You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
327 lines
8.7 KiB
327 lines
8.7 KiB
// Package query implements the custom query format used to filter event
|
|
// subscriptions in Tendermint.
|
|
//
|
|
// Query expressions describe properties of events and their attributes, using
|
|
// strings like:
|
|
//
|
|
// abci.invoice.number = 22 AND abci.invoice.owner = 'Ivan'
|
|
//
|
|
// Query expressions can handle attribute values encoding numbers, strings,
|
|
// dates, and timestamps. The complete query grammar is described in the
|
|
// query/syntax package.
|
|
//
|
|
package query
|
|
|
|
import (
|
|
"fmt"
|
|
"regexp"
|
|
"strconv"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/tendermint/tendermint/abci/types"
|
|
"github.com/tendermint/tendermint/libs/pubsub/query/syntax"
|
|
)
|
|
|
|
// All is a query that matches all events.
|
|
var All *Query
|
|
|
|
// A Query is the compiled form of a query.
|
|
type Query struct {
|
|
ast syntax.Query
|
|
conds []condition
|
|
}
|
|
|
|
// New parses and compiles the query expression into an executable query.
|
|
func New(query string) (*Query, error) {
|
|
ast, err := syntax.Parse(query)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return Compile(ast)
|
|
}
|
|
|
|
// MustCompile compiles the query expression into an executable query.
|
|
// In case of error, MustCompile will panic.
|
|
//
|
|
// This is intended for use in program initialization; use query.New if you
|
|
// need to check errors.
|
|
func MustCompile(query string) *Query {
|
|
q, err := New(query)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
return q
|
|
}
|
|
|
|
// Compile compiles the given query AST so it can be used to match events.
|
|
func Compile(ast syntax.Query) (*Query, error) {
|
|
conds := make([]condition, len(ast))
|
|
for i, q := range ast {
|
|
cond, err := compileCondition(q)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("compile %s: %w", q, err)
|
|
}
|
|
conds[i] = cond
|
|
}
|
|
return &Query{ast: ast, conds: conds}, nil
|
|
}
|
|
|
|
// Matches satisfies part of the pubsub.Query interface. This implementation
|
|
// never reports an error. A nil *Query matches all events.
|
|
func (q *Query) Matches(events []types.Event) (bool, error) {
|
|
if q == nil {
|
|
return true, nil
|
|
}
|
|
return q.matchesEvents(events), nil
|
|
}
|
|
|
|
// String matches part of the pubsub.Query interface.
|
|
func (q *Query) String() string {
|
|
if q == nil {
|
|
return "<empty>"
|
|
}
|
|
return q.ast.String()
|
|
}
|
|
|
|
// Syntax returns the syntax tree representation of q.
|
|
func (q *Query) Syntax() syntax.Query {
|
|
if q == nil {
|
|
return nil
|
|
}
|
|
return q.ast
|
|
}
|
|
|
|
// matchesEvents reports whether all the conditions match the given events.
|
|
func (q *Query) matchesEvents(events []types.Event) bool {
|
|
for _, cond := range q.conds {
|
|
if !cond.matchesAny(events) {
|
|
return false
|
|
}
|
|
}
|
|
return len(events) != 0
|
|
}
|
|
|
|
// A condition is a compiled match condition. A condition matches an event if
|
|
// the event has the designated type, contains an attribute with the given
|
|
// name, and the match function returns true for the attribute value.
|
|
type condition struct {
|
|
tag string // e.g., "tx.hash"
|
|
match func(s string) bool
|
|
}
|
|
|
|
// findAttr returns a slice of attribute values from event matching the
|
|
// condition tag, and reports whether the event type strictly equals the
|
|
// condition tag.
|
|
func (c condition) findAttr(event types.Event) ([]string, bool) {
|
|
if !strings.HasPrefix(c.tag, event.Type) {
|
|
return nil, false // type does not match tag
|
|
} else if len(c.tag) == len(event.Type) {
|
|
return nil, true // type == tag
|
|
}
|
|
var vals []string
|
|
for _, attr := range event.Attributes {
|
|
fullName := event.Type + "." + attr.Key
|
|
if fullName == c.tag {
|
|
vals = append(vals, attr.Value)
|
|
}
|
|
}
|
|
return vals, false
|
|
}
|
|
|
|
// matchesAny reports whether c matches at least one of the given events.
|
|
func (c condition) matchesAny(events []types.Event) bool {
|
|
for _, event := range events {
|
|
if c.matchesEvent(event) {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
// matchesEvent reports whether c matches the given event.
|
|
func (c condition) matchesEvent(event types.Event) bool {
|
|
vs, tagEqualsType := c.findAttr(event)
|
|
if len(vs) == 0 {
|
|
// As a special case, a condition tag that exactly matches the event type
|
|
// is matched against an empty string. This allows existence checks to
|
|
// work for type-only queries.
|
|
if tagEqualsType {
|
|
return c.match("")
|
|
}
|
|
return false
|
|
}
|
|
|
|
// At this point, we have candidate values.
|
|
for _, v := range vs {
|
|
if c.match(v) {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
func compileCondition(cond syntax.Condition) (condition, error) {
|
|
out := condition{tag: cond.Tag}
|
|
|
|
// Handle existence checks separately to simplify the logic below for
|
|
// comparisons that take arguments.
|
|
if cond.Op == syntax.TExists {
|
|
out.match = func(string) bool { return true }
|
|
return out, nil
|
|
}
|
|
|
|
// All the other operators require an argument.
|
|
if cond.Arg == nil {
|
|
return condition{}, fmt.Errorf("missing argument for %v", cond.Op)
|
|
}
|
|
|
|
// Precompile the argument value matcher.
|
|
argType := cond.Arg.Type
|
|
var argValue interface{}
|
|
|
|
switch argType {
|
|
case syntax.TString:
|
|
argValue = cond.Arg.Value()
|
|
case syntax.TNumber:
|
|
argValue = cond.Arg.Number()
|
|
case syntax.TTime, syntax.TDate:
|
|
argValue = cond.Arg.Time()
|
|
default:
|
|
return condition{}, fmt.Errorf("unknown argument type %v", argType)
|
|
}
|
|
|
|
mcons := opTypeMap[cond.Op][argType]
|
|
if mcons == nil {
|
|
return condition{}, fmt.Errorf("invalid op/arg combination (%v, %v)", cond.Op, argType)
|
|
}
|
|
out.match = mcons(argValue)
|
|
return out, nil
|
|
}
|
|
|
|
// TODO(creachadair): The existing implementation allows anything number shaped
|
|
// to be treated as a number. This preserves the parts of that behavior we had
|
|
// tests for, but we should probably get rid of that.
|
|
var extractNum = regexp.MustCompile(`^\d+(\.\d+)?`)
|
|
|
|
func parseNumber(s string) (float64, error) {
|
|
return strconv.ParseFloat(extractNum.FindString(s), 64)
|
|
}
|
|
|
|
// A map of operator ⇒ argtype ⇒ match-constructor.
|
|
// An entry does not exist if the combination is not valid.
|
|
//
|
|
// Disable the dupl lint for this map. The result isn't even correct.
|
|
//nolint:dupl
|
|
var opTypeMap = map[syntax.Token]map[syntax.Token]func(interface{}) func(string) bool{
|
|
syntax.TContains: {
|
|
syntax.TString: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
return strings.Contains(s, v.(string))
|
|
}
|
|
},
|
|
},
|
|
syntax.TEq: {
|
|
syntax.TString: func(v interface{}) func(string) bool {
|
|
return func(s string) bool { return s == v.(string) }
|
|
},
|
|
syntax.TNumber: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
w, err := parseNumber(s)
|
|
return err == nil && w == v.(float64)
|
|
}
|
|
},
|
|
syntax.TDate: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
ts, err := syntax.ParseDate(s)
|
|
return err == nil && ts.Equal(v.(time.Time))
|
|
}
|
|
},
|
|
syntax.TTime: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
ts, err := syntax.ParseTime(s)
|
|
return err == nil && ts.Equal(v.(time.Time))
|
|
}
|
|
},
|
|
},
|
|
syntax.TLt: {
|
|
syntax.TNumber: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
w, err := parseNumber(s)
|
|
return err == nil && w < v.(float64)
|
|
}
|
|
},
|
|
syntax.TDate: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
ts, err := syntax.ParseDate(s)
|
|
return err == nil && ts.Before(v.(time.Time))
|
|
}
|
|
},
|
|
syntax.TTime: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
ts, err := syntax.ParseTime(s)
|
|
return err == nil && ts.Before(v.(time.Time))
|
|
}
|
|
},
|
|
},
|
|
syntax.TLeq: {
|
|
syntax.TNumber: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
w, err := parseNumber(s)
|
|
return err == nil && w <= v.(float64)
|
|
}
|
|
},
|
|
syntax.TDate: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
ts, err := syntax.ParseDate(s)
|
|
return err == nil && !ts.After(v.(time.Time))
|
|
}
|
|
},
|
|
syntax.TTime: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
ts, err := syntax.ParseTime(s)
|
|
return err == nil && !ts.After(v.(time.Time))
|
|
}
|
|
},
|
|
},
|
|
syntax.TGt: {
|
|
syntax.TNumber: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
w, err := parseNumber(s)
|
|
return err == nil && w > v.(float64)
|
|
}
|
|
},
|
|
syntax.TDate: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
ts, err := syntax.ParseDate(s)
|
|
return err == nil && ts.After(v.(time.Time))
|
|
}
|
|
},
|
|
syntax.TTime: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
ts, err := syntax.ParseTime(s)
|
|
return err == nil && ts.After(v.(time.Time))
|
|
}
|
|
},
|
|
},
|
|
syntax.TGeq: {
|
|
syntax.TNumber: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
w, err := parseNumber(s)
|
|
return err == nil && w >= v.(float64)
|
|
}
|
|
},
|
|
syntax.TDate: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
ts, err := syntax.ParseDate(s)
|
|
return err == nil && !ts.Before(v.(time.Time))
|
|
}
|
|
},
|
|
syntax.TTime: func(v interface{}) func(string) bool {
|
|
return func(s string) bool {
|
|
ts, err := syntax.ParseTime(s)
|
|
return err == nil && !ts.Before(v.(time.Time))
|
|
}
|
|
},
|
|
},
|
|
}
|