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@thsutton
Last active November 8, 2017 06:19
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Reduce some duplication (by more duplication)
diff --git a/dynamodb/src/main/scala/io/atlassian/aws/dynamodb/DynamoDB.scala b/dynamodb/src/main/scala/io/atlassian/aws/dynamodb/DynamoDB.scala
index e87be02..8331411 100644
--- a/dynamodb/src/main/scala/io/atlassian/aws/dynamodb/DynamoDB.scala
+++ b/dynamodb/src/main/scala/io/atlassian/aws/dynamodb/DynamoDB.scala
@@ -120,19 +120,7 @@ object DynamoDB {
def query[PK, V](ck: Column[PK], cv: Column[V])(q: QueryImpl): DynamoDBAction[Page[PK, V]] =
DynamoDBAction.withClient {
_.query(q.asQueryRequest)
- }.flatMap { res =>
- DynamoDBAction.attempt {
- res.getItems.asScala.toList.traverse[Attempt, V] {
- cv.unmarshall.unmarshall
- }.map { vs =>
- Page(vs,
- Option(res.getLastEvaluatedKey).flatMap {
- lastKey => ck.unmarshall(lastKey.asScala.toMap).toOption
- }
- )
- }
- }
- }
+ }.flatMap( _.decodeAsPage(ck, cv) )
/**
* Scan a table, with pagination.
@@ -143,19 +131,7 @@ object DynamoDB {
def scan[PK, V](ck: Column[PK], cv: Column[V])(q: ScanImpl): DynamoDBAction[Page[PK, V]] =
DynamoDBAction.withClient {
_.scan(q.asScanRequest)
- }.flatMap { res =>
- DynamoDBAction.attempt {
- res.getItems.asScala.toList.traverse[Attempt, V] { v =>
- cv.unmarshall.unmarshall(v)
- }.map { vs =>
- Page(vs,
- Option(res.getLastEvaluatedKey).flatMap {
- lastKey => ck.unmarshall(lastKey.asScala.toMap).toOption
- }
- )
- }
- }
- }
+ }.flatMap( _.decodeAsPage(ck, cv) )
def tableExists(tableName: String): DynamoDBAction[Boolean] =
withClient { client =>
@@ -259,6 +235,28 @@ object DynamoDB {
_.deleteTable(Table.name)
}
+ /** Describes the bit of the ScanResult and QueryResult classes which we use to read the results.
+ */
+ private type ReadOperationResult = {
+ def getItems(): java.util.List[java.util.Map[java.lang.String, AttributeValue]]
+ def getLastEvaluatedKey(): java.util.Map[java.lang.String, AttributeValue]
+ }
+
+ private implicit class ResultWithItems[Result <: ReadOperationResult](result: Result) {
+ def decodeAsPage[PK, V](ck: Column[PK], cv: Column[V]): DynamoDBAction[Page[PK, V]] =
+ DynamoDBAction.attempt {
+ result.getItems().asScala.toList.traverse[Attempt, V] {
+ cv.unmarshall.unmarshall
+ }.map { vs =>
+ Page(vs,
+ Option(result.getLastEvaluatedKey())flatMap {
+ lastKey => ck.unmarshall(lastKey.asScala.toMap).toOption
+ }
+ )
+ }
+ }
+ }
+
sealed trait ReadConsistency
object ReadConsistency {
case object Strong extends ReadConsistency
@thsutton
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thsutton commented Nov 8, 2017

Deletes 26 lines, adds 26 lines.

@thsutton
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thsutton commented Nov 8, 2017

Hmm. Except for the reflection I don't mind this new version.

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