org.apache.iceberg.util

Class SnapshotUtil

java.lang.Object

org.apache.iceberg.util.SnapshotUtil

public class SnapshotUtil
extends java.lang.Object

Method Summary

Modifier and Type	Method and Description
static java.util.List<java.lang.Long>	ancestorIds(Snapshot snapshot, java.util.function.Function<java.lang.Long,Snapshot> lookup)
static java.lang.Iterable<java.lang.Long>	ancestorIdsBetween(long latestSnapshotId, java.lang.Long oldestSnapshotId, java.util.function.Function<java.lang.Long,Snapshot> lookup)
static java.lang.Iterable<Snapshot>	ancestorsBetween(long latestSnapshotId, java.lang.Long oldestSnapshotId, java.util.function.Function<java.lang.Long,Snapshot> lookup)
static java.lang.Iterable<Snapshot>	ancestorsBetween(Table table, long latestSnapshotId, java.lang.Long oldestSnapshotId)
static java.lang.Iterable<Snapshot>	ancestorsOf(long snapshotId, java.util.function.Function<java.lang.Long,Snapshot> lookup)
static java.util.List<java.lang.Long>	currentAncestorIds(Table table) Return the snapshot IDs for the ancestors of the current table state.
static java.lang.Iterable<Snapshot>	currentAncestors(Table table) Returns an iterable that traverses the table's snapshots from the current to the last known ancestor.
static boolean	isAncestorOf(long snapshotId, long ancestorSnapshotId, java.util.function.Function<java.lang.Long,Snapshot> lookup) Returns whether ancestorSnapshotId is an ancestor of snapshotId using the given lookup function.
static boolean	isAncestorOf(Table table, long ancestorSnapshotId) Returns whether ancestorSnapshotId is an ancestor of the table's current state.
static boolean	isAncestorOf(Table table, long snapshotId, long ancestorSnapshotId) Returns whether ancestorSnapshotId is an ancestor of snapshotId.
static boolean	isParentAncestorOf(Table table, long snapshotId, long ancestorParentSnapshotId) Returns whether some ancestor of snapshotId has parentId matches ancestorParentSnapshotId
static Snapshot	latestSnapshot(TableMetadata metadata, java.lang.String branch) Fetch the snapshot at the head of the given branch in the given table.
static Snapshot	latestSnapshot(Table table, java.lang.String branch) Fetch the snapshot at the head of the given branch in the given table.
static java.util.List<DataFile>	newFiles(java.lang.Long baseSnapshotId, long latestSnapshotId, java.util.function.Function<java.lang.Long,Snapshot> lookup, FileIO io)
static Snapshot	oldestAncestor(Table table) Traverses the history of the table's current snapshot and finds the oldest Snapshot.
static Snapshot	oldestAncestorAfter(Table table, long timestampMillis) Traverses the history of the table's current snapshot, finds the oldest snapshot that was committed either at or after a given time.
static Snapshot	oldestAncestorOf(long snapshotId, java.util.function.Function<java.lang.Long,Snapshot> lookup) Traverses the history and finds the oldest ancestor of the specified snapshot.
static Snapshot	oldestAncestorOf(Table table, long snapshotId)
static Schema	schemaFor(Table table, long snapshotId) Returns the schema of the table for the specified snapshot.
static Schema	schemaFor(Table table, java.lang.Long snapshotId, java.lang.Long timestampMillis) Convenience method for returning the schema of the table for a snapshot, when we have a snapshot id or a timestamp.
static Schema	schemaFor(TableMetadata metadata, java.lang.String branch) Return the schema of the snapshot at a given branch.
static Schema	schemaFor(Table table, java.lang.String branch) Return the schema of the snapshot at a given branch.
static Snapshot	snapshotAfter(Table table, long snapshotId) Traverses the history of the table's current snapshot and finds the snapshot with the given snapshot id as its parent.
static long	snapshotIdAsOfTime(Table table, long timestampMillis) Returns the ID of the most recent snapshot for the table as of the timestamp.
static java.util.List<java.lang.Long>	snapshotIdsBetween(Table table, long fromSnapshotId, long toSnapshotId) Returns list of snapshot ids in the range - (fromSnapshotId, toSnapshotId]

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

isAncestorOf

public static boolean isAncestorOf(Table table,
                                   long snapshotId,
                                   long ancestorSnapshotId)

Returns whether ancestorSnapshotId is an ancestor of snapshotId.

isAncestorOf

public static boolean isAncestorOf(long snapshotId,
                                   long ancestorSnapshotId,
                                   java.util.function.Function<java.lang.Long,Snapshot> lookup)

Returns whether ancestorSnapshotId is an ancestor of snapshotId using the given lookup function.

isAncestorOf

public static boolean isAncestorOf(Table table,
                                   long ancestorSnapshotId)

Returns whether ancestorSnapshotId is an ancestor of the table's current state.

isParentAncestorOf

public static boolean isParentAncestorOf(Table table,
                                         long snapshotId,
                                         long ancestorParentSnapshotId)

Returns whether some ancestor of snapshotId has parentId matches ancestorParentSnapshotId

currentAncestors

public static java.lang.Iterable<Snapshot> currentAncestors(Table table)

Returns an iterable that traverses the table's snapshots from the current to the last known ancestor.

Parameters:

table - a Table

Returns:

an iterable from the table's current snapshot to its last known ancestor

currentAncestorIds

public static java.util.List<java.lang.Long> currentAncestorIds(Table table)

Return the snapshot IDs for the ancestors of the current table state.

Ancestor IDs are ordered by commit time, descending. The first ID is the current snapshot, followed by its parent, and so on.

Parameters:

table - a Table

Returns:

a set of snapshot IDs of the known ancestor snapshots, including the current ID

oldestAncestor

public static Snapshot oldestAncestor(Table table)

Traverses the history of the table's current snapshot and finds the oldest Snapshot.

Returns:

null if there is no current snapshot in the table, else the oldest Snapshot.

oldestAncestorOf

public static Snapshot oldestAncestorOf(Table table,
                                        long snapshotId)

oldestAncestorOf

public static Snapshot oldestAncestorOf(long snapshotId,
                                        java.util.function.Function<java.lang.Long,Snapshot> lookup)

Traverses the history and finds the oldest ancestor of the specified snapshot.

Oldest ancestor is defined as the ancestor snapshot whose parent is null or has been expired. If the specified snapshot has no parent or parent has been expired, the specified snapshot itself is returned.

Parameters:

snapshotId - the ID of the snapshot to find the oldest ancestor

lookup - lookup function from snapshot ID to snapshot

Returns:

null if there is no current snapshot in the table, else the oldest Snapshot.

ancestorsOf

public static java.lang.Iterable<Snapshot> ancestorsOf(long snapshotId,
                                                       java.util.function.Function<java.lang.Long,Snapshot> lookup)

oldestAncestorAfter

public static Snapshot oldestAncestorAfter(Table table,
                                           long timestampMillis)

Traverses the history of the table's current snapshot, finds the oldest snapshot that was committed either at or after a given time.

Parameters:

table - a table

timestampMillis - a timestamp in milliseconds

Returns:

the first snapshot after the given timestamp, or null if the current snapshot is older than the timestamp

Throws:

java.lang.IllegalStateException - if the first ancestor after the given time can't be determined

snapshotIdsBetween

public static java.util.List<java.lang.Long> snapshotIdsBetween(Table table,
                                                                long fromSnapshotId,
                                                                long toSnapshotId)

Returns list of snapshot ids in the range - (fromSnapshotId, toSnapshotId]

This method assumes that fromSnapshotId is an ancestor of toSnapshotId.

ancestorIdsBetween

public static java.lang.Iterable<java.lang.Long> ancestorIdsBetween(long latestSnapshotId,
                                                                    java.lang.Long oldestSnapshotId,
                                                                    java.util.function.Function<java.lang.Long,Snapshot> lookup)

ancestorsBetween

public static java.lang.Iterable<Snapshot> ancestorsBetween(Table table,
                                                            long latestSnapshotId,
                                                            java.lang.Long oldestSnapshotId)

ancestorsBetween

public static java.lang.Iterable<Snapshot> ancestorsBetween(long latestSnapshotId,
                                                            java.lang.Long oldestSnapshotId,
                                                            java.util.function.Function<java.lang.Long,Snapshot> lookup)

ancestorIds

public static java.util.List<java.lang.Long> ancestorIds(Snapshot snapshot,
                                                         java.util.function.Function<java.lang.Long,Snapshot> lookup)

newFiles

public static java.util.List<DataFile> newFiles(java.lang.Long baseSnapshotId,
                                                long latestSnapshotId,
                                                java.util.function.Function<java.lang.Long,Snapshot> lookup,
                                                FileIO io)

snapshotAfter

public static Snapshot snapshotAfter(Table table,
                                     long snapshotId)

Traverses the history of the table's current snapshot and finds the snapshot with the given snapshot id as its parent.

Returns:

the snapshot for which the given snapshot is the parent

Throws:

java.lang.IllegalArgumentException - when the given snapshotId is not found in the table

java.lang.IllegalStateException - when the given snapshotId is not an ancestor of the current table state

snapshotIdAsOfTime

public static long snapshotIdAsOfTime(Table table,
                                      long timestampMillis)

Returns the ID of the most recent snapshot for the table as of the timestamp.

Parameters:

table - a Table

timestampMillis - the timestamp in millis since the Unix epoch

Returns:

the snapshot ID

Throws:

java.lang.IllegalArgumentException - when no snapshot is found in the table older than the timestamp

schemaFor

public static Schema schemaFor(Table table,
                               long snapshotId)

Returns the schema of the table for the specified snapshot.

Parameters:

table - a Table

snapshotId - the ID of the snapshot

Returns:

the schema

schemaFor

public static Schema schemaFor(Table table,
                               java.lang.Long snapshotId,
                               java.lang.Long timestampMillis)

Convenience method for returning the schema of the table for a snapshot, when we have a snapshot id or a timestamp. Only one of them should be specified (non-null), or an IllegalArgumentException is thrown.

Parameters:

table - a Table

snapshotId - the ID of the snapshot

timestampMillis - the timestamp in millis since the Unix epoch

Returns:

the schema

Throws:

java.lang.IllegalArgumentException - if both snapshotId and timestampMillis are non-null

schemaFor

public static Schema schemaFor(Table table,
                               java.lang.String branch)

Return the schema of the snapshot at a given branch.

If branch does not exist, the table schema is returned because it will be the schema when the new branch is created.

Parameters:

table - a Table

branch - branch name of the table (nullable)

Returns:

schema of the specific snapshot at the given branch

schemaFor

public static Schema schemaFor(TableMetadata metadata,
                               java.lang.String branch)

Return the schema of the snapshot at a given branch.

If branch does not exist, the table schema is returned because it will be the schema when the new branch is created.

Parameters:

metadata - a TableMetadata

branch - branch name of the table (nullable)

Returns:

schema of the specific snapshot at the given branch

latestSnapshot

public static Snapshot latestSnapshot(Table table,
                                      java.lang.String branch)

Fetch the snapshot at the head of the given branch in the given table.

This method calls Table.currentSnapshot() instead of using branch API Table.snapshot(String) for the main branch so that existing code still goes through the old code path to ensure backwards compatibility.

Parameters:

table - a Table

branch - branch name of the table (nullable)

Returns:

the latest snapshot for the given branch

latestSnapshot

public static Snapshot latestSnapshot(TableMetadata metadata,
                                      java.lang.String branch)

Fetch the snapshot at the head of the given branch in the given table.

This method calls TableMetadata.currentSnapshot() instead of using branch API TableMetadata.ref(String)} for the main branch so that existing code still goes through the old code path to ensure backwards compatibility.

If branch does not exist, the table's latest snapshot is returned it will be the schema when the new branch is created.

Parameters:

metadata - a TableMetadata

branch - branch name of the table metadata (nullable)

Returns:

the latest snapshot for the given branch