Refactor query evaluation.

This copies the evaluation logic from the current rules/ package.
The new engine handles the execution process from query string to final result.
It provides query timeout and cancellation and general flexibility for
future changes.

functions.go: Add evaluation implementation. Slight changes to in/out data but
	not to the processing logic.
quantile.go: No changes.
analyzer.go: No changes.
engine.go: Actually new part. Mainly consists of evaluation methods
	which were not changed.
setup_test.go: Copy of rules/helpers_test.go to setup test storage.
promql_test.go: Copy of rules/rules_test.go.

Godeps/Godeps.json

@@ -7,6 +7,10 @@
 			"Comment": "null-5",
 			"Rev": "75cd24fc2f2c2a2088577d12123ddee5f54e0675"
 		},
+		{
+			"ImportPath": "github.com/prometheus/procfs",
+			"Rev": "92faa308558161acab0ada1db048e9996ecec160"
+		},
 		{
 			"ImportPath": "github.com/beorn7/perks/quantile",
 			"Rev": "b965b613227fddccbfffe13eae360ed3fa822f8d"

Godeps/_workspace/src/golang.org/x/net/context/context.go

@@ -0,0 +1,447 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package context defines the Context type, which carries deadlines,
+// cancelation signals, and other request-scoped values across API boundaries
+// and between processes.
+//
+// Incoming requests to a server should create a Context, and outgoing calls to
+// servers should accept a Context.  The chain of function calls between must
+// propagate the Context, optionally replacing it with a modified copy created
+// using WithDeadline, WithTimeout, WithCancel, or WithValue.
+//
+// Programs that use Contexts should follow these rules to keep interfaces
+// consistent across packages and enable static analysis tools to check context
+// propagation:
+//
+// Do not store Contexts inside a struct type; instead, pass a Context
+// explicitly to each function that needs it.  The Context should be the first
+// parameter, typically named ctx:
+//
+// 	func DoSomething(ctx context.Context, arg Arg) error {
+// 		// ... use ctx ...
+// 	}
+//
+// Do not pass a nil Context, even if a function permits it.  Pass context.TODO
+// if you are unsure about which Context to use.
+//
+// Use context Values only for request-scoped data that transits processes and
+// APIs, not for passing optional parameters to functions.
+//
+// The same Context may be passed to functions running in different goroutines;
+// Contexts are safe for simultaneous use by multiple goroutines.
+//
+// See http://blog.golang.org/context for example code for a server that uses
+// Contexts.
+package context
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+	"time"
+)
+
+// A Context carries a deadline, a cancelation signal, and other values across
+// API boundaries.
+//
+// Context's methods may be called by multiple goroutines simultaneously.
+type Context interface {
+	// Deadline returns the time when work done on behalf of this context
+	// should be canceled.  Deadline returns ok==false when no deadline is
+	// set.  Successive calls to Deadline return the same results.
+	Deadline() (deadline time.Time, ok bool)
+
+	// Done returns a channel that's closed when work done on behalf of this
+	// context should be canceled.  Done may return nil if this context can
+	// never be canceled.  Successive calls to Done return the same value.
+	//
+	// WithCancel arranges for Done to be closed when cancel is called;
+	// WithDeadline arranges for Done to be closed when the deadline
+	// expires; WithTimeout arranges for Done to be closed when the timeout
+	// elapses.
+	//
+	// Done is provided for use in select statements:
+	//
+	//  // Stream generates values with DoSomething and sends them to out
+	//  // until DoSomething returns an error or ctx.Done is closed.
+	//  func Stream(ctx context.Context, out <-chan Value) error {
+	//  	for {
+	//  		v, err := DoSomething(ctx)
+	//  		if err != nil {
+	//  			return err
+	//  		}
+	//  		select {
+	//  		case <-ctx.Done():
+	//  			return ctx.Err()
+	//  		case out <- v:
+	//  		}
+	//  	}
+	//  }
+	//
+	// See http://blog.golang.org/pipelines for more examples of how to use
+	// a Done channel for cancelation.
+	Done() <-chan struct{}
+
+	// Err returns a non-nil error value after Done is closed.  Err returns
+	// Canceled if the context was canceled or DeadlineExceeded if the
+	// context's deadline passed.  No other values for Err are defined.
+	// After Done is closed, successive calls to Err return the same value.
+	Err() error
+
+	// Value returns the value associated with this context for key, or nil
+	// if no value is associated with key.  Successive calls to Value with
+	// the same key returns the same result.
+	//
+	// Use context values only for request-scoped data that transits
+	// processes and API boundaries, not for passing optional parameters to
+	// functions.
+	//
+	// A key identifies a specific value in a Context.  Functions that wish
+	// to store values in Context typically allocate a key in a global
+	// variable then use that key as the argument to context.WithValue and
+	// Context.Value.  A key can be any type that supports equality;
+	// packages should define keys as an unexported type to avoid
+	// collisions.
+	//
+	// Packages that define a Context key should provide type-safe accessors
+	// for the values stores using that key:
+	//
+	// 	// Package user defines a User type that's stored in Contexts.
+	// 	package user
+	//
+	// 	import "golang.org/x/net/context"
+	//
+	// 	// User is the type of value stored in the Contexts.
+	// 	type User struct {...}
+	//
+	// 	// key is an unexported type for keys defined in this package.
+	// 	// This prevents collisions with keys defined in other packages.
+	// 	type key int
+	//
+	// 	// userKey is the key for user.User values in Contexts.  It is
+	// 	// unexported; clients use user.NewContext and user.FromContext
+	// 	// instead of using this key directly.
+	// 	var userKey key = 0
+	//
+	// 	// NewContext returns a new Context that carries value u.
+	// 	func NewContext(ctx context.Context, u *User) context.Context {
+	// 		return context.WithValue(ctx, userKey, u)
+	// 	}
+	//
+	// 	// FromContext returns the User value stored in ctx, if any.
+	// 	func FromContext(ctx context.Context) (*User, bool) {
+	// 		u, ok := ctx.Value(userKey).(*User)
+	// 		return u, ok
+	// 	}
+	Value(key interface{}) interface{}
+}
+
+// Canceled is the error returned by Context.Err when the context is canceled.
+var Canceled = errors.New("context canceled")
+
+// DeadlineExceeded is the error returned by Context.Err when the context's
+// deadline passes.
+var DeadlineExceeded = errors.New("context deadline exceeded")
+
+// An emptyCtx is never canceled, has no values, and has no deadline.  It is not
+// struct{}, since vars of this type must have distinct addresses.
+type emptyCtx int
+
+func (*emptyCtx) Deadline() (deadline time.Time, ok bool) {
+	return
+}
+
+func (*emptyCtx) Done() <-chan struct{} {
+	return nil
+}
+
+func (*emptyCtx) Err() error {
+	return nil
+}
+
+func (*emptyCtx) Value(key interface{}) interface{} {
+	return nil
+}
+
+func (e *emptyCtx) String() string {
+	switch e {
+	case background:
+		return "context.Background"
+	case todo:
+		return "context.TODO"
+	}
+	return "unknown empty Context"
+}
+
+var (
+	background = new(emptyCtx)
+	todo       = new(emptyCtx)
+)
+
+// Background returns a non-nil, empty Context. It is never canceled, has no
+// values, and has no deadline.  It is typically used by the main function,
+// initialization, and tests, and as the top-level Context for incoming
+// requests.
+func Background() Context {
+	return background
+}
+
+// TODO returns a non-nil, empty Context.  Code should use context.TODO when
+// it's unclear which Context to use or it's is not yet available (because the
+// surrounding function has not yet been extended to accept a Context
+// parameter).  TODO is recognized by static analysis tools that determine
+// whether Contexts are propagated correctly in a program.
+func TODO() Context {
+	return todo
+}
+
+// A CancelFunc tells an operation to abandon its work.
+// A CancelFunc does not wait for the work to stop.
+// After the first call, subsequent calls to a CancelFunc do nothing.
+type CancelFunc func()
+
+// WithCancel returns a copy of parent with a new Done channel. The returned
+// context's Done channel is closed when the returned cancel function is called
+// or when the parent context's Done channel is closed, whichever happens first.
+//
+// Canceling this context releases resources associated with it, so code should
+// call cancel as soon as the operations running in this Context complete.
+func WithCancel(parent Context) (ctx Context, cancel CancelFunc) {
+	c := newCancelCtx(parent)
+	propagateCancel(parent, &c)
+	return &c, func() { c.cancel(true, Canceled) }
+}
+
+// newCancelCtx returns an initialized cancelCtx.
+func newCancelCtx(parent Context) cancelCtx {
+	return cancelCtx{
+		Context: parent,
+		done:    make(chan struct{}),
+	}
+}
+
+// propagateCancel arranges for child to be canceled when parent is.
+func propagateCancel(parent Context, child canceler) {
+	if parent.Done() == nil {
+		return // parent is never canceled
+	}
+	if p, ok := parentCancelCtx(parent); ok {
+		p.mu.Lock()
+		if p.err != nil {
+			// parent has already been canceled
+			child.cancel(false, p.err)
+		} else {
+			if p.children == nil {
+				p.children = make(map[canceler]bool)
+			}
+			p.children[child] = true
+		}
+		p.mu.Unlock()
+	} else {
+		go func() {
+			select {
+			case <-parent.Done():
+				child.cancel(false, parent.Err())
+			case <-child.Done():
+			}
+		}()
+	}
+}
+
+// parentCancelCtx follows a chain of parent references until it finds a
+// *cancelCtx.  This function understands how each of the concrete types in this
+// package represents its parent.
+func parentCancelCtx(parent Context) (*cancelCtx, bool) {
+	for {
+		switch c := parent.(type) {
+		case *cancelCtx:
+			return c, true
+		case *timerCtx:
+			return &c.cancelCtx, true
+		case *valueCtx:
+			parent = c.Context
+		default:
+			return nil, false
+		}
+	}
+}
+
+// removeChild removes a context from its parent.
+func removeChild(parent Context, child canceler) {
+	p, ok := parentCancelCtx(parent)
+	if !ok {
+		return
+	}
+	p.mu.Lock()
+	if p.children != nil {
+		delete(p.children, child)
+	}
+	p.mu.Unlock()
+}
+
+// A canceler is a context type that can be canceled directly.  The
+// implementations are *cancelCtx and *timerCtx.
+type canceler interface {
+	cancel(removeFromParent bool, err error)
+	Done() <-chan struct{}
+}
+
+// A cancelCtx can be canceled.  When canceled, it also cancels any children
+// that implement canceler.
+type cancelCtx struct {
+	Context
+
+	done chan struct{} // closed by the first cancel call.
+
+	mu       sync.Mutex
+	children map[canceler]bool // set to nil by the first cancel call
+	err      error             // set to non-nil by the first cancel call
+}
+
+func (c *cancelCtx) Done() <-chan struct{} {
+	return c.done
+}
+
+func (c *cancelCtx) Err() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.err
+}
+
+func (c *cancelCtx) String() string {
+	return fmt.Sprintf("%v.WithCancel", c.Context)
+}
+
+// cancel closes c.done, cancels each of c's children, and, if
+// removeFromParent is true, removes c from its parent's children.
+func (c *cancelCtx) cancel(removeFromParent bool, err error) {
+	if err == nil {
+		panic("context: internal error: missing cancel error")
+	}
+	c.mu.Lock()
+	if c.err != nil {
+		c.mu.Unlock()
+		return // already canceled
+	}
+	c.err = err
+	close(c.done)
+	for child := range c.children {
+		// NOTE: acquiring the child's lock while holding parent's lock.
+		child.cancel(false, err)
+	}
+	c.children = nil
+	c.mu.Unlock()
+
+	if removeFromParent {
+		removeChild(c.Context, c)
+	}
+}
+
+// WithDeadline returns a copy of the parent context with the deadline adjusted
+// to be no later than d.  If the parent's deadline is already earlier than d,
+// WithDeadline(parent, d) is semantically equivalent to parent.  The returned
+// context's Done channel is closed when the deadline expires, when the returned
+// cancel function is called, or when the parent context's Done channel is
+// closed, whichever happens first.
+//
+// Canceling this context releases resources associated with it, so code should
+// call cancel as soon as the operations running in this Context complete.
+func WithDeadline(parent Context, deadline time.Time) (Context, CancelFunc) {
+	if cur, ok := parent.Deadline(); ok && cur.Before(deadline) {
+		// The current deadline is already sooner than the new one.
+		return WithCancel(parent)
+	}
+	c := &timerCtx{
+		cancelCtx: newCancelCtx(parent),
+		deadline:  deadline,
+	}
+	propagateCancel(parent, c)
+	d := deadline.Sub(time.Now())
+	if d <= 0 {
+		c.cancel(true, DeadlineExceeded) // deadline has already passed
+		return c, func() { c.cancel(true, Canceled) }
+	}
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err == nil {
+		c.timer = time.AfterFunc(d, func() {
+			c.cancel(true, DeadlineExceeded)
+		})
+	}
+	return c, func() { c.cancel(true, Canceled) }
+}
+
+// A timerCtx carries a timer and a deadline.  It embeds a cancelCtx to
+// implement Done and Err.  It implements cancel by stopping its timer then
+// delegating to cancelCtx.cancel.
+type timerCtx struct {
+	cancelCtx
+	timer *time.Timer // Under cancelCtx.mu.
+
+	deadline time.Time
+}
+
+func (c *timerCtx) Deadline() (deadline time.Time, ok bool) {
+	return c.deadline, true
+}
+
+func (c *timerCtx) String() string {
+	return fmt.Sprintf("%v.WithDeadline(%s [%s])", c.cancelCtx.Context, c.deadline, c.deadline.Sub(time.Now()))
+}
+
+func (c *timerCtx) cancel(removeFromParent bool, err error) {
+	c.cancelCtx.cancel(false, err)
+	if removeFromParent {
+		// Remove this timerCtx from its parent cancelCtx's children.
+		removeChild(c.cancelCtx.Context, c)
+	}
+	c.mu.Lock()
+	if c.timer != nil {
+		c.timer.Stop()
+		c.timer = nil
+	}
+	c.mu.Unlock()
+}
+
+// WithTimeout returns WithDeadline(parent, time.Now().Add(timeout)).
+//
+// Canceling this context releases resources associated with it, so code should
+// call cancel as soon as the operations running in this Context complete:
+//
+// 	func slowOperationWithTimeout(ctx context.Context) (Result, error) {
+// 		ctx, cancel := context.WithTimeout(ctx, 100*time.Millisecond)
+// 		defer cancel()  // releases resources if slowOperation completes before timeout elapses
+// 		return slowOperation(ctx)
+// 	}
+func WithTimeout(parent Context, timeout time.Duration) (Context, CancelFunc) {
+	return WithDeadline(parent, time.Now().Add(timeout))
+}
+
+// WithValue returns a copy of parent in which the value associated with key is
+// val.
+//
+// Use context Values only for request-scoped data that transits processes and
+// APIs, not for passing optional parameters to functions.
+func WithValue(parent Context, key interface{}, val interface{}) Context {
+	return &valueCtx{parent, key, val}
+}
+
+// A valueCtx carries a key-value pair.  It implements Value for that key and
+// delegates all other calls to the embedded Context.
+type valueCtx struct {
+	Context
+	key, val interface{}
+}
+
+func (c *valueCtx) String() string {
+	return fmt.Sprintf("%v.WithValue(%#v, %#v)", c.Context, c.key, c.val)
+}
+
+func (c *valueCtx) Value(key interface{}) interface{} {
+	if c.key == key {
+		return c.val
+	}
+	return c.Context.Value(key)
+}

Godeps/_workspace/src/golang.org/x/net/context/context_test.go

@@ -0,0 +1,575 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package context
+
+import (
+	"fmt"
+	"math/rand"
+	"runtime"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+// otherContext is a Context that's not one of the types defined in context.go.
+// This lets us test code paths that differ based on the underlying type of the
+// Context.
+type otherContext struct {
+	Context
+}
+
+func TestBackground(t *testing.T) {
+	c := Background()
+	if c == nil {
+		t.Fatalf("Background returned nil")
+	}
+	select {
+	case x := <-c.Done():
+		t.Errorf("<-c.Done() == %v want nothing (it should block)", x)
+	default:
+	}
+	if got, want := fmt.Sprint(c), "context.Background"; got != want {
+		t.Errorf("Background().String() = %q want %q", got, want)
+	}
+}
+
+func TestTODO(t *testing.T) {
+	c := TODO()
+	if c == nil {
+		t.Fatalf("TODO returned nil")
+	}
+	select {
+	case x := <-c.Done():
+		t.Errorf("<-c.Done() == %v want nothing (it should block)", x)
+	default:
+	}
+	if got, want := fmt.Sprint(c), "context.TODO"; got != want {
+		t.Errorf("TODO().String() = %q want %q", got, want)
+	}
+}
+
+func TestWithCancel(t *testing.T) {
+	c1, cancel := WithCancel(Background())
+
+	if got, want := fmt.Sprint(c1), "context.Background.WithCancel"; got != want {
+		t.Errorf("c1.String() = %q want %q", got, want)
+	}
+
+	o := otherContext{c1}
+	c2, _ := WithCancel(o)
+	contexts := []Context{c1, o, c2}
+
+	for i, c := range contexts {
+		if d := c.Done(); d == nil {
+			t.Errorf("c[%d].Done() == %v want non-nil", i, d)
+		}
+		if e := c.Err(); e != nil {
+			t.Errorf("c[%d].Err() == %v want nil", i, e)
+		}
+
+		select {
+		case x := <-c.Done():
+			t.Errorf("<-c.Done() == %v want nothing (it should block)", x)
+		default:
+		}
+	}
+
+	cancel()
+	time.Sleep(100 * time.Millisecond) // let cancelation propagate
+
+	for i, c := range contexts {
+		select {
+		case <-c.Done():
+		default:
+			t.Errorf("<-c[%d].Done() blocked, but shouldn't have", i)
+		}
+		if e := c.Err(); e != Canceled {
+			t.Errorf("c[%d].Err() == %v want %v", i, e, Canceled)
+		}
+	}
+}
+
+func TestParentFinishesChild(t *testing.T) {
+	// Context tree:
+	// parent -> cancelChild
+	// parent -> valueChild -> timerChild
+	parent, cancel := WithCancel(Background())
+	cancelChild, stop := WithCancel(parent)
+	defer stop()
+	valueChild := WithValue(parent, "key", "value")
+	timerChild, stop := WithTimeout(valueChild, 10000*time.Hour)
+	defer stop()
+
+	select {
+	case x := <-parent.Done():
+		t.Errorf("<-parent.Done() == %v want nothing (it should block)", x)
+	case x := <-cancelChild.Done():
+		t.Errorf("<-cancelChild.Done() == %v want nothing (it should block)", x)
+	case x := <-timerChild.Done():
+		t.Errorf("<-timerChild.Done() == %v want nothing (it should block)", x)
+	case x := <-valueChild.Done():
+		t.Errorf("<-valueChild.Done() == %v want nothing (it should block)", x)
+	default:
+	}
+
+	// The parent's children should contain the two cancelable children.
+	pc := parent.(*cancelCtx)
+	cc := cancelChild.(*cancelCtx)
+	tc := timerChild.(*timerCtx)
+	pc.mu.Lock()
+	if len(pc.children) != 2 || !pc.children[cc] || !pc.children[tc] {
+		t.Errorf("bad linkage: pc.children = %v, want %v and %v",
+			pc.children, cc, tc)
+	}
+	pc.mu.Unlock()
+
+	if p, ok := parentCancelCtx(cc.Context); !ok || p != pc {
+		t.Errorf("bad linkage: parentCancelCtx(cancelChild.Context) = %v, %v want %v, true", p, ok, pc)
+	}
+	if p, ok := parentCancelCtx(tc.Context); !ok || p != pc {
+		t.Errorf("bad linkage: parentCancelCtx(timerChild.Context) = %v, %v want %v, true", p, ok, pc)
+	}
+
+	cancel()
+
+	pc.mu.Lock()
+	if len(pc.children) != 0 {
+		t.Errorf("pc.cancel didn't clear pc.children = %v", pc.children)
+	}
+	pc.mu.Unlock()
+
+	// parent and children should all be finished.
+	check := func(ctx Context, name string) {
+		select {
+		case <-ctx.Done():
+		default:
+			t.Errorf("<-%s.Done() blocked, but shouldn't have", name)
+		}
+		if e := ctx.Err(); e != Canceled {
+			t.Errorf("%s.Err() == %v want %v", name, e, Canceled)
+		}
+	}
+	check(parent, "parent")
+	check(cancelChild, "cancelChild")
+	check(valueChild, "valueChild")
+	check(timerChild, "timerChild")
+
+	// WithCancel should return a canceled context on a canceled parent.
+	precanceledChild := WithValue(parent, "key", "value")
+	select {
+	case <-precanceledChild.Done():
+	default:
+		t.Errorf("<-precanceledChild.Done() blocked, but shouldn't have")
+	}
+	if e := precanceledChild.Err(); e != Canceled {
+		t.Errorf("precanceledChild.Err() == %v want %v", e, Canceled)
+	}
+}
+
+func TestChildFinishesFirst(t *testing.T) {
+	cancelable, stop := WithCancel(Background())
+	defer stop()
+	for _, parent := range []Context{Background(), cancelable} {
+		child, cancel := WithCancel(parent)
+
+		select {
+		case x := <-parent.Done():
+			t.Errorf("<-parent.Done() == %v want nothing (it should block)", x)
+		case x := <-child.Done():
+			t.Errorf("<-child.Done() == %v want nothing (it should block)", x)
+		default:
+		}
+
+		cc := child.(*cancelCtx)
+		pc, pcok := parent.(*cancelCtx) // pcok == false when parent == Background()
+		if p, ok := parentCancelCtx(cc.Context); ok != pcok || (ok && pc != p) {
+			t.Errorf("bad linkage: parentCancelCtx(cc.Context) = %v, %v want %v, %v", p, ok, pc, pcok)
+		}
+
+		if pcok {
+			pc.mu.Lock()
+			if len(pc.children) != 1 || !pc.children[cc] {
+				t.Errorf("bad linkage: pc.children = %v, cc = %v", pc.children, cc)
+			}
+			pc.mu.Unlock()
+		}
+
+		cancel()
+
+		if pcok {
+			pc.mu.Lock()
+			if len(pc.children) != 0 {
+				t.Errorf("child's cancel didn't remove self from pc.children = %v", pc.children)
+			}
+			pc.mu.Unlock()
+		}
+
+		// child should be finished.
+		select {
+		case <-child.Done():
+		default:
+			t.Errorf("<-child.Done() blocked, but shouldn't have")
+		}
+		if e := child.Err(); e != Canceled {
+			t.Errorf("child.Err() == %v want %v", e, Canceled)
+		}
+
+		// parent should not be finished.
+		select {
+		case x := <-parent.Done():
+			t.Errorf("<-parent.Done() == %v want nothing (it should block)", x)
+		default:
+		}
+		if e := parent.Err(); e != nil {
+			t.Errorf("parent.Err() == %v want nil", e)
+		}
+	}
+}
+
+func testDeadline(c Context, wait time.Duration, t *testing.T) {
+	select {
+	case <-time.After(wait):
+		t.Fatalf("context should have timed out")
+	case <-c.Done():
+	}
+	if e := c.Err(); e != DeadlineExceeded {
+		t.Errorf("c.Err() == %v want %v", e, DeadlineExceeded)
+	}
+}
+
+func TestDeadline(t *testing.T) {
+	c, _ := WithDeadline(Background(), time.Now().Add(100*time.Millisecond))
+	if got, prefix := fmt.Sprint(c), "context.Background.WithDeadline("; !strings.HasPrefix(got, prefix) {
+		t.Errorf("c.String() = %q want prefix %q", got, prefix)
+	}
+	testDeadline(c, 200*time.Millisecond, t)
+
+	c, _ = WithDeadline(Background(), time.Now().Add(100*time.Millisecond))
+	o := otherContext{c}
+	testDeadline(o, 200*time.Millisecond, t)
+
+	c, _ = WithDeadline(Background(), time.Now().Add(100*time.Millisecond))
+	o = otherContext{c}
+	c, _ = WithDeadline(o, time.Now().Add(300*time.Millisecond))
+	testDeadline(c, 200*time.Millisecond, t)
+}
+
+func TestTimeout(t *testing.T) {
+	c, _ := WithTimeout(Background(), 100*time.Millisecond)
+	if got, prefix := fmt.Sprint(c), "context.Background.WithDeadline("; !strings.HasPrefix(got, prefix) {
+		t.Errorf("c.String() = %q want prefix %q", got, prefix)
+	}
+	testDeadline(c, 200*time.Millisecond, t)
+
+	c, _ = WithTimeout(Background(), 100*time.Millisecond)
+	o := otherContext{c}
+	testDeadline(o, 200*time.Millisecond, t)
+
+	c, _ = WithTimeout(Background(), 100*time.Millisecond)
+	o = otherContext{c}
+	c, _ = WithTimeout(o, 300*time.Millisecond)
+	testDeadline(c, 200*time.Millisecond, t)
+}
+
+func TestCanceledTimeout(t *testing.T) {
+	c, _ := WithTimeout(Background(), 200*time.Millisecond)
+	o := otherContext{c}
+	c, cancel := WithTimeout(o, 400*time.Millisecond)
+	cancel()
+	time.Sleep(100 * time.Millisecond) // let cancelation propagate
+	select {
+	case <-c.Done():
+	default:
+		t.Errorf("<-c.Done() blocked, but shouldn't have")
+	}
+	if e := c.Err(); e != Canceled {
+		t.Errorf("c.Err() == %v want %v", e, Canceled)
+	}
+}
+
+type key1 int
+type key2 int
+
+var k1 = key1(1)
+var k2 = key2(1) // same int as k1, different type
+var k3 = key2(3) // same type as k2, different int
+
+func TestValues(t *testing.T) {
+	check := func(c Context, nm, v1, v2, v3 string) {
+		if v, ok := c.Value(k1).(string); ok == (len(v1) == 0) || v != v1 {
+			t.Errorf(`%s.Value(k1).(string) = %q, %t want %q, %t`, nm, v, ok, v1, len(v1) != 0)
+		}
+		if v, ok := c.Value(k2).(string); ok == (len(v2) == 0) || v != v2 {
+			t.Errorf(`%s.Value(k2).(string) = %q, %t want %q, %t`, nm, v, ok, v2, len(v2) != 0)
+		}
+		if v, ok := c.Value(k3).(string); ok == (len(v3) == 0) || v != v3 {
+			t.Errorf(`%s.Value(k3).(string) = %q, %t want %q, %t`, nm, v, ok, v3, len(v3) != 0)
+		}
+	}
+
+	c0 := Background()
+	check(c0, "c0", "", "", "")
+
+	c1 := WithValue(Background(), k1, "c1k1")
+	check(c1, "c1", "c1k1", "", "")
+
+	if got, want := fmt.Sprint(c1), `context.Background.WithValue(1, "c1k1")`; got != want {
+		t.Errorf("c.String() = %q want %q", got, want)
+	}
+
+	c2 := WithValue(c1, k2, "c2k2")
+	check(c2, "c2", "c1k1", "c2k2", "")
+
+	c3 := WithValue(c2, k3, "c3k3")
+	check(c3, "c2", "c1k1", "c2k2", "c3k3")
+
+	c4 := WithValue(c3, k1, nil)
+	check(c4, "c4", "", "c2k2", "c3k3")
+
+	o0 := otherContext{Background()}
+	check(o0, "o0", "", "", "")
+
+	o1 := otherContext{WithValue(Background(), k1, "c1k1")}
+	check(o1, "o1", "c1k1", "", "")
+
+	o2 := WithValue(o1, k2, "o2k2")
+	check(o2, "o2", "c1k1", "o2k2", "")
+
+	o3 := otherContext{c4}
+	check(o3, "o3", "", "c2k2", "c3k3")
+
+	o4 := WithValue(o3, k3, nil)
+	check(o4, "o4", "", "c2k2", "")
+}
+
+func TestAllocs(t *testing.T) {
+	bg := Background()
+	for _, test := range []struct {
+		desc       string
+		f          func()
+		limit      float64
+		gccgoLimit float64
+	}{
+		{
+			desc:       "Background()",
+			f:          func() { Background() },
+			limit:      0,
+			gccgoLimit: 0,
+		},
+		{
+			desc: fmt.Sprintf("WithValue(bg, %v, nil)", k1),
+			f: func() {
+				c := WithValue(bg, k1, nil)
+				c.Value(k1)
+			},
+			limit:      3,
+			gccgoLimit: 3,
+		},
+		{
+			desc: "WithTimeout(bg, 15*time.Millisecond)",
+			f: func() {
+				c, _ := WithTimeout(bg, 15*time.Millisecond)
+				<-c.Done()
+			},
+			limit:      8,
+			gccgoLimit: 13,
+		},
+		{
+			desc: "WithCancel(bg)",
+			f: func() {
+				c, cancel := WithCancel(bg)
+				cancel()
+				<-c.Done()
+			},
+			limit:      5,
+			gccgoLimit: 8,
+		},
+		{
+			desc: "WithTimeout(bg, 100*time.Millisecond)",
+			f: func() {
+				c, cancel := WithTimeout(bg, 100*time.Millisecond)
+				cancel()
+				<-c.Done()
+			},
+			limit:      8,
+			gccgoLimit: 25,
+		},
+	} {
+		limit := test.limit
+		if runtime.Compiler == "gccgo" {
+			// gccgo does not yet do escape analysis.
+			// TOOD(iant): Remove this when gccgo does do escape analysis.
+			limit = test.gccgoLimit
+		}
+		if n := testing.AllocsPerRun(100, test.f); n > limit {
+			t.Errorf("%s allocs = %f want %d", test.desc, n, int(limit))
+		}
+	}
+}
+
+func TestSimultaneousCancels(t *testing.T) {
+	root, cancel := WithCancel(Background())
+	m := map[Context]CancelFunc{root: cancel}
+	q := []Context{root}
+	// Create a tree of contexts.
+	for len(q) != 0 && len(m) < 100 {
+		parent := q[0]
+		q = q[1:]
+		for i := 0; i < 4; i++ {
+			ctx, cancel := WithCancel(parent)
+			m[ctx] = cancel
+			q = append(q, ctx)
+		}
+	}
+	// Start all the cancels in a random order.
+	var wg sync.WaitGroup
+	wg.Add(len(m))
+	for _, cancel := range m {
+		go func(cancel CancelFunc) {
+			cancel()
+			wg.Done()
+		}(cancel)
+	}
+	// Wait on all the contexts in a random order.
+	for ctx := range m {
+		select {
+		case <-ctx.Done():
+		case <-time.After(1 * time.Second):
+			buf := make([]byte, 10<<10)
+			n := runtime.Stack(buf, true)
+			t.Fatalf("timed out waiting for <-ctx.Done(); stacks:\n%s", buf[:n])
+		}
+	}
+	// Wait for all the cancel functions to return.
+	done := make(chan struct{})
+	go func() {
+		wg.Wait()
+		close(done)
+	}()
+	select {
+	case <-done:
+	case <-time.After(1 * time.Second):
+		buf := make([]byte, 10<<10)
+		n := runtime.Stack(buf, true)
+		t.Fatalf("timed out waiting for cancel functions; stacks:\n%s", buf[:n])
+	}
+}
+
+func TestInterlockedCancels(t *testing.T) {
+	parent, cancelParent := WithCancel(Background())
+	child, cancelChild := WithCancel(parent)
+	go func() {
+		parent.Done()
+		cancelChild()
+	}()
+	cancelParent()
+	select {
+	case <-child.Done():
+	case <-time.After(1 * time.Second):
+		buf := make([]byte, 10<<10)
+		n := runtime.Stack(buf, true)
+		t.Fatalf("timed out waiting for child.Done(); stacks:\n%s", buf[:n])
+	}
+}
+
+func TestLayersCancel(t *testing.T) {
+	testLayers(t, time.Now().UnixNano(), false)
+}
+
+func TestLayersTimeout(t *testing.T) {
+	testLayers(t, time.Now().UnixNano(), true)
+}
+
+func testLayers(t *testing.T, seed int64, testTimeout bool) {
+	rand.Seed(seed)
+	errorf := func(format string, a ...interface{}) {
+		t.Errorf(fmt.Sprintf("seed=%d: %s", seed, format), a...)
+	}
+	const (
+		timeout   = 200 * time.Millisecond
+		minLayers = 30
+	)
+	type value int
+	var (
+		vals      []*value
+		cancels   []CancelFunc
+		numTimers int
+		ctx       = Background()
+	)
+	for i := 0; i < minLayers || numTimers == 0 || len(cancels) == 0 || len(vals) == 0; i++ {
+		switch rand.Intn(3) {
+		case 0:
+			v := new(value)
+			ctx = WithValue(ctx, v, v)
+			vals = append(vals, v)
+		case 1:
+			var cancel CancelFunc
+			ctx, cancel = WithCancel(ctx)
+			cancels = append(cancels, cancel)
+		case 2:
+			var cancel CancelFunc
+			ctx, cancel = WithTimeout(ctx, timeout)
+			cancels = append(cancels, cancel)
+			numTimers++
+		}
+	}
+	checkValues := func(when string) {
+		for _, key := range vals {
+			if val := ctx.Value(key).(*value); key != val {
+				errorf("%s: ctx.Value(%p) = %p want %p", when, key, val, key)
+			}
+		}
+	}
+	select {
+	case <-ctx.Done():
+		errorf("ctx should not be canceled yet")
+	default:
+	}
+	if s, prefix := fmt.Sprint(ctx), "context.Background."; !strings.HasPrefix(s, prefix) {
+		t.Errorf("ctx.String() = %q want prefix %q", s, prefix)
+	}
+	t.Log(ctx)
+	checkValues("before cancel")
+	if testTimeout {
+		select {
+		case <-ctx.Done():
+		case <-time.After(timeout + timeout/10):
+			errorf("ctx should have timed out")
+		}
+		checkValues("after timeout")
+	} else {
+		cancel := cancels[rand.Intn(len(cancels))]
+		cancel()
+		select {
+		case <-ctx.Done():
+		default:
+			errorf("ctx should be canceled")
+		}
+		checkValues("after cancel")
+	}
+}
+
+func TestCancelRemoves(t *testing.T) {
+	checkChildren := func(when string, ctx Context, want int) {
+		if got := len(ctx.(*cancelCtx).children); got != want {
+			t.Errorf("%s: context has %d children, want %d", when, got, want)
+		}
+	}
+
+	ctx, _ := WithCancel(Background())
+	checkChildren("after creation", ctx, 0)
+	_, cancel := WithCancel(ctx)
+	checkChildren("with WithCancel child ", ctx, 1)
+	cancel()
+	checkChildren("after cancelling WithCancel child", ctx, 0)
+
+	ctx, _ = WithCancel(Background())
+	checkChildren("after creation", ctx, 0)
+	_, cancel = WithTimeout(ctx, 60*time.Minute)
+	checkChildren("with WithTimeout child ", ctx, 1)
+	cancel()
+	checkChildren("after cancelling WithTimeout child", ctx, 0)
+}

Godeps/_workspace/src/golang.org/x/net/context/withtimeout_test.go

@@ -0,0 +1,26 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package context_test
+
+import (
+	"fmt"
+	"time"
+
+	"golang.org/x/net/context"
+)
+
+func ExampleWithTimeout() {
+	// Pass a context with a timeout to tell a blocking function that it
+	// should abandon its work after the timeout elapses.
+	ctx, _ := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	select {
+	case <-time.After(200 * time.Millisecond):
+		fmt.Println("overslept")
+	case <-ctx.Done():
+		fmt.Println(ctx.Err()) // prints "context deadline exceeded"
+	}
+	// Output:
+	// context deadline exceeded
+}

promql/analyzer.go

@@ -0,0 +1,170 @@
+// Copyright 2013 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 promql
+
+import (
+	"errors"
+	"time"
+
+	"golang.org/x/net/context"
+
+	clientmodel "github.com/prometheus/client_golang/model"
+
+	"github.com/prometheus/prometheus/storage/local"
+)
+
+// An Analyzer traverses an expression and determines which data has to be requested
+// from the storage. It is bound to a context that allows cancellation and timing out.
+type Analyzer struct {
+	// The storage from which to query data.
+	Storage local.Storage
+	// The expression being analyzed.
+	Expr Expr
+	// The time range for evaluation of Expr.
+	Start, End clientmodel.Timestamp
+
+	// The preload times for different query time offsets.
+	offsetPreloadTimes map[time.Duration]preloadTimes
+}
+
+// preloadTimes tracks which instants or ranges to preload for a set of
+// fingerprints. One of these structs is collected for each offset by the query
+// analyzer.
+type preloadTimes struct {
+	// Instants require single samples to be loaded along the entire query
+	// range, with intervals between the samples corresponding to the query
+	// resolution.
+	instants map[clientmodel.Fingerprint]struct{}
+	// Ranges require loading a range of samples at each resolution step,
+	// stretching backwards from the current evaluation timestamp. The length of
+	// the range into the past is given by the duration, as in "foo[5m]".
+	ranges map[clientmodel.Fingerprint]time.Duration
+}
+
+// Analyze the provided expression and attach metrics and fingerprints to data-selecting
+// AST nodes that are later used to preload the data from the storage.
+func (a *Analyzer) Analyze(ctx context.Context) error {
+	a.offsetPreloadTimes = map[time.Duration]preloadTimes{}
+
+	getPreloadTimes := func(offset time.Duration) preloadTimes {
+		if _, ok := a.offsetPreloadTimes[offset]; !ok {
+			a.offsetPreloadTimes[offset] = preloadTimes{
+				instants: map[clientmodel.Fingerprint]struct{}{},
+				ranges:   map[clientmodel.Fingerprint]time.Duration{},
+			}
+		}
+		return a.offsetPreloadTimes[offset]
+	}
+
+	// Retrieve fingerprints and metrics for the required time range for
+	// each metric or matrix selector node.
+	Inspect(a.Expr, func(node Node) bool {
+		switch n := node.(type) {
+		case *VectorSelector:
+			pt := getPreloadTimes(n.Offset)
+			fpts := a.Storage.GetFingerprintsForLabelMatchers(n.LabelMatchers)
+			n.fingerprints = fpts
+			n.metrics = map[clientmodel.Fingerprint]clientmodel.COWMetric{}
+			n.iterators = map[clientmodel.Fingerprint]local.SeriesIterator{}
+			for _, fp := range fpts {
+				// Only add the fingerprint to the instants if not yet present in the
+				// ranges. Ranges always contain more points and span more time than
+				// instants for the same offset.
+				if _, alreadyInRanges := pt.ranges[fp]; !alreadyInRanges {
+					pt.instants[fp] = struct{}{}
+				}
+				n.metrics[fp] = a.Storage.GetMetricForFingerprint(fp)
+			}
+		case *MatrixSelector:
+			pt := getPreloadTimes(n.Offset)
+			fpts := a.Storage.GetFingerprintsForLabelMatchers(n.LabelMatchers)
+			n.fingerprints = fpts
+			n.metrics = map[clientmodel.Fingerprint]clientmodel.COWMetric{}
+			n.iterators = map[clientmodel.Fingerprint]local.SeriesIterator{}
+			for _, fp := range fpts {
+				if pt.ranges[fp] < n.Range {
+					pt.ranges[fp] = n.Range
+					// Delete the fingerprint from the instants. Ranges always contain more
+					// points and span more time than instants, so we don't need to track
+					// an instant for the same fingerprint, should we have one.
+					delete(pt.instants, fp)
+				}
+				n.metrics[fp] = a.Storage.GetMetricForFingerprint(fp)
+			}
+		}
+		return true
+	})
+
+	// Currently we do not return an error but we might place a context check in here
+	// or extend the stage in some other way.
+	return nil
+}
+
+// Prepare the expression evaluation by preloading all required chunks from the storage
+// and setting the respective storage iterators in the AST nodes.
+func (a *Analyzer) Prepare(ctx context.Context) (local.Preloader, error) {
+	const env = "query preparation"
+
+	if a.offsetPreloadTimes == nil {
+		return nil, errors.New("analysis must be performed before preparing query")
+	}
+	var err error
+	// The preloader must not be closed unless an error ocurred as closing
+	// unpins the preloaded chunks.
+	p := a.Storage.NewPreloader()
+	defer func() {
+		if err != nil {
+			p.Close()
+		}
+	}()
+
+	// Preload all analyzed ranges.
+	for offset, pt := range a.offsetPreloadTimes {
+		if err = contextDone(ctx, env); err != nil {
+			return nil, err
+		}
+
+		start := a.Start.Add(-offset)
+		end := a.End.Add(-offset)
+		for fp, rangeDuration := range pt.ranges {
+			err = p.PreloadRange(fp, start.Add(-rangeDuration), end, *stalenessDelta)
+			if err != nil {
+				return nil, err
+			}
+		}
+		for fp := range pt.instants {
+			err = p.PreloadRange(fp, start, end, *stalenessDelta)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	// Attach storage iterators to AST nodes.
+	Inspect(a.Expr, func(node Node) bool {
+		switch n := node.(type) {
+		case *VectorSelector:
+			for _, fp := range n.fingerprints {
+				n.iterators[fp] = a.Storage.NewIterator(fp)
+			}
+		case *MatrixSelector:
+			for _, fp := range n.fingerprints {
+				n.iterators[fp] = a.Storage.NewIterator(fp)
+			}
+		}
+		return true
+	})
+
+	return p, nil
+}

promql/ast.go

@@ -180,7 +180,7 @@ type ParenExpr struct {
 
 // StringLiteral represents a string.
 type StringLiteral struct {
-	Str string
+	Val string
 }
 
 // UnaryExpr represents a unary operation on another expression.

promql/engine_test.go

@@ -0,0 +1,272 @@
+package promql
+
+import (
+	"reflect"
+	"sync"
+	"testing"
+	"time"
+
+	"golang.org/x/net/context"
+
+	"github.com/prometheus/prometheus/storage/local"
+)
+
+func TestQueryTimeout(t *testing.T) {
+	*defaultQueryTimeout = 5 * time.Millisecond
+	defer func() {
+		// Restore default query timeout
+		*defaultQueryTimeout = 2 * time.Minute
+	}()
+
+	storage, closer := local.NewTestStorage(t, 1)
+	defer closer.Close()
+
+	engine := NewEngine(storage)
+	defer engine.Stop()
+
+	query, err := engine.NewQuery("foo = bar")
+	if err != nil {
+		t.Fatalf("error parsing query: %s", err)
+	}
+
+	// Timeouts are not exact but checked in designated places. For example between
+	// invoking handlers. Thus, we reigster two handlers that take some time to ensure we check
+	// after exceeding the timeout.
+	// Should the implementation of this area change, the test might have to be adjusted.
+	engine.RegisterRecordHandler("test", func(context.Context, *RecordStmt) error {
+		time.Sleep(10 * time.Millisecond)
+		return nil
+	})
+	engine.RegisterRecordHandler("test2", func(context.Context, *RecordStmt) error {
+		time.Sleep(10 * time.Millisecond)
+		return nil
+	})
+
+	res := query.Exec()
+	if res.Err == nil {
+		t.Fatalf("expected timeout error but got none")
+	}
+	if _, ok := res.Err.(ErrQueryTimeout); res.Err != nil && !ok {
+		t.Fatalf("expected timeout error but got: %s", res.Err)
+	}
+}
+
+func TestQueryCancel(t *testing.T) {
+	storage, closer := local.NewTestStorage(t, 1)
+	defer closer.Close()
+
+	engine := NewEngine(storage)
+	defer engine.Stop()
+
+	query1, err := engine.NewQuery("foo = bar")
+	if err != nil {
+		t.Fatalf("error parsing query: %s", err)
+	}
+	query2, err := engine.NewQuery("foo = baz")
+	if err != nil {
+		t.Fatalf("error parsing query: %s", err)
+	}
+
+	// As for timeouts, cancellation is only checked at designated points. We ensure
+	// that we reach one of those points using the same method.
+	engine.RegisterRecordHandler("test1", func(context.Context, *RecordStmt) error {
+		<-time.After(2 * time.Millisecond)
+		return nil
+	})
+	engine.RegisterRecordHandler("test2", func(context.Context, *RecordStmt) error {
+		<-time.After(2 * time.Millisecond)
+		return nil
+	})
+
+	// Cancel query after starting it.
+	var wg sync.WaitGroup
+	var res *Result
+
+	wg.Add(1)
+	go func() {
+		res = query1.Exec()
+		wg.Done()
+	}()
+	<-time.After(1 * time.Millisecond)
+	query1.Cancel()
+	wg.Wait()
+
+	if res.Err == nil {
+		t.Fatalf("expected cancellation error for query1 but got none")
+	}
+	if _, ok := res.Err.(ErrQueryCanceled); res.Err != nil && !ok {
+		t.Fatalf("expected cancellation error for query1 but got: %s", res.Err)
+	}
+
+	// Canceling query before starting it must have no effect.
+	query2.Cancel()
+	res = query2.Exec()
+	if res.Err != nil {
+		t.Fatalf("unexpeceted error on executing query2: %s", res.Err)
+	}
+}
+
+func TestEngineShutdown(t *testing.T) {
+	storage, closer := local.NewTestStorage(t, 1)
+	defer closer.Close()
+
+	engine := NewEngine(storage)
+
+	query1, err := engine.NewQuery("foo = bar")
+	if err != nil {
+		t.Fatalf("error parsing query: %s", err)
+	}
+	query2, err := engine.NewQuery("foo = baz")
+	if err != nil {
+		t.Fatalf("error parsing query: %s", err)
+	}
+
+	handlerExecutions := 0
+
+	// Shutdown engine on first handler execution. Should handler execution ever become
+	// concurrent this test has to be adjusted accordingly.
+	engine.RegisterRecordHandler("test", func(context.Context, *RecordStmt) error {
+		handlerExecutions++
+		engine.Stop()
+		time.Sleep(10 * time.Millisecond)
+		return nil
+	})
+	engine.RegisterRecordHandler("test2", func(context.Context, *RecordStmt) error {
+		handlerExecutions++
+		engine.Stop()
+		time.Sleep(10 * time.Millisecond)
+		return nil
+	})
+
+	// Stopping the engine should cancel the base context. While setting up queries is
+	// still possible their context is canceled from the beginning and execution should
+	// terminate immediately.
+
+	res := query1.Exec()
+	if res.Err == nil {
+		t.Fatalf("expected error on shutdown during query but got none")
+	}
+	if handlerExecutions != 1 {
+		t.Fatalf("expected only one handler to be executed before query cancellation but got %d executons", handlerExecutions)
+	}
+
+	res2 := query2.Exec()
+	if res2.Err == nil {
+		t.Fatalf("expected error on querying shutdown engine but got none")
+	}
+	if handlerExecutions != 1 {
+		t.Fatalf("expected no handler execution for query after engine shutdown")
+	}
+
+}
+
+func TestAlertHandler(t *testing.T) {
+	storage, closer := local.NewTestStorage(t, 1)
+	defer closer.Close()
+
+	engine := NewEngine(storage)
+	defer engine.Stop()
+
+	qs := `ALERT Foo IF bar FOR 5m WITH {a="b"} SUMMARY "sum" DESCRIPTION "desc"`
+
+	doQuery := func(expectFailure bool) *AlertStmt {
+		query, err := engine.NewQuery(qs)
+		if err != nil {
+			t.Fatalf("error parsing query: %s", err)
+		}
+		res := query.Exec()
+		if expectFailure && res.Err == nil {
+			t.Fatalf("expected error but got none.")
+		}
+		if res.Err != nil && !expectFailure {
+			t.Fatalf("error on executing alert query: %s", res.Err)
+		}
+		// That this alert statement is correct is tested elsewhere.
+		return query.Statements()[0].(*AlertStmt)
+	}
+
+	// We expect an error if nothing is registered to handle the query.
+	alertStmt := doQuery(true)
+
+	receivedCalls := 0
+
+	// Ensure that we receive the correct statement.
+	engine.RegisterAlertHandler("test", func(ctx context.Context, as *AlertStmt) error {
+		if !reflect.DeepEqual(alertStmt, as) {
+			t.Errorf("received alert statement did not match input: %q", qs)
+			t.Fatalf("no match\n\nexpected:\n%s\ngot: \n%s\n", Tree(alertStmt), Tree(as))
+		}
+		receivedCalls++
+		return nil
+	})
+
+	for i := 0; i < 10; i++ {
+		doQuery(false)
+		if receivedCalls != i+1 {
+			t.Fatalf("alert handler was not called on query execution")
+		}
+	}
+
+	engine.UnregisterAlertHandler("test")
+
+	// We must receive no further calls after unregistering.
+	doQuery(true)
+	if receivedCalls != 10 {
+		t.Fatalf("received calls after unregistering alert handler")
+	}
+}
+
+func TestRecordHandler(t *testing.T) {
+	storage, closer := local.NewTestStorage(t, 1)
+	defer closer.Close()
+
+	engine := NewEngine(storage)
+	defer engine.Stop()
+
+	qs := `foo = bar`
+
+	doQuery := func(expectFailure bool) *RecordStmt {
+		query, err := engine.NewQuery(qs)
+		if err != nil {
+			t.Fatalf("error parsing query: %s", err)
+		}
+		res := query.Exec()
+		if expectFailure && res.Err == nil {
+			t.Fatalf("expected error but got none.")
+		}
+		if res.Err != nil && !expectFailure {
+			t.Fatalf("error on executing record query: %s", res.Err)
+		}
+		return query.Statements()[0].(*RecordStmt)
+	}
+
+	// We expect an error if nothing is registered to handle the query.
+	recordStmt := doQuery(true)
+
+	receivedCalls := 0
+
+	// Ensure that we receive the correct statement.
+	engine.RegisterRecordHandler("test", func(ctx context.Context, rs *RecordStmt) error {
+		if !reflect.DeepEqual(recordStmt, rs) {
+			t.Errorf("received record statement did not match input: %q", qs)
+			t.Fatalf("no match\n\nexpected:\n%s\ngot: \n%s\n", Tree(recordStmt), Tree(rs))
+		}
+		receivedCalls++
+		return nil
+	})
+
+	for i := 0; i < 10; i++ {
+		doQuery(false)
+		if receivedCalls != i+1 {
+			t.Fatalf("record handler was not called on query execution")
+		}
+	}
+
+	engine.UnregisterRecordHandler("test")
+
+	// We must receive no further calls after unregistering.
+	doQuery(true)
+	if receivedCalls != 10 {
+		t.Fatalf("received calls after unregistering record handler")
+	}
+}

promql/functions.go

@@ -13,6 +13,18 @@
 
 package promql
 
+import (
+	"container/heap"
+	"math"
+	"sort"
+	"strconv"
+	"time"
+
+	clientmodel "github.com/prometheus/client_golang/model"
+
+	"github.com/prometheus/prometheus/storage/metric"
+)
+
 // Function represents a function of the expression language and is
 // used by function nodes.
 type Function struct {
@@ -20,7 +32,477 @@ type Function struct {
 	ArgTypes     []ExprType
 	OptionalArgs int
 	ReturnType   ExprType
-	Call         func()
+	Call         func(ev *evaluator, args Expressions) Value
+}
+
+// === time() clientmodel.SampleValue ===
+func funcTime(ev *evaluator, args Expressions) Value {
+	return &Scalar{
+		Value:     clientmodel.SampleValue(ev.Timestamp.Unix()),
+		Timestamp: ev.Timestamp,
+	}
+}
+
+// === delta(matrix ExprMatrix, isCounter=0 ExprScalar) Vector ===
+func funcDelta(ev *evaluator, args Expressions) Value {
+	isCounter := len(args) >= 2 && ev.evalInt(args[1]) > 0
+	resultVector := Vector{}
+
+	// If we treat these metrics as counters, we need to fetch all values
+	// in the interval to find breaks in the timeseries' monotonicity.
+	// I.e. if a counter resets, we want to ignore that reset.
+	var matrixValue Matrix
+	if isCounter {
+		matrixValue = ev.evalMatrix(args[0])
+	} else {
+		matrixValue = ev.evalMatrixBounds(args[0])
+	}
+	for _, samples := range matrixValue {
+		// No sense in trying to compute a delta without at least two points. Drop
+		// this vector element.
+		if len(samples.Values) < 2 {
+			continue
+		}
+
+		counterCorrection := clientmodel.SampleValue(0)
+		lastValue := clientmodel.SampleValue(0)
+		for _, sample := range samples.Values {
+			currentValue := sample.Value
+			if isCounter && currentValue < lastValue {
+				counterCorrection += lastValue - currentValue
+			}
+			lastValue = currentValue
+		}
+		resultValue := lastValue - samples.Values[0].Value + counterCorrection
+
+		targetInterval := args[0].(*MatrixSelector).Range
+		sampledInterval := samples.Values[len(samples.Values)-1].Timestamp.Sub(samples.Values[0].Timestamp)
+		if sampledInterval == 0 {
+			// Only found one sample. Cannot compute a rate from this.
+			continue
+		}
+		// Correct for differences in target vs. actual delta interval.
+		//
+		// Above, we didn't actually calculate the delta for the specified target
+		// interval, but for an interval between the first and last found samples
+		// under the target interval, which will usually have less time between
+		// them. Depending on how many samples are found under a target interval,
+		// the delta results are distorted and temporal aliasing occurs (ugly
+		// bumps). This effect is corrected for below.
+		intervalCorrection := clientmodel.SampleValue(targetInterval) / clientmodel.SampleValue(sampledInterval)
+		resultValue *= intervalCorrection
+
+		resultSample := &Sample{
+			Metric:    samples.Metric,
+			Value:     resultValue,
+			Timestamp: ev.Timestamp,
+		}
+		resultSample.Metric.Delete(clientmodel.MetricNameLabel)
+		resultVector = append(resultVector, resultSample)
+	}
+	return resultVector
+}
+
+// === rate(node ExprMatrix) Vector ===
+func funcRate(ev *evaluator, args Expressions) Value {
+	args = append(args, &NumberLiteral{1})
+	vector := funcDelta(ev, args).(Vector)
+
+	// TODO: could be other type of ExprMatrix in the future (right now, only
+	// MatrixSelector exists). Find a better way of getting the duration of a
+	// matrix, such as looking at the samples themselves.
+	interval := args[0].(*MatrixSelector).Range
+	for i := range vector {
+		vector[i].Value /= clientmodel.SampleValue(interval / time.Second)
+	}
+	return vector
+}
+
+// === sort(node ExprVector) Vector ===
+func funcSort(ev *evaluator, args Expressions) Value {
+	byValueSorter := vectorByValueHeap(ev.evalVector(args[0]))
+	sort.Sort(byValueSorter)
+	return Vector(byValueSorter)
+}
+
+// === sortDesc(node ExprVector) Vector ===
+func funcSortDesc(ev *evaluator, args Expressions) Value {
+	byValueSorter := vectorByValueHeap(ev.evalVector(args[0]))
+	sort.Sort(sort.Reverse(byValueSorter))
+	return Vector(byValueSorter)
+}
+
+// === topk(k ExprScalar, node ExprVector) Vector ===
+func funcTopk(ev *evaluator, args Expressions) Value {
+	k := ev.evalInt(args[0])
+	if k < 1 {
+		return Vector{}
+	}
+	vector := ev.evalVector(args[1])
+
+	topk := make(vectorByValueHeap, 0, k)
+
+	for _, el := range vector {
+		if len(topk) < k || topk[0].Value < el.Value {
+			if len(topk) == k {
+				heap.Pop(&topk)
+			}
+			heap.Push(&topk, el)
+		}
+	}
+	sort.Sort(sort.Reverse(topk))
+	return Vector(topk)
+}
+
+// === bottomk(k ExprScalar, node ExprVector) Vector ===
+func funcBottomk(ev *evaluator, args Expressions) Value {
+	k := ev.evalInt(args[0])
+	if k < 1 {
+		return Vector{}
+	}
+	vector := ev.evalVector(args[1])
+
+	bottomk := make(vectorByValueHeap, 0, k)
+	bkHeap := reverseHeap{Interface: &bottomk}
+
+	for _, el := range vector {
+		if len(bottomk) < k || bottomk[0].Value > el.Value {
+			if len(bottomk) == k {
+				heap.Pop(&bkHeap)
+			}
+			heap.Push(&bkHeap, el)
+		}
+	}
+	sort.Sort(bottomk)
+	return Vector(bottomk)
+}
+
+// === drop_common_labels(node ExprVector) Vector ===
+func funcDropCommonLabels(ev *evaluator, args Expressions) Value {
+	vector := ev.evalVector(args[0])
+	if len(vector) < 1 {
+		return Vector{}
+	}
+	common := clientmodel.LabelSet{}
+	for k, v := range vector[0].Metric.Metric {
+		// TODO(julius): Should we also drop common metric names?
+		if k == clientmodel.MetricNameLabel {
+			continue
+		}
+		common[k] = v
+	}
+
+	for _, el := range vector[1:] {
+		for k, v := range common {
+			if el.Metric.Metric[k] != v {
+				// Deletion of map entries while iterating over them is safe.
+				// From http://golang.org/ref/spec#For_statements:
+				// "If map entries that have not yet been reached are deleted during
+				// iteration, the corresponding iteration values will not be produced."
+				delete(common, k)
+			}
+		}
+	}
+
+	for _, el := range vector {
+		for k := range el.Metric.Metric {
+			if _, ok := common[k]; ok {
+				el.Metric.Delete(k)
+			}
+		}
+	}
+	return vector
+}
+
+// === round(vector ExprVector, toNearest=1 Scalar) Vector ===
+func funcRound(ev *evaluator, args Expressions) Value {
+	// round returns a number rounded to toNearest.
+	// Ties are solved by rounding up.
+	toNearest := float64(1)
+	if len(args) >= 2 {
+		toNearest = ev.evalFloat(args[1])
+	}
+	// Invert as it seems to cause fewer floating point accuracy issues.
+	toNearestInverse := 1.0 / toNearest
+
+	vector := ev.evalVector(args[0])
+	for _, el := range vector {
+		el.Metric.Delete(clientmodel.MetricNameLabel)
+		el.Value = clientmodel.SampleValue(math.Floor(float64(el.Value)*toNearestInverse+0.5) / toNearestInverse)
+	}
+	return vector
+}
+
+// === scalar(node ExprVector) Scalar ===
+func funcScalar(ev *evaluator, args Expressions) Value {
+	v := ev.evalVector(args[0])
+	if len(v) != 1 {
+		return &Scalar{clientmodel.SampleValue(math.NaN()), ev.Timestamp}
+	}
+	return &Scalar{clientmodel.SampleValue(v[0].Value), ev.Timestamp}
+}
+
+// === count_scalar(vector ExprVector) model.SampleValue ===
+func funcCountScalar(ev *evaluator, args Expressions) Value {
+	return &Scalar{
+		Value:     clientmodel.SampleValue(len(ev.evalVector(args[0]))),
+		Timestamp: ev.Timestamp,
+	}
+}
+
+func aggrOverTime(ev *evaluator, args Expressions, aggrFn func(metric.Values) clientmodel.SampleValue) Value {
+	matrix := ev.evalMatrix(args[0])
+	resultVector := Vector{}
+
+	for _, el := range matrix {
+		if len(el.Values) == 0 {
+			continue
+		}
+
+		el.Metric.Delete(clientmodel.MetricNameLabel)
+		resultVector = append(resultVector, &Sample{
+			Metric:    el.Metric,
+			Value:     aggrFn(el.Values),
+			Timestamp: ev.Timestamp,
+		})
+	}
+	return resultVector
+}
+
+// === avg_over_time(matrix ExprMatrix) Vector ===
+func funcAvgOverTime(ev *evaluator, args Expressions) Value {
+	return aggrOverTime(ev, args, func(values metric.Values) clientmodel.SampleValue {
+		var sum clientmodel.SampleValue
+		for _, v := range values {
+			sum += v.Value
+		}
+		return sum / clientmodel.SampleValue(len(values))
+	})
+}
+
+// === count_over_time(matrix ExprMatrix) Vector ===
+func funcCountOverTime(ev *evaluator, args Expressions) Value {
+	return aggrOverTime(ev, args, func(values metric.Values) clientmodel.SampleValue {
+		return clientmodel.SampleValue(len(values))
+	})
+}
+
+// === floor(vector ExprVector) Vector ===
+func funcFloor(ev *evaluator, args Expressions) Value {
+	vector := ev.evalVector(args[0])
+	for _, el := range vector {
+		el.Metric.Delete(clientmodel.MetricNameLabel)
+		el.Value = clientmodel.SampleValue(math.Floor(float64(el.Value)))
+	}
+	return vector
+}
+
+// === max_over_time(matrix ExprMatrix) Vector ===
+func funcMaxOverTime(ev *evaluator, args Expressions) Value {
+	return aggrOverTime(ev, args, func(values metric.Values) clientmodel.SampleValue {
+		max := math.Inf(-1)
+		for _, v := range values {
+			max = math.Max(max, float64(v.Value))
+		}
+		return clientmodel.SampleValue(max)
+	})
+}
+
+// === min_over_time(matrix ExprMatrix) Vector ===
+func funcMinOverTime(ev *evaluator, args Expressions) Value {
+	return aggrOverTime(ev, args, func(values metric.Values) clientmodel.SampleValue {
+		min := math.Inf(1)
+		for _, v := range values {
+			min = math.Min(min, float64(v.Value))
+		}
+		return clientmodel.SampleValue(min)
+	})
+}
+
+// === sum_over_time(matrix ExprMatrix) Vector ===
+func funcSumOverTime(ev *evaluator, args Expressions) Value {
+	return aggrOverTime(ev, args, func(values metric.Values) clientmodel.SampleValue {
+		var sum clientmodel.SampleValue
+		for _, v := range values {
+			sum += v.Value
+		}
+		return sum
+	})
+}
+
+// === abs(vector ExprVector) Vector ===
+func funcAbs(ev *evaluator, args Expressions) Value {
+	vector := ev.evalVector(args[0])
+	for _, el := range vector {
+		el.Metric.Delete(clientmodel.MetricNameLabel)
+		el.Value = clientmodel.SampleValue(math.Abs(float64(el.Value)))
+	}
+	return vector
+}
+
+// === absent(vector ExprVector) Vector ===
+func funcAbsent(ev *evaluator, args Expressions) Value {
+	if len(ev.evalVector(args[0])) > 0 {
+		return Vector{}
+	}
+	m := clientmodel.Metric{}
+	if vs, ok := args[0].(*VectorSelector); ok {
+		for _, matcher := range vs.LabelMatchers {
+			if matcher.Type == metric.Equal && matcher.Name != clientmodel.MetricNameLabel {
+				m[matcher.Name] = matcher.Value
+			}
+		}
+	}
+	return Vector{
+		&Sample{
+			Metric: clientmodel.COWMetric{
+				Metric: m,
+				Copied: true,
+			},
+			Value:     1,
+			Timestamp: ev.Timestamp,
+		},
+	}
+}
+
+// === ceil(vector ExprVector) Vector ===
+func funcCeil(ev *evaluator, args Expressions) Value {
+	vector := ev.evalVector(args[0])
+	for _, el := range vector {
+		el.Metric.Delete(clientmodel.MetricNameLabel)
+		el.Value = clientmodel.SampleValue(math.Ceil(float64(el.Value)))
+	}
+	return vector
+}
+
+// === exp(vector ExprVector) Vector ===
+func funcExp(ev *evaluator, args Expressions) Value {
+	vector := ev.evalVector(args[0])
+	for _, el := range vector {
+		el.Metric.Delete(clientmodel.MetricNameLabel)
+		el.Value = clientmodel.SampleValue(math.Exp(float64(el.Value)))
+	}
+	return vector
+}
+
+// === sqrt(vector VectorNode) Vector ===
+func funcSqrt(ev *evaluator, args Expressions) Value {
+	vector := ev.evalVector(args[0])
+	for _, el := range vector {
+		el.Metric.Delete(clientmodel.MetricNameLabel)
+		el.Value = clientmodel.SampleValue(math.Sqrt(float64(el.Value)))
+	}
+	return vector
+}
+
+// === ln(vector ExprVector) Vector ===
+func funcLn(ev *evaluator, args Expressions) Value {
+	vector := ev.evalVector(args[0])
+	for _, el := range vector {
+		el.Metric.Delete(clientmodel.MetricNameLabel)
+		el.Value = clientmodel.SampleValue(math.Log(float64(el.Value)))
+	}
+	return vector
+}
+
+// === log2(vector ExprVector) Vector ===
+func funcLog2(ev *evaluator, args Expressions) Value {
+	vector := ev.evalVector(args[0])
+	for _, el := range vector {
+		el.Metric.Delete(clientmodel.MetricNameLabel)
+		el.Value = clientmodel.SampleValue(math.Log2(float64(el.Value)))
+	}
+	return vector
+}
+
+// === log10(vector ExprVector) Vector ===
+func funcLog10(ev *evaluator, args Expressions) Value {
+	vector := ev.evalVector(args[0])
+	for _, el := range vector {
+		el.Metric.Delete(clientmodel.MetricNameLabel)
+		el.Value = clientmodel.SampleValue(math.Log10(float64(el.Value)))
+	}
+	return vector
+}
+
+// === deriv(node ExprMatrix) Vector ===
+func funcDeriv(ev *evaluator, args Expressions) Value {
+	resultVector := Vector{}
+	matrix := ev.evalMatrix(args[0])
+
+	for _, samples := range matrix {
+		// No sense in trying to compute a derivative without at least two points.
+		// Drop this vector element.
+		if len(samples.Values) < 2 {
+			continue
+		}
+
+		// Least squares.
+		n := clientmodel.SampleValue(0)
+		sumY := clientmodel.SampleValue(0)
+		sumX := clientmodel.SampleValue(0)
+		sumXY := clientmodel.SampleValue(0)
+		sumX2 := clientmodel.SampleValue(0)
+		for _, sample := range samples.Values {
+			x := clientmodel.SampleValue(sample.Timestamp.UnixNano() / 1e9)
+			n += 1.0
+			sumY += sample.Value
+			sumX += x
+			sumXY += x * sample.Value
+			sumX2 += x * x
+		}
+		numerator := sumXY - sumX*sumY/n
+		denominator := sumX2 - (sumX*sumX)/n
+
+		resultValue := numerator / denominator
+
+		resultSample := &Sample{
+			Metric:    samples.Metric,
+			Value:     resultValue,
+			Timestamp: ev.Timestamp,
+		}
+		resultSample.Metric.Delete(clientmodel.MetricNameLabel)
+		resultVector = append(resultVector, resultSample)
+	}
+	return resultVector
+}
+
+// === histogram_quantile(k ExprScalar, vector ExprVector) Vector ===
+func funcHistogramQuantile(ev *evaluator, args Expressions) Value {
+	q := clientmodel.SampleValue(ev.evalFloat(args[0]))
+	inVec := ev.evalVector(args[1])
+
+	outVec := Vector{}
+	signatureToMetricWithBuckets := map[uint64]*metricWithBuckets{}
+	for _, el := range inVec {
+		upperBound, err := strconv.ParseFloat(
+			string(el.Metric.Metric[clientmodel.BucketLabel]), 64,
+		)
+		if err != nil {
+			// Oops, no bucket label or malformed label value. Skip.
+			// TODO(beorn7): Issue a warning somehow.
+			continue
+		}
+		signature := clientmodel.SignatureWithoutLabels(el.Metric.Metric, excludedLabels)
+		mb, ok := signatureToMetricWithBuckets[signature]
+		if !ok {
+			el.Metric.Delete(clientmodel.BucketLabel)
+			el.Metric.Delete(clientmodel.MetricNameLabel)
+			mb = &metricWithBuckets{el.Metric, nil}
+			signatureToMetricWithBuckets[signature] = mb
+		}
+		mb.buckets = append(mb.buckets, bucket{upperBound, el.Value})
+	}
+
+	for _, mb := range signatureToMetricWithBuckets {
+		outVec = append(outVec, &Sample{
+			Metric:    mb.metric,
+			Value:     clientmodel.SampleValue(quantile(q, mb.buckets)),
+			Timestamp: ev.Timestamp,
+		})
+	}
+
+	return outVec
 }
 
 var functions = map[string]*Function{
@@ -28,164 +510,207 @@ var functions = map[string]*Function{
 		Name:       "abs",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcAbs,
 	},
 	"absent": {
 		Name:       "absent",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcAbsent,
 	},
 	"avg_over_time": {
 		Name:       "avg_over_time",
 		ArgTypes:   []ExprType{ExprMatrix},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcAvgOverTime,
 	},
 	"bottomk": {
 		Name:       "bottomk",
 		ArgTypes:   []ExprType{ExprScalar, ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcBottomk,
 	},
 	"ceil": {
 		Name:       "ceil",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcCeil,
 	},
 	"count_over_time": {
 		Name:       "count_over_time",
 		ArgTypes:   []ExprType{ExprMatrix},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcCountOverTime,
 	},
 	"count_scalar": {
 		Name:       "count_scalar",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprScalar,
-		Call:       func() {},
+		Call:       funcCountScalar,
 	},
 	"delta": {
 		Name:         "delta",
 		ArgTypes:     []ExprType{ExprMatrix, ExprScalar},
 		OptionalArgs: 1, // The 2nd argument is deprecated.
 		ReturnType:   ExprVector,
-		Call:         func() {},
+		Call:         funcDelta,
 	},
 	"deriv": {
 		Name:       "deriv",
 		ArgTypes:   []ExprType{ExprMatrix},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcDeriv,
 	},
 	"drop_common_labels": {
 		Name:       "drop_common_labels",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcDropCommonLabels,
 	},
 	"exp": {
 		Name:       "exp",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcExp,
 	},
 	"floor": {
 		Name:       "floor",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcFloor,
 	},
 	"histogram_quantile": {
 		Name:       "histogram_quantile",
 		ArgTypes:   []ExprType{ExprScalar, ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcHistogramQuantile,
 	},
 	"ln": {
 		Name:       "ln",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcLn,
 	},
 	"log10": {
 		Name:       "log10",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcLog10,
 	},
 	"log2": {
 		Name:       "log2",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcLog2,
 	},
 	"max_over_time": {
 		Name:       "max_over_time",
 		ArgTypes:   []ExprType{ExprMatrix},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcMaxOverTime,
 	},
 	"min_over_time": {
 		Name:       "min_over_time",
 		ArgTypes:   []ExprType{ExprMatrix},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcMinOverTime,
 	},
 	"rate": {
 		Name:       "rate",
 		ArgTypes:   []ExprType{ExprMatrix},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcRate,
 	},
 	"round": {
 		Name:         "round",
 		ArgTypes:     []ExprType{ExprVector, ExprScalar},
 		OptionalArgs: 1,
 		ReturnType:   ExprVector,
-		Call:         func() {},
+		Call:         funcRound,
 	},
 	"scalar": {
 		Name:       "scalar",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprScalar,
-		Call:       func() {},
+		Call:       funcScalar,
 	},
 	"sort": {
 		Name:       "sort",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcSort,
 	},
 	"sort_desc": {
 		Name:       "sort_desc",
 		ArgTypes:   []ExprType{ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcSortDesc,
+	},
+	"sqrt": {
+		Name:       "sqrt",
+		ArgTypes:   []ExprType{ExprVector},
+		ReturnType: ExprVector,
+		Call:       funcSqrt,
 	},
 	"sum_over_time": {
 		Name:       "sum_over_time",
 		ArgTypes:   []ExprType{ExprMatrix},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcSumOverTime,
 	},
 	"time": {
 		Name:       "time",
 		ArgTypes:   []ExprType{},
 		ReturnType: ExprScalar,
-		Call:       func() {},
+		Call:       funcTime,
 	},
 	"topk": {
 		Name:       "topk",
 		ArgTypes:   []ExprType{ExprScalar, ExprVector},
 		ReturnType: ExprVector,
-		Call:       func() {},
+		Call:       funcTopk,
 	},
 }
 
-// GetFunction returns a predefined Function object for the given name.
-func GetFunction(name string) (*Function, bool) {
+// getFunction returns a predefined Function object for the given name.
+func getFunction(name string) (*Function, bool) {
 	function, ok := functions[name]
 	return function, ok
 }
+
+type vectorByValueHeap Vector
+
+func (s vectorByValueHeap) Len() int {
+	return len(s)
+}
+
+func (s vectorByValueHeap) Less(i, j int) bool {
+	if math.IsNaN(float64(s[i].Value)) {
+		return true
+	}
+	return s[i].Value < s[j].Value
+}
+
+func (s vectorByValueHeap) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s *vectorByValueHeap) Push(x interface{}) {
+	*s = append(*s, x.(*Sample))
+}
+
+func (s *vectorByValueHeap) Pop() interface{} {
+	old := *s
+	n := len(old)
+	el := old[n-1]
+	*s = old[0 : n-1]
+	return el
+}
+
+type reverseHeap struct {
+	heap.Interface
+}
+
+func (s reverseHeap) Less(i, j int) bool {
+	return s.Interface.Less(j, i)
+}

promql/parse.go

@@ -565,7 +565,7 @@ func (p *parser) aggrExpr() *AggregateExpr {
 func (p *parser) call(name string) *Call {
 	const ctx = "function call"
 
-	fn, exist := GetFunction(name)
+	fn, exist := getFunction(name)
 	if !exist {
 		p.errorf("unknown function with name %q", name)
 	}

promql/parse_test.go

@@ -1069,7 +1069,7 @@ func mustLabelMatcher(mt metric.MatchType, name clientmodel.LabelName, val clien
 }
 
 func mustGetFunction(name string) *Function {
-	f, ok := GetFunction(name)
+	f, ok := getFunction(name)
 	if !ok {
 		panic(fmt.Errorf("function %q does not exist", name))
 	}

promql/printer.go

@@ -25,6 +25,47 @@ import (
 	"github.com/prometheus/prometheus/utility"
 )
 
+func (matrix Matrix) String() string {
+	metricStrings := make([]string, 0, len(matrix))
+	for _, sampleStream := range matrix {
+		metricName, hasName := sampleStream.Metric.Metric[clientmodel.MetricNameLabel]
+		numLabels := len(sampleStream.Metric.Metric)
+		if hasName {
+			numLabels--
+		}
+		labelStrings := make([]string, 0, numLabels)
+		for label, value := range sampleStream.Metric.Metric {
+			if label != clientmodel.MetricNameLabel {
+				labelStrings = append(labelStrings, fmt.Sprintf("%s=%q", label, value))
+			}
+		}
+		sort.Strings(labelStrings)
+		valueStrings := make([]string, 0, len(sampleStream.Values))
+		for _, value := range sampleStream.Values {
+			valueStrings = append(valueStrings,
+				fmt.Sprintf("\n%v @[%v]", value.Value, value.Timestamp))
+		}
+		metricStrings = append(metricStrings,
+			fmt.Sprintf("%s{%s} => %s",
+				metricName,
+				strings.Join(labelStrings, ", "),
+				strings.Join(valueStrings, ", ")))
+	}
+	sort.Strings(metricStrings)
+	return strings.Join(metricStrings, "\n")
+}
+
+func (vector Vector) String() string {
+	metricStrings := make([]string, 0, len(vector))
+	for _, sample := range vector {
+		metricStrings = append(metricStrings,
+			fmt.Sprintf("%s => %v @[%v]",
+				sample.Metric,
+				sample.Value, sample.Timestamp))
+	}
+	return strings.Join(metricStrings, "\n")
+}
+
 // Tree returns a string of the tree structure of the given node.
 func Tree(node Node) string {
 	return tree(node, "")
@@ -175,7 +216,7 @@ func (node *ParenExpr) String() string {
 }
 
 func (node *StringLiteral) String() string {
-	return fmt.Sprintf("%q", node.Str)
+	return fmt.Sprintf("%q", node.Val)
 }
 
 func (node *UnaryExpr) String() string {
@@ -321,7 +362,7 @@ func (node *MatrixSelector) DotGraph() string {
 
 // DotGraph returns a DOT representation of the string literal.
 func (node *StringLiteral) DotGraph() string {
-	return fmt.Sprintf("%#p[label=\"'%q'\"];\n", node, node.Str)
+	return fmt.Sprintf("%#p[label=\"'%q'\"];\n", node, node.Val)
 }
 
 // DotGraph returns a DOT representation of the unary expression.

promql/quantile.go

@@ -0,0 +1,106 @@
+// Copyright 2015 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 promql
+
+import (
+	"math"
+	"sort"
+
+	clientmodel "github.com/prometheus/client_golang/model"
+)
+
+// Helpers to calculate quantiles.
+
+// excludedLabels are the labels to exclude from signature calculation for
+// quantiles.
+var excludedLabels = map[clientmodel.LabelName]struct{}{
+	clientmodel.MetricNameLabel: struct{}{},
+	clientmodel.BucketLabel:     struct{}{},
+}
+
+type bucket struct {
+	upperBound float64
+	count      clientmodel.SampleValue
+}
+
+// buckets implements sort.Interface.
+type buckets []bucket
+
+func (b buckets) Len() int           { return len(b) }
+func (b buckets) Swap(i, j int)      { b[i], b[j] = b[j], b[i] }
+func (b buckets) Less(i, j int) bool { return b[i].upperBound < b[j].upperBound }
+
+type metricWithBuckets struct {
+	metric  clientmodel.COWMetric
+	buckets buckets
+}
+
+// quantile calculates the quantile 'q' based on the given buckets. The buckets
+// will be sorted by upperBound by this function (i.e. no sorting needed before
+// calling this function). The quantile value is interpolated assuming a linear
+// distribution within a bucket. However, if the quantile falls into the highest
+// bucket, the upper bound of the 2nd highest bucket is returned. A natural
+// lower bound of 0 is assumed if the upper bound of the lowest bucket is
+// greater 0. In that case, interpolation in the lowest bucket happens linearly
+// between 0 and the upper bound of the lowest bucket. However, if the lowest
+// bucket has an upper bound less or equal 0, this upper bound is returned if
+// the quantile falls into the lowest bucket.
+//
+// There are a number of special cases (once we have a way to report errors
+// happening during evaluations of AST functions, we should report those
+// explicitly):
+//
+// If 'buckets' has fewer than 2 elements, NaN is returned.
+//
+// If the highest bucket is not +Inf, NaN is returned.
+//
+// If q<0, -Inf is returned.
+//
+// If q>1, +Inf is returned.
+func quantile(q clientmodel.SampleValue, buckets buckets) float64 {
+	if q < 0 {
+		return math.Inf(-1)
+	}
+	if q > 1 {
+		return math.Inf(+1)
+	}
+	if len(buckets) < 2 {
+		return math.NaN()
+	}
+	sort.Sort(buckets)
+	if !math.IsInf(buckets[len(buckets)-1].upperBound, +1) {
+		return math.NaN()
+	}
+
+	rank := q * buckets[len(buckets)-1].count
+	b := sort.Search(len(buckets)-1, func(i int) bool { return buckets[i].count >= rank })
+
+	if b == len(buckets)-1 {
+		return buckets[len(buckets)-2].upperBound
+	}
+	if b == 0 && buckets[0].upperBound <= 0 {
+		return buckets[0].upperBound
+	}
+	var (
+		bucketStart float64
+		bucketEnd   = buckets[b].upperBound
+		count       = buckets[b].count
+	)
+	if b > 0 {
+		bucketStart = buckets[b-1].upperBound
+		count -= buckets[b-1].count
+		rank -= buckets[b-1].count
+	}
+	return bucketStart + (bucketEnd-bucketStart)*float64(rank/count)
+}

promql/setup_test.go

@@ -0,0 +1,486 @@
+// Copyright 2013 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 promql
+
+import (
+	"time"
+
+	clientmodel "github.com/prometheus/client_golang/model"
+
+	"github.com/prometheus/prometheus/storage/local"
+	"github.com/prometheus/prometheus/storage/metric"
+)
+
+var testSampleInterval = time.Duration(5) * time.Minute
+var testStartTime = clientmodel.Timestamp(0)
+
+func getTestValueStream(startVal, endVal, stepVal clientmodel.SampleValue, startTime clientmodel.Timestamp) (resultValues metric.Values) {
+	currentTime := startTime
+	for currentVal := startVal; currentVal <= endVal; currentVal += stepVal {
+		sample := metric.SamplePair{
+			Value:     currentVal,
+			Timestamp: currentTime,
+		}
+		resultValues = append(resultValues, sample)
+		currentTime = currentTime.Add(testSampleInterval)
+	}
+	return resultValues
+}
+
+func getTestVectorFromTestMatrix(matrix Matrix) Vector {
+	vector := Vector{}
+	for _, sampleStream := range matrix {
+		lastSample := sampleStream.Values[len(sampleStream.Values)-1]
+		vector = append(vector, &Sample{
+			Metric:    sampleStream.Metric,
+			Value:     lastSample.Value,
+			Timestamp: lastSample.Timestamp,
+		})
+	}
+	return vector
+}
+
+func storeMatrix(storage local.Storage, matrix Matrix) {
+	pendingSamples := clientmodel.Samples{}
+	for _, sampleStream := range matrix {
+		for _, sample := range sampleStream.Values {
+			pendingSamples = append(pendingSamples, &clientmodel.Sample{
+				Metric:    sampleStream.Metric.Metric,
+				Value:     sample.Value,
+				Timestamp: sample.Timestamp,
+			})
+		}
+	}
+	for _, s := range pendingSamples {
+		storage.Append(s)
+	}
+	storage.WaitForIndexing()
+}
+
+var testVector = getTestVectorFromTestMatrix(testMatrix)
+
+var testMatrix = Matrix{
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "http_requests",
+				clientmodel.JobLabel:        "api-server",
+				"instance":                  "0",
+				"group":                     "production",
+			},
+		},
+		Values: getTestValueStream(0, 100, 10, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "http_requests",
+				clientmodel.JobLabel:        "api-server",
+				"instance":                  "1",
+				"group":                     "production",
+			},
+		},
+		Values: getTestValueStream(0, 200, 20, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "http_requests",
+				clientmodel.JobLabel:        "api-server",
+				"instance":                  "0",
+				"group":                     "canary",
+			},
+		},
+		Values: getTestValueStream(0, 300, 30, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "http_requests",
+				clientmodel.JobLabel:        "api-server",
+				"instance":                  "1",
+				"group":                     "canary",
+			},
+		},
+		Values: getTestValueStream(0, 400, 40, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "http_requests",
+				clientmodel.JobLabel:        "app-server",
+				"instance":                  "0",
+				"group":                     "production",
+			},
+		},
+		Values: getTestValueStream(0, 500, 50, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "http_requests",
+				clientmodel.JobLabel:        "app-server",
+				"instance":                  "1",
+				"group":                     "production",
+			},
+		},
+		Values: getTestValueStream(0, 600, 60, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "http_requests",
+				clientmodel.JobLabel:        "app-server",
+				"instance":                  "0",
+				"group":                     "canary",
+			},
+		},
+		Values: getTestValueStream(0, 700, 70, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "http_requests",
+				clientmodel.JobLabel:        "app-server",
+				"instance":                  "1",
+				"group":                     "canary",
+			},
+		},
+		Values: getTestValueStream(0, 800, 80, testStartTime),
+	},
+	// Single-letter metric and label names.
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "x",
+				"y": "testvalue",
+			},
+		},
+		Values: getTestValueStream(0, 100, 10, testStartTime),
+	},
+	// Counter reset in the middle of range.
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "testcounter_reset_middle",
+			},
+		},
+		Values: append(getTestValueStream(0, 40, 10, testStartTime), getTestValueStream(0, 50, 10, testStartTime.Add(testSampleInterval*5))...),
+	},
+	// Counter reset at the end of range.
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "testcounter_reset_end",
+			},
+		},
+		Values: append(getTestValueStream(0, 90, 10, testStartTime), getTestValueStream(0, 0, 10, testStartTime.Add(testSampleInterval*10))...),
+	},
+	// For label-key grouping regression test.
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "label_grouping_test",
+				"a": "aa",
+				"b": "bb",
+			},
+		},
+		Values: getTestValueStream(0, 100, 10, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "label_grouping_test",
+				"a": "a",
+				"b": "abb",
+			},
+		},
+		Values: getTestValueStream(0, 200, 20, testStartTime),
+	},
+	// Two histograms with 4 buckets each (*_sum and *_count not included,
+	// only buckets). Lowest bucket for one histogram < 0, for the other >
+	// 0. They have the same name, just separated by label. Not useful in
+	// practice, but can happen (if clients change bucketing), and the
+	// server has to cope with it.
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "testhistogram_bucket",
+				"le":    "0.1",
+				"start": "positive",
+			},
+		},
+		Values: getTestValueStream(0, 50, 5, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "testhistogram_bucket",
+				"le":    ".2",
+				"start": "positive",
+			},
+		},
+		Values: getTestValueStream(0, 70, 7, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "testhistogram_bucket",
+				"le":    "1e0",
+				"start": "positive",
+			},
+		},
+		Values: getTestValueStream(0, 110, 11, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "testhistogram_bucket",
+				"le":    "+Inf",
+				"start": "positive",
+			},
+		},
+		Values: getTestValueStream(0, 120, 12, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "testhistogram_bucket",
+				"le":    "-.2",
+				"start": "negative",
+			},
+		},
+		Values: getTestValueStream(0, 10, 1, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "testhistogram_bucket",
+				"le":    "-0.1",
+				"start": "negative",
+			},
+		},
+		Values: getTestValueStream(0, 20, 2, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "testhistogram_bucket",
+				"le":    "0.3",
+				"start": "negative",
+			},
+		},
+		Values: getTestValueStream(0, 20, 2, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "testhistogram_bucket",
+				"le":    "+Inf",
+				"start": "negative",
+			},
+		},
+		Values: getTestValueStream(0, 30, 3, testStartTime),
+	},
+	// Now a more realistic histogram per job and instance to test aggregation.
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job1",
+				"instance":                  "ins1",
+				"le":                        "0.1",
+			},
+		},
+		Values: getTestValueStream(0, 10, 1, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job1",
+				"instance":                  "ins1",
+				"le":                        "0.2",
+			},
+		},
+		Values: getTestValueStream(0, 30, 3, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job1",
+				"instance":                  "ins1",
+				"le":                        "+Inf",
+			},
+		},
+		Values: getTestValueStream(0, 40, 4, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job1",
+				"instance":                  "ins2",
+				"le":                        "0.1",
+			},
+		},
+		Values: getTestValueStream(0, 20, 2, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job1",
+				"instance":                  "ins2",
+				"le":                        "0.2",
+			},
+		},
+		Values: getTestValueStream(0, 50, 5, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job1",
+				"instance":                  "ins2",
+				"le":                        "+Inf",
+			},
+		},
+		Values: getTestValueStream(0, 60, 6, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job2",
+				"instance":                  "ins1",
+				"le":                        "0.1",
+			},
+		},
+		Values: getTestValueStream(0, 30, 3, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job2",
+				"instance":                  "ins1",
+				"le":                        "0.2",
+			},
+		},
+		Values: getTestValueStream(0, 40, 4, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job2",
+				"instance":                  "ins1",
+				"le":                        "+Inf",
+			},
+		},
+		Values: getTestValueStream(0, 60, 6, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job2",
+				"instance":                  "ins2",
+				"le":                        "0.1",
+			},
+		},
+		Values: getTestValueStream(0, 40, 4, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job2",
+				"instance":                  "ins2",
+				"le":                        "0.2",
+			},
+		},
+		Values: getTestValueStream(0, 70, 7, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "request_duration_seconds_bucket",
+				clientmodel.JobLabel:        "job2",
+				"instance":                  "ins2",
+				"le":                        "+Inf",
+			},
+		},
+		Values: getTestValueStream(0, 90, 9, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "vector_matching_a",
+				"l": "x",
+			},
+		},
+		Values: getTestValueStream(0, 100, 1, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "vector_matching_a",
+				"l": "y",
+			},
+		},
+		Values: getTestValueStream(0, 100, 2, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "vector_matching_b",
+				"l": "x",
+			},
+		},
+		Values: getTestValueStream(0, 100, 4, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "cpu_count",
+				"instance":                  "0",
+				"type":                      "numa",
+			},
+		},
+		Values: getTestValueStream(0, 500, 30, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "cpu_count",
+				"instance":                  "0",
+				"type":                      "smp",
+			},
+		},
+		Values: getTestValueStream(0, 200, 10, testStartTime),
+	},
+	{
+		Metric: clientmodel.COWMetric{
+			Metric: clientmodel.Metric{
+				clientmodel.MetricNameLabel: "cpu_count",
+				"instance":                  "1",
+				"type":                      "smp",
+			},
+		},
+		Values: getTestValueStream(0, 200, 20, testStartTime),
+	},
+}