Remove TimestampLeaseAwareTransactionManger (#7427)

.palantir/revapi.yml

@@ -452,6 +452,30 @@ acceptedBreaks:
     - code: "java.method.addedToInterface"
       new: "method void com.palantir.atlasdb.transaction.api.Transaction::onCommitOrAbort(java.lang.Runnable)"
       justification: "similar to onSuccess, already used in other prod codepaths"
+  "0.1187.0":
+    com.palantir.atlasdb:atlasdb-api:
+    - code: "java.class.removed"
+      old: "interface com.palantir.atlasdb.transaction.api.TimestampLeaseAwareTransactionManager"
+      justification: "Discussed: break is intended, see Compatibility section here\
+        \ https://github.com/palantir/atlasdb/pull/7427#issue-2638127226"
+    - code: "java.method.addedToInterface"
+      new: "method long com.palantir.atlasdb.transaction.api.TransactionManager::getLeasedTimestamp(com.palantir.atlasdb.common.api.timelock.TimestampLeaseName)"
+      justification: "Discussed: break is intended, see Compatibility section here\
+        \ https://github.com/palantir/atlasdb/pull/7427#issue-2638127226"
+  "0.1188.0-rc1":
+    com.palantir.atlasdb:atlasdb-api:
+    - code: "java.method.addedToInterface"
+      new: "method long com.palantir.atlasdb.transaction.api.TransactionManager::getMinLeasedTimestamp(com.palantir.atlasdb.common.api.timelock.TimestampLeaseName)"
+      justification: "Discussed: break is intended, see Compatibility section here\
+        \ https://github.com/palantir/atlasdb/pull/7427\\#issue-2638127226"
+    - code: "java.method.removed"
+      old: "method long com.palantir.atlasdb.transaction.api.AutoDelegate_TransactionManager::getLeasedTimestamp(com.palantir.atlasdb.common.api.timelock.TimestampLeaseName)"
+      justification: "Discussed: break is intended, see Compatibility section here\
+        \ https://github.com/palantir/atlasdb/pull/7427\\#issue-2638127226"
+    - code: "java.method.removed"
+      old: "method long com.palantir.atlasdb.transaction.api.TransactionManager::getLeasedTimestamp(com.palantir.atlasdb.common.api.timelock.TimestampLeaseName)"
+      justification: "Discussed: break is intended, see Compatibility section here\
+        \ https://github.com/palantir/atlasdb/pull/7427\\#issue-2638127226"
   "0.770.0":
     com.palantir.atlasdb:atlasdb-api:
     - code: "java.class.removed"

atlasdb-api/src/main/java/com/palantir/atlasdb/transaction/api/TimestampLeaseAwareTransaction.java

@@ -35,7 +35,7 @@ public interface TimestampLeaseAwareTransaction {
      * If {@code numLeasedTimestamps} is greater than 0, fresh timestamps will be fetched from {@link TransactionManager#getTimelockService()}
      * and will be provided to the pre-commit lambda via the supplier on {@code Consumer<LongSupplier>}.
      * <p>
-     * Clients can use {@link TimestampLeaseAwareTransactionManager#getLeasedTimestamp(TimestampLeaseName)}
+     * Clients can use {@link TransactionManager#getLeasedTimestamp(TimestampLeaseName)}
      * to fetch a timestamp before the earliest leased timestamp for a given {@code timestampLeaseName} on open
      * transactions.
      *

atlasdb-api/src/main/java/com/palantir/atlasdb/transaction/api/TransactionManager.java

@@ -15,11 +15,15 @@
  */
 package com.palantir.atlasdb.transaction.api;
 
+import com.google.errorprone.annotations.RestrictedApi;
 import com.palantir.atlasdb.cell.api.DdlManager;
 import com.palantir.atlasdb.cleaner.api.Cleaner;
+import com.palantir.atlasdb.common.api.annotations.ReviewedRestrictedApiUsage;
+import com.palantir.atlasdb.common.api.timelock.TimestampLeaseName;
 import com.palantir.atlasdb.keyvalue.api.KeyValueService;
 import com.palantir.atlasdb.keyvalue.api.watch.LockWatchManager;
 import com.palantir.atlasdb.metrics.Timed;
+import com.palantir.atlasdb.transaction.api.TimestampLeaseAwareTransaction.PreCommitAction;
 import com.palantir.atlasdb.transaction.service.TransactionService;
 import com.palantir.exception.NotInitializedException;
 import com.palantir.lock.HeldLocksToken;
@@ -415,6 +419,37 @@ <T, C extends PreCommitCondition, E extends Exception> T runTaskWithConditionRea
     @Timed
     long getUnreadableTimestamp();
 
+    /**
+     * Returns a timestamp that is before any leased timestamps returned by the consumer on
+     * {@link TimestampLeaseAwareTransaction#preCommit(TimestampLeaseName, int, PreCommitAction)}
+     * for a {@code timestampLeaseName} in open transactions.
+     * <p>
+     * This is similar to {@link TransactionManager#getImmutableTimestamp()} as it returns a timestamp before timestamps
+     * in open transactions, but for the immutable timestamp the timestamps considered are start timestamps for open
+     * transactions, while for leased timestamps the timestamps considered are leased timestamps from the corresponding
+     * {@code timestampLeaseName} in open transactions.
+     * <p>
+     * If no transactions with a {@code timestampLeaseName} lock are open, this method returns a new fresh timestamp
+     * (i.e. equivalent to {@link TimelockService#getFreshTimestamp()}).
+     * <p>
+     * Consumers should fetch the leased timestamp outside of transactions that potentially use it - if fetching the
+     * leased timestamp inside a transaction, it's possible for the transaction's start timestamp < leased timestamp,
+     * meaning the transaction cannot read all data up to leased timestamp.
+     *
+     * @param leaseName the name of the lease the timestamps are bound to
+     * @return the timestamp that is before any timestamp returned by the consumer of
+     * {@link TimestampLeaseAwareTransaction#preCommit(TimestampLeaseName, int, PreCommitAction)}
+     * for open transactions.
+     */
+    @RestrictedApi(
+            explanation = "This API is only meant to be used by AtlasDb proxies that want to make use of the"
+                    + " performance improvements by tracking leased timestamps of open transactions."
+                    + " Misuse of this feature can cause correctness issues.",
+            link = "https://github.com/palantir/atlasdb/pull/7305",
+            allowedOnPath = ".*/src/test/.*", // Unsafe behavior in tests is ok.
+            allowlistAnnotations = {ReviewedRestrictedApiUsage.class})
+    long getMinLeasedTimestamp(TimestampLeaseName leaseName);
+
     /**
      * Clear the timestamp cache. This is mostly useful for tests that perform operations that would invalidate
      * the cache, although this can also be used to free up some memory.

atlasdb-impl-shared/src/main/java/com/palantir/atlasdb/transaction/impl/SnapshotTransactionManager.java

@@ -44,7 +44,6 @@
 import com.palantir.atlasdb.transaction.api.KeyValueServiceStatus;
 import com.palantir.atlasdb.transaction.api.OpenTransaction;
 import com.palantir.atlasdb.transaction.api.PreCommitCondition;
-import com.palantir.atlasdb.transaction.api.TimestampLeaseAwareTransactionManager;
 import com.palantir.atlasdb.transaction.api.Transaction;
 import com.palantir.atlasdb.transaction.api.Transaction.TransactionType;
 import com.palantir.atlasdb.transaction.api.TransactionFailedRetriableException;
@@ -86,8 +85,7 @@
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
-/* package */ class SnapshotTransactionManager extends AbstractLockAwareTransactionManager
-        implements TimestampLeaseAwareTransactionManager {
+/* package */ class SnapshotTransactionManager extends AbstractLockAwareTransactionManager {
     private static final SafeLogger log = SafeLoggerFactory.get(SnapshotTransactionManager.class);
 
     private static final int NUM_RETRIES = 10;
@@ -527,7 +525,7 @@ public long getUnreadableTimestamp() {
 
     @Override
     @ReviewedRestrictedApiUsage
-    public long getLeasedTimestamp(TimestampLeaseName leaseName) {
+    public long getMinLeasedTimestamp(TimestampLeaseName leaseName) {
         return timelockService.getMinLeasedTimestamps(Set.of(leaseName)).get(leaseName);
     }
 

changelog/@unreleased/pr-7427.v2.yml

@@ -0,0 +1,6 @@
+type: fix
+fix:
+  description: Remove `TimestampLeaseAwareTransactionManger` and move `getMinLeasedTimestamp`
+    to be part of `TransactionManager`
+  links:
+  - https://github.com/palantir/atlasdb/pull/7427