httpReqs.With(Labels{"status":"404", "method":"POST"}).Inc() -func (m *MetricVec) With(labels Labels) Metric { - metric, err := m.GetMetricWith(labels) - if err != nil { - panic(err) +func (m *metricVec) hashLabels(labels Labels) (uint64, error) { + if err := validateValuesInLabels(labels, len(m.desc.variableLabels)-len(m.curry)); err != nil { + return 0, err } - return metric + + var ( + h = hashNew() + curry = m.curry + iCurry int + ) + for i, label := range m.desc.variableLabels { + val, ok := labels[label] + if iCurry < len(curry) && curry[iCurry].index == i { + if ok { + return 0, fmt.Errorf("label name %q is already curried", label) + } + h = m.hashAdd(h, curry[iCurry].value) + iCurry++ + } else { + if !ok { + return 0, fmt.Errorf("label name %q missing in label map", label) + } + h = m.hashAdd(h, val) + } + h = m.hashAddByte(h, model.SeparatorByte) + } + return h, nil } -// DeleteLabelValues removes the metric where the variable labels are the same -// as those passed in as labels (same order as the VariableLabels in Desc). It -// returns true if a metric was deleted. -// -// It is not an error if the number of label values is not the same as the -// number of VariableLabels in Desc. However, such inconsistent label count can -// never match an actual Metric, so the method will always return false in that -// case. -// -// Note that for more than one label value, this method is prone to mistakes -// caused by an incorrect order of arguments. Consider Delete(Labels) as an -// alternative to avoid that type of mistake. For higher label numbers, the -// latter has a much more readable (albeit more verbose) syntax, but it comes -// with a performance overhead (for creating and processing the Labels map). -// See also the CounterVec example. -func (m *MetricVec) DeleteLabelValues(lvs ...string) bool { - m.mtx.Lock() - defer m.mtx.Unlock() +// metricWithLabelValues provides the metric and its label values for +// disambiguation on hash collision. +type metricWithLabelValues struct { + values []string + metric Metric +} - h, err := m.hashLabelValues(lvs) - if err != nil { - return false +// curriedLabelValue sets the curried value for a label at the given index. +type curriedLabelValue struct { + index int + value string +} + +// metricMap is a helper for metricVec and shared between differently curried +// metricVecs. +type metricMap struct { + mtx sync.RWMutex // Protects metrics. + metrics map[uint64][]metricWithLabelValues + desc *Desc + newMetric func(labelValues ...string) Metric +} + +// Describe implements Collector. It will send exactly one Desc to the provided +// channel. +func (m *metricMap) Describe(ch chan<- *Desc) { + ch <- m.desc +} + +// Collect implements Collector. +func (m *metricMap) Collect(ch chan<- Metric) { + m.mtx.RLock() + defer m.mtx.RUnlock() + + for _, metrics := range m.metrics { + for _, metric := range metrics { + ch <- metric.metric + } } - return m.deleteByHashWithLabelValues(h, lvs) } -// Delete deletes the metric where the variable labels are the same as those -// passed in as labels. It returns true if a metric was deleted. -// -// It is not an error if the number and names of the Labels are inconsistent -// with those of the VariableLabels in the Desc of the MetricVec. However, such -// inconsistent Labels can never match an actual Metric, so the method will -// always return false in that case. -// -// This method is used for the same purpose as DeleteLabelValues(...string). See -// there for pros and cons of the two methods. -func (m *MetricVec) Delete(labels Labels) bool { +// Reset deletes all metrics in this vector. +func (m *metricMap) Reset() { m.mtx.Lock() defer m.mtx.Unlock() - h, err := m.hashLabels(labels) - if err != nil { - return false + for h := range m.metrics { + delete(m.metrics, h) } - - return m.deleteByHashWithLabels(h, labels) } // deleteByHashWithLabelValues removes the metric from the hash bucket h. If // there are multiple matches in the bucket, use lvs to select a metric and // remove only that metric. -func (m *MetricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool { - metrics, ok := m.children[h] +func (m *metricMap) deleteByHashWithLabelValues( + h uint64, lvs []string, curry []curriedLabelValue, +) bool { + m.mtx.Lock() + defer m.mtx.Unlock() + + metrics, ok := m.metrics[h] if !ok { return false } - i := m.findMetricWithLabelValues(metrics, lvs) + i := findMetricWithLabelValues(metrics, lvs, curry) if i >= len(metrics) { return false } if len(metrics) > 1 { - m.children[h] = append(metrics[:i], metrics[i+1:]...) + m.metrics[h] = append(metrics[:i], metrics[i+1:]...) } else { - delete(m.children, h) + delete(m.metrics, h) } return true } @@ -221,69 +274,35 @@ func (m *MetricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool { // deleteByHashWithLabels removes the metric from the hash bucket h. If there // are multiple matches in the bucket, use lvs to select a metric and remove // only that metric. -func (m *MetricVec) deleteByHashWithLabels(h uint64, labels Labels) bool { - metrics, ok := m.children[h] +func (m *metricMap) deleteByHashWithLabels( + h uint64, labels Labels, curry []curriedLabelValue, +) bool { + metrics, ok := m.metrics[h] if !ok { return false } - i := m.findMetricWithLabels(metrics, labels) + i := findMetricWithLabels(m.desc, metrics, labels, curry) if i >= len(metrics) { return false } if len(metrics) > 1 { - m.children[h] = append(metrics[:i], metrics[i+1:]...) + m.metrics[h] = append(metrics[:i], metrics[i+1:]...) } else { - delete(m.children, h) + delete(m.metrics, h) } return true } -// Reset deletes all metrics in this vector. -func (m *MetricVec) Reset() { - m.mtx.Lock() - defer m.mtx.Unlock() - - for h := range m.children { - delete(m.children, h) - } -} - -func (m *MetricVec) hashLabelValues(vals []string) (uint64, error) { - if len(vals) != len(m.desc.variableLabels) { - return 0, errInconsistentCardinality - } - h := hashNew() - for _, val := range vals { - h = m.hashAdd(h, val) - h = m.hashAddByte(h, model.SeparatorByte) - } - return h, nil -} - -func (m *MetricVec) hashLabels(labels Labels) (uint64, error) { - if len(labels) != len(m.desc.variableLabels) { - return 0, errInconsistentCardinality - } - h := hashNew() - for _, label := range m.desc.variableLabels { - val, ok := labels[label] - if !ok { - return 0, fmt.Errorf("label name %q missing in label map", label) - } - h = m.hashAdd(h, val) - h = m.hashAddByte(h, model.SeparatorByte) - } - return h, nil -} - // getOrCreateMetricWithLabelValues retrieves the metric by hash and label value // or creates it and returns the new one. // // This function holds the mutex. -func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string) Metric { +func (m *metricMap) getOrCreateMetricWithLabelValues( + hash uint64, lvs []string, curry []curriedLabelValue, +) Metric { m.mtx.RLock() - metric, ok := m.getMetricWithLabelValues(hash, lvs) + metric, ok := m.getMetricWithHashAndLabelValues(hash, lvs, curry) m.mtx.RUnlock() if ok { return metric @@ -291,13 +310,11 @@ func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string) m.mtx.Lock() defer m.mtx.Unlock() - metric, ok = m.getMetricWithLabelValues(hash, lvs) + metric, ok = m.getMetricWithHashAndLabelValues(hash, lvs, curry) if !ok { - // Copy to avoid allocation in case wo don't go down this code path. - copiedLVs := make([]string, len(lvs)) - copy(copiedLVs, lvs) - metric = m.newMetric(copiedLVs...) - m.children[hash] = append(m.children[hash], metricWithLabelValues{values: copiedLVs, metric: metric}) + inlinedLVs := inlineLabelValues(lvs, curry) + metric = m.newMetric(inlinedLVs...) + m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: inlinedLVs, metric: metric}) } return metric } @@ -306,9 +323,11 @@ func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string) // or creates it and returns the new one. // // This function holds the mutex. -func (m *MetricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metric { +func (m *metricMap) getOrCreateMetricWithLabels( + hash uint64, labels Labels, curry []curriedLabelValue, +) Metric { m.mtx.RLock() - metric, ok := m.getMetricWithLabels(hash, labels) + metric, ok := m.getMetricWithHashAndLabels(hash, labels, curry) m.mtx.RUnlock() if ok { return metric @@ -316,33 +335,37 @@ func (m *MetricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metr m.mtx.Lock() defer m.mtx.Unlock() - metric, ok = m.getMetricWithLabels(hash, labels) + metric, ok = m.getMetricWithHashAndLabels(hash, labels, curry) if !ok { - lvs := m.extractLabelValues(labels) + lvs := extractLabelValues(m.desc, labels, curry) metric = m.newMetric(lvs...) - m.children[hash] = append(m.children[hash], metricWithLabelValues{values: lvs, metric: metric}) + m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: lvs, metric: metric}) } return metric } -// getMetricWithLabelValues gets a metric while handling possible collisions in -// the hash space. Must be called while holding read mutex. -func (m *MetricVec) getMetricWithLabelValues(h uint64, lvs []string) (Metric, bool) { - metrics, ok := m.children[h] +// getMetricWithHashAndLabelValues gets a metric while handling possible +// collisions in the hash space. Must be called while holding the read mutex. +func (m *metricMap) getMetricWithHashAndLabelValues( + h uint64, lvs []string, curry []curriedLabelValue, +) (Metric, bool) { + metrics, ok := m.metrics[h] if ok { - if i := m.findMetricWithLabelValues(metrics, lvs); i < len(metrics) { + if i := findMetricWithLabelValues(metrics, lvs, curry); i < len(metrics) { return metrics[i].metric, true } } return nil, false } -// getMetricWithLabels gets a metric while handling possible collisions in +// getMetricWithHashAndLabels gets a metric while handling possible collisions in // the hash space. Must be called while holding read mutex. -func (m *MetricVec) getMetricWithLabels(h uint64, labels Labels) (Metric, bool) { - metrics, ok := m.children[h] +func (m *metricMap) getMetricWithHashAndLabels( + h uint64, labels Labels, curry []curriedLabelValue, +) (Metric, bool) { + metrics, ok := m.metrics[h] if ok { - if i := m.findMetricWithLabels(metrics, labels); i < len(metrics) { + if i := findMetricWithLabels(m.desc, metrics, labels, curry); i < len(metrics) { return metrics[i].metric, true } } @@ -351,9 +374,11 @@ func (m *MetricVec) getMetricWithLabels(h uint64, labels Labels) (Metric, bool) // findMetricWithLabelValues returns the index of the matching metric or // len(metrics) if not found. -func (m *MetricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, lvs []string) int { +func findMetricWithLabelValues( + metrics []metricWithLabelValues, lvs []string, curry []curriedLabelValue, +) int { for i, metric := range metrics { - if m.matchLabelValues(metric.values, lvs) { + if matchLabelValues(metric.values, lvs, curry) { return i } } @@ -362,32 +387,51 @@ func (m *MetricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, l // findMetricWithLabels returns the index of the matching metric or len(metrics) // if not found. -func (m *MetricVec) findMetricWithLabels(metrics []metricWithLabelValues, labels Labels) int { +func findMetricWithLabels( + desc *Desc, metrics []metricWithLabelValues, labels Labels, curry []curriedLabelValue, +) int { for i, metric := range metrics { - if m.matchLabels(metric.values, labels) { + if matchLabels(desc, metric.values, labels, curry) { return i } } return len(metrics) } -func (m *MetricVec) matchLabelValues(values []string, lvs []string) bool { - if len(values) != len(lvs) { +func matchLabelValues(values []string, lvs []string, curry []curriedLabelValue) bool { + if len(values) != len(lvs)+len(curry) { return false } + var iLVs, iCurry int for i, v := range values { - if v != lvs[i] { + if iCurry < len(curry) && curry[iCurry].index == i { + if v != curry[iCurry].value { + return false + } + iCurry++ + continue + } + if v != lvs[iLVs] { return false } + iLVs++ } return true } -func (m *MetricVec) matchLabels(values []string, labels Labels) bool { - if len(labels) != len(values) { +func matchLabels(desc *Desc, values []string, labels Labels, curry []curriedLabelValue) bool { + if len(values) != len(labels)+len(curry) { return false } - for i, k := range m.desc.variableLabels { + iCurry := 0 + for i, k := range desc.variableLabels { + if iCurry < len(curry) && curry[iCurry].index == i { + if values[i] != curry[iCurry].value { + return false + } + iCurry++ + continue + } if values[i] != labels[k] { return false } @@ -395,10 +439,31 @@ func (m *MetricVec) matchLabels(values []string, labels Labels) bool { return true } -func (m *MetricVec) extractLabelValues(labels Labels) []string { - labelValues := make([]string, len(labels)) - for i, k := range m.desc.variableLabels { +func extractLabelValues(desc *Desc, labels Labels, curry []curriedLabelValue) []string { + labelValues := make([]string, len(labels)+len(curry)) + iCurry := 0 + for i, k := range desc.variableLabels { + if iCurry < len(curry) && curry[iCurry].index == i { + labelValues[i] = curry[iCurry].value + iCurry++ + continue + } labelValues[i] = labels[k] } return labelValues } + +func inlineLabelValues(lvs []string, curry []curriedLabelValue) []string { + labelValues := make([]string, len(lvs)+len(curry)) + var iCurry, iLVs int + for i := range labelValues { + if iCurry < len(curry) && curry[iCurry].index == i { + labelValues[i] = curry[iCurry].value + iCurry++ + continue + } + labelValues[i] = lvs[iLVs] + iLVs++ + } + return labelValues +} |