Reverse dependencies between bsoncodec and bson

This commit reverses the dependency between the bson and bsoncodec
package. This allows the bson package to contain the Marshal and
Unmarshal family of functions and the Encoder and Decoder types. This
allows future types in the bson package to handle the empty interface.
The default encoders and decoders are split across two packages, because
the bsoncodec package can only provide encoders and decoders for
non-bson package types. The empty interface decoder is defined twice: a
partial version in bsoncdec and a complete version in the bson package.
Almost all users should use a Registry created from both sets of
encoders and decoders.

The bsoncodec package was split into the bsonrw and bsoncodec packages.
The new bsonrw package contains the ValueReader and ValueWriter
definitions and implementations. A new bsonrwtest package was created
with the previously used llValueReaderWriter type that is useful for
unit testing a ValueReader or ValueWriter implementation. This allows
users outside of the bsoncodec and bsonrw packages to use this type with
their own ValueReader and ValueWriter implementations.

The llbson package is renamed bsoncore and moved out of internal. This
will allow other users to directly use this low level bson package.
Eventually the entire BSON library will use bsoncore to handle reading
and writing BSON from and to bytes. This package replaces the elements
package, which will be removed in a future commit.

GODRIVER-592

Change-Id: I1e2dabc83cae9705fc062a6b763e0d2b91cde3ef

Author: skriptble

benchmark/bson.go

@@ -2,7 +2,6 @@ package benchmark
 
 import (
 	"errors"
-	"github.com/mongodb/mongo-go-driver/bson/bsoncodec"
 	"io/ioutil"
 	"path/filepath"
 
@@ -25,7 +24,7 @@ func loadSourceDocument(pathParts ...string) (*bson.Document, error) {
 		return nil, err
 	}
 	doc := bson.NewDocument()
-	err = bsoncodec.UnmarshalExtJSON(data, true, &doc)
+	err = bson.UnmarshalExtJSON(data, true, &doc)
 	if err != nil {
 		return nil, err
 	}

benchmark/bson_map.go

@@ -5,7 +5,7 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/mongodb/mongo-go-driver/bson/bsoncodec"
+	"github.com/mongodb/mongo-go-driver/bson"
 )
 
 func bsonMapDecoding(ctx context.Context, tm TimerManager, iters int, dataSet string) error {
@@ -18,7 +18,7 @@ func bsonMapDecoding(ctx context.Context, tm TimerManager, iters int, dataSet st
 
 	for i := 0; i < iters; i++ {
 		out := make(map[string]interface{})
-		err := bsoncodec.Unmarshal(r, &out)
+		err := bson.Unmarshal(r, &out)
 		if err != nil {
 			return nil
 		}
@@ -36,15 +36,15 @@ func bsonMapEncoding(ctx context.Context, tm TimerManager, iters int, dataSet st
 	}
 
 	doc := make(map[string]interface{})
-	err = bsoncodec.Unmarshal(r, &doc)
+	err = bson.Unmarshal(r, &doc)
 	if err != nil {
 		return err
 	}
 
 	var buf []byte
 	tm.ResetTimer()
 	for i := 0; i < iters; i++ {
-		buf, err = bsoncodec.MarshalAppend(buf[:0], doc)
+		buf, err = bson.MarshalAppend(buf[:0], doc)
 		if err != nil {
 			return nil
 		}

benchmark/bson_struct.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"errors"
 
-	"github.com/mongodb/mongo-go-driver/bson/bsoncodec"
+	"github.com/mongodb/mongo-go-driver/bson"
 )
 
 func BSONFlatStructDecoding(ctx context.Context, tm TimerManager, iters int) error {
@@ -17,7 +17,7 @@ func BSONFlatStructDecoding(ctx context.Context, tm TimerManager, iters int) err
 
 	for i := 0; i < iters; i++ {
 		out := flatBSON{}
-		err := bsoncodec.Unmarshal(r, &out)
+		err := bson.Unmarshal(r, &out)
 		if err != nil {
 			return err
 		}
@@ -32,7 +32,7 @@ func BSONFlatStructEncoding(ctx context.Context, tm TimerManager, iters int) err
 	}
 
 	doc := flatBSON{}
-	err = bsoncodec.Unmarshal(r, &doc)
+	err = bson.Unmarshal(r, &doc)
 	if err != nil {
 		return err
 	}
@@ -41,7 +41,7 @@ func BSONFlatStructEncoding(ctx context.Context, tm TimerManager, iters int) err
 
 	tm.ResetTimer()
 	for i := 0; i < iters; i++ {
-		buf, err = bsoncodec.Marshal(doc)
+		buf, err = bson.Marshal(doc)
 		if err != nil {
 			return err
 		}
@@ -59,7 +59,7 @@ func BSONFlatStructTagsEncoding(ctx context.Context, tm TimerManager, iters int)
 	}
 
 	doc := flatBSONTags{}
-	err = bsoncodec.Unmarshal(r, &doc)
+	err = bson.Unmarshal(r, &doc)
 	if err != nil {
 		return err
 	}
@@ -68,7 +68,7 @@ func BSONFlatStructTagsEncoding(ctx context.Context, tm TimerManager, iters int)
 
 	tm.ResetTimer()
 	for i := 0; i < iters; i++ {
-		buf, err = bsoncodec.MarshalAppend(buf[:0], doc)
+		buf, err = bson.MarshalAppend(buf[:0], doc)
 		if err != nil {
 			return err
 		}
@@ -88,7 +88,7 @@ func BSONFlatStructTagsDecoding(ctx context.Context, tm TimerManager, iters int)
 	tm.ResetTimer()
 	for i := 0; i < iters; i++ {
 		out := flatBSONTags{}
-		err := bsoncodec.Unmarshal(r, &out)
+		err := bson.Unmarshal(r, &out)
 		if err != nil {
 			return err
 		}

bson/array.go

@@ -343,5 +343,33 @@ func (a *Array) Iterator() (*ArrayIterator, error) {
 
 // Equal compares this document to another, returning true if they are equal.
 func (a *Array) Equal(a2 *Array) bool {
-	return a.doc.Equal(a2.doc)
+	if a == nil && a2 == nil {
+		return true
+	}
+
+	if a == nil || a2 == nil {
+		return false
+	}
+
+	if a.doc == nil && a2.doc == nil {
+		return true
+	}
+
+	if a.doc == nil || a2.doc == nil {
+		return false
+	}
+
+	if (len(a.doc.elems) != len(a2.doc.elems)) || (len(a.doc.index) != len(a2.doc.index)) {
+		return false
+	}
+
+	for index := range a.doc.elems {
+		v1 := a.doc.elems[index].value
+		v2 := a2.doc.elems[index].value
+
+		if !v1.Equal(v2) {
+			return false
+		}
+	}
+	return true
 }

bson/bsoncodec/benchmark_test.go renamed to bson/benchmark_test.go

@@ -1,9 +1,7 @@
-package bsoncodec
+package bson
 
 import (
 	"testing"
-
-	"github.com/mongodb/mongo-go-driver/bson"
 )
 
 type encodetest struct {
@@ -117,42 +115,14 @@ var nestedInstance = nestedtest1{
 	},
 }
 
-func BenchmarkEncodingv2(b *testing.B) {
+func BenchmarkEncoding(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		_, _ = Marshal(encodetestInstance)
 	}
 }
 
-func BenchmarkEncodingv2ToDocument(b *testing.B) {
-	var buf []byte
-	for i := 0; i < b.N; i++ {
-		buf, _ = Marshal(encodetestInstance)
-		_, _ = bson.ReadDocument(buf)
-	}
-}
-
-// func BenchmarkEncodingDocument(b *testing.B) {
-// 	for i := 0; i < b.N; i++ {
-// 		_, _ = MarshalDocument(encodetestInstance)
-// 	}
-// }
-
-func BenchmarkEncodingv2Nested(b *testing.B) {
+func BenchmarkEncodingNested(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		_, _ = Marshal(nestedInstance)
 	}
 }
-
-func BenchmarkEncodingv2ToDocumentNested(b *testing.B) {
-	var buf []byte
-	for i := 0; i < b.N; i++ {
-		buf, _ = Marshal(nestedInstance)
-		_, _ = bson.ReadDocument(buf)
-	}
-}
-
-// func BenchmarkEncodingDocumentNested(b *testing.B) {
-// 	for i := 0; i < b.N; i++ {
-// 		_, _ = MarshalDocument(nestedInstance)
-// 	}
-// }

bson/bsoncodec/bson_corpus_spec_test.go renamed to bson/bson_corpus_spec_test.go

@@ -4,7 +4,7 @@
 // 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
 
-package bsoncodec
+package bson
 
 import (
 	"bytes"
@@ -20,7 +20,8 @@ import (
 	"unicode/utf8"
 
 	"github.com/google/go-cmp/cmp"
-	"github.com/mongodb/mongo-go-driver/bson"
+	"github.com/mongodb/mongo-go-driver/bson/bsoncodec"
+	"github.com/mongodb/mongo-go-driver/bson/bsonrw"
 	"github.com/stretchr/testify/require"
 	"github.com/tidwall/pretty"
 )
@@ -57,13 +58,14 @@ type parseErrorTestCase struct {
 	String      string `json:"string"`
 }
 
-const dataDir = "../../data"
+const dataDir = "../data"
 
-var dvd DefaultValueDecoders
-var dve DefaultValueEncoders
+var pc PrimitiveCodecs
+var dvd bsoncodec.DefaultValueDecoders
+var dve bsoncodec.DefaultValueEncoders
 
-var dc = DecodeContext{Registry: NewRegistryBuilder().Build()}
-var ec = EncodeContext{Registry: NewRegistryBuilder().Build()}
+var dc = bsoncodec.DecodeContext{Registry: NewRegistryBuilder().Build()}
+var ec = bsoncodec.EncodeContext{Registry: NewRegistryBuilder().Build()}
 
 func findJSONFilesInDir(t *testing.T, dir string) []string {
 	files := make([]string, 0)
@@ -158,21 +160,21 @@ func normalizeRelaxedDouble(t *testing.T, key string, rEJ string) string {
 	return fmt.Sprintf(`{"%s":%s}`, key, formatDouble(expectedFloat))
 }
 
-// bsonToNative decodes the BSON bytes (b) into a native bson.Document
-func bsonToNative(t *testing.T, b []byte, bType, testDesc string) *bson.Document {
-	doc := bson.NewDocument()
-	err := dvd.DocumentDecodeValue(dc, NewValueReader(b), &doc)
+// bsonToNative decodes the BSON bytes (b) into a native Document
+func bsonToNative(t *testing.T, b []byte, bType, testDesc string) *Document {
+	doc := NewDocument()
+	err := pc.DocumentDecodeValue(dc, bsonrw.NewBSONValueReader(b), &doc)
 	expectNoError(t, err, fmt.Sprintf("%s: decoding %s BSON", testDesc, bType))
 	return doc
 }
 
-// nativeToBSON encodes the native bson.Document (doc) into canonical BSON and compares it to the expected
+// nativeToBSON encodes the native Document (doc) into canonical BSON and compares it to the expected
 // canonical BSON (cB)
-func nativeToBSON(t *testing.T, cB []byte, doc *bson.Document, testDesc, bType, docSrcDesc string) {
+func nativeToBSON(t *testing.T, cB []byte, doc *Document, testDesc, bType, docSrcDesc string) {
 	actualB := new(bytes.Buffer)
-	vw, err := NewBSONValueWriter(actualB)
+	vw, err := bsonrw.NewBSONValueWriter(actualB)
 	expectNoError(t, err, fmt.Sprintf("%s: creating ValueWriter", testDesc))
-	err = dve.DocumentEncodeValue(ec, vw, doc)
+	err = pc.DocumentEncodeValue(ec, vw, doc)
 	expectNoError(t, err, fmt.Sprintf("%s: encoding %s BSON", testDesc, bType))
 
 	if diff := cmp.Diff(cB, actualB.Bytes()); diff != "" {
@@ -182,16 +184,16 @@ func nativeToBSON(t *testing.T, cB []byte, doc *bson.Document, testDesc, bType,
 	}
 }
 
-// jsonToNative decodes the extended JSON string (ej) into a native bson.Document
-func jsonToNative(t *testing.T, ej, ejType, testDesc string) *bson.Document {
-	doc := bson.NewDocument()
+// jsonToNative decodes the extended JSON string (ej) into a native Document
+func jsonToNative(t *testing.T, ej, ejType, testDesc string) *Document {
+	doc := NewDocument()
 	err := UnmarshalExtJSON([]byte(ej), ejType != "relaxed", &doc)
 	expectNoError(t, err, fmt.Sprintf("%s: decoding %s extended JSON", testDesc, ejType))
 	return doc
 }
 
-// nativeToJSON encodes the native bson.Document (doc) into an extended JSON string
-func nativeToJSON(t *testing.T, ej string, doc *bson.Document, testDesc, ejType, ejShortName, docSrcDesc string) {
+// nativeToJSON encodes the native Document (doc) into an extended JSON string
+func nativeToJSON(t *testing.T, ej string, doc *Document, testDesc, ejType, ejShortName, docSrcDesc string) {
 	actualEJ, err := MarshalExtJSON(doc, ejType != "relaxed", true)
 	expectNoError(t, err, fmt.Sprintf("%s: encoding %s extended JSON", testDesc, ejType))
 
@@ -296,8 +298,8 @@ func runTest(t *testing.T, file string) {
 			b, err := hex.DecodeString(d.Bson)
 			expectNoError(t, err, d.Description)
 
-			doc := bson.NewDocument()
-			err = dvd.DocumentDecodeValue(dc, NewValueReader(b), &doc)
+			doc := NewDocument()
+			err = pc.DocumentDecodeValue(dc, bsonrw.NewBSONValueReader(b), &doc)
 			expectError(t, err, fmt.Sprintf("%s: expected decode error", d.Description))
 		}
 
@@ -314,11 +316,11 @@ func runTest(t *testing.T, file string) {
 
 			switch test.BsonType {
 			case "0x00":
-				doc := bson.NewDocument()
+				doc := NewDocument()
 				err := UnmarshalExtJSON([]byte(s), true, &doc)
 				expectError(t, err, fmt.Sprintf("%s: expected parse error", p.Description))
 			case "0x13":
-				ejvr := newExtJSONValueReader(strings.NewReader(s), true)
+				ejvr := bsonrw.NewExtJSONValueReader(strings.NewReader(s), true)
 				_, err := ejvr.ReadDecimal128()
 				expectError(t, err, fmt.Sprintf("%s: expected parse error", p.Description))
 			default:
@@ -334,3 +336,19 @@ func Test_BsonCorpus(t *testing.T) {
 		runTest(t, file)
 	}
 }
+
+func expectNoError(t *testing.T, err error, desc string) {
+	if err != nil {
+		t.Helper()
+		t.Errorf("%s: Unepexted error: %v", desc, err)
+		t.FailNow()
+	}
+}
+
+func expectError(t *testing.T, err error, desc string) {
+	if err == nil {
+		t.Helper()
+		t.Errorf("%s: Expected error", desc)
+		t.FailNow()
+	}
+}