Revert "syncmap"

This reverts commit cd76858.

Author: FGasper

internal/verifier/compare.go

@@ -6,7 +6,6 @@ import (
 	"time"
 
 	"github.com/10gen/migration-verifier/internal/types"
-	"github.com/10gen/migration-verifier/syncmap"
 	"github.com/pkg/errors"
 	"go.mongodb.org/mongo-driver/bson"
 	"go.mongodb.org/mongo-driver/mongo"
@@ -16,8 +15,6 @@ import (
 
 const readTimeout = 10 * time.Minute
 
-type docCacheMap = syncmap.SyncMap[string, bson.Raw]
-
 func (verifier *Verifier) FetchAndCompareDocuments(
 	givenCtx context.Context,
 	task *VerificationTask,
@@ -76,8 +73,8 @@ func (verifier *Verifier) compareDocsFromChannels(
 
 	namespace := task.QueryFilter.Namespace
 
-	srcCache := &docCacheMap{}
-	dstCache := &docCacheMap{}
+	srcCache := map[string]bson.Raw{}
+	dstCache := map[string]bson.Raw{}
 
 	// This is the core document-handling logic. It either:
 	//
@@ -87,7 +84,7 @@ func (verifier *Verifier) compareDocsFromChannels(
 	handleNewDoc := func(doc bson.Raw, isSrc bool) error {
 		mapKey := getMapKey(doc, mapKeyFieldNames)
 
-		var ourMap, theirMap *docCacheMap
+		var ourMap, theirMap map[string]bson.Raw
 
 		if isSrc {
 			ourMap = srcCache
@@ -98,22 +95,22 @@ func (verifier *Verifier) compareDocsFromChannels(
 		}
 		// See if we've already cached a document with this
 		// mapKey from the other channel.
-		theirDoc, exists := theirMap.Load(mapKey)
+		theirDoc, exists := theirMap[mapKey]
 
 		// If there is no such cached document, then cache the newly-received
 		// document in our map then proceed to the next document.
 		//
 		// (We'll remove the cache entry when/if the other channel yields a
 		// document with the same mapKey.)
 		if !exists {
-			ourMap.Store(mapKey, doc)
+			ourMap[mapKey] = doc
 			return nil
 		}
 
 		// We have two documents! First we remove the cache entry. This saves
 		// memory, but more importantly, it lets us know, once we exhaust the
 		// channels, which documents were missing on one side or the other.
-		theirMap.Delete(mapKey)
+		delete(theirMap, mapKey)
 
 		// Now we determine which document came from whom.
 		var srcDoc, dstDoc bson.Raw
@@ -230,9 +227,9 @@ func (verifier *Verifier) compareDocsFromChannels(
 	// missing on the other side. We add results for those.
 
 	// We might as well pre-grow the slice:
-	results = slices.Grow(results, srcCache.Len()+dstCache.Len())
+	results = slices.Grow(results, len(srcCache)+len(dstCache))
 
-	srcCache.Range(func(_ string, doc bson.Raw) bool {
+	for _, doc := range srcCache {
 		results = append(
 			results,
 			VerificationResult{
@@ -243,11 +240,9 @@ func (verifier *Verifier) compareDocsFromChannels(
 				dataSize:  len(doc),
 			},
 		)
+	}
 
-		return true
-	})
-
-	dstCache.Range(func(_ string, doc bson.Raw) bool {
+	for _, doc := range dstCache {
 		results = append(
 			results,
 			VerificationResult{
@@ -258,9 +253,7 @@ func (verifier *Verifier) compareDocsFromChannels(
 				dataSize:  len(doc),
 			},
 		)
-
-		return true
-	})
+	}
 
 	return results, docCount, byteCount, nil
 }