[Kernel] Add an end2end prototype of Coordinated Commit read support …

…in kernel

kernel/kernel-api/src/main/java/io/delta/kernel/commit/Commit.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.delta.kernel.commit;
+
+import io.delta.kernel.utils.FileStatus;
+
+/**
+ * Representation of a commit file
+ */
+public class Commit {
+
+    private long version;
+
+    private FileStatus fileStatus;
+
+    private long commitTimestamp;
+
+    public Commit(long version, FileStatus fileStatus, long commitTimestamp) {
+        this.version = version;
+        this.fileStatus = fileStatus;
+        this.commitTimestamp = commitTimestamp;
+    }
+
+    public long getVersion() {
+        return version;
+    }
+
+    public FileStatus getFileStatus() {
+        return fileStatus;
+    }
+
+    public long getCommitTimestamp() {
+        return commitTimestamp;
+    }
+
+    public Commit withFileStatus(FileStatus fileStatus) {
+        return new Commit(version, fileStatus, commitTimestamp);
+    }
+
+    public Commit withCommitTimestamp(long commitTimestamp) {
+        return new Commit(version, fileStatus, commitTimestamp);
+    }
+}

kernel/kernel-api/src/main/java/io/delta/kernel/commit/CommitFailedException.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.delta.kernel.commit;
+
+import java.util.Iterator;
+import java.util.Map;
+
+/**
+ * Exception raised by
+ * {@link io.delta.kernel.engine.CommitCoordinatorClientHandler#commit(
+ * String, Map, long, Iterator, UpdatedActions)}
+ *
+ * <pre>
+ *  | retryable | conflict  | meaning                                                         |
+ *  |   no      |   no      | something bad happened (e.g. auth failure)                      |
+ *  |   no      |   yes     | permanent transaction conflict (e.g. multi-table commit failed) |
+ *  |   yes     |   no      | transient error (e.g. network hiccup)                           |
+ *  |   yes     |   yes     | physical conflict (allowed to rebase and retry)                 |
+ *  </pre>
+ */
+public class CommitFailedException extends Exception {
+
+    private boolean retryable;
+
+    private boolean conflict;
+
+    private String message;
+
+    public CommitFailedException(boolean retryable, boolean conflict, String message) {
+        this.retryable = retryable;
+        this.conflict = conflict;
+        this.message = message;
+    }
+
+    public boolean getRetryable() {
+        return retryable;
+    }
+
+    public boolean getConflict() {
+        return conflict;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+}

kernel/kernel-api/src/main/java/io/delta/kernel/commit/CommitResponse.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.delta.kernel.commit;
+
+import java.util.Iterator;
+import java.util.Map;
+
+/**
+ * Response container for
+ * {@link io.delta.kernel.engine.CommitCoordinatorClientHandler#commit(
+ * String, Map, long, Iterator, UpdatedActions)}.
+ */
+public class CommitResponse {
+
+    private Commit commit;
+
+    public CommitResponse(Commit commit) {
+        this.commit = commit;
+    }
+
+    public Commit getCommit() {
+        return commit;
+    }
+}

kernel/kernel-api/src/main/java/io/delta/kernel/commit/GetCommitsResponse.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.delta.kernel.commit;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Response container for
+ * {@link io.delta.kernel.engine.CommitCoordinatorClientHandler#getCommits(
+ * String, Map, Long, Long)}.
+ */
+public class GetCommitsResponse {
+    private List<Commit> commits;
+
+    private long latestTableVersion;
+
+    public GetCommitsResponse(List<Commit> commits, long latestTableVersion) {
+        this.commits = commits;
+        this.latestTableVersion = latestTableVersion;
+    }
+
+    public List<Commit> getCommits() {
+        return commits;
+    }
+
+    public long getLatestTableVersion() {
+        return latestTableVersion;
+    }
+}

kernel/kernel-api/src/main/java/io/delta/kernel/commit/UpdatedActions.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.delta.kernel.commit;
+
+import io.delta.kernel.commit.actions.AbstractCommitInfo;
+import io.delta.kernel.commit.actions.AbstractMetadata;
+import io.delta.kernel.commit.actions.AbstractProtocol;
+
+/**
+ * A container class to inform the CommitCoordinatorClientHandler about any changes in
+ * Protocol/Metadata
+ */
+public class UpdatedActions {
+    private AbstractCommitInfo commitInfo;
+
+    private AbstractMetadata newMetadata;
+
+    private AbstractProtocol newProtocol;
+
+    private AbstractMetadata oldMetadata;
+
+    private AbstractProtocol oldProtocol;
+
+    public UpdatedActions(
+        AbstractCommitInfo commitInfo,
+        AbstractMetadata newMetadata,
+        AbstractProtocol newProtocol,
+        AbstractMetadata oldMetadata,
+        AbstractProtocol oldProtocol) {
+        this.commitInfo = commitInfo;
+        this.newMetadata = newMetadata;
+        this.newProtocol = newProtocol;
+        this.oldMetadata = oldMetadata;
+        this.oldProtocol = oldProtocol;
+    }
+
+    public AbstractCommitInfo getCommitInfo() {
+        return commitInfo;
+    }
+
+    public AbstractMetadata getNewMetadata() {
+        return newMetadata;
+    }
+
+    public AbstractProtocol getNewProtocol() {
+        return newProtocol;
+    }
+
+    public AbstractMetadata getOldMetadata() {
+        return oldMetadata;
+    }
+
+    public AbstractProtocol getOldProtocol() {
+        return oldProtocol;
+    }
+}

kernel/kernel-api/src/main/java/io/delta/kernel/commit/actions/AbstractCommitInfo.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.delta.kernel.commit.actions;
+
+/**
+ * Interface for objects that represents the base information for a commit.
+ * Commits need to provide an in-commit timestamp. This timestamp is used
+ * to specify the exact time the commit happened and determines the target
+ * version for time-based time travel queries.
+ */
+public interface AbstractCommitInfo {
+
+    /**
+     * Get the timestamp of the commit as millis after the epoch.
+     */
+    long getCommitTimestamp();
+}

kernel/kernel-api/src/main/java/io/delta/kernel/commit/actions/AbstractMetadata.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.delta.kernel.commit.actions;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Interface for metadata actions in Delta. The metadata defines the metadata
+ * of the table.
+ */
+public interface AbstractMetadata {
+
+    /**
+     * A unique table identifier.
+     */
+    String getId();
+
+    /**
+     * User-specified table identifier.
+     */
+    String getName();
+
+    /**
+     * User-specified table description.
+     */
+    String getDescription();
+
+    /** The table provider format. */
+    String getProvider();
+
+    /** The format options */
+    Map<String, String> getFormatOptions();
+
+    /**
+     * The table schema in string representation.
+     */
+    String getSchemaString();
+
+    /**
+     * List of partition columns.
+     */
+    List<String> getPartitionColumns();
+
+    /**
+     * The table properties defined on the table.
+     */
+    Map<String, String> getConfiguration();
+
+    /**
+     * Timestamp for the creation of this metadata.
+     */
+    Long getCreatedTime();
+}