Add field path queries for json and comparison operators

It's now possible to query a JSON field using a GJSON path.

   SET fleet truck1 FIELD props '{"speed":58,"name":"Andy"}' POINT 33 -112

You can then use the GJSON type path to return the objects that match the WHERE.

   SCAN fleet WHERE props.speed 50 inf
   SCAN fleet WHERE props.name Andy Andy

Included in this commit is support for '==', '<', '>', '<=', '>=', and '!='.
The previous queries could be written like:

    SCAN fleet WHERE props.speed > 50
    SCAN fleet WHERE props.name == Andy

internal/field/field.go

@@ -34,7 +34,7 @@ func (v Value) IsZero() bool {
 }
 
 func (v Value) Equals(b Value) bool {
-	return v.kind == b.kind && v.data == b.data
+	return !v.Less(b) && !b.Less(v)
 }
 
 func (v Value) Kind() Kind {

internal/field/list_binary.go

@@ -3,8 +3,11 @@ package field
 import (
 	"encoding/binary"
 	"strconv"
+	"strings"
 	"unsafe"
 
+	"github.com/tidwall/gjson"
+	"github.com/tidwall/pretty"
 	"github.com/tidwall/tile38/internal/sstring"
 )
 
@@ -250,6 +253,15 @@ func putfield(b []byte, f Field, s, e int) *byte {
 
 // Get a field from the list. Or returns ZeroField if not found.
 func (fields List) Get(name string) Field {
+	var isj bool
+	var jname string
+	var jpath string
+	dot := strings.IndexByte(name, '.')
+	if dot != -1 {
+		isj = true
+		jname = name[:dot]
+		jpath = name[dot+1:]
+	}
 	b := ptob(fields.p)
 	var i int
 	for {
@@ -274,11 +286,23 @@ func (fields List) Get(name string) Field {
 			data = btoa(b[i+n : i+n+x])
 			i += n + x
 		}
+		if kind == JSON && isj {
+			if jname < fname {
+				break
+			}
+			if fname == jname {
+				res := gjson.Get(data, jpath)
+				if res.Exists() {
+					return bfield(name, Kind(res.Type), res.String())
+				}
+			}
+		} else {
 			if name < fname {
 				break
 			}
 			if fname == name {
-			return bfield(fname, kind, data)
+				return bfield(name, kind, data)
+			}
 		}
 	}
 	return ZeroField
@@ -360,3 +384,21 @@ func MakeList(fields []Field) List {
 	}
 	return list
 }
+
+func (fields List) String() string {
+	var dst []byte
+	dst = append(dst, '{')
+	var i int
+	fields.Scan(func(f Field) bool {
+		if i > 0 {
+			dst = append(dst, ',')
+		}
+		dst = gjson.AppendJSONString(dst, f.Name())
+		dst = append(dst, ':')
+		dst = append(dst, f.Value().JSON()...)
+		i++
+		return true
+	})
+	dst = append(dst, '}')
+	return string(pretty.UglyInPlace(dst))
+}

internal/field/list_test.go

@@ -179,3 +179,54 @@ func TestRandom(t *testing.T) {
 	}
 
 }
+
+func TestJSONGet(t *testing.T) {
+
+	var list List
+	list = list.Set(Make("hello", "world"))
+	list = list.Set(Make("hello", `"world"`))
+	list = list.Set(Make("jello", "planet"))
+	list = list.Set(Make("telly", `{"a":[1,2,3],"b":null,"c":true,"d":false}`))
+	list = list.Set(Make("belly", `{"a":{"b":{"c":"fancy"}}}`))
+	json := list.String()
+	exp := `{"belly":{"a":{"b":{"c":"fancy"}}},"hello":"world","jello":` +
+		`"planet","telly":{"a":[1,2,3],"b":null,"c":true,"d":false}}`
+	if json != exp {
+		t.Fatalf("expected '%s', got '%s'", exp, json)
+	}
+	data := list.Get("hello").Value().Data()
+	if data != "world" {
+		t.Fatalf("expected '%s', got '%s'", "world", data)
+	}
+	data = list.Get("telly").Value().Data()
+	if data != `{"a":[1,2,3],"b":null,"c":true,"d":false}` {
+		t.Fatalf("expected '%s', got '%s'",
+			`{"a":[1,2,3],"b":null,"c":true,"d":false}`, data)
+	}
+	data = list.Get("belly").Value().Data()
+	if data != `{"a":{"b":{"c":"fancy"}}}` {
+		t.Fatalf("expected '%s', got '%s'",
+			`{"a":{"b":{"c":"fancy"}}}`, data)
+	}
+	data = list.Get("belly.a").Value().Data()
+	if data != `{"b":{"c":"fancy"}}` {
+		t.Fatalf("expected '%s', got '%s'",
+			`{"b":{"c":"fancy"}}`, data)
+	}
+	data = list.Get("belly.a.b").Value().Data()
+	if data != `{"c":"fancy"}` {
+		t.Fatalf("expected '%s', got '%s'",
+			`{"c":"fancy"}`, data)
+	}
+	data = list.Get("belly.a.b.c").Value().Data()
+	if data != `fancy` {
+		t.Fatalf("expected '%s', got '%s'",
+			`fancy`, data)
+	}
+	// Tile38 defaults non-existent fields to zero.
+	data = list.Get("belly.a.b.c.d").Value().Data()
+	if data != `0` {
+		t.Fatalf("expected '%s', got '%s'",
+			`0`, data)
+	}
+}

internal/server/token.go

@@ -77,6 +77,20 @@ func mGTE(a, b field.Value) bool { return !mLT(a, b) }
 func mEQ(a, b field.Value) bool  { return a.Equals(b) }
 
 func (where whereT) match(value field.Value) bool {
+	switch where.min.Data() {
+	case "<":
+		return mLT(value, where.max)
+	case "<=":
+		return mLTE(value, where.max)
+	case ">":
+		return mGT(value, where.max)
+	case ">=":
+		return mGTE(value, where.max)
+	case "==":
+		return mEQ(value, where.max)
+	case "!=":
+		return !mEQ(value, where.max)
+	}
 	if !where.minx {
 		if mLT(value, where.min) { // if value < where.min {
 			return false
@@ -276,18 +290,17 @@ func (s *Server) parseSearchScanBaseTokens(
 				}
 				var minx, maxx bool
 				smin = strings.ToLower(smin)
-				if smin == "-inf" {
+				smax = strings.ToLower(smax)
-					smin = "-inf"
+				if smax == "+inf" || smax == "inf" {
-				} else {
+					smax = "inf"
+				}
+				switch smin {
+				case "<", "<=", ">", ">=", "==", "!=":
+				default:
 					if strings.HasPrefix(smin, "(") {
 						minx = true
 						smin = smin[1:]
 					}
-				}
-				smax = strings.ToLower(smax)
-				if smax == "+inf" || smax == "inf" {
-					smax = "inf"
-				} else {
 					if strings.HasPrefix(smax, "(") {
 						maxx = true
 						smax = smax[1:]

tests/keys_test.go

@@ -459,6 +459,22 @@ func keys_FIELDS_test(mc *mockServer) error {
 		Do("GET", "fleet", "truck1", "WITHFIELDS").JSON().Str(`{"ok":true,"object":{"type":"Point","coordinates":[33,-112]}}`),
 		Do("SET", "fleet", "truck1", "FIELD", "speed", "2", "POINT", "-112", "33").JSON().OK(),
 		Do("GET", "fleet", "truck1", "WITHFIELDS").JSON().Str(`{"ok":true,"object":{"type":"Point","coordinates":[33,-112]},"fields":{"speed":2}}`),
+
+		// Do some GJSON queries.
+		Do("SET", "fleet", "truck2", "FIELD", "hello", `{"world":"tom"}`, "POINT", "-112", "33").JSON().OK(),
+		Do("SCAN", "fleet", "WHERE", "hello", `{"world":"tom"}`, `{"world":"tom"}`, "COUNT").JSON().Str(`{"ok":true,"count":1,"cursor":0}`),
+		Do("SCAN", "fleet", "WHERE", "hello.world", `tom`, `tom`, "COUNT").JSON().Str(`{"ok":true,"count":1,"cursor":0}`),
+		// The next scan does not match on anything, but since we're matching
+		// on zeros, which is the default, then all (two) objects are returned.
+		Do("SCAN", "fleet", "WHERE", "hello.world.1", `0`, `0`, "IDS").JSON().Str(`{"ok":true,"ids":["truck1","truck2"],"count":2,"cursor":0}`),
+		Do("SCAN", "fleet", "WHERE", "hello.world", ">", `tom`, "IDS").JSON().Str(`{"ok":true,"ids":[],"count":0,"cursor":0}`),
+		Do("SCAN", "fleet", "WHERE", "hello.world", ">=", `Tom`, "IDS").JSON().Str(`{"ok":true,"ids":["truck2"],"count":1,"cursor":0}`),
+		Do("SCAN", "fleet", "WHERE", "hello.world", ">=", `tom`, "IDS").JSON().Str(`{"ok":true,"ids":["truck2"],"count":1,"cursor":0}`),
+		Do("SCAN", "fleet", "WHERE", "hello.world", "==", `tom`, "IDS").JSON().Str(`{"ok":true,"ids":["truck2"],"count":1,"cursor":0}`),
+		Do("SCAN", "fleet", "WHERE", "hello.world", "<", `tom`, "IDS").JSON().Str(`{"ok":true,"ids":["truck1"],"count":1,"cursor":0}`),
+		Do("SCAN", "fleet", "WHERE", "hello.world", "<=", `tom`, "IDS").JSON().Str(`{"ok":true,"ids":["truck1","truck2"],"count":2,"cursor":0}`),
+		Do("SCAN", "fleet", "WHERE", "hello.world", "<", `uom`, "IDS").JSON().Str(`{"ok":true,"ids":["truck1","truck2"],"count":2,"cursor":0}`),
+		Do("SCAN", "fleet", "WHERE", "hello.world", "!=", `tom`, "IDS").JSON().Str(`{"ok":true,"ids":["truck1"],"count":1,"cursor":0}`),
 	)
 }